Aire Acondicionado SEBD036406

SEBM036406

© 2005 All Rights Reserved Printed in Japan 01-05(03)

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CONTENTS 01 GENERAL

No. of page

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10 DENSO (Freon Gas Type) 11

STRUCTURE AND FUNCTION........................................................................................... 11-1

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TESTING AND ADJUSTING................................................................................................ 12-1

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DISASSEMBLY AND ASSEMBLY ....................................................................................... 13-1

20 ZEXEL (DIESEL KIKl) 21

STRUCTURE AND FUNCTION........................................................................................... 21-1

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TESTING AND ADJUSTING................................................................................................ 22-1

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DISASSEMBLY AND ASSEMBLY ....................................................................................... 23-1

30 DAIKIN 31

STRUCTURE AND FUNCTION........................................................................................... 31-1

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TESTING AND ADJUSTING................................................................................................ 32-1

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DISASSEMBLY AND ASSEMBLY ....................................................................................... 33-1

40 DENSO (New Refrigerant Type) 41

STRUCTURE AND FUNCTION........................................................................................... 41-1

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TESTING AND ADJUSTING................................................................................................ 42-1

50 TAKAHASHI WORKS 51

STRUCTURE AND FUNCTION........................................................................................... 51-1

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TESTING AND ADJUSTING................................................................................................ 52-1

60 SANDEN 61

STRUCTURE AND FUNCTION........................................................................................... 61-1

62

TESTING AND ADJUSTING................................................................................................ 62-1

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DISASSEMBLY AND ASSEMBLY ....................................................................................... 63-1

70 ZEXEL VALEO (NEW REFRIGERANT (R134a) TYPE)

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STRUCTURE AND FUNCTION........................................................................................... 71-1

72

TESTING AND ADJUSTING................................................................................................ 72-1

73

TROUBLESHOOTING ......................................................................................................... 73-1

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LIST OF REVISED PAGES

DENSO : Denso Corporation Corporate name has Changed From Nippon Denso to Denso Corporation in 1996. ZEXEL : Zexel Valeo Climate Control Corporation Corporate name has Changed From Diesel Kiki to Zexel in 1990, and From Zexel to Zexel Valeo Climate Control Corporation in 2001. DAIKIN : Daikin Industries, Ltd. Corporate name has changed From Daikin Kogyo to Daikin Industries, Ltd. in1982.

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00-6 (5)

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SAFETY

SAFETY NOTICE

SAFETY SAFETY NOTICE IMPORTANT SAFETY NOTICE Proper service and repair is extremely important for safe machine operation. The service and repair techniques recommended by Komatsu and described in this manual are both effective and safe. Some of these techniques require the use of tools specially designed by Komatsu for the specific purpose. To prevent injury to workers, the symbol k is used to mark safety precautions in this manual. The cautions accompanying these symbols should always be followed carefully. If any dangerous situation arises or may possibly arise, first consider safety, and take the necessary actions to deal with the situation.

GENERAL PRECAUTIONS Mistakes in operation are extremely dangerous. Read the Operation and Maintenance Manual carefully BEFORE operating the machine. 1. Before carrying out any greasing or repairs, read all the precautions given on the decals which are fixed to the machine. 2. When carrying out any operation, always wear safety shoes and helmet. Do not wear loose work clothes, or clothes with buttons missing. • •

Always wear safety glasses when hitting parts with a hammer. Always wear safety glasses when grinding parts with a grinder, etc.

3. If welding repairs are needed, always have a trained, experienced welder carry out the work. When carrying out welding work, always wear welding gloves, apron, hand shield, cap and other clothes suited for welding work. 4. When carrying out any operation with two or more workers, always agree on the operating procedure before starting. Always inform your fellow workers before starting any step of the operation. Before starting work, hang UNDER REPAIR signs on the controls in the operator's compartment. 5. Keep all tools in good condition and learn the correct way to use them.

6. Decide a place in the repair workshop to keep tools and removed parts. Always keep the tools and parts in their correct places. Always keep the work area clean and make sure that there is no dirt or oil on the floor. Smoke only in the areas provided for smoking. Never smoke while working. PREPARATIONS FOR WORK 7. Before adding oil or making any repairs, park the machine on hard, level ground, and block the wheels or tracks to prevent the machine from moving. 8. Before starting work, lower blade, ripper, bucket or any other work equipment to the ground. If this is not possible, insert the safety pin or use blocks to prevent the work equipment from falling. In addition, be sure to lock all the control levers and hang warning signs on them. 9. When disassembling or assembling, support the machine with blocks, jacks or stands before starting work. 10.Remove all mud and oil from the steps or other places used to get on and off the machine. Always use the handrails, ladders or steps when getting on or off the machine. Never jump on or off the machine. If it is impossible to use the handrails, ladders or steps, use a stand to provide safe footing.

00-3

SAFETY

PRECAUTIONS DURING WORK 11. When removing the oil filler cap, drain plug or hydraulic pressure measuring plugs, loosen them slowly to prevent the oil from spurting out. Before disconnecting or removing components of the oil, water or air circuits, first remove the pressure completely from the circuit. 12.The water and oil in the circuits are hot when the engine is stopped, so be careful not to get burned. Wait for the oil and water to cool before carrying out any work on the oil or water circuits. 13.Before starting work, remove the leads from the battery. Always remove the lead from the negative (–) terminal first. 14.When raising heavy components, use a hoist or crane. Check that the wire rope, chains and hooks are free from damage. Always use lifting equipment which has ample capacity. Install the lifting equipment at the correct places. Use a hoist or crane and operate slowly to prevent the component from hitting any other part. Do not work with any part still raised by the hoist or crane. 15.When removing covers which are under internal pressure or under pressure from a spring, always leave two bolts in position on opposite sides. Slowly release the pressure, then slowly loosen the bolts to remove. 16.When removing components, be careful not to break or damage the wiring. Damaged wiring may cause electrical fires. 17.When removing piping, stop the fuel or oil from spilling out. If any fuel or oil drips onto the floor, wipe it up immediately. Fuel or oil on the floor can cause you to slip, or can even start fires. 18.As a general rule, do not use gasoline to wash parts. In particular, use only the minimum of gasoline when washing electrical parts.

00-4

SAFETY NOTICE

19.Be sure to assemble all parts again in their original places. Replace any damaged parts with new parts. • When installing hoses and wires, be sure that they will not be damaged by contact with other parts when the machine is being operated. 20.When installing high pressure hoses, make sure that they are not twisted. Damaged tubes are dangerous, so be extremely careful when installing tubes for high pressure circuits. Also, check that connecting parts are correctly installed. 21.When assembling or installing parts, always use the specified tightening torques. When installing protective parts such as guards, or parts which vibrate violently or rotate at high speed, be particularly careful to check that they are installed correctly. 22.When aligning two holes, never insert your fingers or hand. Be careful not to get your fingers caught in a hole. 23.When measuring hydraulic pressure, check that the measuring tool is correctly assembled before taking any measurements. 24.Take care when removing or installing the tracks of track-type machines. When removing the track, the track separates suddenly, so never let anyone stand at either end of the track.

FOREWORD

GENERAL

FOREWORD GENERAL

This shop manual has been prepared as an aid to improve the quality of repairs by giving the serviceman an accurate understanding of the product and by showing him the correct way to perform repairs and make judgements. Make sure you understand the contents of this manual and use it to full effect at every opportunity.

This shop manual mainly contains the necessary technical information for operations performed in a service workshop. For ease of understanding, the manual is divided into the following chapters; these chapters are further divided into the each main group of components.

STRUCTURE AND FUNCTION This section explains the structure and function of each component. It serves not only to give an understanding of the structure, but also serves as reference material for troubleshooting. In addition, this section may contain hydraulic circuit diagrams, electric circuit diagrams, and maintenance standards. TESTING AND ADJUSTING This section explains checks to be made before and after performing repairs, as well as adjustments to be made at completion of the checks and repairs. Troubleshooting charts correlating "Problems" with "Causes" are also included in this section. DISASSEMBLY AND ASSEMBLY This section explains the procedures for removing, installing, disassembling and assembling each component, as well as precautions for them. MAINTENANCE STANDARD This section gives the judgment standards for inspection of disassembled parts. The contents of this section may be described in STRUCTURE AND FUNCTION. OTHERS This section mainly gives hydraulic circuit diagrams and electric circuit diagrams. In addition, this section may give the specifications of attachments and options together.

NOTICE The specifications contained in this shop manual are subject to change at any time and without any advance notice. Use the specifications given in the book with the latest date.

00-5

FOREWORD

HOW TO READ THE SHOP MANUAL

HOW TO READ THE SHOP MANUAL

REVISED EDITION MARK

VOLUMES Shop manuals are issued as a guide to carrying out repairs. They are divided as follows:

When a manual is revised, an edition mark ((1)(2)(3)....) is recorded on the bottom of the pages.

Chassis volume: Issued for every machine model Engine volume: Issued for each engine series Each issued as one Electrical volume: Attachments volume: · volume to cover all models

REVISIONS

}

These various volumes are designed to avoid duplicating the same information. Therefore, to deal with all repairs for any model , it is necessary that chassis, engine, electrical and attachment volumes be available. DISTRIBUTION AND UPDATING Any additions, amendments or other changes will be sent to KOMATSU distributors. Get the most up-todate information before you start any work. FILING METHOD 1. See the page number on the bottom of the page. File the pages in correct order. 2. Following examples show how to read the page number. Example 1 (Chassis volume): 10 - 3 Item number (10. Structure and Function) Consecutive page number for each item. Example 2 (Engine volume): 12 - 5 Unit number (1. Engine) Item number (2. Testing and Adjusting) Consecutive page number for each item. 3. Additional pages: Additional pages are indicated by a hyphen (-) and number after the page number. File as in the example. Example: 12-203 10-4 12-203-1 10-4-1 Added pages 12-203-2 10-4-2 12-204 10-5

00-6

Revised pages are shown in the LIST OF REVISED PAGES next to the CONTENTS page. SYMBOLS So that the shop manual can be of ample practical use, important safety and quality portions are marked with the following symbols.

Symbol

Item

Remarks

k

Safety

Special safety precautions are necessary when performing the work.

Caution

Special technical precautions or other precautions for preserving standards are necessary when performing the work.

Weight

Weight of parts of systems. Caution necessary when selecting hoisting wire, or when working posture is important, etc.

Tightening torque

Places that require special attention for the tightening torque during assembly.

Coat

Places to be coated with adhesives and lubricants, etc.

5

Oil, water

Places where oil, water or fuel must be added, and the capacity.

6

Drain

Places where oil or water must be drained, and quantity to be drained.

a

4

3 2

FOREWORD

HOISTING INSTRUCTIONS

HOISTING INSTRUCTIONS HOISTING k Heavy parts (25 kg or more) must be lifted with a hoist, etc. In the DISASSEMBLY AND ASSEMBLY section, every part weighing 25 kg or more is indicated clearly with the symbol 4 •

If a part cannot be smoothly removed from the machine by hoisting, the following checks should be made: 1) Check for removal of all bolts fastening the part to the relative parts. 2) Check for existence of another part causing interference with the part to be removed.

WIRE ROPES 1) Use adequate ropes depending on the weight of parts to be hoisted, referring to the table below: Wire ropes (Standard "Z" or "S" twist ropes without galvanizing) Rope diameter

Allowable load

mm

kN

tons

10 11.5 12.5 14 16 18 20 22.4 30 40 50 60

9.8 13.7 15.7 21.6 27.5 35.3 43.1 54.9 98.1 176.5 274.6 392.2

1.0 1.4 1.6 2.2 2.8 3.6 4.4 5.6 10.0 18.0 28.0 40.0

Slinging near the edge of the hook may cause the rope to slip off the hook during hoisting, and a serious accident can result. Hooks have maximum strength at the middle portion.

100%

88%

79%

71%

41% SAD00479

3) Do not sling a heavy load with one rope alone, but sling with two or more ropes symmetrically wound onto the load.

k Slinging with one rope may cause turning of the load during hoisting, untwisting of the rope, or slipping of the rope from its original winding position on the load, which can result in a dangerous accident.

4) Do not sling a heavy load with ropes forming a wide hanging angle from the hook. When hoisting a load with two or more ropes, the force subjected to each rope will increase with the hanging angles. The table below shows the variation of allowable load kN {kg} when hoisting is made with two ropes, each of which is allowed to sling up to 9.8 kN {1000 kg} vertically, at various hanging angles. When two ropes sling a load vertically, up to 19.6 kN {2000 kg} of total weight can be suspended. This weight becomes 9.8 kN {1000 kg} when two ropes make a 120° hanging angle. On the other hand, two ropes are subjected to an excessive force as large as 39.2 kN {4000 kg} if they sling a 19.6 kN {2000 kg} load at a lifting angle of 150°.

★ The allowable load value is estimated to be onesixth or one-seventh of the breaking strength of the rope used. 2) Sling wire ropes from the middle portion of the hook.

00-7

FOREWORD

METHOD OF DISASSEMBLING, CONNECTING PUSH-PULL TYPE COUPLER

METHOD OF DISASSEMBLING, CONNECTING PUSH-PULL TYPE COUPLER k Before carrying out the following work, release the residual pressure from the hydraulic tank. For details, see TESTING AND ADJUSTING, Releasing residual pressure from hydraulic tank.

k Even if the residual pressure is released from the hydraulic tank, some hydraulic oil flows out when the hose is disconnected. Accordingly, prepare an oil receiving container. Disconnection 1) Release the residual pressure from the hydraulic tank. For details, see TESTING AND ADJUSTING, Releasing residual pressure from hydraulic tank. 2) Hold adapter (1) and push hose joint (2) into mating adapter (3). (See Fig. 1) ★ The adapter can be pushed in about 3.5 mm. ★ Do not hold rubber cap portion (4). 3) After hose joint (2) is pushed into adapter (3), press rubber cap portion (4) against (3) until it clicks. (See Fig. 2) 4) Hold hose adapter (1) or hose (5) and pull it out. (See Fig. 3) ★ Since some hydraulic oil flows out, prepare an oil receiving container. Connection 1) Hold hose adapter (1) or hose (5) and insert it in mating adapter (3), aligning them with each other. (See Fig. 4) ★ Do not hold rubber cap portion (4). 2) After inserting the hose in the mating adapter perfectly, pull it back to check its connecting condition. (See Fig. 5) ★ When the hose is pulled back, the rubber cap portion moves toward the hose about 3.5 mm. This does not indicate abnormality, however.

00-8

Type 1

FOREWORD

METHOD OF DISASSEMBLING, CONNECTING PUSH-PULL TYPE COUPLER

Type 3

1) Hold the mouthpiece of the tightening portion and push body (2) in straight until sliding prevention ring (1) contacts contact surface a of the hexagonal portion at the male end.

1) Hold the mouthpiece of the tightening portion and push body (2) in straight until sliding prevention ring (1) contacts contact surface a of the hexagonal portion at the male end.

2) Hold in the condition in Step 1), and turn lever (4) to the right (clockwise).

2) Hold in the condition in Step 1), and push until cover (3) contacts contact surface a of the hexagonal portion at the male end.

3) Hold in the condition in Steps 1) and 2), and pull out whole body (2) to disconnect it.

3) Hold in the condition in Steps 1) and 2), and pull out whole body (2) to disconnect it.

•

•

Disassembly

Type 2

Hold the mouthpiece of the tightening portion and push body (2) in straight until sliding prevention ring (1) contacts contact surface a of the hexagonal portion at the male end to connect it.

Connection

Hold the mouthpiece of the tightening portion and push body (2) in straight until sliding prevention ring (1) contacts contact surface a of the hexagonal portion at the male end to connect it.

00-9

FOREWORD

COATING MATERIALS

COATING MATERIALS ★ The recommended coating materials such as adhesives, gasket sealants and greases used for disassembly and assembly are listed below. ★ For coating materials not listed below, use the equivalent of products shown in this list. Category

Komatsu code

Part No.

Q'ty

Container

Main applications, features

LT-1A

790-129-9030

150 g

Tube

• Used to prevent rubber gaskets, rubber cushions, and cock plug from coming out.

LT-1B

790-129-9050

20 g (2 pcs.)

Polyethylene container

• Used in places requiring an immediately effective, strong adhesive. Used for plastics (except polyethylene, polyprophylene, tetrafluoroethlene and vinyl chloride), rubber, metal and non-metal.

LT-2

09940-00030

50 g

Polyethylene container

• Features: Resistance to heat and chemicals • Used for anti-loosening and sealant purpose for bolts and plugs.

LT-3

790-129-9060 (Set of adhesive and hardening agent)

Adhesive: 1 kg Hardening agent: 500 g

Can

LT-4

790-129-9040

250 g

Polyethylene container

Holtz MH 705

790-126-9120

75 g

Tube

• Used as heat-resisting sealant for repairing engine.

50 g

Polyethylene container

• Quick hardening type adhesive • Cure time: within 5 sec. to 3 min. • Used mainly for adhesion of metals, rubbers, plastics and woods.

Adhesives

Three bond 1735

790-129-9140

• Used as adhesive or sealant for metal, glass and plastic.

Aron-alpha 201

790-129-9130

2g

Polyethylene container

• Quick hardening type adhesive • Quick cure type (max. strength after 30 minutes) • Used mainly for adhesion of rubbers, plastics and metals.

Loctite 648-50

79A-129-9110

50 cc

Polyethylene container

• Resistance to heat, chemicals • Used at joint portions subject to high temperatures.

LG-1

790-129-9010

200 g

Tube

• Used as adhesive or sealant for gaskets and packing of power train case, etc.

LG-5

790-129-9080

1 kg

Can

• Used as sealant for various threads, pipe joints, flanges. • Used as sealant for tapered plugs, elbows, nipples of hydraulic piping.

Tube

• Features: Silicon based, resistance to heat, cold • Used as sealant for flange surface, tread. • Used as sealant for oil pan, final drive case, etc.

LG-6

790-129-9020

200 g

Gasket sealant LG-7

790-129-9070

1 kg

Tube

• Features: Silicon based, quick hardening type • Used as sealant for flywheel housing, intake manifold, oil pan, thermostat housing, etc.

Three bond 1211

790-129-9090

100 g

Tube

• Used as heat-resisting sealant for repairing engine.

Tube

• Features: Silicone type, heat resistant, vibration resistant, and impact resistant sealing material • Used as sealing material for transfer case

Three bond 1207B

00-10

• Used as sealant for machined holes.

419-15-18131

100 g

FOREWORD

Molybdenum disulphide lubricant

Grease

Primer

Adhesive

Caulking material

Komatsu code

Part No.

Q'ty

Container

Main applications, features

LM-G

09940-00051

60 g

Can

• Used as lubricant for sliding portion (to prevent from squeaking).

Tube

• Used to prevent seizure or scuffling of the thread when press fitting or shrink fitting. • Used as lubricant for linkage, bearings, etc.

LM-P

09940-00040

G2-LI

SYG2-400LI SYG2-350LI SYG2-400LI-A SYG2-160LI SYGA-160CNLI

G2-CA

SYG2-400CA SYG2-350CA SYG2-400CA-A SYG2-160CA SYGA-160CNCA

Molybdenum disulphide grease LM-G (G2-M)

SYG2-400M SYG2-400M-A SYGA-16CNM

Hyper White Grease G2-T G0-T (*) *: For use in cold district

SYG2-400T-A SYG2-16CNT SYG0-400T-A (*) SYG0-16CNT (*)

Biogrease G2B G2-BT (*) *: For high temperature and large load

SYG2-400B SYGA-16CNB SYG2-400BT (*) SYGA-16CNBT (*)

200 g

• General purpose type Various

Various

Various

Various

400 g × 10 Bellows type 400 g × 20 Bellows type 16 kg Can

400 g 16 kg

400 g 16 kg

• Since this grease is decomposed by bacteria in short period, it has Bellows type less effects on microorganisms, Can animals, and plants.

20 ml

Glass container

SUNSTAR GLASS PRIMER 580 SUPER

20 ml

Glass container

SUNSTAR PENGUINE SEAL 580 SUPER "S" or "W"

• Used for heavy load portion

• Seizure resistance and heat resistance higher than molybdenum diBellows type sulfide grease Can • Since this grease is white, it does not stand out against machine body.

SUNSTAR PAINT PRIMER 580 SUPER

417-926-3910

• Used for normal temperature, light load bearing at places in contact with water or steam.

320 ml

Polyethylene container

Sika Japan, Sikaflex 256HV

20Y-54-39850

310 ml

Polyethylene container

SUNSTAR PENGUINE SEAL No. 2505

417-926-3920

320 ml

Polyethylene container

SEKISUI SILICONE SEALANT

20Y-54-55130

333 ml

Polyethylene container

• Used as primer for cab side (Using limit: 4 months) • Used as primer for glass side (Using limit: 4 months) Adhesive for cab glass

Category

COATING MATERIALS

• "S" is used for high-temperature season (April - October) and "W" for low-temperature season (November - April) as adhesive for glass. (Using limit: 4 months) • Used as adhesive for glass. (Using limit: 6 months) • Used to seal joints of glass parts. (Using limit: 4 months) • Used to seal front window. (Using limit: 6 months)

00-11

FOREWORD

STANDARD TIGHTENING TORQUE

STANDARD TIGHTENING TORQUE STANDARD TIGHTENING TORQUE TABLE (WHEN USING TORQUE WRENCH) ★ In the case of metric nuts and bolts for which there is no special instruction, tighten to the torque given in the table below. Tightening torque Thread diameter of bolt

Width across flats

mm

mm

Nm

kgm

6 8 10 12 14

10 13 17 19 22

11.8 – 14.7 27 – 34 59 – 74 98 – 123 153 – 190

1.2 – 1.5 2.8 – 3.5 6 – 7.5 10 – 12.5 15.5 – 19.5

16 18 20 22 24

24 27 30 32 36

235 – 285 320 – 400 455 – 565 610 – 765 785 – 980

23.5 – 29.5 33 – 41 46.5 – 58 62.5 – 78 80 – 100

27 30 33 36 39

41 46 50 55 60

1150 – 1440 1520 – 1910 1960 – 2450 2450 – 3040 2890 – 3630

118 – 147 155 – 195 200 – 250 250 – 310 295 – 370

Thread diameter of bolt

Width across flats

mm

mm

Nm

kgm

6 8 10 12

10 13 14 27

5.9 – 9.8 13.7 – 23.5 34.3 – 46.1 74.5 – 90.2

0.6 – 1.0 1.4 – 2.4 3.5 – 4.7 7.6 – 9.2

Tightening torque

Sealing surface

TABLE OF TIGHTENING TORQUES FOR FLARED NUTS ★ In the case of flared nuts for which there is no special instruction, tighten to the torque given in the table below.

SAD00483

Thread diameter

Width across flat

mm

mm

Nm

kgm

14 18 22 24 30 33 36 42

19 24 27 32 36 41 46 55

24.5 ± 4.9 49 ± 19.6 78.5 ± 19.6 137.3 ± 29.4 176.5 ± 29.4 196.1 ± 49 245.2 ± 49 294.2 ± 49

2.5 ± 0.5 5±2 8±2 14 ± 3 18 ± 3 20 ± 5 25 ± 5 30 ± 5

00-12

Tightening torque

FOREWORD

STANDARD TIGHTENING TORQUE

TABLE OF TIGHTENING TORQUES FOR SPLIT FLANGE BOLTS ★ In the case of split flange bolts for which there is no special instruction, tighten to the torque given in the table below.

Thread diameter

Width across flat

Tightening torque

mm

mm

Nm

kgm

10 12 16

14 17 22

59 – 74 98 – 123 235 – 285

6 – 7.5 10 – 12.5 23.5 – 29.5

TABLE OF TIGHTENING TORQUES FOR O-RING BOSS PIPING JOINTS ★ Unless there are special instructions, tighten the O-ring boss piping joints to the torque below.

Thread diameter

Width across flat

mm

mm

14 20 24 33 42

Varies depending on type of connector.

Tightening torque (Nm {kgm})

Norminal No.

02 03, 04 05, 06 10, 12 14

Range 35 – 63 84 – 132 128 – 186 363 – 480 746 – 1010

{3.5 – 6.5} {8.5 – 13.5} {13.0 – 19.0} {37.0 – 49.0} {76.0 – 103}

Target 44 {4.5} 103 {10.5} 157 {16.0} 422 {43.0} 883 {90.0}

TABLE OF TIGHTENING TORQUES FOR O-RING BOSS PLUGS ★ Unless there are special instructions, tighten the O-ring boss plugs to the torque below.

Thread diameter

Width across flat

mm

mm

08 10 12 14 16 18 20 24 30 33 36 42 52

14 17 19 22 24 27 30 32 32 — 36 — —

Tightening torque (Nm {kgm})

Norminal No.

08 10 12 14 16 18 20 24 30 33 36 42 52

Range 5.88 – 8.82 9.8 – 12.74 14.7 – 19.6 19.6 – 24.5 24.5 – 34.3 34.3 – 44.1 44.1 – 53.9 58.8 – 78.4 93.1 – 122.5 107.8 – 147.0 127.4 – 176.4 181.3 – 240.1 274.4 – 367.5

{0.6 – 0.9} {1.0 – 1.3} {1.5 – 2.0} {2.0 – 2.5} {2.5 – 3.5} {3.5 – 4.5} {4.5 – 5.5} {6.0 – 8.0} {9.5 – 12.5} {11.0 – 15.0} {13.0 – 18.0} {18.5 – 24.5} {28.0 – 37.5}

Target 7.35 {0.75} 11.27 {1.15} 17.64 {1.8} 22.54 {2.3} 29.4 {3.0} 39.2 {4.0} 49.0 {5.0} 68.6 {7.0} 107.8 {11.0} 124.4 {13.0} 151.9 {15.5} 210.7 {21.5} 323.4 {33.0}

00-13

FOREWORD

STANDARD TIGHTENING TORQUE

TIGHTENING TORQUE FOR 102 ENGINE SERIES 1) BOLT AND NUTS Use these torques for bolts and nuts (unit: mm) of Cummins Engine. Thread diameter

Tightening torque

mm

Nm

kgm

10 0 2 24 0 4 43 0 6 77 0 12

6 8 10 12

1.02 0 0.20 2.45 0 0.41 4.38 0 0.61 7.85 0 1.22

2) EYE JOINTS Use these torques for eye joints (unit: mm) of Cummins Engine. Thread diameter

Tightening torque

mm

Nm

kgm

802 10 0 2 12 0 2 24 0 4 36 0 5

6 8 10 12 14

0.81 0 0.20 1.02 0 0.20 1.22 0 0.20 2.45 0 0.41 3.67 0 0.51

3) TAPERED SCREWS Use these torques for tapered screws (unit: inch) of Cummins Engine. Thread diameter

Tightening torque

inch

Nm

kgm

301 802 12 0 2 15 0 2 24 0 4 36 0 5 60 0 9

1 / 16 1/8 1/4 3/8 1/2 3/4 1

0.31 0 0.10 0.81 0 0.20 1.22 0 0.20 1.53 0 0.41 2.45 0 0.41 3.67 0 0.51 6.12 0 0.92

TIGHTENING TORQUE TABLE FOR HOSES (TAPER SEAL TYPE AND FACE SEAL TYPE) ★ Tighten the hoses (taper seal type and face seal type) to the following torque, unless otherwise specified. ★ Apply the following torque when the threads are coated (wet) with engine oil. Tightening torque (Nm {kgm}) Nominal size Width across of hose flats

Taper seal type

Face seal type

Nominal thread Thread size size Root diameter - Threads per (mm) inch, Thread series (mm) (Reference)

Range

Target

34 – 54 {3.5 – 5.5}

44 {4.5}

–

9 — – 18UN 16

14.3

34 – 63 {3.5 – 6.5}

44 {4.5}

14

–

–

22

54 – 93 {5.5 – 9.5}

74 {7.5}

–

11 — – 16UN 16

17.5

24

59 – 98 {6.0 – 10.0}

78 {8.0}

18

–

–

04

27

84 – 132 {8.5 – 13.5}

103 {10.5}

22

13 — – 16UN 16

20.6

05

32

128 – 186 {13.0 – 19.0}

157 {16.0}

24

1 – 14UNS

25.4

06

36

177 – 245 {18.0 – 25.0}

216 {22.0}

30

3 1 — – 12UN 16

30.2

(10)

41

177 – 245 {18.0 – 25.0}

216 {22.0}

33

–

–

(12)

46

197 – 294 {20.0 – 30.0}

245 {25.0}

36

–

–

(14)

55

246 – 343 {25.0 – 35.0}

294 {30.0}

42

–

–

02

03

00-14

19

FOREWORD

ELECTRIC WIRE CODE

ELECTRIC WIRE CODE In the wiring diagrams, various colors and symbols are employed to indicate the thickness of wires. This wire code table will help you understand WIRING DIAGRAMS. Example: 5WB indicates a cable having a nominal number 5 and white coating with black stripe. CLASSIFICATION BY THICKNESS Copper wire Cable O.D. (mm)

Current rating (A)

Applicable circuit

0.88

2.4

12

Starting, lighting, signal etc.

0.32

2.09

3.1

20

Lighting, signal etc.

65

0.32

5.23

4.6

37

Charging and signal

15

84

0.45

13.36

7.0

59

Starting (Glow plug)

40

85

0.80

42.73

11.4

135

Starting

60

127

0.80

63.84

13.6

178

Starting

100

217

0.80

109.1

17.6

230

Starting

Norminal number

Number of strands

Dia. of strands (mm2)

Cross section (mm2)

0.85

11

0.32

2

26

5

CLASSIFICATION BY COLOR AND CODE Circuits Priority Classification

1

Primary

Charging

Ground

Starting

Lighting

Instrument

Signal

Other

Code

W

B

B

R

Y

G

L

Color

White

Black

Black

Red

Yellow

Green

Blue

Code

WR

—

BW

RW

YR

GW

LW

2 Color White & Red

—

Code

—

WB

White & Black Red & White Rellow & Red Green & White Blue & White BY

RB

YB

GR

LR

3

4

Auxiliary

Color White & Black

—

Code

—

WL

Black & Yellow Red & Black Yellow & Black Green & Red Blue & Yellow BR

Color White & Blue

—

Code

—

—

Color White & Green

—

—

Code

—

—

—

Color

—

—

—

WG

RY

Black & Red Red & Yellow RG

YG

GY

LY

Yellow & Green

Green & Yellow

Blue & Yellow

YL

GB

LB

5 Red & Green Yellow & Blue Green & Black Blue & Black RL

YW

GL

6 Red & Blue Yellow & White Green & Blue

n n

00-15

FOREWORD

CONVERSION TABLE

CONVERSION TABLE METHOD OF USING THE CONVERSION TABLE The Conversion Table in this section is provided to enable simple conversion of figures. For details of the method of using the Conversion Table, see the example given below.

EXAMPLE • Method of using the Conversion Table to convert from millimeters to inches 1. Convert 55 mm into inches. (1) Locate the number 50 in the vertical column at the left side, take this as A, then draw a horizontal line from A. (2) Locate the number 5 in the row across the top, take this as B, then draw a perpendicular line down from B. (3) Take the point where the two lines cross as C. This point C gives the value when converting from millimeters to inches. Therefore, 55 mm = 2.165 inches. 2. Convert 550 mm into inches. (1) The number 550 does not appear in the table, so divide by 10 (move the decimal point one place to the left) to convert it to 55 mm. (2) Carry out the same procedure as above to convert 55 mm to 2.165 inches. (3) The original value (550 mm) was divided by 10, so multiply 2.165 inches by 10 (move the decimal point one place to the right) to return to the original value. This gives 550 mm = 21.65 inches. B Millimeters to inches 1 mm = 0.03937 in

A

00-16

0

1

2

3

4

0 10 20 30 40

0 0.394 0.787 1.181 1.575

0.039 0.433 0.827 1.220 1.614

0.079 0.472 0.866 1.260 1.654

0.118 0.512 0.906 1.299 1.693

0.157 0.551 0.945 1.339 1.732

50 60 70 80 90

1.969 2.362 2.756 3.150 3.543

2.008 2.402 2.795 3.189 3.583

2.047 2.441 2.835 3.228 3.622

2.087 2.480 2.874 3.268 3.661

2.126 2.520 2.913 3.307 3.701

5 0.197 0.591 0.984 1.378 1.772 C 2.165 2.559 2.953 3.346 3.740

6

7

8

9

0.236 0.630 1.024 1.417 1.811

0.276 0.669 1.063 1.457 1.850

0.315 0.709 1.102 1.496 1.890

0.354 0.748 1.142 1.536 1.929

2.205 2.598 2.992 3.386 3.780

2.244 2.638 3.032 3.425 3.819

2.283 2.677 3.071 3.465 3.858

2.323 2.717 3.110 3.504 3.898

FOREWORD

CONVERSION TABLE

Millimeters to Inches 1 mm = 0.03937 in

0

1

2

3

4

5

6

7

8

9

0

0.039

0.079

0.118

0.157

0.197

0.236

0.276

0.315

0.354

10

0.394

0.433

0.472

0.512

0.551

0.591

0.630

0.669

0.709

0.748

20

0.787

0.827

0.866

0.906

0.945

0.984

1.024

1.063

1.102

1.142

30

1.181

1.220

1.260

1.299

1.339

1.378

1.417

1.457

1.496

1.536

40

1.575

1.614

1.654

1.693

1.732

1.772

1.811

1.850

1.890

1.929

50

1.969

2.008

2.047

2.087

2.126

2.165

2.205

2.244

2.283

2.323

60

2.362

2.402

2.441

2.480

2.520

2.559

2.598

2.638

2.677

2.717

70

2.756

2.795

2.835

2.874

2.913

2.953

2.992

3.032

3.071

3.110

80

3.150

3.189

3.228

3.268

3.307

3.346

3.386

3.425

3.465

3.504

90

3.543

3.583

3.622

3.661

3.701

3.740

3.780

3.819

3.858

3.898

0

Kilogram to Pound 1 kg = 2.2046 lb

0 0

0

1

2

3

4

5

6

7

8

9

2.20

4.41

6.61

8.82

11.02

13.23

15.43

17.64

19.84

10

22.05

24.25

26.46

28.66

30.86

33.07

35.27

37.48

39.68

41.89

20

44.09

46.30

48.50

50.71

51.91

55.12

57.32

59.53

61.73

63.93

30

66.14

68.34

70.55

72.75

74.96

77.16

79.37

81.57

83.78

85.98

40

88.18

90.39

92.59

94.80

97.00

99.21

101.41

103.62

105.82

108.03

50

110.23

112.44

114.64

116.85

119.05

121.25

123.46

125.66

127.87

130.07

60

132.28

134.48

136.69

138.89

141.10

143.30

145.51

147.71

149.91

152.12

70

154.32

156.53

158.73

160.94

163.14

165.35

167.55

169.76

171.96

174.17

80

176.37

178.57

180.78

182.98

185.19

187.39

189.60

191.80

194.01

196.21

90

198.42

200.62

202.83

205.03

207.24

209.44

211.64

213.85

216.05

218.26

00-17

FOREWORD

CONVERSION TABLE

Liter to U.S. Gallon 1l = 0.2642 U.S. Gal

0

1

2

3

4

5

6

7

8

9

0

0.264

0.528

0.793

1.057

1.321

1.585

1.849

2.113

2.378

10

2.642

2.906

3.170

3.434

3.698

3.963

4.227

4.491

4.755

5.019

20

5.283

5.548

5.812

6.076

6.340

6.604

6.869

7.133

7.397

7.661

30

7.925

8.189

8.454

8.718

8.982

9.246

9.510

9.774

10.039

10.303

40

10.567

10.831

11.095

11.359

11.624

11.888

12.152

12.416

12.680

12.944

50

13.209

13.473

13.737

14.001

14.265

14.529

14.795

15.058

15.322

15.586

60

15.850

16.115

16.379

16.643

16.907

17.171

17.435

17.700

17.964

18.228

70

18.492

18.756

19.020

19.285

19.549

19.813

20.077

20.341

20.605

20.870

80

21.134

21.398

21.662

21.926

22.190

22.455

22.719

22.983

23.247

23.511

90

23.775

24.040

24.304

24.568

24.832

25.096

25.361

25.625

25.889

26.153

0

Liter to U.K. Gallon 1l = 0.21997 U.K. Gal

0

1

2

3

4

5

6

7

8

9

0

0.220

0.440

0.660

0.880

1.100

1.320

1.540

1.760

1.980

10

2.200

2.420

2.640

2.860

3.080

3.300

3.520

3.740

3.950

4.179

20

4.399

4.619

4.839

5.059

5.279

5.499

5.719

5.939

6.159

6.379

30

6.599

6.819

7.039

7.259

7.479

7.969

7.919

8.139

8.359

8.579

40

8.799

9.019

9.239

9.459

9.679

9.899

10.119

10.339

10.559

10.778

50

10.998

11.281

11.438

11.658

11.878

12.098

12.318

12.528

12.758

12.978

60

13.198

13.418

13.638

13.858

14.078

14.298

14.518

14.738

14.958

15.178

70

15.398

15.618

15.838

16.058

16.278

16.498

16.718

16.938

17.158

17.378

80

17.598

17.818

18.037

18.257

18.477

18.697

18.917

19.137

19.357

19.577

90

19.797

20.017

20.237

20.457

20.677

20.897

21.117

21.337

21.557

21.777

0

00-18

FOREWORD

CONVERSION TABLE

kgm to ft. lb 1 kgm = 7.233 ft. lb

0

1

2

3

4

5

6

7

8

9

0

0

7.2

14.5

21.7

28.9

36.2

43.4

50.6

57.9

65.1

10

72.3

79.6

86.8

94.0

101.3

108.5

115.7

123.0

130.2

137.4

20

144.7

151.9

159.1

166.4

173.6

180.8

188.1

195.3

202.5

209.8

30

217.0

224.2

231.5

238.7

245.9

253.2

260.4

267.6

274.9

282.1

40

289.3

296.6

303.8

311.0

318.3

325.5

332.7

340.0

347.2

354.4

50

361.7

368.9

376.1

383.4

390.6

397.8

405.1

412.3

419.5

426.8

60

434.0

441.2

448.5

455.7

462.9

470.2

477.4

484.6

491.8

499.1

70

506.3

513.5

520.8

528.0

535.2

542.5

549.7

556.9

564.2

571.4

80

578.6

585.9

593.1

600.3

607.6

614.8

622.0

629.3

636.5

643.7

90

651.0

658.2

665.4

672.7

679.9

687.1

694.4

701.6

708.8

716.1

100

723.3

730.5

737.8

745.0

752.2

759.5

766.7

773.9

781.2

788.4

110

795.6

802.9

810.1

817.3

824.6

831.8

839.0

846.3

853.5

860.7

120

868.0

875.2

882.4

889.7

896.9

904.1

911.4

918.6

925.8

933.1

130

940.3

947.5

954.8

962.0

969.2

976.5

983.7

990.9

998.2

1005.4

140

1012.6

1019.9

1027.1

1034.3

1041.5

1048.8

1056.0

1063.2

1070.5

1077.7

150

1084.9

1092.2

1099.4

1106.6

1113.9

1121.1

1128.3

1135.6

1142.8

1150.0

160

1157.3

1164.5

1171.7

1179.0

1186.2

1193.4

1200.7

1207.9

1215.1

1222.4

170

1129.6

1236.8

1244.1

1251.3

1258.5

1265.8

1273.0

1280.1

1287.5

1294.7

180

1301.9

1309.2

1316.4

1323.6

1330.9

1338.1

1345.3

1352.6

1359.8

1367.0

190

1374.3

1381.5

1388.7

1396.0

1403.2

1410.4

1417.7

1424.9

1432.1

1439.4

00-19

FOREWORD

CONVERSION TABLE

kg/cm2 to lb/in2 1kg/cm2 = 14.2233 lb/in2

0

1

2

3

4

5

6

7

8

9

0

0

14.2

28.4

42.7

56.9

71.1

85.3

99.6

113.8

128.0

10

142.2

156.5

170.7

184.9

199.1

213.4

227.6

241.8

256.0

270.2

20

284.5

298.7

312.9

327.1

341.4

355.6

369.8

384.0

398.3

412.5

30

426.7

440.9

455.1

469.4

483.6

497.8

512.0

526.3

540.5

554.7

40

568.9

583.2

597.4

611.6

625.8

640.1

654.3

668.5

682.7

696.9

50

711.2

725.4

739.6

753.8

768.1

782.3

796.5

810.7

825.0

839.2

60

853.4

867.6

881.8

896.1

910.3

924.5

938.7

953.0

967.2

981.4

70

995.6

1010

1024

1038

1053

1067

1081

1095

1109

1124

80

1138

1152

1166

1181

1195

1209

1223

1237

1252

1266

90

1280

1294

1309

1323

1337

1351

1365

1380

1394

1408

100

1422

1437

1451

1465

1479

1493

1508

1522

1536

1550

110

1565

1579

1593

1607

1621

1636

1650

1664

1678

1693

120

1707

1721

1735

1749

1764

1778

1792

1806

1821

1835

130

1849

1863

1877

1892

1906

1920

1934

1949

1963

1977

140

1991

2005

2020

2034

2048

2062

2077

2091

2105

2119

150

2134

2148

2162

2176

2190

2205

2219

2233

2247

2262

160

2276

2290

2304

2318

2333

2347

2361

2375

2389

2404

170

2418

2432

2446

2460

2475

2489

2503

2518

2532

2546

180

2560

2574

2589

2603

2617

2631

2646

2660

2674

2688

190

2702

2717

2731

2745

2759

2773

2788

2802

2816

2830

200

2845

2859

2873

2887

2901

2916

2930

2944

2958

2973

210

2987

3001

3015

3030

3044

3058

3072

3086

3101

3115

220

3129

3143

3158

3172

3186

3200

3214

3229

3243

3257

230

3271

3286

3300

3314

3328

3343

3357

3371

3385

3399

240

3414

3428

3442

3456

3470

3485

3499

3513

3527

3542

00-20

FOREWORD

CONVERSION TABLE

Temperature Fahrenheit-Centigrade Conversion ; a simple way to convert a Fahrenheit temperature reading into a Centigrade temperature reading or vice versa is to enter the accompanying table in the center or boldface column of figures. These figures refer to the temperature in either Fahrenheit or Centigrade degrees. If it is desired to convert from Fahrenheit to Centigrade degrees, consider the center column as a table of Fahrenheit temperatures and read the corresponding Centigrade temperature in the column at the left. If it is desired to convert from Centigrade to Fahrenheit degrees, consider the center column as a table of Centigrade values, and read the corresponding Fahrenheit temperature on the right. 1°C = 33.8°F

°C

°F

°C

°F

°C

°F

°C

°F

–40.4 –37.2 –34.4 –31.7 –28.9

–40 –35 –30 –25 –20

–40.0 –31.0 –22.0 –13.0 –4.0

–11.7 –11.1 –10.6 –10.0 –9.4

11 12 13 14 15

51.8 53.6 55.4 57.2 59.0

7.8 8.3 8.9 9.4 10.0

46 47 48 49 50

114.8 116.6 118.4 120.2 122.0

27.2 27.8 28.3 28.9 29.4

81 82 83 84 85

117.8 179.6 181.4 183.2 185.0

–28.3 –27.8 –27.2 –26.7 –26.1

–19 –18 –17 –16 –15

–2.2 –0.4 1.4 3.2 5.0

–8.9 –8.3 –7.8 –7.2 –6.7

16 17 18 19 20

60.8 62.6 64.4 66.2 68.0

10.6 11.1 11.7 12.2 12.8

51 52 53 54 55

123.8 125.6 127.4 129.2 131.0

30.0 30.6 31.1 31.7 32.2

86 87 88 89 90

186.8 188.6 190.4 192.2 194.0

–25.6 –25.0 –24.4 –23.9 –23.3

–14 –13 –12 –11 –10

6.8 8.6 10.4 12.2 14.0

–6.1 –5.6 –5.0 –4.4 –3.9

21 22 23 24 25

69.8 71.6 73.4 75.2 77.0

13.3 13.9 14.4 15.0 15.6

56 57 58 59 0

132.8 134.6 136.4 138.2 140.0

32.8 33.3 33.9 34.4 35.0

91 92 93 94 95

195.8 197.6 199.4 201.2 203.0

–22.8 –22.2 –21.7 –21.1 –20.6

–9 –8 –7 –6 –5

15.8 17.6 19.4 21.2 23.0

–3.3 –2.8 –2.2 –1.7 –1.1

26 27 28 29 30

78.8 80.6 82.4 84.2 86.0

16.1 16.7 17.2 17.8 18.3

61 62 63 64 65

141.8 143.6 145.4 147.2 149.0

35.6 36.1 36.7 37.2 37.8

96 97 98 99 100

204.8 206.6 208.4 210.2 212.0

–20.0 –19.4 –18.9 –18.3 –17.8

–4 –3 –2 –1 0

24.8 26.6 28.4 30.2 32.0

–0.6 0 0.6 1.1 1.7

31 32 33 34 35

87.8 89.6 91.4 93.2 95.0

18.9 19.4 20.0 20.6 21.1

66 67 68 69 70

150.8 152.6 154.4 156.2 158.0

40.6 43.3 46.1 48.9 51.7

105 110 115 120 125

221.0 230.0 239.0 248.0 257.0

–17.2 –16.7 –16.1 –15.6 –15.0

1 2 3 4 5

33.8 35.6 37.4 39.2 41.0

2.2 2.8 3.3 3.9 4.4

36 37 38 39 40

96.8 98.6 100.4 102.2 104.0

21.7 22.2 22.8 23.3 23.9

71 72 73 74 75

159.8 161.6 163.4 165.2 167.0

54.4 57.2 60.0 62.7 65.6

130 135 140 145 150

266.0 275.0 284.0 293.0 302.0

–14.4 –13.9 –13.3 –12.8 –12.2

6 7 8 9 10

42.8 44.6 46.4 48.2 50.0

5.0 5.6 6.1 6.7 7.2

41 42 43 44 45

105.8 107.6 109.4 111.2 113.0

24.4 25.0 25.6 26.1 26.7

76 77 78 79 80

168.8 170.6 172.4 174.2 176.0

68.3 71.1 73.9 76.7 79.4

155 160 165 170 175

311.0 320.0 329.0 338.0 347.0

00-21

FOREWORD

UNITS

UNITS In this manual, the measuring units are indicated with Internatinal System of units (SI). As for reference, conventionally used Gravitational System of units are indicated in parentheses {

}.

Example: N {kg} Nm {kgm} MPa {kg/cm2} kPa {mmH2O} kPa {mmHg} kW/rpm {HP/rpm} g/kWh {g/HPh}

00-22

10-04

01

GENERAL

Basic information on air conditioners ....... 01- 2 • Units related to refrigeration ............... 01- 2 Heat ......................................................... 01- 2 Temperature ........................................... 01- 2 Pressure .................................................. 01- 3 Humidity ................................................. 01- 4 • Principle of cooling ............................... 01- 5 • Refrigerants ............................................ 01- 9 • Refrigerator oil ....................................... 01-10 Applicable machine ..................................... 01-14 Specifications ............................................... 01-16 1. Freon gas (R-12) type ............................ 01-16 2. New refrigerant (R134a) type ............... 01-34 fl Refer to the section 40 for the explanation of New Refrigerant (R134a).

Air conditioner

01-1 1 4

GENERAL

APPLICABLE MACHINE

APPLICABLE MACHINE 1. Freon gas type Applicable machine model Manufacturer

Chapter Bulldozer

DENSO

ZEXEL

DAIKIN

01-14 1 4

10

20

30

D40, 41A-3 D40, 41-5 D50, 53A-17 D50, 53-18 D57S-1 D60, 65A-8 D60, 65-12 D66S-1 D75S-5 D80, 85A-18 D150, 155A-1 D355A-3 D375A-1 D475A-1

—

—

Hydraulic excavator

Motor grader

PC150-3 GD405A-2 PC200-3 GD505A-2 PC220-2 GD505A-3 PC300-2 GD525A-1 PC300-3 GD605A-2 PC400-1 GD605A-3 PC400-3 GD605A-5 PC650-1, 3, 5 GD625A-1 PC1500-1 GD655A-2 PC100, 120-5, 6 GD705A-2 PC200, 210, GD705A-3 PC220-6 GD705A-4 PC1000-1 GD805A-1 PC1600-1 GD825A-1 PW150-1 GD825A-2 PW200-1

—

—

—

—

Dump truck HD325-6 HD465-5 HD785-3 HD1200M-1

HD180-4 HD200-2 HD205-3 HD320, 325-3 HD325-5 HD465-2 HD465-3 HD785-1 HD785-2 HD1200-1 HD1200M-1 HD1600M-1

—

Wheel loader

WA200-1 WA250-3 WA300-1 WA320-3 WA350-1 WA380-3 WA400-1 WA420-3 WA450-1 WA470-3 WA500-1 WA600-1 WA700-1 WA800-2

—

WA200-1 WA300-1 WA350-1 WA400-1 WA450-1 WA500-1 WA600-1 WA800-1

Air conditioner

GENERAL

APPLICABLE SPECIFlCATIONS MACHINE

2. New refrigerant type Applicable machine model Manufacturer

Chapter Bulldozer

DENSO

40

ZEXEL

-

TAKAHASHI WORKS

SANDEN

Air conditioner

D40, 41-5 D50, 53-18 D60, 65-12 D275AX-5 D375A-3 D375A-5 D475A-3 D575A-2 D575A-3

Hydraulic excavator PC200-6 PC210-6 PC220-6 PC650-5 PC1000-1 PC1600-1

Motor grader GD305A-1 GD355A-1 GD405A-2 GD505A-3 GD605A-5 GD705A-4 GD825A-2

Dump truck HD255-5 HD325-6 HD465-5 HD605-5 HD785-3 HD785-5 HD985-5 HD1200-1 HM400-1

Wheel loader WA80-3 WA120-3 WA180-3 WA250-3 WA320-3 WA380-3 WA420-3 WA470-3 WA500-1 WA500-3 WA600-1 WA600-3 WA700-1 WA700-3 WA800-2 WA800-3 WA900-3 WA1200-3

HD205-3

50

PC100-6 PC120-6 PC300-5 PC400-5 A57

60

PC27MR-2 PC30MR-2 PC35MR-2 PC40MR-2 PC50MR-2

GD305A-2 GD355A-3 GD405A-3

01-15 (5)

GENERAL

SPECIFlCATIONS

SPECIFlCATIONS 1. FREON GAS (R-12) TYPE DENSO Manufacturer

DENSO D40, 41A-3 D50, 53A-17 D57S-1 D60, 65A-8 D75S-5

Applicable machine

D80, 85A-18 D150, 155A-1 D355A-3

D66S-1

Power source

D375A-1 D475A-1

DC, 24V

Cooling capacity

kcal/h

3,200

3,400

3,200

3,500

Heating capacity

kcal/h

4,800

4,500

4,800

4,500

Compressor

Type

Crank type(2M110B)

Crank type(2M126B)

No. of cylinders-bore x stroke

mm

2-50 x 28

2-50 x 32

Max. speed

rpm

2,200

2,180

cc/rev

110

126

Delivery Magnet clutch type Power consumption of clutch

Electromagnetic, dry disc 40

W

Dryer, receiver Condenser fan

Condenser type Motor type Power consumption Max. air flow

W m3/min

Plate fin

70F

Cooling by engine fan

125

-

23.3

20.5

424

cc

Evaporator type

475 Plate fin

Blower

Type

Max. air flow

W m3/min

160 7

6.3

Refrigerant Refrigerator oil

Amount

Protective equipment

01-16 (5)

7

3-stage selection (H,M, L) Air mix type

Refrigerating method

Name of refrigerator oil

Corrugated fin

150

Temperature control

Amount

580

Sirocco fan

Air flow control

Name of refrigerant

-

Fusible plug (melting point : 100-105fC/30 kg/cm2),desiccant

Auxiliary equipment

Power consumption of motor

-

ON io OFF

Air flow control

Capacity

Corrugated fin

Vapour (gas) compression refrigerating system R-12 kg

1.6-2.0

1.5-1.7

DENSO OIL 6 or SUNISO 4 GS cc

210

300

Fusible plug (receiver)

Air conditioner

GENERAL

SPECIFlCATIONS

DENSO D40, 41-5 D50, 53-18

D60, 65-12

DC, 24V

2,650 v 265

3,500 v 350

5,300 v 530

-

Crank type(2M110B) Crank type(2M126B) 2-50 x 28 3,000 110

126

Electromagnetic, dry disc 40 Corrugated fin

Plate fin

70F

Cooling by engine fan

Max. 80 v 20%

-

1,100 m3/n v 200

-

Hi io Lo

-

Fusible plug (103fC-110fC) 600 Plate fin

Corrugated fin

Sirocco fan 70

330 v 10% m3/n

180W v 10% 460 v 10%

Hi io Med io Lo Thermistor type (ON io OFF)

Reheat type

Vapour (gas) compression refrigerating system R-12 1.0 ND-Oil 6 210

380

Fusible plug (receiver)

Air conditioner

01-17 (5) 4

GENERAL

SPECIFlCATIONS

Manufacturer

DENSO PC100, 120-5, 6 PC200, 210, 220-6 PC150-3, PC300-3 PC200-3, PC400-1 PC220-3, PC400-3 PC300-2 PW150-1, PW200-1

Applicable machine

Power source

PC650-1, 3, 5 PC1500-1 PC1000-1 PC1600-1

DC, 24V

Cooling capacity

kcal/h

2,800

3,200

Heating capacity

kcal/h

3,100

4,800

Compressor

Type

Crank type(2M110B)

No. of cylinders-bore x stroke

mm

Max. speed

rpm

Delivery

110

40

W

Aluminium tube, corrugated fin

Motor type Power consumption Max. air flow

70F W

80

125

m3/min

15

20.5 ON io OFF

Air flow control

Fusible plug (melting point : 100-105fC/ 30 kg/cm2), desiccant

Auxiliary equipment Capacity

cc

Evaporator type

525

475

Corrugated fin

Plate fin

Blower

Type Power consumption of motor Max. air flow

Sirocco fan W

150

160

m3/min

5.5

6.3

Air flow control

3-stage selection (H,M, L)

Temperature control

Air mix type

Refrigerant

Name of refrigerant

Refrigerator oil

Refrigerating method

Name of refrigerator oil

Amount

Amount

Protective equipment

01-18 (5)

2,200

Electromagnetic, dry disc

Condenser type Dryer, receiver Condenser fan

2,500-3,100

cc/rev

Magnet clutch type Power consumption of clutch

2-50 x 28

Vapour (gas) compression refrigerating system R-12 kg

1.2

1.6-2.0

DENSO OIL 6 or SUNISO 4 GS cc

280

210

Fusible plug (receiver)

Air conditioner

GENERAL

SPECIFlCATIONS

DENSO WA200-1 WA250-3 WA300-1 WA320-3

WA350-1 WA380-3 WA400-1 WA420-3

WA450-1 WA470-3 WA500-1 WA600-1 WA700-1 WA800-2

DC, 24V 3,500 4,000 Crank type(2M126B) 2-50 x 32 126 Electromagnetic, dry disc 40 Copper tube 4 lines plate fin 86F 160 23.3 ON io OFF Fusible plug (melting point : 100-105fC/30 kg/cm2), desiccant

580 Aluminium tube, corrugated fin Sirocco fan 150 Cooling: 7 (Heating: 5.3)

3-stage selection (H,M, L) Air mix type Vapour (gas) compression refrigerating system R-12 1.5-1.6

1.6-1.7

1.5-1.6

DENSO OIL 6 or SUNISO 4 GS 380 Fusible plug (receiver), pressure switch (air conditioner unit)

Air conditioner

01-19 (5) 4

GENERAL

SPECIFlCATIONS

Manufacturer

DENSO

Applicable machine

GD405A-2

GD505A-2 GD605A-3 GD655A-3 GD705A-3 GD705A-4

Power source

GD605A-2 GD655A-2 GD705A-2

GD505A-3 GD525A-1

DC, 24V

Cooling capacity

kcal/h

2,800

2,300

Heating capacity

kcal/h

3,200

3,100

Compressor

Type

Crank type(2M110B)

No. of cylinders-bore x stroke

mm

Max. speed

rpm

Delivery

2-50 x 28 2,196

40

W

Dryer, receiver Condenser fan

Aluminium tube, corrugated fin

Motor type

Max. air flow

70F W

80

125

80

125

m3/min

15

23.3

15

23.3

ON io OFF

Air flow control

Fusible plug (melting point : 100-105fC/30 kg/cm2), desiccant

Auxiliary equipment Capacity

580

cc

Evaporator type

Corrugated fin

Type Blower

Power consumption of motor Max. air flow

Sirocco fan W

110

80

110

m3/min

5.5

4.3

5.5

3-stage selection 2-stage selection 3-stage selection 2-stage selection (H,M, L)

Air flow control Temperature control

Air mix type

Refrigerant Refrigerator oil

Refrigerating method Name of refrigerant

Name of refrigerator oil

Amount

Amount

Protective equipment

01-20 (5)

2,455

Electromagnetic, dry disc

Condenser type

Power consumption

2,057 110

cc/rev

Magnet clutch type Power consumption of clutch

2,470

Vapour (gas) compression refrigerating system R-12 kg

1.6

1.2

1.6

1.2

DENSO OIL 6 or SUNISO 4 GS cc

210 Fusible plug (receiver)

Air conditioner

GENERAL

SPECIFlCATIONS

DENSO GD805A-1 GD825A-1

GD605A-5

GD825A-2

DC, 24V 2,800

3,800

3,200

4,000

Crank type(2M110B)

-

2-50 x 28

2-50 x 32 1,706

1,589

6,000

110

126

Electromagnetic, dry disc 40 Aluminium tube, corrugated fin 70F

Cooling by engine fan

80

-

15

-

ON io OFF

100-105fC/30 kg/cm2

580

600

Corrugated fin

-

Sirocco fan 110

-

5.5

7

3-stage selection Air mix type Vapour (gas) compression refrigerating system R-12 1.6

1.6-2.0

DENSO OIL 6 or SUNISO 4 GS

1.6

DENSO OIL 6

210

300

Fusible plug (receiver)

Air conditioner

01-21 (5) 4

GENERAL

SPECIFlCATIONS

BOSCH (ZEXEL) Manufacturer

BOSCH (ZEXEL)

Applicable machine

HD180-4, HD200-2, HD205-3 (• - #2084), HD320, 325-3, HD325-5, HD465-2, HD465-3, HD785-1, HD785-2, HD1200-1, HD1200M-1, HD1600M-1

Power source

DC, 24V

Cooling capacity

kcal/h

3,100

Heating capacity

kcal/h

3,200

Compressor

Type

Crank type

No. of cylinders-bore x stroke

mm

2-48 x 34

Max. speed

rpm

-

Delivery

cc/rev

Magnet clutch type Power consumption of clutch

Electromagnetic, dry disc W

Dryer, receiver Condenser fan

Condenser type

Max. air flow

Forced cooling by engine fan W

-

m3/min

-

Air flow control

Fusible plug (melting point : 105fC/30 kg/cm2)

Auxiliary equipment Capacity

cc

Evaporator type

Blower

Max. air flow

Sirocco fan W

180

m3/min

450

Air flow control

3-stage selection (H,M, L)

Temperature control

Reheat air mix type

Refrig- Refrigerator oil erant

Refrigerating method

Vapour (gas) compression refrigerating system

Name of refrigerant Amount

R-12 kg

Protective equipment

1.2 SUNISO 351 or SUNISO 5 GS

Name of refrigerator oil Amount

500 Aluminium tube, aluminium fin

Type Power consumption of motor

Max. 30 Corrugated fin

Motor type Power consumption

123

cc

300 Fusible plug (receiver), pressure switch (*1)

*1. Pressure switch: OFF at max. 0.2 MPa {2 kg/cm2}, OFF at min. 2.7 {27 kg/cm2}

01-24 01-22 (5)

Air conditioner

GENERAL

Air conditioner

SPECIFlCATIONS

01-23 (5)

GENERAL

SPECIFlCATIONS

DAIKIN Manufacturer

DAIKIN (TXF40A1) WA350-1 WA400-1

Applicable machine

Power source

(TXF40A2) WA200-1 WA300-1

(TXF40A3) WA600-1 WA800-1

DC, 24V (22V - 30V)

Cooling capacity

kcal/h

3,900

Heating capacity

kcal/h

4,000

Compressor

Type

Vane rotary type (TXC40A, SS170P)

No. of cylinders-bore x stroke

mm

-

Max. speed

rpm

2,000

cc/rev

121

Delivery Magnet clutch type Power consumption of clutch

Electromagnetic, dry disc W

Dryer, receiver Condenser fan

Condenser type

-

Power consumption

W

Max. air flow

3

m /min

Air flow control

cc

Blower

Sirocco fan W

160

m3/min

6.7

Air flow control

3-stage selection (H,M, L)

Temperature control

Air mix type (frost thermo)

Refrig- Refrigerator oil erant

Refrigerating method

R-12 (DF-12) kg

01-28 01-24

1.3 Daphene 7963

Name of refrigerator oil

Protective equipment

(5)

Vapour (gas) compression refrigerating system

Name of refrigerant

Amount

-

Corrugated fin

Type

Amount

35

Fusible plug (melting point : 100-107fC/30 kg/cm2), desiccant

Evaporator type

Max. air flow

190

-

Auxiliary equipment

Power consumption of motor

Max. 40 Aluminium tube, corrugated fin

Motor type

Capacity

(TXF40A4) WA450-1 WA500-1

cc

220 Fusible plug, pressure switch (receiver), temperature fuse (resistor), thermo protector (compressor)

Air conditioner

GENERAL

Air conditioner

SPECIFlCATIONS

01-33 (5)

GENERAL

SPECIFlCATIONS

2. NEW REFRIGERANT (R134a) TYPE DENSO Manufacturer

DENSO D40, 41-5 D50, 53-18

Applicable machine

Power source Cooling capacity

kcal/h

2,650 v 265

Heating capacity

kcal/h

-

Compressor

Type

Dryer, receiver Condenser fan

3,400 v 340

4,300 v 430

4,400 v 440

5,400 v 540

mm

10 x 29.5 x 22.7

Max. speed

rpm

3,000

cc/rev

155

Delivery Magnet clutch type

Electromagnetic, dry disc

Max. air flow

40

W

Motor type Power consumption

W m3/min

Corrugated fin

Plate fin

70F

Cooling by engine fan

Max. 80 v 20%

1,100m3/n v 200 Hi io Lo

Air flow control

250 v 25

-

500 v 50

-

Auxiliary equipment Capacity

370

cc

Evaporator type

Plate fin

Corrugated fin

Type Power consumption of motor Max. air flow

Sirocco fan W m3/min

70

350 v 10% m3/n

Refrigerant Refrigerator oil

Refrigerating method

Name of refrigerator oil Amount

Protective equipment

01-34

460 v 10%

500 v 10%

Thermistor type (ON io OFF)

Temperature control

Amount

180W v 10%

Hi io Med io Lo

Air flow control

Name of refrigerant

D475A-3

Swash plate type(10PA15C)

Condenser type

Blower

DC, 24V

No. of cylinders-bore x stroke

Power consumption of clutch

(5)

D375A-3

D60, 65-12

Reheat type

Vapour (gas) compression refrigerating system R134a kg

1.0 ND-Oil 8

cc

180 Pressure relief valve (compressor)

Air conditioner

GENERAL

SPECIFlCATIONS

DENSO

D275AX-5

D575A-3

3,500 v 350

D375A-5

DC, 24V

4,300 v 430

4,500 v 450

5,400 v 540

Swash plate type(10PA15C) 10 x 29.5 x 22.7 3,000 155 Electromagnetic, dry disc 40 Corrugated fin Cool: 160 v 16 Hot: 150 v 15

Plate fin Cooling by engine fan 500 v 50

250 v 25

370

550 Corrugated fin Sirocco fan

180W v 10% 500 v 10

Hi io Med io Lo Reheat type Vapour (gas) compression refrigerating system R134a 1.0 ND-Oil 8 180 Pressure relief valve Pressure relief valve (compressor)

Air conditioner

01-35 (5) 4

GENERAL

SPECIFlCATIONS

Manufacturer

DENSO PC200-6 PC210-6

Applicable machine

PC220-6

Power source

PC650-5

PC1000-1

DC, 24V

Cooling capacity

kcal/h

3,300

3,200

2,800

Heating capacity

kcal/h

3,700

3,500

3,100

Compressor

Type

Swash plate type(10PA15C)

No. of cylinders-bore x stroke

mm

Max. speed

rpm

Delivery

10 x 29.5 x 22.7 2,000

2,400 155.3

cc/rev

Magnet clutch type Power consumption of clutch

Electromagnetic, dry disc 40

W

Dryer, receiver Condenser fan

Condenser type

Corrugated fin Cooling by engine fan

-

Cooling by engine fan

-

W

-

120

-

80

m3/min

-

30

-

15

-

ON io OFF

-

ON io OFF

Motor type Power consumption Max. air flow Air flow control

Desiccant

Auxiliary equipment Capacity

550

cc

Evaporator type

Corrugated fin -

Type Blower

Power consumption of motor Max. air flow

W

170

m3/min

420

360

Air mix type

Refrigerant Refrigerator oil

Refrigerating method

Name of refrigerator oil

Amount

Amount

Protective equipment

01-36

330

3-stage selection

Temperature control

(5)

150

Air flow control

Name of refrigerant

2,100

Thermostat type

Vapour (gas) compression refrigerating system R134 kg

1.00-1.14

0.98-1.12 DENSO OIL 8

cc

180

220 Receiver

Air conditioner

GENERAL

SPECIFlCATIONS

DENSO

PC1600-1

DC, 24V 3,500 4,500 Swash plate type(10PA15C)

10 x 29.5 x 22.7 2,400 155.3 Electromagnetic, dry disc

40 Corrugated fin Cooling by engine fan 550 Corrugated fin 130 420 3-stage selection Thermostat type Vapour (gas) compression refrigerating system

R134a 1.38-1.52 DENSO OIL 8 180 Receiver

Air conditioner

01-37 (5) 4

GENERAL

SPECIFlCATIONS

Manufacturer

DENSO WA120-3 WA180-3 WA250-3 WA320-3 WA380-3 WA420-3 WA470-3

Applicable machine

Power source

WA500-1 WA600-1 WA700-1 WA800-2 DC, 24V

Cooling capacity

kcal/h

4,000

3,800

Heating capacity

kcal/h

5,100

4,000

Compressor

Type

Swash plate type

No. of cylinders-bore x stroke

mm

30 x 22

Max. speed

rpm

3,000

Delivery

cc/rev

155

Magnet clutch type Power consumption of clutch

Rubber hub Max. 40

W

Dryer, receiver Condenser fan

Condenser type

Serpentine type

Motor type Power consumption Max. air flow

Ferrite (o 70) W

110

m3/min

18

Air flow control

2-stage (Hi/Lo)

Auxiliary equipment

With sight glass

Capacity

370

cc

Evaporator type

Single tank

Type Blower

Power consumption of motor Max. air flow

Ferrite (o 86) W

(Cooler) 225, (Heater) 215

Max. 480

m3/min

9

7

4-stage selection (Hi/Mez//Mel/Lo)

3-stage selection (Hi/Me/Lo)

Air flow control Temperature control

Air mix type

Refrigerant Refrigerator oil

Refrigerating method Name of refrigerant

Name of refrigerator oil

Amount

Amount

Protective equipment

01-38 (5)

Serpentine

Expansion R134a kg

1.3-1.5 ND-OIL 8

cc

180 Pressure switch relief valve

Air conditioner

GENERAL

SPECIFlCATIONS

DENSO WA100-3 WA150-3 WA200-3 WA250-3

WA80-3

WA300-3, WA380-3, WA420-3, WA470-3, WA500-3, WA600-3, WA700-3, WA800-3, WA900-3

WA1200-3

DC, 24V 3,000

4,000

4,300

4,600

5,000 Swash plate type (10P08E)

Swash plate type (10PA15C)

10-25 x 16.9

10-29.5 x 22.7 6,000

82.9

155.3

Electromagnetic, dry disc (S25)

Electromagnetic, dry disc (L50)

Max. 35

Max. 40 Corrugated fin Ferrite motor 80

19

120 x 2

80 x 2

18 x 2

19 x 2

26.7

2-stage (Hi/Lo) 550 Aluminium tube, aluminium fin Sirocco fan 225 9 4-stage selection (Hi/Mz//Ml/Lo) Reheat type Vapour (gas) compression refrigerating system R134a 1.05

1.25

1.40

DENSO OIL 8 120-135

220-235 Pressure switch (*1)

*1. Pressure switch: OFF at max. 0.2 MPa {2 kg/cm2}, OFF at min. 2.7 {27 kg/cm2}

Air conditioner

01-39 (5)

GENERAL

SPECIFlCATIONS

Manufacturer

DENSO GD705A-4 GD605A-5 GD505A-3 GD405A-2 GD355A-1 GD305A-1

GD825A-2 GD505A-3A

Applicable machine

Power source

DC, 24V

Cooling capacity

kcal/h

4,000

Heating capacity

kcal/h

5,100

Compressor

Type

Swash plate type (10PA15C)

No. of cylinders-bore x stroke

mm

10 x 29.5 x 22.7

Max. speed

rpm

6,000

cc/rev

126

Delivery Magnet clutch type Power consumption of clutch

Electromagnetic, dry disc (L50)

Dryer, receiver Condenser fan

Condenser type

Aluminium tube, aluminium fin

Motor type Power consumption Max. air flow

40

W

Cooling by engine fan

-

W

-

132

m3/min

-

18

-

ON io OFF

Air flow control Auxiliary equipment Capacity

-

550

cc

Evaporator type

-

Blower

Type Power consumption of motor Max. air flow

Sirocco fan W

225

3

9.2

m /min

Air flow control

4-stage selection

Temperature control

Air mix type

Refrig- Refrigerator oil erant

Refrigerating method Name of refrigerant Amount

R134a kg

Amount

01-40

1.6

-

DENSO OIL 8

Name of refrigerator oil

Protective equipment

(5)

Gas compression refrigerating system

cc

180 -

Air conditioner

GENERAL

SPECIFlCATIONS

DENSO HD325-6 #5267HD405-6 • - #1054 HD465-5 #4192 HD605-5 • - #1012 HD785-3 #2269 HD985-5 • - #1020 HD1200-1 #1848 -

HD255-5

HM400-1

HD325-6 #5680 HD405-6 #1055 HD465-5 #4626 HD605-5 #1013 HD785-5 #4001 HD985-5 #1021 -

DC, 24V 3,200

4,000

3,500

5,100

Swash plate type (10PA15C)

Swash plate type (10S15C)

Swash plate type (10PA15C)

10-29.5 x 22.7

10-32 x 20.8

10-29.5 x 22.7

6,000 155.3

157.3

155.3

Electromagnetic, dry disc

Electromagnetic, dry disc (L50T)

Electromagnetic, dry disc (L50)

Max. 40 Corrugated fin Forced cooling by engine fan

-

-

-

-

-

-

-

Fusible plug (melting point : 105fC/30 kg/cm2)

550 Aluminium tube, aluminium fin Sirocco fan

150

225

360

550

3-stage selection (H, M, L)

4-stage selection (H, Mz, Ml, L) Reheat type

Vapour (gas) compression refrigerating system R134a 1.1 DENSO OIL 8 180

220-235 Pressure switch (*1)

*1. Pressure switch: OFF at max. 0.2 MPa {2 kg/cm2}, OFF at min. 3.1 {32 kg/cm2}

Air conditioner

01-41 (5)

GENERAL

SPECIFlCATIONS

ZEXEL Manufacturer

ZEXEL

Applicable machine

HD205-3 (#2085 -)

Power source

DC, 24V

Cooling capacity

kcal/h

3,100

Heating capacity

kcal/h

3,200

Compressor

Type

Swash plate type

No. of cylinders-bore x stroke

mm

6-37 x 25.8

Max. speed

rpm

7,000

cc/rev

167

Delivery Magnet clutch type Power consumption of clutch

Dryer, receiver Condenser fan

Condenser

Electromagnetic, dry disc W

Type Heat dissipation

Corrugated fin type kW

Motor type Power consumption Max. air flow

W

-

m3/min

Fusible plug (melting point : 105fC/30 kg/cm2)

Auxiliary equipment cc

Evaporator type

Blower

Max. air flow

Sirocco fan W

180

m3/min

450

Air flow control

3-stage selection (H,M, L)

Temperature control

Reheat air mix type Vapour (gas) compression refrigerating system

Refrig- Refrigerator oil erant

Refrigerating method Name of refrigerant Amount

R134a kg

Name of refrigerator oil Amount

Protective equipment

500 Aluminium tube, aluminium fin

Type Power consumption of motor

Forced cooling by engine fan

Air flow control

Capacity

Max. 45

1.1 ZXL100PG

cc

300 Fusible plug (receiver), pressure switch(*1)

*1. Pressure switch: OFF at max. 0.2 MPa {2 kg/cm2}, OFF at min. 3.1 {32 kg/cm2}

01-42 01-44 (5) (6)

Air conditioner

GENERAL

SPECIFlCATIONS

Manufacturer

ZEXEL PC78US-6 PC78UU-6

Applicable machine Power source

PC128US-2 PC138US-2 DC, 12V

Cooling capacity

kW

5 (Air flow: 450m3/h)

Heating capacity

kW

4.65 (Air flow: 400m3/h)

Compressor

Type

Swash plate (DKS15CH), piston type

No. of cylinders-bore x stroke

mm

6-36 x 24

Max. speed

rpm

7,000

cc/rev

147

Delivery Magnet clutch type Power consumption of clutch

Dryer, Condenser fan receiver

Condenser

Electromagnetic, dry disc

Type Heat dissipation

45

W

kW

Parallel flow type

Sub cool type

8.13 (at 5 m/s)

7.93 (at 5 m/s)

Motor type Power consumption Max. air flow

Cooling by engine fan W

-

m3/min

-

Air flow control

-

Auxiliary equipment Capacity

cc

Desiccant 150g

Desiccant 100g

400

190

Evaporator type

Plate fin

Blower

Type Power consumption of motor Max. air flow

Sirocco fan W

153

3

400

m /h

Air flow control

4-stage selection, automatic

Temperature control

8-stage selection, automatic

Refrig- Refrigerator oil erant

Refrigerating method

Vapour (gas) compression refrigerating system

Name of refrigerant Amount

R134a kg

Name of refrigerator oil Amount

Protective equipment

Air conditioner

0.9 ± 0.05

0.7 ± 0.05 ZXL100PG

cc

Compressor: 210, Receiver dryer (tank): 50 Pressure switch

01-45 (6)

GENERAL

Air conditioner

SPECIFlCATIONS

01-43 (5)

GENERAL

SPECIFlCATIONS

TAKAHASHI WORKS Manufacturer

TAKAHASHI WORKS A57

GD305A-3 GD355A-3 GD405A-3

Vane rotary type

Rotary type (SS-990)

Elliptical type, Vane rotary

-

(No. of vanes : 5)

PC100-6 PC120-6

Applicable machine

PC300-5 PC400-5

Power source

DC, 24V

Cooling capacity

kcal/h

Heating capacity

kcal/h

3,300 4,000

Compressor

Type No. of cylinders-bore x stroke

mm

Max. speed

rpm

Delivery

Aluminium tube, corrugated fin

Corrugated fin

Aluminium tube, corrugated fin

Cooling by engine fan

-

Cooling by engine fan

W

-

160

-

m3/min

-

24

-

-

ON io OFF

-

100-105fC/30 kgm

Desiccant

Desiccant 300 g

600

780

780

Dryer, receiver Condenser fan

cc

Evaporator type

Serpentine

Blower

Type

Max. air flow

W

Refrigerant Refrigerator oil

Amount

Protective equipment

01-50 01-44 (5)

-

Sirocco fan

-

190

-

6.7

Air mix type

Refrigerating method

Name of refrigerator oil

Sirocco fan

selection 3-stage selection 3-stage selection 3-stage (H, M, L)

Temperature control

Amount

Corrugated fin

m3/min

Air flow control

Name of refrigerant

Electromagnetic, dry disc

40 (DC, 24V, 20fC)

Auxiliary equipment

Power consumption of motor

99

40

Air flow control

Capacity

6,500

42.3

W

Motor type

Max. air flow

2,000

Dry single plate type Electromagnetic

Condenser type

Power consumption

6,500

cc/rev

Magnet clutch type Power consumption of clutch

3,700

Electronic thermo Electronic thermo

Vapour (gas) compression refrigerating system R134a kg

0.8

0.95-1.09

(Estimated calculation value : 1.1)

PAG SK20

SK08

Idemitsu [DH-PR] (compressor maker nominal SK20)

220

cc

Receiver

Pressure switch (air conditioner unit), thermal switch (compressor) relief valve (compressor)

Air conditioner

GENERAL

Air conditioner

SPECIFlCATIONS

01-45 (5)

GENERAL

SPECIFlCATIONS

SANDEN Manufacturer

SANDEN PC27MR-2 PC30MR-2 PC35MR-2 PC40MR-2 PC50MR-2

Applicable machine

Power source

DC, 12V

Cooling capacity

kcal/h

3,500

Heating capacity

kcal/h

3,500

Compressor

Type

Swash plate type

No. of cylinders-bore x stroke

mm

7 x 25.4 x 28.1

Max. speed

rpm

9,300

cc/rev

99.8

Delivery Magnet clutch type Power consumption of clutch

Electromagnetic, dry disc W

Dryer, receiver Condenser fan

Condenser type

Plate fin

Motor type Power consumption Max. air flow

Cooling by engine fan W

-

m3/min

-

Air flow control

-

Auxiliary equipment Capacity

Desiccant 100g cc

Evaporator type

Blower

Max. air flow

Sirocco fan W

120

m3/min

6.7

Air flow control

3-stage selection (H,M, L)

Temperature control

Electronic thermostat type

Refrig- Refrigerator oil erant

Refrigerating method

Vapour (gas) compression refrigerating system

Name of refrigerant Amount

R134a kg

Amount

01-60 01-46

0.6-0.7 SP10A

Name of refrigerator oil

Protective equipment

(5)

240 Plate fin

Type Power consumption of motor

43

cc

100 Pressure switch

Air conditioner

STRUCTURE AND FUNCTION

STRUCTURE AND FUNCTION DENSO (FREON GAS TYPE) Piping diagram............................................................................................................................................11- 2 Electric wiring diagram ...............................................................................................................................11- 3 Compressor ................................................................................................................................................11- 4 Magnetic clutch...........................................................................................................................................11- 7 Condenser ..................................................................................................................................................11- 8 Receiver .....................................................................................................................................................11- 10 Air conditioner unit......................................................................................................................................11- 12 1. Expansion valve .....................................................................................................................................11- 13 2. Evaporator ..............................................................................................................................................11- 15 3. Thermostat .............................................................................................................................................11- 15 4. Pressure switch ......................................................................................................................................11- 16 5. Heater.....................................................................................................................................................11- 18 6. Blower unit..............................................................................................................................................11- 18 7. Piping......................................................................................................................................................11- 19 8. Air control system ...................................................................................................................................11- 20 Names and functions..................................................................................................................................11- 21 Operation....................................................................................................................................................11- 22

Air conditioner

11-1 (5) (5)

TROUBLESHOOTING

TESTING AND ADJUSTING DENSO (FREON GAS TYPE) Service tool................................................................................................................................................ 12- 2 1. Gauge manifold ..................................................................................................................................... 12- 2 2. Gas leak detector .................................................................................................................................. 12- 5 3. Valve for service cans............................................................................................................................ 12- 8 Maintenance procedure............................................................................................................................. 12- 9 Troubleshooting ......................................................................................................................................... 12- 23 1. Defective heating .................................................................................................................................. 12- 24 2. Troubleshooting table ............................................................................................................................ 12- 25 3. Defective heating................................................................................................................................... 12- 27 4. Troubleshooting using gauge manifold.................................................................................................. 12- 28

Air conditioner

12-1 (5)

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY AND ASSEMBLY DENSO (FREON GAS TYPE) Special tools .............................................................................................................................................. 13- 2 Disassembly of magnetic clutch ................................................................................................................ 13- 3 Assembly of magnetic clutch ..................................................................................................................... 13- 7 Disassembly of air conditioner unit............................................................................................................ 13- 9 Disassembly of blower unit........................................................................................................................ 13- 20 Disassembly of condenser ........................................................................................................................ 13- 22

Air conditioner

13-1 (5)

STRUCTURE AND FUNCTION

STRUCTURE AND FUNCTION ZEXEL (DIESEL KIKI) Location of unit .......................................................................................................................................... 21- 2 Electrical circuit diagram............................................................................................................................ 21- 3 Piping diagram........................................................................................................................................... 21- 4 Compressor ............................................................................................................................................... 21- 5 Magnetic clutch.......................................................................................................................................... 21- 7 Condenser ................................................................................................................................................. 21- 8 Receiver (liquid tank)................................................................................................................................. 21- 9 Expansion valve ........................................................................................................................................ 21- 10 Evaporator ................................................................................................................................................. 21- 12

Air conditioner

21-1 (5) (5)

TROUBLESHOOTING

TESTING AND ADJUSTING ZEXEL (DIESEL KIKI) Tightening torque tables ............................................................................................................................ 22- 2 Special tools .............................................................................................................................................. 22- 4 Service procedure ..................................................................................................................................... 22- 12 Inspection and maintenance...................................................................................................................... 22- 23 Troubleshooting ......................................................................................................................................... 22- 32

Air conditioner

22-1 (5)

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY AND ASSEMBLY ZEXEL (DIESEL KIKI) Special tools .............................................................................................................................................. 23- 2 Disassembly of compressor assembly ...................................................................................................... 23- 3 Judging defective locations when disassembling ...................................................................................... 23- 6 Disassembly .............................................................................................................................................. 23- 8 Assembly ................................................................................................................................................... 23- 12

Air conditioner

23-1 (5)

STRUCTURE AND FUNCTION

STRUCTURE AND FUNCTION DAIKIN Piping diagram........................................................................................................................................... 31- 2 Electrical circuit diagram............................................................................................................................ 31- 3 Compressor (Rotary type) ......................................................................................................................... 31- 4 Condenser ................................................................................................................................................. 31- 6 Receiver dryer ........................................................................................................................................... 31- 8 Air conditioner unit..................................................................................................................................... 31- 9 Operating procedure.................................................................................................................................. 31- 13

Air conditioner

31-1 (5) (5)

TROUBLESHOOTING

TESTING AND ADJUSTING DAIKIN Service tools .............................................................................................................................................. 32- 2 Service procedure ..................................................................................................................................... 32- 6 In-season checks....................................................................................................................................... 32- 13 Off-season checks ..................................................................................................................................... 32- 13 Using air compressor dipstick.................................................................................................................... 32- 15 Troubleshooting ......................................................................................................................................... 32- 16 Electric system functional sequence..................................................................................................... 32- 16 Defective cooling................................................................................................................................... 32- 17

Air conditioner

32-1 (5)

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY AND ASSEMBLY DAIKIN Tools .......................................................................................................................................................... 33- 2 Disassembly of compressor ...................................................................................................................... 33- 5 Assembly of compressor ........................................................................................................................... 33- 8 Disassembly and testing of air conditioner unit ..........................................................................................33- 11 Condenser unit .......................................................................................................................................... 33- 20 Receiver dryer ........................................................................................................................................... 33- 20

Air conditioner

33-1 (5)

STRUCTURE AND FUNCTION

STRUCTURE AND FUNCTION DENSO (NEW REFRIGERANT TYPE) Fundamentals of air conditioning 1. Principle of air conditioning.................................................................................................................... 41- 2 2. Basic refrigerating cycle ........................................................................................................................ 41- 3 3. Refrigerant............................................................................................................................................. 41- 6 4. Refrigerating cycle of air conditioner ..................................................................................................... 41- 8 Configuration of refrigerating cycle 1. Structure of each refrigerating cycle part............................................................................................... 41- 10 2. Compressor ........................................................................................................................................... 41- 12 3. Magnetic clutch...................................................................................................................................... 41- 16 4. Condenser ............................................................................................................................................. 41- 17 5. Receiver tank......................................................................................................................................... 41- 17 6. Expansion valve .................................................................................................................................... 41- 18 7. Evaporator ............................................................................................................................................. 41- 21 8. Sight glass ............................................................................................................................................. 41- 22 Control system 1. Outline of control ................................................................................................................................... 41- 23 2. Temperature control............................................................................................................................... 41- 24 3. Air flow control ....................................................................................................................................... 41- 25 4. Circulated air and fresh air selection ..................................................................................................... 41- 26 5. Defrosting control .................................................................................................................................. 41- 26 6. Compressor control ............................................................................................................................... 41- 27

Air conditioner

41-1 (5) (5)

STRUCTURE AND FUNCTION

FUNDAMENTALS OF AIR CONDITIONING

FUNDAMENTALS OF AIR CONDITIONING Alcohol evaporates.

1. Principle of air conditioning If alcohol is applied to your skin, you feel cold. If you sprinkle water over your garden in summer, you feel cool. The cause of these phenomena is that alcohol and water absorb heat (which is called latent heat) from material around them when they evaporate. That is, a liquid (such as alcohol, water, etc.) needs heat (heat of vaporization) to change to a gas (alcohol vapor, steam, etc.) and the material from which heat is absorbed (the material in contact with the liquid) is cooled. These natural phenomena directly show the principle of air conditioning. Coolness and coldness are obtained by utilizing these phenomena. If the vapor of the liquid used for air conditioning is discharged into the atmosphere, however, the liquid must be supplied constantly, and that is not practical. Accordingly, the vapor is cooled to be liquefied again and circulated. To liquefy a gas, it must be cooled first. If it is compressed at this time, it is liquefied more easily. Then, a compressor and a condenser are used to compress and cool the gas.

41-2 4

Heat Sanitary cotton soaked in alcohol

(Liquid absorbs heat from material around it) Evaporation Gas

Liquid

Condensation (Heat of gas is radiated)

Air conditioner

STRUCTURE AND FUNCTION

FUNDAMENTALS OF AIR CONDITIONING

2. Basic refrigerating cycle 2.1 Configuration Generally, an air conditioner means equipment which circulates a volatile liquid (called a refrigerant) in a sealed pipe circuit and evaporates and liquefies it repeatedly during circulation. The basic components of this equipment are as follows. • Evaporator The refrigerant evaporates in the evaporator to absorb heats from around the pipe and cool the room. • Compressor The compressor compresses the refrigerant gas evaporated in the evaporator so that the gas will be liquefied easily in the condenser. • Condenser The condenser cools and liquefies the high-temperature and high-pressure refrigerant gas compressed with the compressor. • Expansion valve The expansion valve is a kind of a choke valve, which keeps the pressure in the evaporator low. That is, the high-pressure refrigerant liquid is spouted through a narrow gap into the evaporator, where it becomes low-pressure and low-temperature mist and evaporates rapidly.

Heat is absorbed from material around evaporator.

Expansion valve Evaporator

Compressor

Condenser

Heat is radiated.

Air conditioner

41-3 4

STRUCTURE AND FUNCTION

FUNDAMENTALS OF AIR CONDITIONING

2.2 Good condition for air conditioner The first good condition for an air conditioner is that the refrigerant evaporates at low temperature and liquefies easily and it evaporates much in the evaporator.

Heat is absorbed.

Expansion valve Low pressure High pressure

Liquid Mist Gas

Evaporator

Compressor

Condenser

Heat is radiated.

The condition of the refrigerant in the refrigerating cycle is as follows. 1 The refrigerant compressed in the compressor is high-temperature and high-pressure gas. 2 As the refrigerant passes through the condenser, it is cooled and liquefied. It must be liquefied completely at the outlet of the condenser. If the refrigerant is not cooled sufficiently in the condenser, some of it is still gas at the outlet of the condenser and the refrigerating capacity is lowered. 3 After the liquefied refrigerant passes the expansion valve, it becomes mist. The expansion valve is called the choke valve, too. The high-pressure refrigerant liquid is spouted through a small hole so that it will evaporate easily. 4 In the evaporator, the refrigerant mist evaporates rapidly and absorbs the heat inside the cab. The refrigerant gasifies completely near the outlet of the evaporator.

41-4 4

Air conditioner

STRUCTURE AND FUNCTION

FUNDAMENTALS OF AIR CONDITIONING

If the refrigerant is insufficient, all of it vaporizes before it reaches the evaporator outlet and the evaporator capacity lowers. If the refrigerant is too much, on the other hand, all of it does not vaporize in the evaporator and flows in the compressor in the form of liquid and the compressor may be broken since it compresses the liquid. Accordingly, the quantity of the refrigerant must be controlled according to various conditions. The air conditioner does not only lower the indoor temperature but lowers the indoor humidity to keep the environment fresh. That is, if the warm indoor air passes through the evaporator, it is cooled and its moisture is condensed into water drops on the evaporator fins. As a result, the moisture in the air is removed and the humidity is lowered. The water drops on the fins are discharged out of the machine through a hose.

[Reference] • Condensation If a glass containing iced water is left in the atmosphere, water drops are formed on the glass surface. This phenomenon shows that the steam in the air (the vaporized water which the air always contains) is cooled and condensed by the iced water in the glass. (The iced water is warmed by the heat of condensation.)

Air conditioner

41-5 4

STRUCTURE AND FUNCTION

FUNDAMENTALS OF AIR CONDITIONING

3. Refrigerant A material which circulates in a refrigerating cycle to transfer heat is called the refrigerant. In air conditioners, HFC134a (R134a) which is a kind of Freon and which contains no chlorine is used.

3.1 Characteristics of refrigerant The characteristics of HFC134a (R134a) are shown in the following figure.

Refrigerant temperature (°C)

Gas

Liquefied if cooled by this temperature

Liquid

Gauge pressure

As indicated by the above curve, the refrigerant under high pressure is liquid up to a relatively high temperature. Under low pressure, however, the refrigerant vaporizes at 0°C or even at –10°C. If the refrigerant vaporizes at 0°C, the evaporator is also at 0°C. The air passes through the evaporator is cooled consequently. If the pressure is lowered to a state where the refrigerant vaporizes at –5°C, the evaporator is kept at –5°C. As a result, the surface of the evaporator is frosted and air does not flow well and the refrigerating performance is lowered. The gasified refrigerant must be liquefied. Considering the environment of the condenser on a construction machinery in summer, it is impossible to keep the condenser temperature as low as 40°C. If the condenser temperature can be kept as low as about 60°C, HFC134a is liquefied under pressure of about 1.7 MPa {about 17 kg/cm2}. In addition, if the refrigerant gas is compressed to 1.7 MPa (with the compressor), its temperature rises to about 80°C. That is, the above curve shows the following; The refrigerant gas is heated to about 80°C at the condenser inlet. If it is cooled by about 20°C at the condenser outlet, however, it becomes liquid of about 60°C.

41-6 4

Air conditioner

STRUCTURE AND FUNCTION

FUNDAMENTALS OF AIR CONDITIONING

[Reference] • Refrigerant HFC134a (R134a) HFC134a is used as the refrigerant of air conditioners for the following reasons. 1. HFC134a does not break the ozone layer which preserves the global environment. 2. HFC134a has much heat of vaporization and liquefies easily. 3. HFC134a does not burn or explode. 4. HFC134a is not toxic or corrosive and does not injure foods and clothes. 5. It is easy to obtain HFC134a. • Substitutive Freon CFC12 (R12) which was a conventional Freon (halogenated carbide containing fluorine) had been used for air conditioners of construction machines. In 1996, however, it was resolved in Montreal World Conference that CFC12 should not be used any more to preserve the global environment. As a result, HFC134a (R134a) which does not break the ozone layer is used as a substitute for the conventional Freon.

Air conditioner

41-7 4

STRUCTURE AND FUNCTION

FUNDAMENTALS OF AIR CONDITIONING

4. Refrigerating cycle of air conditioner The refrigerating cycle of an air conditioner consists of a compressor, condenser, receiver tank, expansion valve, evaporator, etc. The refrigerant is circulated in this cycle to absorb the indoor heat with the evaporator and radiate it outside through the condenser.

Evaporator

Cool air

Expansion valve

Service valve on low-pressure side

Indoor air

Refrigerant liquid

Low-pressure and low-temperature refrigerant mist

Heat sensor tube

Indoor air Sight glass High-pressure and hightemperature gas

Service valve on highpressure side

Hot air

Desiccant

Compressor

Receiver tank Condenser Cooling air from front side

The structure of the expansion valve is different and the receiver tank is added in the above cycle compared to the basic refrigerating cycle described before. To cool the air efficiently, much refrigerant must vaporize in the evaporator. In addition, all the refrigerant must vaporize at the evaporator outlet.

41-8 4

Air conditioner

STRUCTURE AND FUNCTION

FUNDAMENTALS OF AIR CONDITIONING

The environment and structure of a construction machine air conditioner are different from a home air conditioner in the following points. 1 Indoor temperature varies largely. The temperature in the operator’s cab is affected by the outside temperature largely. It becomes very high particularly when the machine is parked under a burning sun in summer. That is, The necessary quantity of the refrigerant in the refrigerating cycle varies largely.

2 Compressor speed varies largely. The compressor speed of the home air conditioner is kept constant by the motor. On the other hand, the compressor of the construction machine air conditioner is driven with the engine and its speed varies largely. That is, The circulation rate of the refrigerant in the refrigerating cycle varies largely.

To solve these problems, the expansion valve does not only work as a simple choke valve but regulates the circulation rate of the refrigerant automatically according to the compressor speed and air conditioning load. For this purpose, the receiver is installed to store excessive refrigerant temporarily. An actual construction machine air conditioner has various devices to control temperature, air flow, etc. and keep the operator’s cab comfortable.

Air conditioner

41-9 4

STRUCTURE AND FUNCTION

CONFIGURATION OF REFRIGERATING CYCLE

CONFIGURATION OF REFRIGERATING CYCLE 1. Structure of each refrigerating cycle part An air conditioner consists of many functional parts. The refrigerating cycle parts among them are mainly explained below. fl The diagram shows a general example of system. The shape of each unit may differ according to the machine model.

Evaporator

Expansion valve

Pressure switch

Compressor

Receiver tank Condenser

41-10 4

Air conditioner

STRUCTURE AND FUNCTION

CONFIGURATION OF REFRIGERATING CYCLE

•

Layout of refrigerating cycle fl The diagram shows the equipment for the D475A-3.

1. 2. 3. 4. 5. 6. 7. 8.

Air conditioner compressor Condenser Refrigerant piping Window defroster Side defroster Air conditioner unit Air outlet Blower motor

Air conditioner

9. 10. 11. 12. 13.

Valve (Hot water outlet) Hot water output piping Receiver tank Hot water return piping Valve (Hot water inlet)

A. Outside air B. Inside air C. Hot air/Cool air

41-11 4

STRUCTURE AND FUNCTION

CONFIGURATION OF REFRIGERATING CYCLE

2. Compressor The compressor compresses the refrigerant gas which absorbed the indoor heat through the evaporator so that it will be liquefied easily and sends it to the high-pressure side again. The types of the compressor are classified by the structure as shown below. 1 Swash plate type 2 Through vane type 3 Sliding vane type 4 Scroll type In addition to the above, the variable-capacity compressor is also used. Its capacity changes according to the necessary air conditioning capacity. The swash plate-type compressor is explained below.

2.1 Swash plate-type compressor

Pressure relief valve

Shaft seal Rear housing

Magnetic clutch

Piston Cylinder Swash plate Front housing

41-12 4

Air conditioner

STRUCTURE AND FUNCTION

CONFIGURATION OF REFRIGERATING CYCLE

(1) Structure In the swash plate-type compressor, 3 pairs (6 cylinders) or 5 pairs (10 cylinders) of pistons are set to the swash plate fixed to the shaft diagonally. If the shaft rotates, the swash plate reciprocates the pistons in the axial direction of the shaft. Both ends of each pair of the pistons are in cylinders. When the cylinder of one end of the pistons is in the compression process, the cylinder of the other end is in the suction process.

Cylinder

Piston Swash plate Piston

Shaft

Piston

Arrangement of pistons (10 cylinders)

Principle of swash plate type compressor

On the valve plate at the cylinder end, there are a suction hole and a discharge hole to which a suction valve and a discharge valve are installed respectively. The inside of the compressor is lubricated with the compressor oil containing in the refrigerant gas and the oil splashed by the centrifugal force of the swash plate. Some models are lubricated forcibly with compressor oil by an oil pump.

Discharge valve

Cylinder

Discharge Suction

Valve plate

Suction valve

Piston

Note: Both valves are kept closed in stationary state.

Air conditioner

41-13 4

STRUCTURE AND FUNCTION

CONFIGURATION OF REFRIGERATING CYCLE

(2) Operation

Discharge valve

Discharge valve

Suction valve

Suction valve

1 Suction As the swash plate rotates, the pistons move. If a piston moves and the cylinder capacity is increased and the pressure in the cylinder lowers below the pressure on the low-pressure side of the refrigerating cycle, the suction valve is pushed open and the refrigerant gas flows in the cylinder. At this time, the discharge valve is fitted to the valve plate by the pressure on the high-pressure side to block the discharge hole of the valve plate. Accordingly, the refrigerant gas does not flow back from the highpressure side into the cylinder. 2 Compression If the cylinder capacity is reduced and the pressure in the cylinder rises above the pressure on the discharge side (high-pressure side), the discharge valve opens and the high-temperature and highpressure refrigerant gas is sent to the condenser. At this time, the suction valve is fitted to the valve plate by the pressure in the cylinder to block the suction hole of the valve plate. Accordingly, the refrigerant gas does not flow back into the suction side (low-pressure side).

41-14 4

Air conditioner

STRUCTURE AND FUNCTION

[Reference] • Pressure relief valve If the pressure on the high pressure side of the refrigerating cycle rises abnormally for some reason, the pressure relief valve of the compressor discharges a part of the refrigerant. Usually, however, the high-pressure pressure switch installed to the control system operates first to stop the compressor. Accordingly, the pressure relief valve does not operate immediately.

CONFIGURATION OF REFRIGERATING CYCLE

Pressure relief valve

fl Once the pressure relief valve operates, remove the cause. If the cause is not removed, the pressure relief valve will operate again.

Gas discharge path when relief valve operates

Air conditioner

41-15 4

STRUCTURE AND FUNCTION

CONFIGURATION OF REFRIGERATING CYCLE

3. Magnetic clutch Magnetic clutch

The air conditioner compressor is driven with the engine. Accordingly, it must be stopped or started again when the temperature reaches the set temperature or rises high. The magnetic clutch installed to the compressor is used for this purpose.

The clutch hub of the magnetic clutch is fitted to the crankshaft of the compressor. While the compressor is turned off, only the pulley rotates. If the air conditioner switch is turned on, a current flows in the coil embedded in the stator. As a result, the stator becomes a strong electromagnet and attracts the clutch hub and the compressor rotates together with the pulley.

Center piece

Pulley

Damper

Compressor shaft

Stator coil

Principle

Rotor Stator coil Snap ring Bearing

Stator Center piece

Structure

41-16 4

Air conditioner

STRUCTURE AND FUNCTION

CONFIGURATION OF REFRIGERATING CYCLE

4. Condenser The condenser cools the high-temperature and high-pressure refrigerant gas sent from the compressor to liquefied it. The condenser consists of tubes, fins, and a fan motor and is installed to the machine body. The refrigerant gas discharged from the compressor is about 1.7 MPa {about 17 kg/cm2} in pressure and about 80°C in temperature, for example. When this refrigerant passes through the tubes, it is cooled and liquefied. Note: The pressure and temperature of the refrigerant vary with the atmospheric temperature, operating condition, etc.

5. Receiver tank The refrigerant liquefied in the condenser is stored in the receiver temporarily so that it can be supplied to the evaporator according to the air conditioning load. The receiver tank has strainers and desiccant in it to remove "dirt" and "moisture" contained in the refrigerating cycle. If there is moisture in the refrigerating cycle, it can corrode the functional parts and can be frozen in the small hole of the expansion valve to block the refrigerant flow. a In this case, replace the receiver tank since the absorbing performance of the desiccant is lost. If the strainer is clogged badly (If the high pressure rises and the low pressure lowers), replace the receiver tank since the strainer cannot be cleaned.

[Reference] • Separation of refrigerant gas and liquid The receiver tank does not only store the refriegerant temporarily but separates the refrigerant gas and liquid. All the refrigerant cooled in the condenser may not be liquefied, depending on the atmosphere condition. If the refrigerant gas is sent to the expansion valve, the air conditioning capacity is lowered. The refrigerant liquid is accumulated on the lower side of the receiver tank and the refrigerant gas is accumulated on the upper side. Since the refrigerant is taken out through the outlet pipe installed to the bottom of the receiver tank, the gas is separated from the liquid.

Air conditioner

Desiccant Strainer

Refrigerant gas

Refrigerant liquid

41-17 (6)

STRUCTURE AND FUNCTION

CONFIGURATION OF REFRIGERATING CYCLE

6. Expansion valve The expansion valve has the following 2 functions. (1) Expand the high-temperature and high-pressure refrigerant liquid sent from the receiver rapidly and change it to low-temperature and low-pressure mist by spouting it through a small hole. (2) Regulate the refrigerant flow rate according to the vaporizing condition of the refrigerant in the evaporator.

Expansion valve

Evaporator

To utilize the evaporator capacity fully, the refrigerant liquid must so absorb the heat from the air around the evaporator that it will vaporize completely at the evaporator outlet. For this porpose, the refrigerant flow rate is regulated automatically according to the fluctuation of the indoor temperature (air conditioning load) and the fluctuation of the compressor speed. a If the refrigerant flow rate is insufficient, the refrigerant in the evaporator vaporizes early and the cooling effect lowers. If the former is too high, on the other hand, the excessive refrigerant liquid does not vaporize but returns to the compressor, and the cooling effect lowers and the compressor valve is damaged.

6.1 Regulation of refrigerant flow rate The refrigerant flow rate is regulated basically with the diaphragm chamber and the needle valve coupled with it. In the following figure, chamber A of the diaphragm chamber is filled with the refrigerant gas and sealed. The pressure in chamber A is high (low) when the refrigerant temperature near the evaporator outlet is high (low). (Since how the pressure in chamber A changes depends on the structure of the expansion valve, the concrete operation is explained later.) On the other hand, the evaporation pressure in the evaporator is applied from near the evaporator outlet to chamber B. While the refrigerant flow rate is constant, the diaphragm keeps the opening rate of the needle valve constant with the pressure in chambers A and B and the force of the spring. If the air conditioning load (indoor temperature, etc.) changes, the pressure in chamber A changes and moves the needle valve to the right or left to regulate the refrigerant flow rate.

From receiver tank

Needle valve

(High pressure)

Diaphragm

Filled with refrigerant gas and sealed

Spring

Refrigerant temperature near evaporator outlet is transmitted. Evaporator To compressor (Low pressure)

41-18 (6)

Air conditioner

STRUCTURE AND FUNCTION

CONFIGURATION OF REFRIGERATING CYCLE

6.2 Expansion valve (Box type) (1) Structure

(Evaporator)

The box-type expansion valve consists a diaphragm, heat sensor rod, needle valve (ball), etc. The upper part of the diaphragm is filled with the refrigerant and sealed. The pressure at the evaporator outlet is applied to the lower part of the diaphragm.

Diaphragm

Spring

Heat sensor rod Needle (From receiver valve tank)

(To compressor)

(2) Operation The heat sensor rod senses the refrigerant temperature after it passes through the evaporator. The temperature at this time is transmitted through the heat sensor rod to the refrigerant gas in the upper part of the diaphragm chamber. As a result, the gas pressure changes according to the temperature and moves the heat sensor rod coupled with the diaphragm to regulate the opening rate of the needle valve. • When evaporator outlet temperature is low (When air conditioning load is low) The gas pressure in the diaphragm chamber lowers and the gas volume decreases. As a result, the heat sensor rod moves to the right to close the needle valve. • When evaporator outlet temperature is high (When air conditioning load is high) The gas pressure in the diaphragm chamber rises and the gas volume increases. As a result, the heat sensor rod moves to the left to open the needle valve, and more refrigerant is supplied to the evaporator.

(Evaporator)

Heat sensor rod Diaphragm

From receiver tank (High pressure)

Air conditioner

Needle valve

To compressor (Low pressure)

41-19 4

STRUCTURE AND FUNCTION

[Reference] • Expansion valve of even internal pressure type If the evaporator capacity is relatively little, this expansion valve of even internal pressure type is used. In this type, the evaporation pressure of the evaporator under the diaphragm is applied through the small hole (inlet of the evaporator) in the expansion valve. The other structure and operation are the same with the conventional type described above.

CONFIGURATION OF REFRIGERATING CYCLE

Capillary tube Diaphragm Needle valve Refrigerant inlet Heat sensor tube

Pressure spring

Adjusting screw

Pe: Evaporator inlet pressure Ps: Spring force Pf: Pressure in heat sensor tube

• Expansion valve of even external pressure type If the evaporation pressure is sensed at the inlet of a large-sized evaporator, it is affected by the internal path resistance. To avoid this, an even-pressure tube is passed from near the evaporator outlet to sense the pressure. The above described conventional valve is this type.

[Evaporator inlet] Liquid 100%

State of refrigerant

• Flow regulation standard of expansion valve To efficiently cool the indoor air which passes through the evaporator, the refrigerant in the evaporator must vaporize well to cool the air and must vaporize completely near the evaporator outlet. The figure at right shows this state of the refrigerant. The refrigerant liquid and gas are mixed together, that is, the refrigerant vapor is saturated in the part from the evaporator inlet to point A. Accordingly, the temperature is kept constant in this part. All the refrigerant is evaporated completely in the part from point A to point B, however, and its temperature rises (Superheated vapor). The flow regulation standard of the expansion valve is so set that the superheating temperature of the refrigerant vapor will be constant (e.g. 10°C).

[Evaporator outlet]

Temperature is constant. Gas Liquid

Superheating temperature (10°C)

Gas 100%

Saturated vapor (Mixture of liquid Superheated vapor and gas) (Gas 100%)

Diaphragm

Capillary tube Needle valve External even-pressure tube

Refrigerant inlet Pressure spring

Part of saturated vapor

41-20 4

Part of superheated vapor L

Air conditioner

STRUCTURE AND FUNCTION

CONFIGURATION OF REFRIGERATING CYCLE

7. Evaporator The refrigerant mist cooled and decompressed through the expansion valve vaporizes in large quantities. As a result, the evaporator is cooled. The warm air in the cab is moved and cooled through the evaporator by the fan. If the warm air is cooled below the dew point by the evaporator fins, the moisture in it condenses into water drops on the evaporator fins. These water drops are discharged through the drain hose out of the cab.

Serpentine type

(1) Cooler unit An actual evaporator has an expansion valve, thermistor, etc., and they are handled as a unit. It is equipped with a blower motor and even a heater core on some models.

Evaporator

Expansion valve

Thermistor

Outside view

Inside of unit

(2) Thermistor The thermistor is installed to the rear of the evaporator to sense the temperature of the air just after cooled by the evaporator.

Air conditioner

41-21 4

STRUCTURE AND FUNCTION

CONFIGURATION OF REFRIGERATING CYCLE

8. Sight glass The sight glass is "an window" to observe the condition of the refrigerant flowing through the refrigeranting cycle. Generally, if bubbles are seen in this window, the refrigerant is insufficient. If the quantity of the refrigerant is proper, no bubbles are seen. The sight glass is usually installed to the top of the receiver. If it cannot be used at that position, it may be installed to the piping.

Sight glass

a No bubbles are seen, too, when there is not refrigerant (or there is too much refrigerant). a When HFC134a is used, if the testing conditions such as the compressor speed, pressure, etc. are wrong, bubbles are seen. a If the operation of the air conditioner is continued while the refrigerant is insufficient, the compressor may be broken.

41-22 (6)

Air conditioner

STRUCTURE AND FUNCTION

CONTROL SYSTEM

CONTROL SYSTEM To use the functions of the air conditioner fully and keep the inside of the cab comfortable, the air outlet mode and various items, as well as the temperature and air flow, must be controlled.

1. Outline of control 1.1 Control panel

fl The figure below shows the control panel of D375A.

Air conditioner switch

Blower switch

Circulated air and fresh air selector switch

Temperature control switch

1 Temperature control switch Used to control the temperature steplessly from low level to high level. 2 Circulated air and fresh air selector switch Used to select “Fresh air” or “Circulated air”. 3 Blower switch Used to set the air flow to 3 levels. 4 Air conditioner switch Used to turn on and off the air conditioner.

Air conditioner

41-23 4

STRUCTURE AND FUNCTION

CONTROL SYSTEM

1.2 Contents of control The main controls of the air conditioner are as follows. Item

Outline of control •

The temperature of the air cooled by the evaporator is measured with a thermistor and the compressor is turned on and off automatically at the set temperatures.

•

The blower motor speed is set to 3 levels.

• •

The damper to select fresh air or circulated air is controlled. The damper to select air outlet in the cooling mode and heating mode is controlled.

4. Defrosting control

• •

Frosting of the evaporator is prevented. Thermistor is used for this control.

5. Compressor control

•

Abnormal refrigerant pressure is detected.

1. Temperature control

2. Air flow control 3. Circulated air and fresh air selection

2. Temperature control 2.1 Thermistor method When the cooler unit and heater unit are independent from each other and the airs from them cannot be mixed, the thermistor method is applied. The thermistor is a semiconductor, the resistance of which varies remarkably with the temperature. As shown in the figure, the resistance of the thermistor decreases as the temperature rises, and increases as the temperature lowers. The thermistor is installed to the rear of the evaporator to sense the temperature of the air flowing through the evaporator. The temperature control switch is on the control panel. The temperature is controlled by comparing the signal of the temperature control switch (desired temperature) with the signal of the thermistor in the air conditioner amplifier and turning on and off the compressor through the magnetic clutch. The signal of the thermistor is used to prevent frosting of the evaporator, too (This is described later).

Thermistor

Structure

Resistance

Temperature (°C)

Characteristics of thermistor

41-24 4

Air conditioner

STRUCTURE AND FUNCTION

CONTROL SYSTEM

3. Air flow control Fresh air The quantity of the air blown into the cab is controlled by adjusting the blower motor speed. The blower motor is a ferrite motor. Its speed (air flow) is controlled to 3 levels by changing the resistor conected to the motor in series with the blower switch as shown in the circuit diagram. Circulated air

[Reference] • Motor speed The speed (N) of a DC motor is in proportion to the motor terminal voltage (V) and in inverse proportion to the magnetic flux (ø).

Ferrite magnet

Speed N = K V/ø q

If ferrite magnets are used, the magnetic flux (ø) is constant. Accordingly, the speed is controlled by changing the voltage applied to the motor with the resistor connected to the motor in series.

4. Circulated air and fresh air selection If the circulated air and fresh air selector switch on the control panel is operated, the damper moves to select the fresh air or the circulated air. Fresh air: The outside air is taken into the cab. This mode is selected normally. Circulated air: This mode is used when the outside air is dirty or you need to cool or heat the cab quickly.

Air conditioner

41-25 (6)

STRUCTURE AND FUNCTION

CONTROL SYSTEM

5. Defrosting control If warm air blows against the evaporator fins and cooled there, the moisture in the air condenses into water drops on the evaporator fins. If the fin temperature is below 0°C at this time, the water drops are frozen or frosted. This phenomenon is called frosting. If frosting occurs, the heat exchange efficiency of the evaporator lowers and the full cooling capacity is not obtained. Frosting can be prevented by the following method. Thermostat method (ON/OFF switch) The evaporator temperature is sensed from the signal of the evaporator sensor installed to the rear of the evaporator. The compressor is turned OFF before the evaporator is frosted.

Evaporator sensor

41-26 (6)

Air conditioner

STRUCTURE AND FUNCTION

CONTROL SYSTEM

6. Compressor control

Location of pressure switch

Judgment of abnormal refrigerant pressure

Receiver tank

Condenser

Expansion valve

Evaporator

The pressure on the high-pressure side of the refrigerating cycle is sensed with a pressure switch. If it rises high abnormally, the compressor is stopped to prevent a trouble in the refrigerating cycle devices. Generally, the refrigerant pressure is sensed with a pressure switch installed between the receiver tank on the high-pressure side and expansion valve.

Compressor

(1) Pressure switch The pressure switch is a dual type, that is, it can detects both abnormally high pressure and abnormally low pressure.

Contact mechanism

1 Detection of abnormally high pressure If the high pressure in the refrigerating cycle rises abnormally, it can cause a trouble or breakage of the devices. Generally, the pressure switch to detect high pressure is turned off when the pressure rises above about 3.1 MPa {32 kg/cm2}.

Structure

Characteristics 2 Detection of abnormally low pressure When the refrigerant in the refrigerating cycle is extremely insufficient or lost completely because of leakage, etc., if the compressor is started, it is not lubricated well and may be seized. To prevent this, the pressure switch turns off the compressor when the pressure on the high-pressure side lowers below about 0.2 MPa {2.0 kg/cm2} because of insufficiency of the refrigerant.

Air conditioner

41-27 4

TROUBLESHOOTING

TESTING AND ADJUSTING DENSO (NEW REFRIGERANT TYPE) Service tools 1. Service tool kit ....................................................................................................................................... 42- 2 2. Gauge manifold ..................................................................................................................................... 42- 3 3. Gas leak detector .................................................................................................................................. 42- 7 4. Vacuum pump........................................................................................................................................ 42- 8 5. Service can valve .................................................................................................................................. 42- 9 6. Belt tension gauge................................................................................................................................. 42- 10 7. Connection of service tools ....................................................................................................................42- 11 Troubleshooting 1. Troubleshooting procedure.................................................................................................................... 42- 12 2. Inspection of refrigerating cycle............................................................................................................. 42- 19 3. Check for abnormal noise...................................................................................................................... 42- 27 4. Electric system ...................................................................................................................................... 42- 29 5. Replacement of parts ............................................................................................................................ 42- 30 Charging with refrigerant 1. Precautions for charging with refrigerant............................................................................................... 42- 32 2. Evacuation............................................................................................................................................. 42- 34 3. Charging with refrigerant ....................................................................................................................... 42- 37 4. Check of quantity of refrigerant ............................................................................................................. 42- 41 Periodic inspection and maintenance 1. Inspection and maintenance items ........................................................................................................ 42- 44 2. Check of quantity of refrigerant ............................................................................................................. 42- 45 3. Inspection of functional parts................................................................................................................. 42- 46

Air conditioner

42-1 (5)

TESTING AND ADJUSTING

SERVICE TOOLS

SERVICE TOOLS The following tools and devices are necessary for servicing the air conditioners. (1) Service tool kit (2) Vacuum pump (3) Torque wrench (4) Belt tension gauge (5) Gas leak detector (6) General tools

1. Service tool kit The service tool kit is a kit of the gauge manifold and the small tools shown below.

Gauge manifold

Low-pressure charging hose (Blue)

High-pressure charging hose (Red)

Quick joint (LO)

Center charging hose (Green) Service can T-joint Quick joint (HI)

Service can valve

Service tools for HFC134a

fl For air conditioners which use HFC134a (R134a), use the service tool kit for HFC134a, the joints of which are so changed that the air conditioners will not be charged with wrong refrigerant.

42-2 4

Air conditioner

TESTING AND ADJUSTING

SERVICE TOOLS

2. Gauge manifold The gauge manifold is used to check the operating pressure of the refrigerating cycle, evacuate the refrigerating cycle, and charge the refrigerating cycle with refrigerant.

2.1 Structure of gauge manifold The knobs on the front side of the gauge manifold are used to open and close the valves securely. The marks of “LO” and “HI” on those knobs denote the “low-pressure valve” and “high-pressure valve” respectively.

Low-pressure gauge

High-pressure gauge

Low-pressure gauge

High-pressure gauge

Air purge valve is built in.

Air purge valve is built in. Low-pressure valve (LO)

High-pressure valve (HI)

Outside view

Air conditioner

Low-pressure valve (LO)

High-pressure valve (HI)

Internal circuit

42-3 4

TESTING AND ADJUSTING

2.2 Handling of gauge manifold

SERVICE TOOLS

Closed

Closed

(2) When low-pressure valve (LO) is opened and high-pressure valve (HI) is closed

Open

Closed

(3) When low-pressure valve (LO) is closed and high-pressure valve (HI) is opened

Closed

Open

(4) When both low-pressure valve (LO) and highpressure valve (HI) are opened

Open

Open

You can form the following 4 circuits by opening or closing the high-pressure and low-pressure valves. (1) When both low-pressure valve (LO) and highpressure valve (HI) are closed

42-4 4

Air conditioner

TESTING AND ADJUSTING

SERVICE TOOLS

2.3 Charging hoses The 3 charging hoses are colored in blue, green, and red. Connect the blue hose to the low-pressure side, the green one to the central adapter, and the red one to the high-pressure side. When storing the gauge manifold, be sure to connect each charging hose to an adapter to prevent “dirt” and “water” from entering the gauge manifold.

Blue Red

The nut at the end of each hose has packing in it. If you screw it lightly over the mating adapter, it is connected securely. You do not need to tighten it with priers, etc. Green

Air conditioner

42-5 4

TESTING AND ADJUSTING

2.4 Quick joint

SERVICE TOOLS

Quick joint

Charging hose

With the quick joint (having a check valve), you can connect each hose of the gauge manifold to the charging valve in an instant. Charging valve

(1) Connection of quick joint Press the quick joint against the charging valve and push part A until a click is heard.

Sleeve

“Click”

fl When pressing the quick joint to connect it, take care not to bend the pipe. fl If the sleeve has moved without connecting the joint to the charging valve, set it to the original position again, then try again. fl If any refrigerant is left in the charging hose, the quick joint may not be connected easily. In this case, release the residual pressure from the hose.

Press the pusher to release the residual pressure.

(2) Disconnection of quick joint Securing part A of the quick joint, slide up part B (sleeve).

Sleeve

“Click”

fl After disconnecting the quick joint, cap the charging valve.

42-6 4

Air conditioner

TESTING AND ADJUSTING

SERVICE TOOLS

3. Gas leak detector The gas leak detector is an electric tester used to check each joint of the refrigerating cycle for refrigerant leakage. Apply the probe to a part to be checked and move it slowly to check for leakage. If any refrigerant leaks from that part, the sounding intervals and flashing intervals become short. This leak detector can be used for both HFC134a (R134a) and R12 which is used for the conventional air conditioners.

Battery charger

Internal battery

Sensor (Under cover)

Speaker Sensitivity selector switch

Suction probe Power switch Check leak bottle

Gas leak detector

fl The conventional leak tester of halide torch type cannot detect HFC134a (R134a) which does not contain chlorine.

Air conditioner

42-7 4

TESTING AND ADJUSTING

SERVICE TOOLS

4. Vacuum pump When charging a refrigerating cycle with refrigerant, you must remove the all water from it. For this purpose, the refrigerating cycle is evacuated with a vacuum pump (Evacuation will be described later).

fl When a vacuum pump for conventional refrigerant R12 is used for HFC134a (R134a), a vacuum pump adapter is necessary. With this adapter, the above vacuum pump can be used for both HFC134a (R134a) and R12. [The current vacuum pump (manufactured by our company) can be used for both new and conventional refrigerants.]

[Reference] • Vacuum pump adapter After the refrigerating cycle of an air conditioner is evacuated, if the vacuum pump is stopped, the oil in the vacuum pump flows back into the charging hose since the inside of the gauge manifold hose is a vacuum. If the refrigerating cycle is charged with the refrigerant under this condition, the vacuum pump oil left in the charging hose flows together with the refrigerant into the refrigerating cycle. The adapter equipped with a solenoid valve is used to prevent the backflow of the oil from the vacuum pump. If the solenoid valve is turned on, it closes to stop the inflow of the atmosphere and the refrigerating cycle can be evacuated. If it is turned off, it allows inflow of the atmosphere and the refrigerating cycle cannot be evacuated.

Vacuum pump adapter

Solenoid valve Atmosphere

Atmosphere

Blind cap

42-8 4

Vacuum pump

Air conditioner

TESTING AND ADJUSTING

SERVICE TOOLS

5. Service can valve

Handle

The service can valve is used to supply the refrigerant from a service can to the refrigerating cycle. Handling method 1 Turn the handle to the left end to raise the needle. Be sure to raise the disc at this time, too. 2 Screw the service can valve into the service can, then tighten the disc. At this time, take care sufficiently not to damage the service can by tightening the disc too strongly. 3 Install the charging hose (green) of the gauge manifold to the valve. 4 Turn the handle of the service can valve to the right to lower the needle and make a hole in the service can. 5 Turn the handle to the left to raise the needle, and the refrigerant flows through the valve into the refrigerating cycle. 6 To stop supplying the refrigerant, turn the handle to the right end to lower the needle.

Hose adapter Needle Disc

Packing Service can

fl Check that the packing is usable. If the packing is coated with compressor oil, it lasts long.

Air conditioner

42-9 4

TESTING AND ADJUSTING

SERVICE TOOLS

6. Belt tension gauge If the belt tension is not proper, the lives of the bearings and belt are shortened. The belt tension gauge is used to measure the belt tension correctly and easily. Be sure to use this gauge particularly to adjust the tension of the V-belt.

If the remote cable is connected to the belt tension gauge, you can measure the belt tension efficiently even if the engine compartment is narrow.

Remote cable

42-10 4

Air conditioner

TESTING AND ADJUSTING

SERVICE TOOLS

7. Connection of service tools Connect the gauge manifold, vacuum pump, and other service tools as shown below. (1) Close the high-pressure valve (HI) and low-pressure valve (LO) of the gauge manifold. (2) Connect the red (HI) and blue (LO) charging hoses to the service valves of the high-pressure and low-pressure pipes. The service valves may be installed to the compressor. Use the quick joints to connect the hoses. (3) Connect the green hose at the center of the gauge manifold to the following parts. 1 For evacuation: Connect to the vacuum pump. fl Be sure to use the vacuum pump adapter. 2 For charging with refrigerant: Connect to the service can valve of the service can.

High-pressure valve Vacuum pump

Low-pressure valve

Blue quick joint

Red Green Service can valve

Service valve on low-pressure side

Service valve on highpressure side

Refrigerant can Compressor

 When connecting the charging hoses, take care not to mistake the high-pressure side and lowpressure side of the gauge manifold. fl Connect the quick joints at the ends of both high-pressure hose and low-pressure hose. If either one is not connected, the atmosphere enters it and a vacuum is not obtained. (The check valve of the quick joint cannot maintain a vacuum.)

Air conditioner

42-11 4

TESTING AND ADJUSTING

TROUBLESHOOTING

TROUBLESHOOTING 1. Troubleshooting procedure The following figure shows the basic troubleshooting procedure. The troubles of an air conditioner are roughly classified into the troubles of the refrigerating cycle and those of the electric system. In this chapter, the troubleshooting method is explained according to the basic procedure.

Examination by interview

Confirmation of trouble

Basic inspection

• Control mechanism • V-belt • Sight glass • Pipe joints

Troubleshooting

Inspection of refrigerating cycle

Check for abnormal noise

Inspection of electric system

Replacement of parts (Repair and check)

Completion

42-12 4

Air conditioner

TESTING AND ADJUSTING

TROUBLESHOOTING

1.1 Examination by interview and confirmation of trouble Before carrying out troubleshooting, you must check the contents and condition of the trouble thoroughly. If the trouble occurs sometime or cannot be reproduced, “examination by interview” to obtain the occurrence condition of the trouble is important. • What Model and serial No. • When Date, time, and frequency of occurrence • Where Condition of working place • Condition Working condition, and weather • How How operator felt about trouble

1.2 Basic inspection (1) Inspection of Control mechanism Operate the levers and switches on the control panel to see if they work smoothly and securely. s Check the fuses, if necessary.

(2) Inspection of V-belt Check that the belt tension is proper and belt is not damaged.

(3) Inspection of quantity of refrigerant through sight glass If many bubbles are seen in through the sight glass, the refrigerant may be insufficient. In this case, inspect with the gauge manifold. (For the criterion, see 4.2 CHARGlNG WITH REFRIGERANT, inspection through sight glass.) (4) Inspection of pipe joints If a pipe joint is coated with oil, the refrigerant may be leaking through it. In this case, wipe off the oil and check for refrigerant leakage.

Air conditioner

42-13 4 (5)

TESTING AND ADJUSTING

TROUBLESHOOTING

1.3 Troubleshooting 1.3.1 Troubles in cooling mode DEFROSTER-FACE mixed blow type Cause

a. Air flow is insufficient

YES 2 YES Is rotation normal? 1 Does blower motor rotate?

NO

Remedy

• Clogging of indoor air filter • Clogging of outdoor air filter • Obstacle near air suction opening • Deformed or broken blower • Frosting of evaporator

• Clean filter • Clean filter • Remove obstacle • Replace blower • Stop air conditioner and melt ice Go to Causes and remedies of troubles, A • Dirt sticking to evaporator surface • Clean evaporator surface • Low source voltage • Check battery charge system • Bad contact of battery terminal • Repair • Defective blower motor • Replace • Defective blower Hl relay • Replace • Breakage of resistor (Blower rotates at only Hl) • Breakage of fuse

• Replace

NO • Defective power-up relay on machine side • Defective blower motor • Interference of blower with case • Defective blower switch • Defective grounding to chassis • Defective wiring or disconnection of connector

b. Air flow is normal

• Entry of outside air

• Removal of air mixing link

YES Is compressor pressure normal? 1 Does compressor rotate normally?

NO

NO

• Pressure on low-pressure side is too high (Above about 0.29 MPa) • Pressure on high-pressure side is too low (Below about 0.98 MPa) • Pressure on low-pressure side is too low (Below about 0.05 MPa) • Pressures on both highpressure side and low-pressure side are high • Pressures on both highpressure side and low-pressure side are low

• Go to Causes and remedies of troubles, C-2 • Go to Causes and remedies of troubles, C-3 • Go to Causes and remedies of troubles, C-4 • Go to Causes and remedies of troubles, C-5 • Insufficient refrigerant

• Breakage or slip of V-belt • Defective compressor (Locked) • Defective magnetic clutch

• Replace V-belt • Replace • Repair or replace Go to Causes and remedies of troubles, D-1 • Check wiring Go to Causes and remedies of troubles, D-2

• Clutch is not engaged because of trouble in electric system

c. Refrigerant pressure is abnormally high or low High-pressure cutting system operates Low-pressure cutting system operates

42-14 (5)

• Replace • Repair • Replace panel • Ground securely • Check wiring • Close windows and door Adjust Circulated air and fresh air selector damper • Set link again

YES 2

• Replace fuse Go to Causes and remedies of troubles, B • Replace

• Go to Causes and remedies of troubles, C-1

• Go to Causes and remedies of troubles, C-3

-

-

Air conditioner

TESTING AND ADJUSTING

TROUBLESHOOTING

DEFROSTER-FACE separate blow type Cause

a. Air flow is insufficient

YES 2 YES Is rotation normal? 1 Does blower motor rotate?

NO

• Clean filter • Clean filter • Remove obstacle • Replace blower • Stop air conditioner and melt ice Go to Causes and remedies of troubles, A • Dirt sticking to evaporator surface • Clean evaporator surface • Low source voltage • Check battery charge system • Bad contact of battery terminal • Repair • Defective blower motor • Replace • Defective blower Hl relay • Replace • Defective power transistor

• Replace

• Breakage of fuse

• Replace fuse Go to Causes and remedies of troubles, B • Replace

NO • Defective power-up relay on machine side • Defective blower motor • Interference of blower with case • Defective blower switch • Defective grounding to chassis • Defective wiring or disconnection of connector

b. Air flow is normal

• Entry of outside air

YES 2

• Removal of air mixing link

YES Is compressor pressure normal? 1 Does compressor rotate normally?

NO

NO

Air conditioner

• Close windows and door Adjust Circulated air and fresh air selector damper • Set link again • Go to Causes and remedies of troubles, C-2 • Go to Causes and remedies of troubles, C-3 • Go to Causes and remedies of troubles, C-4 • Go to Causes and remedies of troubles, C-5 • Insufficient refrigerant

• Breakage or slip of V-belt • Defective compressor (Locked) • Defective magnetic clutch

• Replace V-belt • Replace • Repair or replace Go to Causes and remedies of troubles, D-1 • Check wiring Go to Causes and remedies of troubles, D-2

c. Refrigerant pressure is abnormally high or low

Low-pressure cutting system operates

• Replace • Repair • Replace panel • Ground securely • Check wiring

• Pressure on low-pressure side is too high (Above about 0.29 MPa) • Pressure on high-pressure side is too low (Below about 0.98 MPa) • Pressure on low-pressure side is too low (Below about 0.05 MPa) • Pressures on both highpressure side and low-pressure side are high • Pressures on both highpressure side and low-pressure side are low

• Clutch is not engaged because of trouble in electric system

High-pressure cutting system operates

Remedy

• Clogging of indoor air filter • Clogging of outdoor air filter • Obstacle near air suction opening • Deformed or broken blower • Frosting of evaporator

• Go to Causes and remedies of troubles, C-1

-

• Go to Causes and remedies of troubles, C-3

-

42-14-1 42-15 (5) (5)

TESTING AND ADJUSTING

42-16 (5)

TROUBLESHOOTING

Air conditioner

TESTING AND ADJUSTING

TROUBLESHOOTING

• Causes and remedies of troubles No.

Cause

• Defective magnetic clutch circuit • Defective frost sensor wiring • Defective frost sensor characteristics • Defective adjustment of gap between frost sensor and evaporator (Defective sensitivity)

Remedy

• Check clutch circuit and replace relay • Check for short circuit, then repair or replace • Check characteristics and replace sensor • Adjust gap to 12 v 5mm

Voltage is applied to magnetic clutch A

• Defective magnetic clutch circuit • Check clutch circuit and replace relay • Check for short circuit, then repair or • Defective thermostat wiring replace • Check operation and replace thermo• Malfunction of thermostat stat Voltage is not applied to magnetic clutch

B

-

1

C

2

Air conditioner

• Defective magnetic clutch

• Replace

• Blower motor is locked • Wrong wiring • Short circuit of wiring

• Replace blower motor • Repair • Repair or replace

• Ambient temperature is abnormally high • Insufficient cooling by condenser - Fins are clogged with dirt and soil • Too much refrigerant • Air in refrigerating cycle

• Too much refrigerant •Breakage of head gasket • Defective •Breakage of suction valve compressor •Foreign matter caught in suction valve • Expansion valve •Defective valve is opened too •Bad contact of heat sensor much tube

-

• Clean fins(with water) • Discharge refrigerant properly • Discharge all refrigerant, then evacuate refrigerating cycle and charge it with refrigerant again by proper quantity • Discharge refrigerant properly • Replace compressor • Replace • Repair

42-15 42-17 (5)

TESTING AND ADJUSTING

No.

TROUBLESHOOTING

Cause

• Ambient temperature is abnormally low • Refrigerant is insufficient

3

•Swash plate shoe is locked •Piston is locked •Defective suction/ discharge valve • Defective •Clogging of valve expansion valve •Leakage of refrigerant from heat sensor tube •Tentative clogging by freezing of valve • Defective compressor

• Ambient temperature is abnormally low • Refrigerant is insufficient

C

4

• Clogging of refrigerating cycle • Defective expansion valve

•Clogging of valve Leakage of refrigerant from heat sensor tube •Tentative clogging by freezing of valve • Frosting of evaporator

5

42-18 42-16 (5)

• Insufficient cooling by condenser • Too much refrigerant

Remedy

• Charge with proper quantity of refrigerant • Perform leak test and repair leaking part, then charge with refrigerant • Replace compressor • Replace valve • Replace valve • Replace valve and receiver, then evacuate sufficiently • Charge with proper quantity of refrigerant • Perform leak test and repair leaking part, then charge with refrigerant • Replace receiver and dryer • Replace piping • Replace valve • Replace valve • Replace valve and receiver, then evacuate sufficiently • (Go to A) • Clean fins • Discharge refrigerant properly

Air conditioner

TESTING AND ADJUSTING

No.

1

D

2

Air conditioner

TROUBLESHOOTING

Cause

Remedy

• Breakage of stator coil • Too much air gap between rotor and stator Key is broken or not inserted • Slip of clutch Oil on clutch surface Layer short circuit or low battery voltage • Foreign matter caught between rotor and stator

• Replace • Repair or replace

• • • •

Remove oil Replace Charge Overhaul

• • • • •

• • • • •

Replace control panel Replace control panel Replace Replace Replace

Defective air conditioner switch Defective blower switch Defective compressor clutch relay Defective thermo-sensor Defective refrigerant high-pressure/lowpressure switch • Abnormally high Too high pressure on (above 2.5 MPa high-pressure {25 kg/cm2}) side Too low (below 0.9 MPa {10 kg/cm2})

• Replace key

• (Go to C-1)

• (Go to C-4)

42-17 4

TESTING AND ADJUSTING

1.3.2

TROUBLESHOOTING

Troubles in heating mode

fl Be sure to check that the pump pressure is normal and the heater hoses IN and OUT are connected correctly. a. Air flow is insufficient fl See 1.3.1 Troubles in cooling mode.

b. Air flow is normal 1 YES Is hot water temperature normal?

1 YES Does temperature regulator LED operate normally?

NO

1.3.4

• Air in hot water circuit • Clogging or bend of piping • Ambient temperature is very low • Engine water level is low

• Bleed air • Repair or replace — • Supply water to proper level • Replace heater core

• Entry of outside air

• Close windows and door

• Disconnection of temperature regulator link • Entry of foreign matter

• Set link again

• Defective or broken wiring or disconnection of connector • Defective servomotor

• Check wiring

• Clogging of drain hole

• Clean

• Disconnection of link

• Set link again

• Defective or broken wiring or disconnection of connector • Defective servomotor • Entry of foreign matter

• Check wiring

• Remove foreign matter

• Replace

Water leakage into cab

Defective selection of circulated air and fresh air 1 YES

Is circulated air/fresh air servomotor normal?

NO

42-18 4

Remedy

• Breakage of heater core

NO

1.3.3

Cause

• Replace • Remove foreign matter

Air conditioner

TESTING AND ADJUSTING

TROUBLESHOOTING

2. Inspection of refrigerating cycle 2.1 Inspection with gauge manifold Measure the low pressure and high pressure of the refrigerating cycle with the gauge manifold under the following condition, then carry out troubleshooting. fl For connection of the gauge manifold, see 7. Connection of service tools. Warm up the engine, then measure under the following condition. • Door: Open fully • Air conditioner suction opening temperature: 30°C – 35°C • Circulated air/Fresh air selector switch: Circulated air • Blower speed: HI • Engine speed: 1,500 rpm • Temperature control: Lowest temperature fl The values indicated by the gauge manifold may vary more or less with the condition.

(1) When normal The pressures must be as follows under the above condition. Pressure on low-pressure side: 0.15 – 0.25 MPa {1.5 – 2.5 kg/cm2} Pressure on high-pressure side: 1.37 – 1.57 MPa {14 – 16 kg/cm2} The illustrated gauges have only the divisions of SI units. The actual gauges have the divisions of the conventional units, too, however.

Low-pressure side

High-pressure side

Low-pressure side

High-pressure side

(2) When refrigerant is insufficient • Trouble 1 Both pressures on the low-pressure side and high-pressure side are low. 2 Bubbles pass the sight glass continuously. 3 Air is not cooled well. • Cause 1 Refrigerant is insufficient or it is leaking. • Points of remedy 1 Check and repair refrigerant leaking point. 2 Charge with refrigerant again.

Air conditioner

42-19 4

TESTING AND ADJUSTING

(3) Too much refrigerant in refrigerating cycle or insufficient cooling by condenser • Trouble 1 Both pressures on the low-pressure side and high-pressure side are high. 2 No bubbles are seen in the sight glass even in the low speed range. 3 Air is not cooled well. • Cause 1 Too much refrigerant is in the refrigerating cycle. 2 Insufficient cooling by the condenser. • Points of remedy 1 Adjust the quantity of refrigerant properly. 2 Clean the condenser. 3 Inspect the cooling system of the machine (electric fan, etc.)

TROUBLESHOOTING

Low-pressure side

High-pressure side

Low-pressure side

High-pressure side

Low-pressure side

High-pressure side

(4) Water in refrigerating cycle • Trouble 1 After a certain using time, the pressure on the low-pressure side becomes negative gradually. • Cause 1 Water is in the refrigerating cycle. • Points of remedy 1 Replace the receiver tank. 2 Before charging the refrigerating cycle with refrigerant, evacuate it thoroughly to remove all water.

(5) Insufficient compression by compressor • Trouble 1 The pressure on the low-pressure side is high and that on the high-pressure side is low. 2 Just after the air conditioner is turned off, the pressures on the high-pressure side and lowpressure side become the same. • Cause 1 The compressor is defective. • Points of remedy 1 Inspect and repair the compressor.

42-20 4

Air conditioner

TESTING AND ADJUSTING

TROUBLESHOOTING

(6) Refrigerant does not circulate (Refrigerating cycle is clogged) • Trouble 1 If the refrigerating cycle is clogged completely, the pressure on the low-pressure side becomes negative soon. If the former is clogged a little, the latter becomes negative gradually. 2 The temperatures before and after the clogged part are different. • Cause 1 Dirt, water, etc. block the small hole of the expansion valve or they are frozen, and the refrigerant does not flow. • Points of remedy 1 Replace the receiver tank. 2 Evacuate the refrigerating cycle thoroughly.

Low-pressure side

High-pressure side

Low-pressure side

High-pressure side

Low-pressure side

High-pressure side

(7) Air in refrigerating cycle • Trouble 1 Both pressures on the low-pressure side and high-pressure side are high. 2 The low-pressure piping is not cold. 3 Bubbles are seen in the sight glass. • Cause 1 Air in the refrigerating cycle. • Points of remedy 1 Replace refrigerant. 2 Evacuate the refrigerating cycle thoroughly.

(8) Too wide opening of expansion valve • Trouble 1 Both pressures on the low-pressure side and high-pressure side are high. 2 Low-pressure piping is coated with frost (dews). • Cause 1 The expansion valve does not work normally. • Points of remedy 1 Check the installation condition of the heat sensor tube.

Air conditioner

42-21 4

TESTING AND ADJUSTING

TROUBLESHOOTING

2.2 Troubleshooting table No.

Trouble

Related section

Condition

Possible cause

1

Pressure on low-pressure side is abnormally high (above about 0.3 MPa {3.1 kg/cm2})

Compressor

Just after compressor is stopped, pressures on highpressure side and low-pressure side become the same.

Defective compression by compressor

Replace compressor

Expansion valve

Both pressures on high-pressure side and low-pressure side are high. Low-pressure hose and parts near service valve on low-pressure side are abnormally cold and piping is coated with frost (dews).

Expansion valve is opened too wide (Defective adjustment)

Replace expansion valve

Bad contact (Removal) of heat sensor tube

Stick heat sensor tube firmly

Both pressures on high-pressure side and low-pressure side are high. If condenser is cooled forcibly, pressure on low-pressure side lowers.

Too much refrigerant in refrigerating cycle

Adjust quantity of refrigerant properly

Insufficient cooling by condenser

Clean condenser fins (with water) or check and repair it Check and repair cooling system on machine side (electric fan, radiator, etc.)

Condenser cooling fan does not suck in air sufficiently (Cooling air is insufficient)

Looseness or breakage of fan belt

Tense or replace belt.

If electric fan is used, motor is defective or fan slips

Replace motor or fix fan

Installation of fan in reverse

Install in normal direction

Fan shroud is not installed

Install genuine shroud

Condenser fins are clogged with dirt

Clean condenser fins (with water) or check and repair it

Insufficient cooling water or oil

Charge with refrigerant to proper level.

Wrong ignition timing

Adjust

Trouble or insufficient capacity of water pump

Repair or replace

Radiator fins are clogged with dirt

Clean fins (with water)

Bubbles do not disappear from sight glass even if condenser is cooled with water

Too much refrigerant in refrigerating cycle

Adjust quantity of refrigerant properly

Just after compressor stops, pressure lowers by about 0.2 MPa {2 kg/cm2}

Air in refrigerating cycle

Replace refrigerant (Evacuate refrigerating cycle thoroughly)

Other sections

Thermal load is too high

Ambient temperature is abnormally high

Cool condenser efficiently

Expansion valve

Expansion valve is not frosted and low-pressure piping is not cold

Clogging of expansion valve (Defective adjustment, entry of foreign matter, etc.)

Replace expansion valve

Leakage of refrigerant from heat sensor tube

Replace expansion valve

Temporary clogging of expansion valve caused by freezing (Trouble by water in refrigerating cycle)

Replace expansion valve, receiver tank, and drier, then evacuate refrigerating cycle thoroughly

Expansion valve is clogged a little (Defective adjustment or entry of foreign matter)

Replace expansion valve

Refrigerating cycle

Pressure on highpressure side is abnormally high (above about 2 MPa {20 kg/cm2})

2

Condenser

Engine

Refrigerating cycle

3

Pressure on low-pressure side is abnormally low (below about 0.05 MPa {0.5 kg/cm2})

Engine is overheated

Expansion valve is frosted

42-22 4

Remedy

Air conditioner

TESTING AND ADJUSTING

TROUBLESHOOTING

No.

Trouble

Related section

Condition

3

Pressure on low-pressure side is abnormally low (below about 0.05 MPa{0.5 kg/cm2})

Refrigerating cycle

Air is not cooled well and bubbles pass through sight glass continuously

5

6

7

Pressure on highpressure side is abnormally low (below about 1 MPa{10 kg/ cm2})

Leakage of refrigerant and oil

Magnetic clutch is not engaged

Magnetic clutch slips

Air conditioner

Remedy

Insufficient refrigerant

Charge with refrigerant to proper level.

Leakage of refrigerant

Check and repair leaking part

Receiver tank and drier are abnormally cold (frosted)

Clogging of receiver tank and drier (Entry of foreign matter, etc.)

Replace receiver tank and drier (Evacuate refrigerating cycle thoroughly)

Blown air temperature is low and air flow is little

Evaporator is frosted

Check and adjust amplifier and thermistor

Thermal load is too low

Ambient temperature is abnormally low

—

Compressor

Just after compressor is stopped, pressures on highpressure side and low-pressure side become the same.

Defective compression by compressor

Replace compressor

Expansion valve

Expansion valve is not frosted and low-pressure piping is not cold

Clogging of expansion valve (Defective adjustment, entry of foreign matter, etc.)

Replace expansion valve

Leakage of refrigerant from heat sensor tube

Replace expansion valve

Temporary clogging of expansion valve caused by freezing (Trouble by water in refrigerating cycle)

Replace expansion valve, receiver, and drier, then evacuate refrigerating cycle thoroughly

Other sections

4

Possible cause

Refrigerating cycle

Air is not cooled well and bubbles pass through sight glass continuously

Insufficient refrigerant

Charge with refrigerant to proper level.

Compressor

Shaft seals are stained with oil clearly and refrigerant is lost

Refrigerant leakage through shaft seals

Replace compressor

Refrigerating cycle

Pipe joints are stained with oil clearly and refrigerant is lost

Leakage of gas from pipe joints

Retighten joints or replace piping

Clutch

When air conditioner switch is turned ON, clutch is not engaged

Broken coil

Replace

Disconnection, defective wiring, or bad contact in wiring parts (ground wire, fuse, etc.)

Connect, repair, or replace disconnected parts

Bad contact or defective operation of switches

Repair or replace

When air conditioner switch is turned ON, rotor moves. If rotor is pushed with fingers, it is attracted.

Too wide clearance between rotor and stator

Repair or replace

Clutch slips during rotation

Low battery voltage

Charge battery

Clutch surface is stained with oil

Remove oil

Layer short circuit in coil

Replace

Clutch

42-23 4

TESTING AND ADJUSTING

TROUBLESHOOTING

2.3 Check for refrigerant leakage If refrigerant seems to be leaking as a result of the basic inspection, check for leakage with the gas leak tester according to the following procedure.

(1) Preliminary check Connect the gauge manifold and check the condition of the refrigerant remaining in the refrigerating cycle. Then, add new refrigerant, if necessary, to heighten the pressure in the refrigerating cycle and increase the accuracy of the gas leak check. 1 Read the gauge pressure while the compressor is stopped. The ambient temperature must be 15°C or higher at this time. 2 If the gauge pressure is 0.4 MPa {4 kg/cm2} or higher, start the inspection. 3 If the gauge pressure is below 0.4 MPa {4 kg/ cm2}, add new refrigerant to heighten the gauge pressure above 0.4 MPa {4 kg/cm2}, then start the inspection.

fl Perform the gas leak test in a place ventilated well. An electric gas leak tester may react to gasoline, diesel fuel, exhaust gas of a car, etc. If it does so, it will misjudge. fl Gas leaking from a pipe joint, etc. is blown away by even a light wind. Accordingly, apply the probe tip all around the joint.

Gas leak tester Probe

Probe

 Do not check for refrigerant leakage with a leak detector of halide torch type. Since this detector detects gas leakage by utilizing reaction to chlorine, it cannot detect refrigerant HFC-134a which does not contain chlorine. In addition, it decomposes HFC-134a into harmful matters. Accordingly, do not use it.

42-24 4

Air conditioner

TESTING AND ADJUSTING

TROUBLESHOOTING

(2) Refrigerant leakage check procedure

Refrigerant leakage check in machine cab

Is oozing oil from each pipe joint detected visually or by feeling with fingers?

YES YES

Does leak tester react on refrigerant?

Repair joint.

NO Charge with specified quantity of refrigerant and turn on air conditioner. After vibrating devices and applying pressure to them, check for leakage again.

Check connecting surfaces for flaw and corrosion. If they are normal, replace O-ring and check again.

Refrigerant leakage check in operator's cab (from cooler unit) (with engine stopped)

Set blower to HI and ventilate unit with fresh air for about 15 seconds.

Select circulated air and leave for about 10 minutes (with blower turned off).

Does leak tester react on refrigerant in each air outlet?

YES

Check each part to specify leaking part.

NO Turn blower on for a moment (0.5 seconds) and off, then check each air outlet for leakage again.

Air conditioner

42-25 4

TESTING AND ADJUSTING

TROUBLESHOOTING

[Reference] • Check for refrigerant leakage by applying air pressure) When it seems that little refrigerant is left in the refrigerating cycle, the leak check accuracy can be increased by heightening the internal pressure of the refrigerating cycle with compressed nitrogen gas or air. 1. Necessary tools 1 Air attachment: Special attachment to connect gauge manifold 2 Plug: Plug to connect to utility piping of factory (Select a proper plug on the market) 2. Check method (1) Read the gauge pressure while the compressor is stopped. (The ambient temperature must be 15°C or above at this time.) 1 If the gauge pressure is about 0.2 – 0.4 MPa {2 – 4 kg/cm2}, apply air pressure and start the inspection. 2 If the gauge pressure is below 0.2 MPa {2 kg/cm2}, add new refrigerant until the gauge pressure rises above 0.4 MPa {4 kg/cm2}, then apply air pressure and start the inspection. (2) Check for refrigerant leakage with a gas leak tester. (3) After checking for refrigerant leakage, be sure to replace the mixture of the air and refrigerant with new refrigerant.

1 Using the gauge, air attachment, and plug, connect an air compressor to the air conditioner piping. 2 Start the air compressor to supply air. fl Air pressure: Approx. 1.0 MPa {10 kg/cm2} 3 After applying air pressure, close the valves of the gauge to keep the pressure in the air conditioner piping. fl Be sure to drain water from the air compressor used for applying air pressure. If it is drained, little water is supplied to the refrigerating cycle. fl The applied air pressure must be 1.0 MPa {10 kg/cm2} or less.

42-26 4

Air attachment Plug

To air compressor

To air conditioner piping

Air conditioner

TESTING AND ADJUSTING

TROUBLESHOOTING

3. Check for abnormal noise (1) Since an abnormal noise is produced under various operating conditions, check the following. • Is the abnormal noise produced even after the air conditioner is turned off? • Is the abnormal noise produced only while the air conditioner is turned on? • Is the abnormal noise produced at intervals, continuously, or just after the air conditioner is turned on? To specify the noise generating part, check the result of the examination by interview carefully. (2) The general parts which can produce abnormal noises and the causes of those noises are as follows. V-belt

Looseness Wear or damage of bearing

Magnetic clutch Contact of stator and rotor

Production of noise

Foreign matter in motor Blower motor Insufficient tightening of blower Looseness of bracket bolts Defective valves Compressor Wear or damage or bearing Misalignment Defective tightening and installation of clamps Piping Improper safety gap

Air conditioner

42-27 4

TESTING AND ADJUSTING

TROUBLESHOOTING

[Reference] • Identification of noise producing part A noise producing part can be identified with a stethoscope. How to check the abnormal noise from the compressor with the stethoscope is explained below, as an example. If an abnormal noise is heard from around the compressor, you must see if it is produced by loosened bracket bolts, auxiliary parts used to secure the compressor and belt, or internal parts of the compressor. 1 Apply the stethoscope to the auxiliary parts to find out the noise source. 2 Apply the stethoscope to the compressor to see if a noise similar to the above is heard. If the similar noise is heard, the compressor may have a trouble. 3 Generally, if the compressor has a trouble, it produces an abnormal noise, regardless of the engine speed.

42-28 4

Air conditioner

TESTING AND ADJUSTING

TROUBLESHOOTING

4. Electric system 4.1 Inspection of electric system See the circuit diagram (refer to the Shop Manual for each machine) and understand the electric circuit. Then, check the connections of the electric parts systematically with a circuit tester, etc. The parts to be inspected generally are as follows. (1) Breakage of fuse 1) Referring to the wiring diagram, check the circuits where a fuse may be broken. 2) To check each functional part for internal short circuit, disconnect its connector. (2) Bad contact of connector 1) Note that a functional part may not work because of bad contact of its connector. 2) Unstable operation and malfunction under vibration are caused by bad contact of a connector in many cases. (3) Defective grounding to chassis Even if a ground wire seems firm, it may be insulated by paint film, rust, etc. a PC400-7 is used as an example in the following explanation.

4.2 General block diagram (PC400-7) and circuit diagram

a Blower relay R30 and compressor relay R31 are installed to the side of the air conditioner unit (on the left side of the unit).

Air conditioner

42-29 (6)

TESTING AND ADJUSTING

TROUBLESHOOTING

Circuit diagram related to air conditioner (PC400, 400LC-7, PC450, 450LC-7)

42-29-1 (6)

Air conditioner

TESTING AND ADJUSTING

TROUBLESHOOTING

4.3 General drawing of air conditioner unit (PC400-7)

4.4 Self-diagnosis (PC400-7) 1. Turn the starting switch ON and turn switch (1) of control panel P OFF. 2. Hold " " and "v" of temperature setting switch (2) simultaneously for 3 seconds. v

3. The error codes are displayed in (3). 4. Press " " or "v" of temperature setting switch (2) to check all the error codes. v

Display of error codes and failure modes Display

Failure mode

E--

No failures

E11

Disconnection in internal air sensor

E12

Short circuit in internal air sensor

E15

Disconnection in water temperature sensor

E16

Short circuit in water temperature sensor

E17

Disconnection in sunlight sensor

E18

Short circuit in sunlight sensor

E43

Abnormality in air outlet damper

E44

Abnormality in air mix damper

E45

Abnormality in internal/external air damper

a The sunlight sensor is "S" at the top of the monitor panel.

Air conditioner

42-29-2 (6)

TESTING AND ADJUSTING

TROUBLESHOOTING

5. Replacement of parts 5.1 Interchangeability of air conditioner parts The refrigerating cycle parts, functional parts closely related to them, and compressor oil for an air conditioner which uses HFC134a (R134a) are not interchangeable with those for an air conditioner which uses R12. Accordingly, different joints are used for each part of these air conditioners so that a wrong part will not be used. Since the compressor oil, O-ring, etc. cannot be distinguished at a glance, classify them into the HFC134a (R134a) group and the R12 group securely.

5.2 Connection of piping (1) O-ring • • •

If any piping or refrigerating cycle part is removed, be sure to use a new O-ring for HFC134a (R134a). When removing an O-ring, use a soft rod such as a toothpick so that the piping will not be damaged. When connecting the piping, apply compressor oil to the O-ring and tighten the adapter to the specified torque.

(2) Tightening torque Connector

Nut type

Tube size or bolt size

Tightening torque Nm {kgcm}

φ 8 pipe

12 – 15 {120 – 150}

D1/2 pipe

20 – 25 {200 – 250}

D5/8 pipe

30 – 35 {300 – 350}

M6 bolt (4T) of receiver

4.0 – 7.0 {40 – 70}

M6 bolt (6T) other than above

8.0 – 12 {80 – 120}

Nut type

Block joint

Block joint

42-30 4

Air conditioner

TESTING AND ADJUSTING

TROUBLESHOOTING

5.3 Adding compressor oil (1) When replacing function part When replacing a functional part (condenser, evaporator, etc.), add the following quantity of new compressor oil. fl Add compressor oil for HFC134a (R134a). Supplementary oil is supplied in 40-cc cans.

Replacement parts

Quantity of supplementary compressor oil (Reference value)

Compressor

Condenser

Evaporator

Receiver tank

Piping

80 cc

40 cc

40 cc

10 cc

10 cc (per piece)

• Piston-type compressor (10P, 10PA series): ND-OIL8 Compressor oil • Vane-type compressor (TV, SV series): ND-OIL9

(2) When replacing compressor A new compressor is filled with oil necessary for the refrigerating cycle. Accordingly, when replacing an existing compressor, drain the excessive oil from the new compressor.

New compressor

Compressor to be replaced

fl Since the compressor oil for HFC134a (R134a) absorbs moisture easily, seal the oil can immediately after supplying the oil.

5.4 Charging with refrigerant After replacing a refrigerating cycle part, be sure to perform the following work. • Evacuation • Charging with refrigerant For the procedure for the above work, see Charging with refrigerant.

Air conditioner

Drain excessive oil (A – B).

42-31 4

TESTING AND ADJUSTING

CHARGING WITH REFRIGERANT

CHARGING WITH REFRIGERANT 1. Precautions for charging with refrigerant ( Safety items) (1) Only the appointed person must work. Since high-pressure refrigerant is dangerous, only the appointed person must handle it. Appointed person

If refrigerant liquid enters your eyes, the water in the eyeballs is frozen and you may lose your eyesight. Accordingly, be sure to put on protective goggles for safety while you are charging the air conditioner with refrigerant. If the refrigerant liquid is splashed over your hands, you may be frostbitten. Take care extremely. When installing and removing the service can and connecting and disconnecting the charging hoses, take care particularly.

Put on protective goggles.

(2) Put on protective goggles during work.

(3) Never work near your face. Never install and remove the service can or connect and disconnect the gauge manifold and compressor charging hoses near your face. If the refrigerant liquid spouts out, you may be injured seriously.

 Actions to take when refrigerant enters your eyes

Eye doctor

1) Do not rub your eyes with the hands or a handkerchief. 2) Immediately wash your eyes with clean water for more than 15 minutes, then see a eye doctor.

42-32 4

Air conditioner

TESTING AND ADJUSTING

CHARGING WITH REFRIGERANT

(4) Take care in handling the high-pressure valve. When charging the air conditioner with the refrigerant while the engine is running, never open the high-pressure valve (HI) of the gauge manifold.  If the high-pressure valve is opened by mistake, the high-pressure gas may flow back into the service can to burst.

Never open this valve.

(5) Never heat the service can. If the service can is heated directly or put in a hot water, the pressure in it rises to burst the can, and that can injure you seriously. 1) If it is obliged to warm the service can in winter, be sure to use water under 40°C. 2) Never put the service can in boiling water. 3) Do not put the service can on a hot engine, etc. Hot water

Below 40°C

(6) Do not leak the refrigerant gas near a fire or a hot part of a stove, etc. If the refrigerant gas comes in contact with the fire or hot part, it is decomposed into harmful matters.

(7) Charge the refrigerating cycle with the refrigerant in a place ventilated well.

Do not leak!

(8) Never return the refrigerant to the service can. If the refrigerant in the refrigerating cycle is returned to the service can, the can may burst, and that is very dangerous.

(9) Do not apply pressure higher than 1 MPa {10 kg/cm2} to the service can. (10)Do not shake the service can strongly. If the service can is not installed securely, it may come off.

(11)When storing and handling the service can, observe the following. 1) Store the service can away from children. 2) Do not put the service can in direct sunshine, near a fire, or hot place. 3) Do not store the service can in a place where it may be corroded. (Take care of humidity.) 4) Do not give a shock to the service can by dropping it, etc. Air conditioner

42-33 4

TESTING AND ADJUSTING

CHARGING WITH REFRIGERANT

2. Evacuation If a refrigerating cycle part is replaced, the refrigerating cycle is opened to the atmosphere. Since air always contains moisture, it must be dried. If there is any moisture in the refrigerating cycle, it may be frozen in the small of the expansion valve and may rust the compressor valves, and that can cause a trouble, even if it is little in quantity. Accordingly, the moisture in the refrigerating cycle must be removed before the refrigerant is supplied. To remove the moisture, the refrigerating cycle is evacuated with a vacuum pump to vaporize the moisture. This work is called evacuation.

Check and repair of connections

Charging with refrigerant

Max. –0.1 MPa (–750 mmHg) Gauge pointer returns

Check of airtightness with refrigerant

Leaving for a while (5 minutes)

Check of indication of gauge

10 minutes

Stop of evacuation

Start of evacuation

Check of airtightness

Supply refrigerant in gas state until gauge pressure rises to 0.1 MPa (1 kg/cm2).

2.1 Connection of gauge manifold (1) Connect the charging hoses to the high-pressure and low-pressure service valves. fl Red hose — High-pressure side (Mark of H) fl Blue hose — Low-pressure side (Mark of L) (2) Connect the central charging hose (green) of the gauge manifold to the vacuum pump.

 Take care not to mistake the high-pressure side 

Valves LO – Closed HI – Closed

Low-pressure valve (LO) High-pressure valve (HI)

and low-pressure side. The service valves may be installed to the compressor.

Red Blue Green

Service valve on low-pressure side

Vacuum pump

Service valve on high-pressure side

42-34 4

Air conditioner

TESTING AND ADJUSTING

CHARGING WITH REFRIGERANT

2.2 Evacuation (1) Open the high-pressure valve (HI) and low-pressure valve (LO) of the gauge manifold. (2) Turn on the vacuum pump to start evacuation (for 10 minutes). (3) After the low-pressure gauge reaches –0.1 MPa {–750 mmHg}, close the high-pressure valve and low-pressure valve of the gauge manifold and turn off the vacuum pump.

Valves LO – Open HI – Open

fl If the vacuum pump is stopped before the valves of the gauge manifold are closed, the atmosphere enters the refrigerating cycle.

Low-pressure side Pump is turned on

High-pressure side

2.3 Check of airtightness 1 (Check of gauge pointer) Leave the high-pressure valve and low-pressure valve of the gauge manifold closed for a while (for 5 minutes) and check that the gauge pointer does not return. fl If the gauge pointer returns, the refrigerant is leaking through some part. In this case, check the pipe connections for looseness and repair them, then evacuate and inspect again.

Valves LO – Closed HI – Closed

Leave for 5 minutes

Low-pressure gauge

Returns Check and repair pipe connections

Air conditioner

42-35 4

TESTING AND ADJUSTING

CHARGING WITH REFRIGERANT

2.4 Check of airtightness 2 (Check with refrigerant) Supply the refrigerant a little to the refrigerating cycle, then check the airtightness with a gas leak detector. (1) Disconnect the charging hose (green) from the vacuum pump and connect it to the service can. For the method of installing the service can, see “Service can valve (on page 42-9)”. (2) Discharge the air from the charging hose (green). 1 Tighten the handle of the service can valve to make a hole in the service can and open the valve. 2 Push the valve of the gauge manifold to discharge the air from the hose with the refrigerant pressure until the refrigerant flows with a hiss.

Valves LO – Closed HI – Closed

Open valve

Push valve

Blue

 At this time, keep both high-pressure valve and 

low-pressure valve of the gauge manifold closed. Take care that the refrigerant will not stick to your hands. (You may be frostbitten.)

(3) Open the high-pressure valve of the gauge manifold and supply the refrigerant until the lowpressure gauge indicates 0.1 MPa {1 kg/cm2}. (4) After supplying the refrigerant, close the highpressure valve. (5) Check for refrigerant leakage carefully with the gas leak detector. If any part is leaking, repair it.

Green Red

To service valve

Valves LO – Closed HI – Open

Service can

After supplying refrigerant, close high-pressure valve.

fl Be sure to use a detector for HFC134a (R134a) to check for refrigerant leakage.

Valve: Open

Low-pressure side Service can High-pressure side

42-36 4

Air conditioner

TESTING AND ADJUSTING

CHARGING WITH REFRIGERANT

3. Charging with refrigerant After evacuating the refrigerating cycle, charge it with the refrigerant according to the following procedure. (1) Stop the engine and supply the refrigerant from the high-pressure side. (2) Run the engine and supply the refrigerant from low-pressure side additionally.

Check for refrigerant leakage

Check of quantity of refrigerant

Supply from lowpressure side

Supply from highpressure side

Check of airtightness

Evacuation

Supply of refrigerant

3.1 Supply from high-pressure side (1) Stop the engine and open the high-pressure valve of the gauge manifold and the service can valve and supply about a can of the refrigerant.

 Never turn on the compressor at this time. If it

 

is turned on, the refrigerant flows back to burst the hoses or service can, and that is very dangerous. Do not turn on the compressor before charging the refrigerating cycle with refrigerant. If it is turned on, it may be seized. Do not open the low-pressure valve of the gauge manifold. If it is opened, the compressor may compress the refrigerant liquid and may be broken.

(2) Close the high-pressure valve of the gauge manifold and the service can valve.

Valves LO – Closed HI – Open

After supplying refrigerant, close high-pressure valve.

Valve: Open Blue

Red

Green Service valve on low-pressure side Service can Service valve on high-pressure side

Air conditioner

42-37 4

TESTING AND ADJUSTING

CHARGING WITH REFRIGERANT

3.2 Supply from low-pressure side (Additional supply) (1) Check that the high-pressure valve of the gauge manifold is closed. (2) Set the machine under the following condition. • Run the engine and open the cab door fully. • Air conditioner switch ....... ON • Temperature control lever ... Lowest temperature • Blower switch ..................... HI • Engine speed ...................... Approx. 1,500 rpm (3) Open the low-pressure valve of the gauge manifold and the service can valve to supply the refrigerant to the specified level. (4) After supplying the refrigerant, close the lowpressure valve of the gauge manifold and the service can valve and stop the engine.

 Never open the high-pressure valve (HI) of the



gauge manifold. If it is opened, the refrigerant flows back to burst the service can or charging hoses, and that is very dangerous. Never hold the service upside down. If it is held upside down, the refrigerant in liquid state is sucked in and compressed by the compressor. As a result, the compressor valves may be broken. Erect the service can to supply refrigerant in gas state.

High-pressure valve: Closed

Note: If this valve is opened, service can will burst and injure you seriously.

Run engine at 1,500 rpm

(Lowest temperature)

Open cab door fully.

Valves LO – Open HI – Closed Low-pressure side

Temperature control lever

Never open highpressure valve. High-pressure side

Valve: Open Blue

Red

Green Low-pressure side

Service can

High-pressure side

42-38 4

Air conditioner

TESTING AND ADJUSTING

[Reference] • Supplying refrigerant when ambient temperature is low When the ambient temperature is low, the refrigerant may not be supplied quickly. In this case, warm the service can in warm water below 40°C to heighten the internal pressure of the can.

 Do not heat the service can in hot water or over a fire. If it is heated so, it will burst and injure you seriously. Be sure to use warm water below 40°C. (Check the temperature with a thermometer.)

CHARGING WITH REFRIGERANT

After supplying refrigerant, close this valve.

Valves LO – Open HI – Closed

Low-pressure valve

High-pressure valve Valve: Open

fl When warming the service can in warm water, do not submerge the service can valve in the water. If it is submerged, moisture may enter the refrigerating cycle. fl Supplying refrigerant when ambient temperature is high When the ambient temperature is high, cool the condenser with an electric fan so that the refrigerant will be supplied quickly.

Air conditioner

Low-pressure side High-pressure side

Warm water below 40°C

42-39 4

TESTING AND ADJUSTING

CHARGING WITH REFRIGERANT

3.3 Replacement of service can If the service can becomes empty while the refrigerant is supplied from it, replace with new can according to the following procedure. (1) Close the high-pressure valve and low-pressure valve of the gauge manifold. (2) Raise the service can valve needle and disc. (3) Install a new service can to the service can valve. (4) Discharge the air from the charging hose according to the following procedure. 1 Tighten the handle of the service can valve to make a hole in the service can and open the valve. 2 Push the valve of the gauge manifold to discharge the air from the hose with the refrigerant pressure until the refrigerant flows with a hiss.

Handle

Hose adapter Needle

Disc

Packing Service can

Valves LO – Closed HI – Closed

 At this time, keep both high-pressure valve and low-pressure valve of the gauge manifold closed.

 Take care that the refrigerant will not stick to your hands. (You may be frostbitten.) (5) Continue supplying the refrigerant.

Open valve

Push valve

Blue

Green Red

To service valve

42-40 4

Service can

Air conditioner

TESTING AND ADJUSTING

CHARGING WITH REFRIGERANT

4. Check of quantity of refrigerant After supplying the refrigerant, check the quantity of supplied refrigerant according to the following procedure.

4.1 Check with gauge manifold (1) Set the machine under the following condition. • Door ................................. Full open • Temperature control ...... Lowest temperature • Blower speed .................. HI • Circulated air/Fresh air selector switch ................ Circulated air • Engine speed .................. 1,500 rpm fl Measure the quantity of the refrigerant while the pressure on the high-pressure side is below 1.86 MPa {19 kg/cm2}. If the ambient temperature is high (above 40°C) and the pressure on the high-pressure side is higher than 1.86 MPa {19 kg/cm2} under the specified judgment condition, perform the following to lower the pressure below 1.86 MPa {19 kg/ cm2}. 1 Close the door fully and set the blower speed to LO. 2 Move the machine indoors or into the shade. (2) Read the gauge manifold. When normal Pressure on low-pressure side: 0.15 – 0.25 MPa {1.5 – 2.0 kg/cm2} Pressure on high-pressure side: 1.37 – 1.57 MPa {14 – 16 kg/cm2}

Low-pressure side

High-pressure side

fl The values indicated by the gauge manifold may vary more or less with the condition. fl Too much refrigerant in the refrigerating cycle can cause insufficient cooling capacity, overheating, etc.

Air conditioner

42-41 4

TESTING AND ADJUSTING

CHARGING WITH REFRIGERANT

4.2 Check with sight glass (Simple inspection) (1) Set the machine under the following condition. • Door ................................. Full open • Temperature control ...... Lowest temperature • Blower speed .................. HI • Circulated air/Fresh air selector switch ................ Circulated air • Engine speed .................. 1,500 rpm (2) Under the above condition, check the refrigerant flow in the sight glass. fl Proper: Little bubbles are seen. If the engine speed is increased from idling to 1,500 rpm, the bubbles disappear and the refrigerant becomes transparent. fl Too much refrigerant: No bubbles are seen. In this case, both pressures on the high-pressure side and low-pressure side are high and the air in the cab is not cooled well. fl Insufficient refrigerant: Bubbles pass the sight glass continuously.

42-42 4

Too much refrigerant

Proper

Insufficient refrigerant

Sight glass

Air conditioner

TESTING AND ADJUSTING

CHARGING WITH REFRIGERANT

4.3 Disconnection of gauge manifold After finishing supplying the refrigerant, stop the engine and disconnect the charging hoses according to the following procedure. (1) Disconnect the charging hose (quick joint) on the low-pressure side from the service valve quickly. (2) Before disconnecting the charging hose on the high-pressure side, wait until the value indicated by the high-pressure gauge lowers sufficiently (to 1 MPa {10 kg/cm2} or below). (3) Disconnect the charging hose on the high-pressure (red) side similarly to the one on the lowpressure side.

Valves LO – Closed HI – Closed

Leave charging hose on high-pressure side until value indicated by highpressure gauge lowers sufficiently, then disconnect it.

Valve: Closed Blue

Red

Green Service valve on low-pressure side

Service can

Service valve on high-pressure side

 Perform the above work as quickly as you can



to minimize the leakage of the refrigerant. When disconnecting the high-pressure charging hose, wait until the gauge indicates 1 MPa {10 kg/ cm2} or less, since compressor oil may spout out together with refrigerant, then disconnect it quickly, covering it with a cloth so that the oil will not be splashed. Take care extremely that the refrigerant will not stick to your hands or enter your eyes. (Put on safety goggles.)

Air conditioner

42-43 4

TESTING AND ADJUSTING

PERIODIC INSPECTION AND MAINTENANCE

PERIODIC INSPECTION AND MAINTENANCE 1. Inspection and maintenance items You are required to inspect and maintain each air conditioner properly to use it always under the best condition. Generally, perform the following inspections and maintenance for the air conditioner. Inspection/Maintenance items

Inspection/Maintenance period 6 months

12 months

Refrigerant (Gas) (Sight glass)

Quantity

q

q

Condenser

Clogging of fins

q

q

Compressor

Operating condition

Air filters (for internal/external air)

Clogging

Belt

Damage and tension

Blower motor

Operating condition and abnormal sound

q

Control mechanism

Operating condition

q

Mounting parts and piping

Mounting condition, looseness of tightening parts and connections, gas leakage, and damage

q q (3 months) q

q

q

q

a The manufacturer (DENSO CO., LTD.) recommends replacing the receiver drier and blower motor every 4 years.

1.1 Inspection and cleaning of condenser fins a For PC400-7 Open the engine right side cover and clean condenser fins (1) with compressed air or water. See Operation manual, Inspection and maintenance, 500-hour maintenance

1.2 Cleaning of air filter (Internal/External air filters) a For PC400-7 • Internal air filter: E (Left rear of seat) • External air filter: F (Open cover at left rear of operator's cab and take out filter) Clean the filter with compressed air or neutral detergent See Operation manual, Inspection and maintenance, 500-hour maintenance

42-44 (6)

Air conditioner

TESTING AND ADJUSTING

PERIODIC INSPECTION AND MAINTENANCE

2. Check of quantity of refrigerant (Check with sight glass) (1) Set the machine under the following condition. • Door ................................. Full open • Temperature control ...... Lowest temperature • Blower speed .................. HI • Circulated air/Fresh air selector switch ................ Circulated air • Engine speed .................. 1,500 rpm • Air conditioner ................ ON (2) Check the condition of the refrigerant in the sight glass. fl Proper: Little bubbles are seen. If the engine speed is increased from idling to 1,500 rpm, the bubbles disappear and the refrigerant becomes transparent. fl Too much refrigerant: No bubbles are seen. In this case, both pressures on the high-pressure side and low-pressure side are high and the air in the cab is not cooled well. fl Insufficient refrigerant: Bubbles pass the sight glass continuously.

Air conditioner

Too much refrigerant

Proper

Insufficient refrigerant

Sight glass

42-45 4

TESTING AND ADJUSTING

PERIODIC INSPECTION AND MAINTENANCE

3. Inspection of functional parts (1) Inspection of control mechanism Operate the levers and switches on the control panel to see if they work smoothly and securely. If any part is troubled, adjust or repair it.

Sm

oot

h

(2) Inspection of belt Check the belt for damage. If it is damaged, replace it. In addition, check the belt tension (See the Shop Manual for each machine). If it is out of the standard range, adjust it.

Inspection of idling-up speed Check the idling-up speed. (See the Shop Manual for each machine.) If it is out of the standard range, adjust it.

(3) Inspection of compressor and magnetic clutch Turn the air conditioner switch on to see if the magnetic clutch is turned on. Check that magnetic clutch and compressor for abnormal noise. If any abnormal noise is produced, adjust or repair.

42-46 4

Air conditioner

TESTING AND ADJUSTING

PERIODIC INSPECTION AND MAINTENANCE

(4) Inspection of idler pulley

Repair me, please!

Check the idler pulley for abnormal noise. If any abnormal noise is produced, adjust or repair.

(5) Cleaning of condenser If much soil and dirt stick to the condenser fins, the cooling capacity is lowered. Accordingly, wash away the soil and dirt with water. If the fins are dirty extremely, clean them with a soft brush.

(6) Inspection of each fitting part Check each fitting part (mounting bolt, screw, nut, etc.) for looseness. If any part is loosened, retighten it.

Check the pipe joints for oil sticking to them. If any joint is coated with oil, the refrigerant may be leaking through it. In this case, check the joint with a gas leak detector. If the refrigerant is leaking, repair or replace the joint.

Air conditioner

Inspect with gas leak detector!

(7) Inspection of pipe joints

42-47 4

STRUCTURE AND FUNCTION

STRUCTURE AND FUNCTION TAKAHASHI WORKS Outline ....................................................................................................................................................... 51- 2 Refrigerating cycle system diagram .......................................................................................................... 51- 4 Compressor ............................................................................................................................................... 51- 6 Condenser ................................................................................................................................................. 51- 9 Receiver drier ............................................................................................................................................ 51- 9 Air conditioner unit..................................................................................................................................... 51- 10 • Air circuit...................................................................................................................................................51- 11 • Evaporator............................................................................................................................................... 51- 12 • Expansion valve ...................................................................................................................................... 51- 13 • High and low pressure switch.................................................................................................................. 51- 14 • Heater core.............................................................................................................................................. 51- 15 • Water valve ............................................................................................................................................. 51- 15 • Temperature regulation amplifier............................................................................................................. 51- 16 • Blower motor ........................................................................................................................................... 51- 16 • Resistor ................................................................................................................................................... 51- 16 • Damper actuator...................................................................................................................................... 51- 17 • Relay ....................................................................................................................................................... 51- 17 • Internal air filter and external air filter ...................................................................................................... 51- 17

Air conditioner

51-1 (5) (5)

STRUCTURE AND FUNCTION

OUTLINE

OUTLINE Reference: The following figure shows PC100-6 as an example.

4. Receiver drier 5. Air conditioner unit 6. Duct

1. Control switch 2. Compressor 3. Condenser

•

PC100-6 is equipped with an air conditioner of full heat type, in which the cooler and heater are arranged in series against air flow and made in 1 unit.

•

The compressor is of vane rotary type. It is driven by the engine through V-belt to compress refrigerant gas of low pressure and lower temperature. As a result, the pressure and temperature of the refrigerant gas are heightened, and then the refrigerant gas is sent to the condenser.

51-2 (5) (5)

•

The air conditioner unit is installed to the rear of the operator's seat in the cabin. The air cooled or heated in this unit is sent through the ducts to the air blow grilles at the rear and right of the operator's seat.

•

The air temperature, air outlet, selection of external or internal air, and strength of air flow are selected with the air conditioner switches on the control panel.

Air conditioner

STRUCTURE AND FUNCTION

OUTLINE

Layout of air conditioner parts in cab

1. Grille for rear FACE (Air flow direction: Changeable vertically and horizontally) 2. Heater core 3. Evaporator 4. EXTERNAL/INTERNAL air changeover damper 5. External air filter 6. Internal air filter 7. Blower motor 8. Refrigerant inlet (M16 x 1.5) 9. Refrigerant outlet (M22 x 1.5) 10. Hot water inlet 11. Hot water outlet 12. Selector damper 13. FOOT grill (Air flow direction: Fixed)

Air conditioner

14. DEFROSTER grill (Air flow direction: Changeable vertically and horizontally) 15. FOOT-DEFROSTER selector lever (Operated manually) 16. Right side FACE grill (Air flow direction: Changeable vertically and horizontally) 17. FACE control wire 18. Control panel 19. Chassis-side wiring harness a. b. c. d. e. f. g.

FACE FACE External air inlet Internal air inlet FOOT DEFROSTER FACE

51-3 (5) (5)

STRUCTURE AND FUNCTION

REFRIGERATING CYCLE CIRCUIT DIAGRAM

REFRIGERATING CYCLE CIRCUIT DIAGRAM

51-4 (5) (5)

Air conditioner

STRUCTURE AND FUNCTION

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23.

Air outlet Heater core Evaporator Blower motor Expansion valve High and low pressure switch Relief valve Liquid eye Magnetic clutch Thermal switch Filter Desiccating agent Receiver drier Condenser Electric cooling fan Compressor Filter Filter Heat sensor tube Thermistor Water valve Control switch Air outlet

Air conditioner

REFRIGERATING CYCLE CIRCUIT DIAGRAM

A. B. C. D.

Evaporation Expansion Compression Condensation

a. b. c. d.

Charged with gas Liquid of low temperature and low pressure Temperature: 50 - 60fC Temperature: 8 - 15fC Pressure: 0.1 - 0.2 MPa {1 - 2 kg/cm2} Liquid of high temperature and high pressure Suction Discharge Gas of high temperature and high pressure Temperature: 50 - 60fC Liquid of high temperature and high pressure Temperature: 80 - 120fC (Reference value for normal operation) Pressure: 1.37 - 1.57 MPa {14 - 16 kg/cm2} (Reference value for normal operation) Gas of low temperature and low pressure External air Internal air Hot water OUT Hot water IN

e. f. g. h. i. j. k.

l. m. n. o. p.

51-5 (5) (5)

STRUCTURE AND FUNCTION

COMPRESSOR

COMPRESSOR The rotation of the engine is transmitted through the belt to the clutch, which is turned ON and OFF by the temperature regulator thermostat. Then, the rotor of the compressor coupled directly with the clutch is rotated. The rotor has 5 vanes. As the rotor rotates, the vanes slide on the inside wall of the cylinder to compress and suck the refrigerant gas repeatedly.

Function •

The compressor sucks the refrigerant gas of low pressure and low temperature evaporated in the evaporator and compresses it. The pressure and temperature of the compressed refrigerant gas become high, and then the refrigerant gas is discharged into the condenser. The refrigerant gas is circulated in the refrigerating cycle. The temperature and pressure of the refrigerant gas are heightened by the compressor, and then the refrigerant gas is cooled and liquefied in the condenser

51-6 (5) (5)

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. a. b.

Oil separator Front head Mechanical seal Clutch Front side block Case Rear side block Rotor Cylinder Vane Discharge opening Suction opening

Air conditioner

STRUCTURE AND FUNCTION

COMPRESSOR

Operation processes of compressor (1) Starting suction Suction of the refrigerant gas starts when vane A passes by suction opening (1) (White arrow). As the rotor rotates, the space (hatched part) formed by vanes A and E, rotor, and cylinder is increased to continue sucking the refrigerant gas.

(2) Finishing suction (Closing) - Starting compression Suction finishes when vane E passes by suction opening (1). The hatched part in the figure at this time is the maximum space and compression starts at this point.

(3) Compression - Discharge The compressed refrigerant gas pushes up the lead valve installed at discharge opening (2) and goes out (Black arrows). Just after this time, vane A starts suction through suction opening (1) on the opposite side. s As explained above, each compression space

performs the cycle of suction, compression, and discharge 2 times in 1 turn. Accordingly, the compressor performs 10 cycles in 1 turn.

Air conditioner

51-7 (5) (5)

STRUCTURE AND FUNCTION

COMPRESSOR

Relief valve (Installed to compressor) When the high pressure in a car air conditioner for R12 becomes abnormally, a melt bolt is melted to discharge the refrigerant into the atmosphere to protect the air conditioner cycle. In this case, all the refrigerant in the cycle is discharged. On the other hand, a car air conditioner for R134a employs a pressure relief valve instead of the melt bolt to minimize discharge of the refrigerant when abnormally high pressure is generated. The refrigerant discharge route made when the relief valve operates is shown in the figure. s Operating pressure

Start of blowing: 3.4 MPa {35 kg/cm2} Stop of blowing: 2.9 MPa {30 kg/cm2}

Thermal switch (Installed to compressor) This switch is installed near the discharge port of the compressor. It turns the power for the clutch OFF when the temperature of the compressor becomes abnormally high. When the temperature of the compressor lowers to the normal level, the thermal switch turns the power for the clutch ON again. s Operating temperature

ON : 95fC OFF: 140fC

1. 2. 3. 4.

Wiring harness Diaphragm bimetal Compressor Contact

51-8 (5) (5)

Air conditioner

CONDENSER ANR RECEIVER DRIER CONDENSER

STRUCTURE AND FUNCTION

CONDENSER

The refrigerant of high pressure and high temperature sent from the compressor to the condenser is cooled and liquefied with a cooling fan. The condenser consists of aluminum tubes and corrugated fins.

RECEIVER DRIER

The liquefied refrigerant of high pressure and high temperature sent from the condenser is stored in the receiver drier. Even if bubbles are mixed in the liquefied refrigerant, depending on the radiating condition of the condenser, only liquefied refrigerant is sent to the expansion valve. The filter and desiccating agent remove the dirt and water in the cycle. The operator can see the flow of the refrigerant through the liquid eye at the top of the receiver drier

Air conditioner

1. 2. a. b. c. d.

Louver fin Tube made by extrusion Passage of refrigerant gas Passage of air Inlet (M20 x 1.5 with O-ring) Outlet (M16 x 1.5 with O-ring)

to judge the quantity of the refrigerant. 1. Desiccating agent 2. Filter 3. Liquid eye 4. Thread size: M16 x 1.5 a. Flow of liquefied refrigerant from condenser b. Stored liquefied refrigerant c. Connection to air conditioner unit

51-9 (5) (5)

STRUCTURE AND FUNCTION

AIR CONDITIONER UNIT

AIR CONDITIONER UNIT

1. 2. 3. 4. 5.

Drain pan Damper case Heater core Evaporator Blower motor

6. 7. 8. 9.

EXTERNAL/INTERNAL air changeover damper External air filter Internal air filter Cover

The temperature in the cab is controlled through the respective heat exchangers of the refrigerant gas for cooling and the hot water for heating. The external or internal air is sent by the blower in the unit through the filters to the air outlets after divided by the selector damper.

1. 2. 3. 4. 5. 6. 7. 8. 9.

Upper air outlet External air suction opening Internal air suction opening Refrigerant gas inlet (M16 x 1.5 with O-ring) Refrigerant gas outlet (M22 x 1.5 with O-ring) Hot water inlet Hot water outlet Side air outlet Selector duct actuator

51-10 (5)

Air conditioner

STRUCTURE AND FUNCTION

AIR CONDITIONER UNIT

Air circuit

1. External/Internal air changeover damper (Operated with actuator) 2. Fan 3. Evaporator 4. Heater core 5. Damper (Operated with actuator) 6. Blower motor a. b. c. d.

External air Internal air Side air outlet Upper air outlet

Air conditioner

51-11 (5)

STRUCTURE AND FUNCTION

AIR CONDITIONER UNIT

Evaporator

The fins of the evaporator are cooled by the lowtemperature refrigerant mist sent through the expansion valve. Then, the fins cool and dry the warm air sent by the blower motor.

1. 2. 3. 4.

Refrigerant inlet Refrigerant outlet Slit fins Refrigerant passage holes

a. Air (Room temperature) b. Air (Cooled) c. Plate thickness: 5 mm

51-12 (5)

Air conditioner

STRUCTURE AND FUNCTION

AIR CONDITIONER UNIT

Expansion valve The refrigerant liquid of high pressure and high temperature sent from the receiver drier is sprayed through the expansion valve. As a result, the refrigerant becomes mist of low pressure and low temperature. The closing ratio of the expansion valve is changed according to the thermal load of the cab to control the refrigerant flow rate in the refrigerating cycle automatically.

1. 2. 3. 4. 5. 6. 7. 8.

Diaphragm Valve stem Adjustment screw Adjustment spring Ball P2 Evaporator Heat sensor tube (to sense gas temperature on cooler outlet side) 9. Capillary tube a. Refrigerant liquid inlet b. To compressor c. Volume changes according to temperature (Filled with gas).

Air conditioner

51-13 (5)

STRUCTURE AND FUNCTION

AIR CONDITIONER UNIT

High and low pressure switch This switch is installed to the liquid tube. When abnormally low or high pressure is generated in the air conditioner cycle, this switch turns the compressor OFF to protect the parts in the air conditioner cycle. 1. Spring 2. Stopper 3. Contact 4. Plate

5. Belleville spring 6. Diaphragm 7. Pin 8. Terminal a. Refrigerant pressure

Operation • When pressure is normal When the refrigerant pressure is higher than 0.21 MPa {2.1 kg/cm2}, its force is larger than the force of spring (2). As a result, diaphragm (6) is deformed and plate (4) is pushed up to close contact (3).

•

When pressure is abnormally low When the refrigerant pressure is lower than 0.20 MPa {2.0 kg/cm2}, plate (4) is pushed down by the force of spring (2) and contact (3) is opened.

•

When pressure is abnormally high When the refrigerant pressure is lower than 3.1 MPa {32 kg/cm2}, diaphragm (6) is deflected and belleville spring (5) buckles back. As a result, the contact is pushed up and opened through pin (7).

51-14 (5)

Air conditioner

STRUCTURE AND FUNCTION

AIR CONDITIONER UNIT

Heater core

The hot water from the engine flows into the heater core to warm the air flowing through the heater core. The temperature of the air flowing through the heater core can be controlled by adjusting the hot water flow rate with the water valve.

1. 2. 3. 4.

Hot water inlet pipe (φ14 mm) Hot water outlet pipe (φ14 mm) Hot water passage Air passage

a. Hot water inlet b. Hot water outlet

Water valve

The water valve controls the flow rate of the hot water flowing from the engine to the heater core according to the command from the control switch. It is driven by the motor actuator.

1. 2. 3. 4.

Rod Valve Hot water inlet pipe (φ16 mm) Hot water outlet pipe (φ16 mm)

a. Driven by motor b. Hot water inlet c. Hot water outlet

Air conditioner

51-15 (5)

STRUCTURE AND FUNCTION

AIR CONDITIONER UNIT

Temperature regulation amplifier There are relays and a temperature regulation board in this amplifier unit. The thermistor senses hot air from the evaporator and the thermal amplifier compares the hot air temperature with the value set with the control knob and turns the compressor ON and OFF. The thermistor is also used to prevent freezing of the evaporator. 1. Thermistor a. Connected to variable resistor or fixed resistor

Blower motor The blower sucks external or internal air and sends it to the evaporator and heater core to exchange heat. The heat-exchanged air is directed by the damper and sent through the duct to the air outlet grille. The blower motor speed is set to 3 levels by means of resistor according to the fan switch which is set manually. 1. Scroll 2. Motor 3. Sirocco fan Resistor

This resistor is used to lower the blower motor current, or the blower motor speed, to 3 levels.

51-16 (5)

1. Resistor (Low) 2. Resistor (Mid) 3. Temperature fuse (Turned OFF at 76fC, not reset automatically)

Air conditioner

STRUCTURE AND FUNCTION

AIR CONDITIONER UNIT

Damper actuator This motor damper actuator sets the selector damper to the displayed position of the control panel switch. The damper is rotated and sets to 3 positions through reduction gears.

Relay This relay turns a large current ON and OFF according to the signals from the switch and temperature regulation amplifier. 1. Output side 2. Signal input 3. Ground 4. Input side

Internal air filter and external air filter If dust and dirt sticks to the heat exchanger, the cooling and heating capacity is reduced. To prevent this trouble, filters are installed to the internal and external air suction openings of the air conditioner unit to remove the dust and dirt from the air. 1. External air filter 2. Internal air filter

Air conditioner

51-17 (5)

STRUCTURE AND FUNCTION

51-18 (5)

AIR CONDITIONER UNIT

Air conditioner

TESTING AND ADJUSTING

TESTING AND ADJUSTING TAKAHASHI WORKS List of tools for testing, adjusting, and troubleshooting............................................................................ 52-

2

Precautions for measuring refrigerant pressure, charging with refrigerant, and discharging refrigerant. 52-

3

Testing quantity of refrigerant .................................................................................................................. 52-

6

Procedure for charging with refrigerant ................................................................................................... 52- 10 Procedure for replacing service can ........................................................................................................ 52- 13 Procedure for discharging refrigerant ...................................................................................................... 52- 14 Cleaning internal and external air filters .................................................................................................. 52- 16 Troubleshooting ....................................................................................................................................... 52- 101

Air conditioner

52-1 (5) (5)

LIST OF TOOLS FOR TESTING, ADJUSTING, AND TROUBLELIST OF TOOLS FOR TESTING, ADJUSTING, AND TROUBLESHOOTING SHOOTING

TESTING AND ADJUSTING

LIST OF TOOLS FOR TESTING, ADJUSTING, AND TROUBLESHOOTING Testing and adjusting item

Symbol

Part No.

Part name

1 799-703-1200 Service tool kit 799-703-1100 Vacuum pump 799-703-1111 Vacuum pump

Measuring refrigerant pressure in air condiN tioner, charging with refrigerant, and discharging refrigerant

2 799-703-1121 Vacuum pump

52-2 (6) (5)

O

For new refrigerant R134a For new refrigerant R134a in Japan (100 V) For new refrigerant R134a in overseas countries (220 V) For new refrigerant R134a in overseas countries (240 V)

799-702-1320 Vacuum pump

For Freon R12 in USA (115 V)

799-702-1330 Vacuum pump

For Freon R12 in overseas countries (220 V)

3 799-703-1300 Adapter Leakage of refrigerant

Remarks

799-703-1400 Gas leak tester

For use of vacuum pump for R12 For countries other than USA

Air conditioner

PRECAUTIONS FOR MEASURING REFRIGERANT PRESSURE, CHARGTESTING AND ADJUSTING PRECAUTIONS FOR MEASURING CHARGING ING WITH REFRIGERANT, ANDREFRIGERANT DISCHARGINGPRESSURE, REFRIGERANT

PRECAUTIONS FOR MEASURING REFRIGERANT PRESSURE, CHARGING WITH REFRIGERANT, AND DISCHARGING REFRIGERANT 1. Precautions for using service tool kit N1 for car air conditioner • The joints of service tool kit N1 for R134a car air conditioner are different from those for the other refrigerants.

1. 2. 3. 4. 5.

Gauge manifold High-pressure charging hose (Red) Quick joint (Hi) [Large diameter] Center charging hose (Green) Quick joint (Lo) [Small diameter]

Air conditioner

s Use R134a service tool kit N1 for R134a car

air conditioner.

s Do not use R134a service tool kit N1 for R12

car air conditioner.

s Do not use R12 service tool kit.

6. Low-pressure charging hose (Blue) 7. Service can valve 8. Service can valve joint a. Since the threads are course and loosened easily, take care.

52-3 (5) (5)

PRECAUTIONS FOR MEASURING REFRIGERANT PRESSURE, CHARGTESTING AND ADJUSTING PRECAUTIONS FOR MEASURING CHARGING ING WITH REFRIGERANT, ANDREFRIGERANT DISCHARGINGPRESSURE, REFRIGERANT

2. Precautions for connecting quick joint • Press the quick joint against the charging valve and push in part A securely until it clicks. Completion of connection

s When pressing the joint to connect it, take

care not to bend the piping.

s If sleeve (1) has moved without connecting to

the charging valve, return it to the set position and connect again. s If any refrigerant is left in the charging hose, the joint may not be connected easily. In this case, release the residual pressure in the hose.

3. Precautions for disconnecting quick joint • Securing part A of the quick joint, slide part B (sleeve) up. Completion of disconnection s After disconnecting the quick joint, install the

cap to the charging valve.

Precautions for handling R134a charging valve • When operating valve (4) of R134a charging valve (6), observe the following. s When discharging the refrigerant, be sure to

use special quick joint (2).

s Never push in valve (4) with screwdriver (3),

etc. to discharge the refrigerant. If it is pushed in strongly (with force of 2.4N {3 kg} or larger), spring (5) may come off and refrigerant may leak.

52-4 (5) (5)

Air conditioner

PRECAUTIONS FOR MEASURING REFRIGERANT PRESSURE, CHARGTESTING AND ADJUSTING PRECAUTIONS FOR MEASURING CHARGING ING WITH REFRIGERANT, ANDREFRIGERANT DISCHARGINGPRESSURE, REFRIGERANT

5. Precautions for using vacuum pump • If R12 vacuum pump N2 is equipped with vacuum pump adapter N3 additionally, it can be used for both R134a car air conditioner and R12 car air conditioner.

Abnormal indication by gauge

Checking and repairing joints

Charging with refrigerant

Checking for refrigerant leakage

Leaving

Charging with refrigerant

Negative pressure : Min100kPa {750mmHg}

5 min

Checking airtightness

30 min

Stopping evacuation

Precautions for charging with refrigerant and checking for refrigerant leakage • Charge with the refrigerant by the conventional method.

Starting evacuation

6.

(*1)

Charge with refrigerant gas up to gauge pressure of 0.1 MPa {1 kg/cm2}.

s When evacuating, connect the vacuum pump

to the quick joints on both high-pressure and low-pressure sides. If the pump is not connected to both sides, the atmosphere enters through the unconnected joint. (The check valve of the quick joint cannot keep vacuum.)

s Before stopping the vacuum pump (turning the

switch OFF) after evacuating, close the gauge

(

manifold.

)

If the vacuum pump is stopped before the

gauge manifold is closed, the evacuated air conditioner circuit is opened to the atmosphere.

s Precautions for checking refrigerant leakage (*1)

When checking refrigerant leakage from the R134a car air conditioner, be sure to use R134a gas leak tester O. Do not use the R12 gas leak tester, since its sensitivity is too low. a. When using the R12 vacuum pump, use adapter N3. b. Close the gauge manifold before turning the switch OFF.

Air conditioner

52-5 (5) (5)

TESTING AND ADJUSTING

TESTING QUANTITY OF REFRIGERANT

TESTING QUANTITY OF REFRIGERANT 1. Visual inspection (Inspection through liquid eye)

k If the refrigerant liquid enters your eyes or sticks to your hand, you may lose your eyes or your hand skin may be frozen. Accordingly, do not loosen a refrigerant circuit part. • Test the quantity of the refrigerant while the compressor is turned ON under the condition in Table 1. s When the compressor is turned OFF, bubbles are made even if the quantity of the refrigerant is proper. Accordingly, check that the compressor is turned ON when testing the quantity of the refrigerant. Table 1 Item

Condition

Door

Open full

Temperature control

Max.

Blower speed

Hi

External/Internal air

Internal

Engine speed

1,500rpm

Air conditioner switch

ON

s Judge the quantity of the refrigerant while the

pressure on the high pressure side is below 1.9MPa {19kg/cm2}. s When the ambient temperature is high (above 40fC), if the pressure on the high pressure side is higher above 1.9MPa {19kg/cm2} under the judging condition, lower it below 1.9MPa {19kg/cm2} by the following method. 1. Close the door fully and set the blower speed to Lo. 2. Test indoors or under a shade.

52-6 (5) (5)

Air conditioner

TESTING AND ADJUSTING

TESTING QUANTITY OF REFRIGERANT

[Judgment] Check table for quantity of refrigerant Condition of air conditioner

Normal

High-pressure tube is hot and low-presTemperature of high sure tube is cold. and low pressure Temperature differtubes ence between them is clear.

Condition of liquid eye

Almost transparent. Even if some bubbles are flowing, they disappear when engine speed is increased or decreased. See Fig. a.

Abnormal High-pressure tube is warm and lowpressure tube is cool. Temperature difference between them is not so clear.

There is little temperature difference between high-pressure tube and lowpressure tube.

Bubbles flow conFog-like thing flows stantly. Transparent. slightly. White bubbles may flow.

High-pressure tube is hot and low-pressure tube is cool. There is some temperature difference between them. Even if fan is set to Hi (with doors closed) while engine is running idle, no bubbles flow.

See Fig. b.

See Fig. c.

See Fig. d.

Condition of pipe joints

Normal

Some parts are stained with oil.

Some parts are stained with oil badly.

Normal

Condition of this air conditioner

Quantity of refrigerant is proper.

Refrigerant may be leaking a little.

Almost all refrigerant has leaked.

Quantity of refrigerant is too much.

Note that the contents of the above table change a little during the very cold season and very hot season. Generally, bubbles are made easily in the very hot season and are not made easily (the refrigerant becomes transparent) in the very cold season.

1. Liquid eye 2. Receiver drier

Air conditioner

52-7 (5) (5)

TESTING AND ADJUSTING

TESTING QUANTITY OF REFRIGERANT

2. Measuring refrigerant pressure

kTake care that the refrigerant will not stick to your hand. k Put on protective goggles to prevent the refrigerant from entering your eyes. 1) Stop the engine and install service tool kit N1. s Close the high-pressure valve and lowpressure valve of the gauge manifold. s Connect blue hose (1) to the low-pressure piping and red hose (2) to the high-pressure piping. 2) Release air from service tool kit N1. i) Open the high-pressure valve gradually. When the refrigerant comes out of the green charge hose with a hiss, close the high-pressure valve. ii) Open the low-pressure valve gradually. When the refrigerant comes out of the green charge hose with a hiss, close the low-pressure valve. 3) While the compressor is turned ON, measure the refrigerant pressure and air conditioner suction temperature under the condition in Table 2. s If the compressor is turned OFF, the refrigerant pressure lowers extremely. Accordingly, turn the compressor ON when measuring the refrigerant pressure.

Table 2 Item

Condition

Door

Open full

Temperature control

Max.

Blower speed

Hi

External/Internal air

Internal

Engine speed

1,500rpm

Air conditioner switch

ON

s Note that the proper refrigerant pressure depends

on the air conditioner suction temperature. Air conditioner refrigerant pressure standard

Air conditioner suc- High-pressure gauge prestion temperature(fC) sure(MPa{kg/cm2})

52-8 (5) (5)

15

1.03-1.32 {10.5-13.5}

20

1.17-1.47 {12.0-15.0}

25

1.32-1.62 {13.5-16.5}

30

1.47-1.77 {15.0-18.0}

35

1.62-1.91 {16.5-19.5}

a. b. c. d. e.

Quantity of refrigerant is too much Quantity of refrigerant is proper Quantity of refrigerant is insufficient Air conditioner suction temperature High-pressure gauge pressure

Air conditioner

TESTING AND ADJUSTING

TESTING QUANTITY OF REFRIGERANT

[Reference] When the air conditioner suction temperature is in the normal range of 30-35fC, the gauge pressure becomes as shown in Table 3. Table 3 Pressure on low 0.15-0.25MPa{1.5-2.5 kg/cm2} pressure side Pressure on high 1.37-1.57MPa{14-16 kg/cm2} pressure side

s The figure shows the median of the gauge

pressure under the normal condition as an example. 1. Gauge on high pressure side 2. Gauge on low pressure side

Air conditioner

52-9 (5) (5)

TESTING AND ADJUSTING

PROCEDURE FOR CHARGING WITH REFRIGERANT

PROCEDURE FOR CHARGING WITH REFRIGERANT k Take care that the refrigerant will not stick to your hand. k Put on protective goggles to prevent the refrigerant from entering your eyes. s If the quantity of the refrigerant is insufficient, add new refrigerant according to the following procedure. 1. Evacuation 1) Stop the engine and install service tool kit N1. s Close high-pressure valve (1) and lowpressure valve (2) of the gauge manifold (in direction a). s Connect red hose (3) to the high-pressure piping and blue hose (4) to the low-pressure piping. 2) Connect green hose (5) to vacuum pump N2. 3) Open high-pressure valve (1) and low-pressure valve (2) gradually (in direction b). s Do not operate the valves quickly. 4) Turn switch (6) of vacuum pump N2 ON and evacuate the air conditioner circuit for 30 minutes. 5) Close high-pressure valve (1) and low-pressure valve (2) gradually (in direction a) and turn switch (6) of the vacuum pump OFF. 2. Charging with refrigerant 1) Charging from high-pressure side i)

Disconnect charging hose (Green) (5) of the gauge manifold from vacuum pump N2 and connect it to service can (7). s When using 2 service cans, use service can valve T-joint (8). ii) Tighten the handle of service can valve (9) to pierce a hole in service can (7), and then open service can valve (9) (in direction b). iii) Hold the valve of air purge valve (10) with flat-head screwdriver (11) so that the air in green hose (5) and gauge manifold will be discharged by the refrigerant pressure. s Continue the above work until the refrigerant gas comes out with "a hiss". iv) Stop the engine and open high-pressure valve (1) and service can valve (9) to supply the refrigerant from service can (7) (in direction b).

k Never drive the compressor.

k Do not drive the compressor while the air conditioner circuit is not charged with the refrigerant. k Never open low-pressure valve (2). (Set it in direction a.)

52-10 (5)

Air conditioner

TESTING AND ADJUSTING

2)

PROCEDURE FOR CHARGING WITH REFRIGERANT

v) Close high-pressure valve (1) and service can valve (9). Charging from low-pressure side (Additional charge) i) Check that high-pressure valve (1) is closed (in direction a). ii) Open low-pressure valve (2) and service can valve (9) under the condition in Table 1 and supply the refrigerant to a proper level. (Each valve opens when it is set in direction b.)

k Never open high-pressure valve (1).

k Never put service can (7) upside down.

s When measuring the refrigerant pres-

sure, close low-pressure valve (2) and high-pressure valve (1) (in direction a). s Note extremely that the proper refrigerant pressure depends on the air conditioner suction temperature. Table 1 Item

Condition

Door

Open full

Temperature control

Max.

Blower speed

Hi

External/Internal air

Internal

Engine speed

1,500rpm

Air conditioner switch

ON

Air conditioner refrigerant pressure standard Air conditioner suc- High-pressure gauge prestion temperature (fC) sure (MPa{kg/cm2}) 15

1.03-1.32 {10.5-13.5}

20

1.17-1.47 {12.0-15.0}

25

1.32-1.62 {13.5-16.5}

30

1.47-1.77 {15.0-18.0}

35

1.62-1.91 {16.5-19.5}

iii) After finishing charging with the refrigerant, close low-pressure valve (2) and service can valve (9) and stop the engine. iv) Check that the refrigerant is not leaking with gas leak tester O.

Air conditioner

a. b. c. d. e.

Quantity of refrigerant is too much Quantity of refrigerant is proper Quantity of refrigerant is insufficient Air conditioner suction temperature High-pressure gauge pressure

52-11 (5)

TESTING AND ADJUSTING

PROCEDURE FOR CHARGING WITH REFRIGERANT

[Reference] 1. If the refrigerant circuit is empty, supply about 800 g of the refrigerant. 2. When the air conditioner suction temperature is in the normal range of 30-35fC, the gauge pressure becomes as shown in Table 2. Table 2 Pressure on low 0.15-0.25MPa{1.5-2.5 kg/cm2} pressure side Pressure on high 1.37-1.57MPa{14-16 kg/cm2} pressure side

s The figure shows the median of the gauge

pressure under the normal condition as an example.

52-12 (5)

1. Pressure on low pressure side 2. Pressure on high pressure side

Air conditioner

TESTING AND ADJUSTING

PROCEDURE FOR REPLACING SERVICE CAN

PROCEDURE FOR REPLACING SERVICE CAN kTake care that the refrigerant will not stick to your hand.

k Put on protective goggles to prevent the refrigerant from entering your eyes.

1. Close high-pressure valve (1) and low-pressure valve (2) (in direction a).

2. Raise needle (4) and disc (5) of service can valve (3).

3. Install service can valve (3) to new service can (6).

4. Tighten handle (7) of service can valve (3) to pierce a hole in service can (6), and then open handle (7) of service can valve (3) (in direction b). 5. Hold the valve of air purge valve (8) with a flathead screwdriver so that the air in green hose (10) and gauge manifold (11) will be discharged by the refrigerant pressure. s Continue the above work until the refrigerant gas comes out with "a hiss".

Air conditioner

52-13 (5)

TESTING AND ADJUSTING

PROCEDURE FOR DISCHARGING REFRIGERANT

PROCEDURE FOR DISCHARGING REFRIGERANT kTake care that the refrigerant will not stick to your hand. k Put on protective goggles to prevent the refrigerant from entering your eyes. 1)

2)

3)

Stop the engine and install service tool kit N1. s Close the high-pressure valve and lowpressure valve of the gauge manifold. s Connect blue hose (1) to the low-pressure piping and red hose (2) to the high-pressure piping. s If service tool kit N1 has not been removed from the compressor after the refrigerant pressure was measured, start the work with 3) below. Bleed air from service tool kit N1. i) Open the high-pressure valve gradually. When the refrigerant comes out of the green charge hose with "a hiss", close the high-pressure valve. ii) Open the low-pressure valve gradually. When the refrigerant comes out of the green charge hose with "a hiss", close the low-pressure valve. Open the high-pressure valve (Hi) gradually to release the refrigerant until the refrigerant pressure lowers to the proper level when the compressor is turned ON under the condition in Table 1. s Keep the low-pressure valve closed. k Do not operate the high-pressure valve quickly.

s When measuring the refrigerant pressure,

close the low-pressure valve and highpressure valve.

Table 1 Item

Condition

Door

Open full

Temperature control

Max.

Blower speed

Hi

External/Internal air

Internal

Engine speed

1,500rpm

Air conditioner switch

ON

52-14 (5)

Air conditioner

TESTING AND ADJUSTING

PROCEDURE FOR DISCHARGING REFRIGERANT

s Note that the proper refrigerant pressure

depends on the air conditioner suction temperature. Air conditioner refrigerant pressure standard Air conditioner suc- High-pressure gauge prestion temperature (fC) sure (MPa{kg/cm2}) 15

1.03-1.32 {10.5-13.5}

20

1.17-1.47 {12.0-15.0}

25

1.32-1.62 {13.5-16.5}

30

1.47-1.77 {15.0-18.0}

35

1.62-1.91 {16.5-19.5}

[Reference] When the air conditioner suction temperature is in the normal range of 30-35fC, the gauge pressure becomes as shown in Table 3.

a. b. c. d. e.

Quantity of refrigerant is too much Quantity of refrigerant is proper Quantity of refrigerant is insufficient Air conditioner suction temperature High-pressure gauge pressure

Table 3 Pressure on low 0.15-0.25MPa{1.5-2.5 kg/cm2} pressure side Pressure on high 1.37-1.57MPa{14-16 kg/cm2} pressure side

s The figure shows the median of the gauge

pressure under the normal condition as an example.

1. Pressure on low pressure side 2. Pressure on high pressure side

Air conditioner

52-15 (5)

TESTING AND ADJUSTING

CLEANING INTERNAL AND EXTERNAL AIR FILTERS

CLEANING INTERNAL AND EXTERNAL AIR FILTERS 1. Remove the upper 4 bolts of the luggage box and bracket (1).

2. Remove the lower 2 bolts of the luggage box and raise box (2) to remove.

3. Loosen wing bolt (3), move stopper (4), and pull up internal air filter (5) to remove. Pull external air filter (6) aside (to the left of the chassis) to remove.

4. Clean filters (5) and (6) with compressed air. If they are coated with oil or stained badly, wash them in neutral detergent. After washing them in water, dry them up. s If the filters are clogged so badly that they can-

not be cleaned with air or water, replace them.

52-16 (5)

Air conditioner

TROUBLESHOOTING

TROUBLESHOOTING TAKAHASHI WORKS Electric circuit diagram of air conditioner................................................................................................. 52- 102 Wiring diagram related to air conditioner................................................................................................. 52- 104 Flowchart of troubleshooting ................................................................................................................... 52- 108

Air conditioner

52-101 (5)

TROUBLESHOOTING

ELECTRIC CIRCUIT DIAGRAM OF AIR CONDITIONER

ELECTRIC CIRCUIT DIAGRAM OF AIR CONDITIONER

52-102 (5)

Air conditioner

TROUBLESHOOTING

Air conditioner

ELECTRIC CIRCUIT DIAGRAM OF AIR CONDITIONER

52-103 (5)

TROUBLESHOOTING

WIRING DIAGRAM RELATED TO AIR CONDITIONER

WIRING DIAGRAM RELATED TO AIR CONDITIONER *

The actual locations of the Hi, Mid, and Lo blower relays may be different from this drawing. Accordingly, when carrying out troubleshooting, see the color symbols of the wiring harnesses in the electric circuit diagram of the air conditioner and take care not to mistake the relays.

1. Servomotor for internal air and external air 2. Hi blower relay 3. Mid blower relay 4. Lo blower relay Reference: The above figure is seen from front upper part of the chassis.

52-104 (5)

Air conditioner

TROUBLESHOOTING

WIRING DIAGRAM RELATED TO AIR CONDITIONER

1. Thermistor amplifier 2. Power supply relay 3. Hot water selector motor valve 4. Blower motor 5. Servomotor for blow mode Reference: The above figure is seen from front upper part of the chassis.

Air conditioner

52-105 (5)

TROUBLESHOOTING

1. 2. 3. 4. 5. 6. 7.

Wiring harness on chassis side Thermistor amplifier Servomotor for internal air and external air Hi blower relay Mid blower relay Lo blower relay Blower resistor

52-106 (5)

WIRING DIAGRAM RELATED TO AIR CONDITIONER

8. 9. 10. 11. 12. 13.

Blower motor Air conditioner panel Pressure cutout switch Servomotor for blow mode Servomotor for automatic damper Power supply relay

Air conditioner

TROUBLESHOOTING

Air conditioner

WIRING DIAGRAM RELATED TO AIR CONDITIONER

52-107 (5)

M-26(a) WIRING DIAGRAM RELATED TO AIR CONDITIONER

TROUBLESHOOTING

M-26. Air conditioner does not operate * Carry out the following troubleshooting when the battery and battery relay are normal. * Before carrying out the following troubleshooting, check that fuses 3 and 5 are normal. * Before carrying out the following troubleshooting, check that all the related connectors are properly inserted. * Always connect any disconnected connectors before going on to the next step. a) Air does not come out

YES

YES 2 YES Are internal and external air filters clogged?

3 When air conditioner NO panel is replaced, does air come out? • Turn starting switch ON. • Turn Hi, Mid, and Lo switches ON in order. • Turn air conditioner switch ON.

1 Is resistance between fuse 3-M26 (female) (2), fuse 5-M26 (female) (5), and M26 (female) (6)chassis ground normal? • Max. 1Ω • Turn starting switch OFF. • Disconnect M26 and fuses 3 and 5.

6 Is there continuity YES between blower resistor (2)-(5), (6)-(1), 5 and (6)-(4)? Is voltage between YES power supply relay (4) and chassis ground 4 normal? Is resistance of each air conditioner wiring NO harness as shown in Table 1? • Turn starting switch OFF.

• 24 V • Turn starting switch ON. • Turn air conditioner switch ON.

• Turn starting switch OFF. • Disconnect blower resistor.

NO

NO

NO

52-108 (5)

Air conditioner

TROUBLESHOOTING

WIRING DIAGRAM RELATED TO AIR CONDITIONER M-26(a)

Cause

(

Clogging of filters See TESTING AND ADJUSTING, Cleaning internal and external air filters of air conditioner

10 YES Is there continuity 9 YES between blower resistor (1) and (2)? Is voltage between YES Lo blower relay (4) and chassis ground • Turn starting switch NO 8 normal? OFF. Is voltage between • Disconnect blower • 24 V YES Mid blower relay (4) motor. • Turn starting switch ON. and chassis ground NO • Turn air conditioner normal? 7 switch ON. • 24 V Is voltage between Hi • Turn Lo switch ON. YES blower relay (4) and • Turn starting switch ON. chassis ground nor• Turn air conditioner NO mal? switch ON. • Turn Mid switch ON. • 24 V • Turn starting switch ON. NO • Turn air conditioner switch ON. • Turn Hi switch ON. NO

Remedy

)

Clean or replace

Defective air conditioner panel

Replace

Defective air conditioner unit

Replace

Defective blower motor

Replace

Defective Lo blower relay

Replace

Defective Mid blower relay

Replace

Defective Hi blower relay

Replace

Defective blower resistor

Replace

Replace Defective power supply relay

Air conditioner

Defect of defective contact in related wiring harness

Replace

Disconnection or defective contact in wiring harness between fuse 3-M26 (female) (2), fuse 5-M26 (female) (5), or M26 (female) (6)-chassis ground

Repair or replace

52-109 (5)

TROUBLESHOOTING

M-26(a) WIRING DIAGRAM RELATED TO AIR CONDITIONER

Table 1 Terminals of both ends of wiring harness to be measured M26 (male) (5) - power supply relay (female) (1)

M26, power supply relay

M26 (male) (5) - Hi blower relay (female) (3)

M26, Hi blower relay

M26 (male) (5) - Mid blower relay (female) (3)

M26, Mid blower relay

M26 (male) (5) - Lo blower relay (female) (3)

M26, Lo blower relay

M26 (male) (5) - air conditioner panel (female) (11) M26 (male) (6) - air conditioner panel (female) (1)

M26, air conditioner panel

M26 (male) (2) - blower resistor (female) (5)

M26, blower resistor

M26 (male) (6) - blower motor (female) (2)

M26, blower motor

Blower motor (female) (1) - blower resistor (female) (6)

Blower motor, blower resistor

Blower motor (female) (1) - Hi blower relay (female) (4)

Blower motor, Hi blower relay

Blower resistor (female) (2) - power supply relay (female) (2)

Blower resistor, power supply relay

Blower resistor (female) (2) - Hi blower relay (female) (2)

Blower resistor, Hi blower relay

Blower resistor (female) (1) - Mid blower relay (female) (4) Blower resistor (female) (2) - Mid blower relay (female) (2) Blower resistor (female) (2) - Lo blower relay (female) (2) Blower resistor (female) (4) - Lo blower relay (female) (4)

Resistance

Connector to be disconnected

Max. 1Ω

Blower resistor, Mid blower relay Blower resistor, Lo blower relay

Power supply relay (female) (3) - air conditioner panel (female) (6)

Power supply relay, air conditioner panel

Hi blower relay (female) (1) - air conditioner panel (female) (15)

Hi blower relay, air conditioner panel

Mid blower relay (female) (1) - air conditioner panel (female) (5)

Mid blower relay, air conditioner panel

Lo blower relay (female) (1) - air conditioner panel (female) (16)

Lo blower relay, air conditioner panel

52-110 (5)

Air conditioner

TROUBLESHOOTING

Air conditioner

WIRING DIAGRAM RELATED TO AIR CONDITIONER

52-111 (5)

M-26(b) WIRING DIAGRAM RELATED TO AIR CONDITIONER

TROUBLESHOOTING

b) Air comes out but it is not cold Notes) 1. If troubleshooting item 5 cannot be judged, carry out troubleshooting item 6 or call the electric device manufacturer. 2. If the result of troubleshooting item 6 is abnormal, carry out troubleshooting further, referring to Troubleshooting with gauge manifold. YES

1 Is condenser clogged or are fins bent down?

4 YES Is compressor belt tension normal?

3

• Referring to operation manual, test compressor belt tension.

YES Does compressor clutch click?

2

NO

Is voltage between M34 and chassis ground normal?

• Turn starting switch ON. • Turn air conditioner switch ON.

• 24 V • Turn starting switch ON. • Turn air conditioner switch ON.

NO

NO

52-112 (5)

Go to A in page 52-114.

Air conditioner

M-26(b) WIRING DIAGRAM RELATED TO AIR CONDITIONER

TROUBLESHOOTING

Cause

Remedy

Clogging of condenser or bending of fins YES

6 YES

Only pressure on high pressure side is high

Only pressure on high pressure side is low

Only pressure on low pressure side is high NO Only pressure on low pressure side is low

5 YES

Is quantity of refrigerant in receiver tank normal? • Referring to section of checking refrigerant, check refrigerant level visually.

-

Go to item 1 or call electric device manufacturer

Is refrigerant pressure normal? • Referring to section of checking refrigerant, measure refrigerant pressure.

Clean or replace

Both pressures on high and low sides are high

(

Both pressures on high and low sides are low

Too much refrigerant

Entry of air, too much refrigerant, or clogging of condenser

Evacuate, discharge refrigerant, and clean

Insufficient refrigerant, defective compressor, or defective piping on low pressure side (flattening or clogging)

Charge with refrigerant or replace

Defective air conditioner unit or too much refrigerant

Replace or discharge refrigerant

Insufficient refrigerant, defective air conditioner unit, or defective piping on low pressure side

Charge with refrigerant or replace

)

Discharge refrigerant

Insufficient refrigerant See TESTING AND ADJUSTING, Procedure for charging with refrigerant Insufficient refrigerant (See TESTING AND ADJUSTING, Procedure for charging with refrigerant)

(

)

Charge with refrigerant

(

Too much refrigerant See TESTING AND ADJUSTING, Procedure for discharging refrigerant

)

Discharge refrigerant

Too much refrigerant See TESTING AND ADJUSTING, Procedure for discharging refrigerant

NO

Insufficient refrigerant

NO

Air conditioner

Insufficient refrigerant See TESTING AND ADJUSTING, Procedure for charging with refrigerant Insufficient refrigerant (See Procedure for charging with refrigerant)

Charge with refrigerant

Defective adjustment of compressor belt (See operation manual)

Adjust

Defective compressor

Replace

52-113 (5)

M-26(b) WIRING DIAGRAM RELATED TO AIR CONDITIONER

TROUBLESHOOTING

YES

11

8 YES

When air conditioner YES panel is replaced, is air cooled?

10

• Turn starting switch ON. • Turn air conditioner switch ON.

Is voltage between power YES supply relay (4) and chassis ground normal? 9

7

Is resistance between M26 (female) (3) and M34 (female) normal?

A

NO

Is resistance of each air conditioner wiring harness as shown in Table 1?

• 24 V • Turn starting switch ON. • Turn air conditioner switch ON.

Is resistance between pressure cutout switch (1) and (2) normal? • Max. 1Ω • Turn starting switch ON. • Turn air conditioner switch ON. • Disconnect pressure cutout switch.

NO

• Turn starting switch OFF.

• Max. 1Ω • Turn starting switch OFF. • Disconnect M26 and M34.

NO

NO

52-114 (5)

Air conditioner

M-26(b) WIRING DIAGRAM RELATED TO AIR CONDITIONER

TROUBLESHOOTING

Cause

12 When thermistor ampliYES fier is replaced, is air cooled?

Defective air conditioner panel

Replace

Defective thermistor amplifier

Replace

YES

Defective hot water selector motor valve

Replace

NO

Defective air conditioner unit

Replace

Defective pressure cutout switch

Replace

Defective power supply relay

Replace

Defect or defective contact in related wiring harness

Repair or replace

Disconnection or defective contact in wiring harness between M26 (female) (3) M34 (female)

Repair or replace

YES

13

When hot water selec• Turn starting switch tor motor valve is ON. NO replaced, is air cooled? • Turn air conditioner switch ON.

NO

Air conditioner

• Turn starting switch ON. • Turn air conditioner switch ON.

Remedy

52-115 (5)

TROUBLESHOOTING

M-26(b) WIRING DIAGRAM RELATED TO AIR CONDITIONER

Table 1 Terminals of both ends of wiring harness to be measured

Connector to be disconnected

M26 (male) (3) - Pressure cutout switch (female) (2)

M26, pressure cutout switch

M26 (male) (6) - Thermistor amplifier (female) (3)

M26, thermistor amplifier

Blower resistor (female) (2) - Power supply relay (female) (2)

Blower resistor, power supply relay

Power supply relay (female) (4) - Thermistor amplifier (female) (4)

Power supply relay, thermistor amplifier

Thermistor amplifier (female) (2) - Pressure cutout switch (female) (1)

Thermistor amplifier, pressure cutout switch

Hot water selector motor valve (female) (1) - Air conditioner panel (female) (18) Hot water selector motor valve (female) (2) - Air conditioner panel (female) (8) Hot water selector motor valve (female) (3) - Air conditioner panel (female) (19) Hot water selector motor valve (female) (4) - Air conditioner panel (female) (20)

Resistance

Max. 1Ω

Hot water selector motor valve, air conditioner panel

Hot water selector motor valve (female) (5) - Air conditioner panel (female) (10)

52-116 (5)

Air conditioner

M-26(b) WIRING DIAGRAM RELATED TO AIR CONDITIONER

TROUBLESHOOTING

Troubleshooting from gauge pressure •

You can detect a defect in the refrigerating cycle by checking the high and low pressure pointers of the gauge manifold. [Condition] * Warm up the engine, and then check under the following condition. Item

Condition

Door Temperature control Blower speed EXTERNAL/INTERNAL air Engine speed Air conditioner suction temperature and condenser suction temperature Air conditioner switch

Open full Max. Hi INTERNAL 1,500rpm 30fC-35fC ON

1. Air conditioner is normal Pressure on low 0.15-0.25MPa{1.5-2.5kg/cm2} pressure side Pressure on high 1.37-1.57MPa{14-16kg/cm2} pressure side

2. Refrigerant is insufficient Pressure on low pressure side

0.05-0.1MPa{0.5-1.0kg/cm2}

Pressure on high pressure side

0.69-0.9MPa{7-10kg/cm2}

Check and remedy point

Phenomenon

Cause

1.Both pressures on high and low sides are low

• Insufficiency of refrigerant

• Check and repair leaking part.

• Leakage of refrigerant

• Add refrigerant.

2.Bubbles pass through liquid eye constantly 3.Blown air temperature is not low

Air conditioner

• If pressure indicated when gauge is connected is near 0, check and repair leaking part, and then evacuate circuit.

52-117 (5)

M-26(b) WIRING DIAGRAM RELATED TO AIR CONDITIONER

TROUBLESHOOTING

3. Circuit is charged with too much refrigerant or condenser is not cooled sufficiently Pressure on low 0.25-0.35MPa{2.5-3.5kg/cm2} pressure side Pressure on high 1.96-2.45MPa{20-25kg/cm2} pressure side Phenomenon

Cause

1. Both pressures on high and low sides are high

• Too much refrigerant • Insufficient cooling of condenser

2.Even when engine speed is low, no bubbles are seen. 3.Air is not cooled sufficiently

Check and remedy point • Check quantity of refrigerant. • Adjust quantity of refrigerant properly. • Check and repair condenser fins. • Check CHASSIS COOILNG SYSTEM, Fan and radiator, etc.

4. Compressor does not compress normally Pressure on low pressure side

0.4-0.6MPa{4.0-6.0kg/cm2}

Pressure on high pressure side

0.69-0.98MPa{7-10kg/cm2}

Phenomenon

Cause

1.Pressure on low pressure side is high and that on high pressure side is low 2.Just after air conditioner is turned OFF, pressures on high and low pressure sides become the same

• Defective compressor

Check and remedy point • Replace compressor. Reference: If compressor does not compress normally

5. Expansion valve is opened too wide Pressure on low pressure side

0.3-0.4MPa{3.0-4.0kg/cm2}

Pressure on high 1.96-2.45MPa{20-25kg/cm2} pressure side Phenomenon

Cause

1. Both pressures on high and low sides are high

• Defective expansion valve

2. Piping on low pressure side is frosted (or coated with dew)

52-118 (5)

Check and remedy point • Check expansion valve. • Check installation condition of heat sensor tube. Reference: This trouble occurs after expansion valve is replaced in many cases.

Air conditioner

TROUBLESHOOTING

WIRING DIAGRAM RELATED TO AIR CONDITIONER M-26

6. Air is in cycle Pressure on low 2 pressure side 0.25-0.35MPa{2.5-3.0kg/cm } Pressure on high 1.96-2.45MPa{20-25kg/cm2} pressure side Phenomenon 1.Both pressures on high and low sides are high 2.Low-pressure piping is not cold 3.Bubbles pass through liquid eye

Cause • Entry of air

Check and remedy point • Replace refrigerant.

• After finishing work, evacuate cycle securely.

7. Refrigerant does not circulate (Cycle is clogged) Pressure on low pressure side

Negative pressure

Pressure on high pressure side

0.5-0.6MPa{5-6kg/cm2}

Phenomenon

Cause

1. If cycle is clogged fully, negative pressure is indicated soon on low pressure side 2. If cycle is clogged a little, negative pressure is indicated gradually on low pressure side

• Clogging of air conditioner cycle

Check and remedy point • Check receiver, expansion valve, and compressor. Reference: Temperatures at IN and OUT sides of defective part are different. • After finishing work, evacuate cycle securely.

8. Water is in cycle • When normal Pressure on low 0.15-0.25MPa{1.5-2.5kg/cm2} pressure side Pressure on high 2 pressure side 1.37-1.57MPa{14-16kg/cm } • When abnormal Pressure on low pressure side

Negative pressure

Pressure on high pressure side

0.69-0.98MPa{7-10kg/cm2}

Phenomenon

Cause

1. Air conditioner operates normally when it is started. After a while, however, negative pressure is indicated on low pressure side.

• Freezing of water around expansion valve

Air conditioner

Check and remedy point • Check expansion valve, etc. • Replace receiver drier • After finishing work, evacuate cycle securely.

52-119 (5)

M-26(c) WIRING DIAGRAM RELATED TO AIR CONDITIONER

TROUBLESHOOTING

c) Internal air and external air cannot be selected

Cause

Remedy

YES

Defective air conditioner panel

Replace

Defective servomotor for internal air and external air

Replace

Defective linkage or defective air conditioner unit

Adjust or replace

Defect or defective contact in related wiring harness

Repair or replace

1

When air conditioner panel is replaced, can internal air and external air be selected?

3

When servomotor for interYES nal air and external air is 2 • Turn starting switch replaced, can internal air and Is resistance of each ON. external air be selected? air conditioner wiring • Turn air conditioner switch ON. harness as shown in • Change EXTERNAL/ NO Table 1? INTERNAL air changeover switch between EXTERNAL and INTERNAL positions.

YES

NO

• Turn starting switch OFF. NO

Table 1 Terminals of both ends of wiring harness to be measured Servomotor for internal air and external air (female) (1) - Air conditioner panel (female) (17) Servomotor for internal air and external air (female) (2) - Air conditioner panel (female) (13) Servomotor for internal air and external air (female) (3) - Air conditioner panel (female) (3)

52-120 (5)

Connector to be disconnected

Resistance

Servomotor for internal air and external air, air conditioner panel

Max. 1Ω

Air conditioner

TROUBLESHOOTING

WIRING DIAGRAM RELATED TO AIR CONDITIONER M-26(d,e)

d) Air outlet cannot be selected

Cause

Remedy

YES

Defective air conditioner panel

Replace

Defective servomotor for blow mode

Replace

Defective linkage or defective air conditioner unit

Adjust or replace

Defect or defective contact in related wiring harness

Repair or replace

1 3

When air conditioner panel is replaced, can air outlet be selected?

When servomotor YES for blow mode is replaced, can air • Turn starting switch outlet be selected? 2 ON. Is resistance of each • Turn starting switch ON. • Turn air conditioner air conditioner wiring • Turn air conditioner switch ON. switch ON. • Set air outlet selec- NO harness as shown in • Set air outlet selecTable 1? tor switch to FACE and FOOT.

YES

NO

tor switch to FACE and FOOT.

• Turn starting switch OFF. NO

Table 1 Terminals of both ends of wiring harness to be measured Servomotor for blow mode (female) (1) - Air conditioner panel (female) (7) Servomotor for blow mode (female) (2) - Air conditioner panel (female) (4) Servomotor for blow mode (female) (3) - Air conditioner panel (female) (14)

Connector to be disconnected

Resistance

Servomotor for internal air and external air, air conditioner panel

Max. 1Ω

e) Air flow rate does not change

1

YES

Is resistance between Hi and Mid blower relay (2) and (4) normal? • Min. 1ΜΩ • Turn starting switch OFF. • Disconnect related blower relay.

Air conditioner

NO

Cause

Remedy

Defective air conditioner panel

Replace

Melting of contacts between related blower relay (2) - (4)

Replace

52-121 (5)

TROUBLESHOOTING

52-122 (5)

WIRING DIAGRAM RELATED TO AIR CONDITIONER

Air conditioner

STRUCTURE AND FUNCTION

STRUCTURE AND FUNCTION SANDEN Basic system of air, heater, and cooler...................................................................................................... 61- 3 Control panel ............................................................................................................................................. 61- 7 Compressor, condenser, and receiver drier............................................................................................... 61- 9

Air conditioner

61-1 (5)

STRUCTURE AND FUNCTION

61-2 (5)

SANDEN

Air conditioner

STRUCTURE AND FUNCTION

BASIC SYSTEM OF AIR, HEATER, AND COOLER

1. BASIC SYSTEM OF AIR, HEATER, AND COOLER

1. 2. 3. 4. 5. 6. 7.

Air conditioner unit Control panel Condenser Air conditioner piping Compressor Receiver drier Engine coolant piping

a. To engine b. From engine

Outline This system is an air conditioner unit which consists of a evaporator, heater core, blower, etc. and blows out cold air and hot air. • In heating mode Air in the cab is sucked in through the suction opening and heat-exchanged (heated) in the heater core of the air conditioner unit, and then blown out through the duct and grille. The heat source of the heater core is the engine coolant. The blow temperature is adjusted with the temperature adjustment switch on the control panel. If the temperature adjustment switch is operated, the water valve of the air conditioner unit opens or closes to adjust the engine coolant flow rate, or adjust the temperature. • In cooling mode Air in the cab is sucked in through the suction opening and heat-exchanged (dehumidified and cooled) in the evaporator of the air conditioner unit, and then blown out through the duct and grille.

Air conditioner

61-3 (5)

STRUCTURE AND FUNCTION

BASIC SYSTEM OF AIR, HEATER, AND COOLER

1-1. Detail of air conditioner unit

61-4 (5)

Air conditioner

STRUCTURE AND FUNCTION

BASIC SYSTEM OF AIR, HEATER, AND COOLER

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.

41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52.

25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40.

Unit fixing frame Packing Packing Bell mouth Blower case Blower and blower motor assembly Motor fixing plate Packing Unit panel Bracket Packing Packing Wiring harness assembly Band Packing Spacer Intake damper Spring Lever knob Sensor holder Thermistor Evaporator Expansion valve Outlet and inlet pipe assembly (Equipped with dual pressure switch) Packing Resistor Packing Packing Packing External air intake duct EXTERNAL/INTERNAL air changeover lever Heater core and evaporator mounting bracket Heater core Hose clamp Heater hose Hose packing Bracket Bracket Water valve assembly Heat insulation material

Air conditioner

Packing Unit bottom plate Drain fitting Packing Packing Grommet Unit fixing frame Packing Grommet Unit case Packing Packing

61-5 (5)

STRUCTURE AND FUNCTION

BASIC SYSTEM OF AIR, HEATER, AND COOLER

1-2. Component parts in air conditioner unit (Parts related to control) Resistor The resistor outputs signals according to the position of the blower switch to change the fan motor speed of the blower.

Thermistor The thermistor senses the blow-out temperature of the evaporator, outputs signals, and turns the compressor ON and OFF to prevent the evaporator from freezing. It is installed to the outlet side of the evaporator.

Dual pressure switch When the refrigerant pressure on the high pressure side becomes abnormal, the dual pressure switch outputs a signal to turn the compressor OFF to protect the refrigerating cycle. This switch is installed to the high-pressure piping side of the outlet and inlet pipe assembly. This switch is turned OFF when the refrigerant pressure is below 0.1MPa {2.0 kg/cm2} or above 3.1MPa {32 kg/cm2}.

61-6 (5)

Air conditioner

STRUCTURE AND FUNCTION

CONTROL PANEL

2. CONTROL PANEL

1. 2. 3. 4. 5. 6. 7. 8.

Band Air conditioner relay Knob Air conditioner switch Nameplate Case Air flow selector switch (Blower switch) Temperature adjustment switch (Thermal control knob) 9. Bracket 10. Control amplifier

Outline The control panel compares and calculates the input signals of various switches and sensors with the microcomputer of the control amplifier in it and controls the water valve actuator, blower motor, and compressor.

2-1. Operation unit of panel 1. Temperature adjustment switch 2. Air flow selector switch 3. Air conditioner switch

Air conditioner

61-7 (5)

STRUCTURE AND FUNCTION

CONTROL PANEL

2-2. Component parts in control box Temperature adjustment switch (Thermal control knob) If the knob of the temperature adjustment switch is turned, the ON-OFF operation point of the air conditioner compressor and the opening ratio of the water valve change. As a result, the temperature of the air from the evaporator and heater core changes. Consequently, the temperature of the air blown out from the air conditioner unit changes.

Air conditioner switch If this switch is pressed while the air flow selector switch is turned ON, the compressor operates according to the position of the temperature adjustment switch and blow-out temperature of the evaporator.

Air flow selector switch (Blower switch) If the knob of the air flow selector switch is turned, the air flow from the air conditioner unit is stopped or set to 3 levels.

Compressor relay The compressor relay turns the compressor ON and OFF according to the setting of the control amplifier and electronic thermal control system.

61-8 (5)

Air conditioner

STRUCTURE AND FUNCTION

COMPRESSOR, CONDENSER, AND RECEIVER DRIER

3. COMPRESSOR, CONDENSER, AND RECEIVER DRIER

1. 2. 3. 4. 5. 6. 7. 8.

Air conditioner piping (Low pressure) Air conditioner piping (High pressure) Condenser Air conditioner piping (High pressure) Bracket Receiver drier Air conditioner piping (High pressure) Compressor

Outline The refrigerant gas returned from the evaporator is compressed by the compressor and its temperature and pressure rise. Then, it is sent to the condenser and cooled and liquefied there. Dirt and water in the refrigerant liquid are removed by the receiver drier. Then, the refrigerant liquid is sent through the expansion valve to the evaporator and evaporated there.

a. From air conditioner unit (evaporator) b. To air conditioner unit (evaporator)

Air conditioner

61-9 (5)

STRUCTURE AND FUNCTION

61-10 (5)

COMPRESSOR, CONDENSER, AND RECEIVER DRIER

Air conditioner

TROUBLESHOOTING

TESTING AND ADJUSTING SANDEN Troubleshooting ........................................................................................................................................ 62-101

Air conditioner

62-1 (5)

TROUBLESHOOTING

62-2 (5)

Air conditioner

TROUBLESHOOTING

TROUBLESHOOTING SANDEN Information in troubleshooting table ......................................................................................................... 62-102 Air conditioner is defective........................................................................................................................ 62-103 Related electric circuit diagram ................................................................................................................ 62-107

Air conditioner

62-101 (5)

TROUBLESHOOTING

INFORMATION IN TROUBLESHOOTING TABLE

INFORMATION IN TROUBLESHOOTING TABLE s The following information is summarized in the troubleshooting table and the related electrical circuit dia-

gram. Before carrying out troubleshooting, understand that information fully.

User code

Error code

Failure code

Panel display

Panel display

Panel display

Trouble

Trouble name displayed in trouble record

Contents of trouble Condition at the time when the monitor panel or controller detects the trouble Action of monitor The action taken by the monitor panel or controller to protect the system or devices when the panel or controller monitor panel or controller detects the trouble Problem that The problem that appears on the machine as a result of the action taken by the monitor panel appears on or controller (shown above) machine Related information Information related to the detected trouble or troubleshooting Cause

Standard value in normal state/Remarks on troubleshooting • Standard value in normal state to judge possible causes • Remarks on judgment

1

2

Possible causes and standard value 3 in normal state

(

Possible causes of trouble Given numbers are reference numbers, which do not indicate priority

)

• Disconnection Connector is connected imperfectly or harness is broken. • Grounding fault Harness which is not connected to chassis ground circuit is in contact with chassis ground circuit. • Short circuit with power source Harness which is not connected to power source (24-V) circuit is in contact with power source (24-V) circuit.

4

5

62-102 (5)

Air conditioner

TROUBLESHOOTING

AIR CONDITIONER IS DEFECTIVE

AIR CONDITIONER IS DEFECTIVE a) Air conditioner does not operate User code

Error code

Failure code

-

-

-

Trouble

Air conditioner is defective a) Air conditioner does not operate

Contents of trouble • The air conditioner does not operate. Action of monitor panel or controller Problem that appears on machine • Check that the fuse is not broken and the wiring harness between connectors is free of disconnection in advance. Related information • If the air conditioner switch is turned ON but no air comes out when the air flow selector switch (blower switch) is turned ON (set in position 1, 2, or 3), carry out troubleshooting for "b) Air does not come out or air flow does not change" in advance. Cause

Standard value in normal state/Remarks on troubleshooting

s Prepare with starting switch OFF, then carry out trouble-

shooting without turning starting switch ON.

1

Defective air conditioner switch

Air conditioner switch connector C-D

Possible causes and standard value in normal state

2

3

Disconnection in wiring harness (Disconnection in wiring harness or defective contact in connector) Short circuit with chassis ground in wiring harness (Contact with ground circuit)

Switch position

Resistance

ON

Max. 1Ω

OFF

Min. 1MΩ

s Prepare with starting switch OFF, then carry out trouble-

shooting without turning starting switch ON.

Referring to the circuit diagram, check continuity between connectors.

Resistance

Max. 1Ω

s Prepare with starting switch OFF, then carry out trouble-

shooting without turning starting switch ON.

Referring to the circuit diagram, check insulation between each connector and ground (excluding ground circuit).

ResisMin. 1MΩ tance

s Prepare with starting switch OFF, then turn starting switch

ON and carry out troubleshooting.

4

Air conditioner

Defective control amplifier

Replace with normal control amplifier.

Condition becomes normal Condition does not become normal

Control amplifier is defective Control amplifier is normal

62-103 (5)

TROUBLESHOOTING

AIR CONDITIONER IS DEFECTIVE

b) Air does not come out or air flow does not change User code Error code Failure code Air conditioner is defective Trouble b) Air does not come out Contents of trouble • Air does not come out or air flow does not change Action of monitor panel or controller Problem that appears on machine Related information • Check that the fuse is not broken and the wiring harness between connectors is free of disconnection in advance. Cause

Possible causes and standard value in normal state

62-104 (5)

1

Defective air flow selector switch (blower switch)

2

Defective resistor

3

Defective blower motor

4

Disconnection in wiring harness (Disconnection in wiring harness or defective contact in connector)

5

Short circuit with chassis ground in wiring harness (Contact with ground circuit)

6

Defective control amplifier

Standard value in normal state/Remarks on troubleshooting

s Prepare with starting switch OFF, then carry out trouble-

shooting without turning starting switch ON. Knob position Resistance Air flow selector switch terminal 0 Min. 1MΩ Between all terminals Max. 1Ω Between B - L/R, B - L/W, and L/R - L/W 1 Min. 1MΩ Between terminals other than above Max. 1Ω Between B - L/R, B - L/Y, and L/R - L/Y 2 Min. 1MΩ Between terminals other than above Max. 1Ω Between B - L/R, B - L/B, and L/R - L/B 3 Min. 1MΩ Between terminals other than above s Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Resistor terminals Resistance Between L and M1 Approx. 1.8Ω Between M1 and M2 Approx. 0.7Ω Between M2 and M0 Approx. 0.3Ω s Prepare with starting switch OFF, then turn starting switch ON and carry out troubleshooting. Blower motor is Condition Replace with defective becomes normal normal blower Blower motor is Condition does not motor normal become normal s Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Referring to the circuit diagram, check ResisMax. 1Ω continuity between connectors. tance s Prepare with starting switch OFF, then carry out trouble-

shooting without turning starting switch ON. Referring to the circuit diagram, check Resisinsulation between each connector and tance Min. 1MΩ ground (excluding ground circuit). s Prepare with starting switch OFF, then turn starting switch ON and carry out troubleshooting. Condition Control ampliReplace with becomes normal fier is defective normal control Condition does not Control ampliamplifier become normal fier is normal

Air conditioner

TROUBLESHOOTING

AIR CONDITIONER IS DEFECTIVE

c) Blow-out temperature cannot be adjusted User code

Error code

Failure code

-

-

-

Trouble

Air conditioner is defective c) Blow-out temperature cannot be adjusted

Contents of trouble • The blow-out temperature cannot be adjusted. Action of monitor panel or controller Problem that appears on machine Check that hot water is supplied to the inlet side of the water valve in advance. Related information •• Check that the fuse is not broken and the wiring harness between connectors is free of disconnection in advance. Cause

1

Defective temperature adjustment switch

2

Defective water valve assembly

3

Disconnection in wiring harness (Disconnection in wiring harness or defective contact in connector)

4

Short circuit with chassis ground in wiring harness (Contact with ground circuit)

5

Defective control amplifier

Possible causes and standard value in normal state

Air conditioner

Standard value in normal state/Remarks on troubleshooting

s Prepare with starting switch OFF, then turn starting switch ON and turn

blower switch ON (Set it in 1, 2, or 3) and carry out troubleshooting. Voltage Temperature adjustment switch connector (2) Changes between G/B-G/W 0 and approx. 5 V Changes between G/B-Y/B 0 and approx. 5 V G/B-Y/W Approx. 5V s Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Temperature adjustment switch Knob position Resistance connector (2) (Switch side) COOL-MAX m Middle position Approx. 2.3kΩm Max. 1Ω Y/W-Y/B Max. 1Ω Middle position m HOT-MAX COOL-MAX m Middle position Approx. 2.3kΩ Y/W-G/W Middle position m HOT-MAX Approx. 2.3kΩm Max. 1Ω s Prepare with starting switch OFF, then turn starting switch ON and turn blower switch ON (Set it in 1, 2, or 3) and carry out troubleshooting. Operation Rod operates according to operation of temperature adjustment switch s Prepare with starting switch OFF, then turn starting switch ON and carry out troubleshooting. Replace with normal Condition becomes normal Water valve assembly is defective water valve assembly Condition does not become normal Water valve assembly is normal s Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Referring to the circuit diagram, check continu- Resisity between connectors. tance Max. 1Ω s Prepare with starting switch OFF, then carry out trouble-

shooting without turning starting switch ON. Referring to the circuit diagram, check insulation between Resis- Min. 1MΩ tance each connector and ground (excluding ground circuit). s Prepare with starting switch OFF, then turn starting switch ON and carry out troubleshooting. Condition becomes normal Control amplifier is defective Replace with normal control amplifier Condition does not become normal Control amplifier is normal

62-105 (5)

TROUBLESHOOTING

AIR CONDITIONER IS DEFECTIVE

d) Air is not cooled or temperature cannot be adjusted (Electrical system) User code

Error code

-

Failure code

-

-

Trouble

Air conditioner is defective d) Air is not cooled or temperature cannot be adjusted (Electrical system)

Contents of trouble • Air is not cooled or temperature cannot be adjusted (Electrical system). Action of monitor panel or controller Problem that appears on machine Related information

• When the ambient temperature is below 2fC, this phenomenon does not indicate a trouble. • Check that the fuse is not broken and the wiring harness between connectors is free of disconnection in advance. Cause 1

Defective compressor clutch

2

Defective dual pressure switch

3

Defective air conditioner switch

4

Defective compressor relay

5

Defective thermistor

6

Disconnection in wiring harness (Disconnection in wiring harness or defective contact in connector)

7

Short circuit with chassis ground in wiring harness (Contact with ground circuit)

8

Defective control amplifier

Possible causes and standard value in normal state

62-106 (5)

Standard value in normal state/Remarks on troubleshooting

s Prepare with starting switch OFF, then turn starting switch

ON and carry out troubleshooting. Between (12) and chassis ground Voltage 10-15V s Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Resis- Max. 1Ω Dual pressure switch connector tance s Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Air conditioner switch Switch position Resistance connector ON Max. 1Ω C-D OFF Min. 1MΩ s Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Compressor relay connector (1)-(2)

Resistance Approx. 320Ω

Source voltage Resistance between (1) and (2) Applied Max. 1Ω (3)-(4) Not applied Min. 1MΩ s Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Thermistor connector Test temperature Resistance 0fC Approx. 7.2kΩ B/W-B/R 25fC Approx. 2.2kΩ s Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Referring to the circuit diagram, check ResisMax. 1Ω continuity between connectors. tance s Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Referring to the circuit diagram, check Resisinsulation between each connector and Min. 1MΩ tance ground (excluding ground circuit). s Prepare with starting switch OFF, then turn starting switch ON and carry out troubleshooting. Condition Control amplifier is defective Replace with becomes normal normal control Condition does not Control amplifier is normal amplifier become normal Compressor relay connector

Air conditioner

TROUBLESHOOTING

AIR CONDITIONER IS DEFECTIVE

Related electric circuit diagram

Air conditioner

62-107 (5)

TROUBLESHOOTING

AIR CONDITIONER IS DEFECTIVE

e) Air is not cooled sufficiently (Mechanical system) User code

Error code

-

Failure code

-

-

Trouble

Air conditioner is defective e) Air is not cooled sufficiently (Mechanical system)

Contents of trouble • Air is not cooled sufficiently because of a trouble in the mechanical system. Action of monitor panel or controller Problem that appears on machine Related information Cause 1

Refrigerant leakage through piping joint or part

• Check, then repair or replace if necessary.

2

Natural leakage through hoses (Refrigerant has not been added for long period)

• Check quantity of refrigerant, then add new refrigerant if necessary.

3

Insufficient refrigerant

• Add refrigerant to proper level.

4

Defective expansion valve

• Check, then repair or replace if necessary. s Check expansion valve for opening too wide and check heat sensor tube for defective contact.

5

Clogging of low-pressure circuit or evaporator

• Check for clogging, then clean or replace.

6

Clogging of evaporator fins

• Check for clogging, then clean evaporator if necessary.

Clogging of filter

• Check, then clean or replace.

Defective installation of thermistor

• Check, then repair or replace if necessary.

9

Air leakage through joint of air conditioner unit and duct

• Check, then repair or replace leaking part.

10

Insufficient set air flow rate

• Increase set air flow rate.

11

Too much refrigerant

• Check quantity of refrigerant, then discharge refrigerant to proper level if necessary.

12

Entry of air

• Evacuate cycle, then charge it with refrigerant to proper level and replace receiver drier.

13

Clogging of condenser fins

• Check for clogging, then clean fins if necessary.

14

Defective compression by compressor

• Check, then repair or replace.

15

Water in refrigerant circuit

• Evacuate cycle, then charge it with refrigerant to proper level and replace receiver drier.

Possible 7 causes and standard value in normal state 8

62-108 (5)

Standard value in normal state/Remarks on troubleshooting

Air conditioner

TROUBLESHOOTING

AIR CONDITIONER IS DEFECTIVE

f) Air is not heated sufficiently (Hot water circuit is defective) User code Error code Failure code Air conditioner is defective Trouble f) Air is not heated sufficiently (Hot water circuit is defective) Contents of trouble Air is not heated sufficiently (Hot water circuit is defective). Action of monitor panel or controller Problem that appears on machine • Check that water is not leaking through the hot water circuit. Related information • Check that air if blown from air outlet. Cause 1

Clogging of heater core fins

2

Air leakage through air conditioner unit

Possible causes and standard value 3 in normal state

Defective water valve (clogging, defective valve)

4

Clogging of heater core

5

Clogging before hot water inlet of heater core

Standard value in normal state/Remarks on troubleshooting • Check heater core fins for clogging. If clogged, clean them. s If this is the cause, the temperature of the heater core hot water inlet is high and that of the heater core hot water outlet is also high. • Check the air conditioner unit for air leakage, then repair or replace if necessary. s If this is the cause, the temperature of the heater core hot water inlet is high and that of the heater core hot water outlet is also high. • Check the water valve for clogging of defect in the valve, then clean or replace it. s If this is the cause, the temperature of the heater core hot water inlet is high but that of the heater core hot water outlet is low. • Check inside of the heater core for clogging, then repair or replace it if necessary. s If this is the cause, the temperature of the heater core hot water inlet is high but that of the heater core hot water outlet is low. • Check the piping before the heater core for clogging, then repair or replace if necessary. s If this is the cause, the temperature of the heater core hot water inlet is low.

g) Abnormal sound comes out User code Contents of trouble Action of monitor panel or controller Problem that appears on machine Related information

Error code Failure code • Abnormal sound comes out. -

Air conditioner is defective g) Abnormal sound comes out

-

1 2 Possible 3 causes and standard value in normal state 4 5 6 7

Air conditioner

Trouble

Cause Defective installation of case mounting bolts (screws) Interference of fan case, etc. or breakage of fan Foreign matter in blower motor or defective blower motor Defective expansion valve Loosened or worn compressor belt Too much or insufficient refrigerant Defective compressor

Standard value in normal state/Remarks on troubleshooting • Check, then repair if necessary. • Check, then repair or replace if necessary. • Check, then remove foreign matter and repair or replace if necessary. • Check, then replace if abnormal sound (blowing sound or hiss of refrigerant) is detected. • Check, then repair or replace if looseness or wear is detected. • Check the quantity of the refrigerant. If it is too much or insufficient, adjust it properly. • Check, then repair or replace if necessary.

62-109 (5)

TROUBLESHOOTING

AIR CONDITIONER IS DEFECTIVE

h) Water leaks User code

Error code

Failure code

-

-

-

Trouble

Air conditioner is defective h) Water leaks

Contents of trouble • Water leaks. Action of monitor panel or controller Problem that appears on machine Related information Cause 1

Clogging of water drain hole in air conditioner unit

• Check, then repair if necessary.

2

Clogging, bending, defective installation, or hole of drain hose of air conditioner unit

• Check, then repair or replace if necessary.

Cracking of air conditioner unit case

• Check, then repair or replace if any crack is detected.

4

Defective mounting bolts (screws) of air conditioner unit case

• Check, then repair or replace if necessary.

5

Development pipe joints of hot water circuit

• Check, then repair or replace if necessary.

6

Defective heater core

• Check, then repair or replace if necessary.

7

Defective water valve

• Check, then repair or replace if necessary.

Possible causes and standard value 3 in normal state

62-110 (5) (5)

Standard value in normal state/Remarks on troubleshooting

Air conditioner

TROUBLESHOOTING

AIR CONDITIONER IS DEFECTIVE

i) Internal air and external air cannot be selected User code

Error code

-

Failure code

-

-

Trouble

Air conditioner is defective i) Internal air and external air cannot be selected

Contents of trouble • Internal air and external air cannot be selected. Action of monitor panel or controller Problem that appears on machine Related information Cause 1

Possible causes and standard value in normal state 2 3

Air conditioner

Standard value in normal state/Remarks on troubleshooting

Malfunction of external/internal air changeover lever

• Check, then clean and repair or replace if necessary.

Malfunction of intake damper

• Check, then clean and repair or replace if necessary.

Clogging of external air intake duct of unit

• Check, then clean if necessary.

62-111 (5) (5)

TROUBLESHOOTING

62-112 (5)

AIR CONDITIONER IS DEFECTIVE

Air conditioner

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY AND ASSEMBLY SANDEN Disassembly, assembly of air conditioner unit .......................................................................................... 63-

2

Disassembly, assembly of control panel....................................................................................................63- 11

Air conditioner

63-1 (5)

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY, ASSEMBLY OF AIR CONDITIONER UNIT

DISASSEMBLY, ASSEMBLY OF AIR CONDITIONER UNIT

63-2 (5)

Air conditioner

DISASSEMBLY AND ASSEMBLY

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. 39. 40.

DISASSEMBLY, ASSEMBLY OF AIR CONDITIONER UNIT

Unit fixing frame Packing Packing Bell mouth Blower case Blower and blower motor assembly Motor fixing plate Packing Unit panel Bracket Packing Packing Wiring harness assembly Band Packing Spacer Intake damper Spring Lever knob Sensor holder Thermistor Evaporator Expansion valve Outlet and inlet pipe assembly (Equipped with dual pressure switch) Packing Resistor Packing Packing Packing External air intake duct EXTERNAL/INTERNAL air changeover lever Heater core and evaporator mounting bracket Heater core Hose clamp Heater hose Hose packing Bracket Bracket Water valve assembly Heat insulation material

Air conditioner

41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52.

Packing Unit bottom plate Drain fitting Packing Packing Grommet Unit fixing frame Packing Grommet Unit case Packing Packing

63-3 (5)

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY, ASSEMBLY OF AIR CONDITIONER UNIT

DISASSEMBLY 1. Remove external/internal air changeover lever (31). 2. Remove unit fixing frame (1). 3. Remove bracket (10) and unit panel (9) from unit case (50).

4. Remove wiring harness assembly (13). 5. Remove blower case (5) from unit case (50).

6. Remove bell mouth (4) from blower case (5).

7. Remove motor fixing plate (7) from blower case (5). 8. Remove clip (53) and fan (54). s Remove fan (54) stamped with R. 9. Pull blower and blower motor assembly (6) out of blower case (5).

63-4 (5)

Air conditioner

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY, ASSEMBLY OF AIR CONDITIONER UNIT

10. Remove unit bottom plate (42) and packing (41) from unit case (50).

11. Remove evaporator, expansion valve, and outlet/inlet pipe assembly (55). s Take care not to damage wiring harness (57).

12. Disassemble the evaporator, expansion valve, and outlet/inlet pipe assembly into evaporator (22), expansion valve (23), and outlet/inlet pipe assembly (24).

13. Remove 2 sensor holders (20) from evaporator (22). 14. Remove thermistor (21) from sensor holder (20).

Air conditioner

63-5 (5)

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY, ASSEMBLY OF AIR CONDITIONER UNIT

15. Remove grommets (49). 16. Remove heater hose (35). 17. Remove brackets (37) and (38) and heater core (33).

18. Remove water valve assembly (39) from unit case (50).

63-6 (5)

Air conditioner

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY, ASSEMBLY OF AIR CONDITIONER UNIT

ASSEMBLY 1. Install water valve assembly (39) to unit case (50).

2. Install heater core (33) and secure it with brackets (37) and (38).

3. Install heater hose (35). s Install hose clamp (34) securely. s Install heater hose (35) so that part "a" will be in parallel.

4. Install grommets (49) to outlet and inlet of the heater pipe. 5. Install thermistor (21) to sensor holder (20). s Install the thermistor so that only sensor unit (56) will be projected to the side of sensor holder (20). 6. Install sensor holder (20) to evaporator (22). s Install the sensor holder so that sensor unit (56) of the thermistor will be set as shown in the following figure. Distance a: 130 mm from end of fine Distance b: 210 mm from end of evaporator (19th fin)

Air conditioner

63-7 (5)

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY, ASSEMBLY OF AIR CONDITIONER UNIT

7. Install expansion valve (23) and outlet/inlet pipe assembly (24) to evaporator (22).

8. Install evaporator, expansion valve, and outlet/ inlet pipe assembly (55). s Put wiring harness (57) on water valve assembly (39) side.

9. Install packing (41) and unit bottom plate (42) to unit case (50).

10. Install blower and blower motor assembly (6) to blower case (5). 11. Install fan (54) to the motor shaft and secure it with clip (53). s Check that there is the a stamp of R on fan (54). 12. Install motor fixing plate (7) to blower case (5) and secure blower and blower motor assembly (6). s Tighten 2 bolts a first.

63-8 (5)

Air conditioner

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY, ASSEMBLY OF AIR CONDITIONER UNIT

s Install blower and blower motor assembly (6)

so that wiring harness (58) and motor cooling hole (59) will be set as shown in the following figure.

s Install the blower and blower motor assembly

so that clearance a between fan (55) and blower case (5) will be as follows. Clearance a: 4 v0.5 mm

13. Install bell mouth (4) to blower case (5).

14. Install blower case (5). s Set the blower case diagonally as shown in the following figure, and then push in the part marked with the arrow to install. s Pass wiring harness (58) through part a in advance.

Air conditioner

63-9 (5)

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY, ASSEMBLY OF AIR CONDITIONER UNIT

15. Connect wiring harness assembly (13) to each part in the unit. 16. Install unit panel (9) to unit case (50). s Fix the grommet of wiring harness assembly (13) to the cut of part a. 17. Install bracket (10).

18. Install unit fixing frame (1). 19. Install external/internal air changeover lever (31).

63-10 (5) (5)

Air conditioner

DISASSEMBLY AND ASSEMBLY

DISASSEMBLY, ASSEMBLY OF CONTROL PANEL

DISASSEMBLY, ASSEMBLY OF CONTROL PANEL

1. 2. 3. 4. 5.

Band Air conditioner relay Knob Air conditioner switch Nameplate

6. 7. 8. 9. 10.

Case Air flow selector switch (Blower switch) Temperature adjustment switch (Thermal control knob) Bracket Control amplifier

DISASSEMBLY

ASSEMBLY

1. Remove knob (3). 2. Remove air flow selector switch (blower switch) (7) and temperature adjustment switch (thermal control knob) (8). 3. Hold the stopper claws and remove air conditioner switch (4). 4. Remove bracket (9) and control amplifier (10) together. s Do not give an impact to these parts. 5. Remove air conditioner relay.

1. Install air conditioner relay (2). 2. Install bracket (9) and control amplifier (10) together. 3. Push air conditioner switch (4) straight into case (6) to install. 4. Install air flow selector switch (blower switch) (7) and temperature adjustment switch (thermal control knob) (8). 5. Install knob (3). s Check that you can operate the control panel smoothly.

Air conditioner

63-11 (5) (5)

STRUCTURE AND FUNCTION

STRUCTURE AND FUNCTION ZEXEL VALEO (NEW REFRIGERANT (R134a) TYPE) Comparison of applicable models and air conditioner units .................................................................... 71-

2

Configuration and functions of refrigerating cycle ................................................................................... 71-

3

Outline of refrigerating cycle.................................................................................................................... 71-

4

Outline of main parts................................................................................................................................ 71-

6

Outline of control system ......................................................................................................................... 71- 10

Air conditioner

71-1 (6)

COMPARISON OF APPLICABLE MODELS AND AIR STRUCTURE AND FUNCTIONCOMPARISON OF APPLICABLE MODELS AND AIR CONDITIONER UNITS CONDITIONER UNITS

COMPARISON OF APPLICABLE MODELS AND AIR CONDITIONER UNITS Note 1) Many machine models are equipped with air conditioners as shown below. For troubleshooting for different models, different wiring harness connectors are checked. The air conditioner units and control units are basically the same, however. Note 2) Some air conditioner units have different configurations, depending on the serial No. and type (automatic or manual) as shown below. They are basically the same, however. The automatic air conditioners for PC78US-6 and PC128US-2 are used as examples for the following explanation. • Applicable models Standard machine models described in this manual Other hydraulic excavator models (Having the same connectors) 1 Other hydraulic excavator models for which this manual can be used for reference a Wiring harnesses are unknown Other models for which this manual can be used for reference a Wiring harnesses are unknown Part No. of air conditioner unit 2 Specification •

PC78US-6 PC78US-6 PC78US-6 S/No. 4001 - 6500 S/No. 6501 and up S/No. 6501 and up PC128US-2 PC128US-2 PC128US-2 S/No. 7301 - 9500 S/No. 9501 and up S/No. 9501 and up PC78UU-6 PC78UU-6 PC78UU-6 PC138US-2 PC138US-2 PC138US-2 PC308US-3

PC228US-3

PC308US-3

CD110R-2

-

GD655-3

22B-979-1660 Common to automatic and manual types

22U-979-1730

22U-979-1720

Special to automatic type

Special to manual type

Comparison of air conditioner units

Common to Special to Special to automatic and automatic type manual type manual types Different part Part name Part No. Part No. Part No. Contents 1 Case assembly 534136-9921 534138-6620 534138-6620 Eliminate lining 2 534136-9321 534138-6720 534138-6720 from case and wind onto evapora3 Evaporator assembly 503700-4760 503700-4770 503700-4770 tor 4 Pipe assembly 534057-3720 535237-9220 535237-9220 Add sight glass Common to automatic and 5 Wiring harness 536021-6501 536021-6501 536022-3500 3 manual types 6 Sensor (Internal air) 582623-8500 582623-8500 Eliminated 7 Bracket 534102-6000 534102-6000 Eliminated 8 Tapping screw 012514-1640 012514-1640 Eliminated Sensor (Water temperature) 582623-1800 582623-1800 Eliminated 9 10 Clip 580529-7000 580529-7000 Eliminated 11 Screw 012155-1440 012155-1440 Eliminated 12 Insulator 583032-2300 583032-2300 Eliminated Specification

71-2 (6)

Air conditioner

STRUCTURE AND FUNCTION

CONFIGURATION AND FUNCTIONS OF REFRIGERATING CYCLE

CONFIGURATION AND FUNCTIONS OF REFRIGERATING CYCLE Component Compressor

Condenser

Expansion valve

Evaporator

Under operator's seat (In air conditioner unit) Makes refrigerant liquid and gas of low temperature which can evaporate easily and controls flow rate.

Under operator's seat (In air conditioner unit) Evaporates refrigerant to absorb heat from (or cool) air around evaporator.

Item Location

Function

Front of radiator in many cases Circulates refrigerant Condenses refrigerant gas and increases its to discharge heat temperature and absorbed in evaporator. pressure so that it can be liquefied easily in condenser. Engine compartment

(Compression of refrigerant) State of refrigerant

Gas

Gas

Adiabatic compression

(Condensation of refrig- (Restriction of refriger- (Evaporation of refrigerant) ant) erant) Gas

Liquid

Constant pressure change

Liquid

Liquid Gas

Adiabatic expansion

Liquid Gas

Gas

Constant pressure change

6249

Air conditioner

71-3 (6)

STRUCTURE AND FUNCTION

OUTLINE OF REFRIGERATING CYCLE

OUTLINE OF REFRIGERATING CYCLE The refrigerating cycle performs the following 4 actions and the refrigerant is liquefied and gasified repeatedly while it is circuited in the cycle.

1. Compression (Compressor) The refrigerant gas is compressed by the compressor to the state where it can be liquefied easily at the normal temperature (ambient temperature). The refrigerant evaporated in the evaporator is sucked in the compressor. This action is performed to keep the refrigerant pressure in the evaporator low so that the refrigerant liquid can continue evaporation actively even if the ambient temperature is close to 0°C. The refrigerant gas sucked in the compressor is compressed in the cylinder and its pressure and temperature are so changed that it can be liquefied easily when it is cooled with the external air at the normal temperature.

2. Condensation (Condenser) The refrigerant gas in the condenser is cooled to be liquefied with the external air. The refrigerant gas of high temperature and high pressure discharged from the compressor is cooled to be liquefied with the external air and then stored in the receiver drier. The heat discharged from the refrigerant of high temperature and high pressure discharged from the compressor is called the condensation heat, which is the total of the heat that the refrigerant absorbed from the operator's cab through the evaporator (vaporization heat) and the work performed to compress the refrigerant (the value converted into heat). During condensation, the refrigerant gas and refrigerant liquid are mixed together in the condenser. While the refrigerant gas changes to the refrigerant liquid, the relationship between the pressure (condensation pressure) and temperature (condensation temperature) is kept constant.

3. Expansion (Expansion valve) The pressure of the refrigerant liquid is lowered by the restricting action of the expansion valve to a level at which the refrigerant is evaporated easily. The action to lower the pressure of the refrigerant to a level at which the refrigerant is evaporated easily before the refrigerant is sent to the evaporator is called expansion. The expansion valve which performs this action also controls the flow rate of the refrigerant. In other words, the quantity of the refrigerant liquid evaporated in the evaporator is decided by the quantity of heat to be removed (refrigeration load) at the specified evaporation temperature (evaporation pressure), and the expansion valve senses it and controls the refrigerant flow rate properly. [* 1] Restriction If there is a sharply narrowed part in a pipe in which a liquid is flowing, it is resistance to the flow. Since the sectional area is increased sharply after this part, the liquid expands quickly and its pressure and temperature lower. No heat is exchanged between the inside and outside of the pipe during this action.

4. Evaporation (Evaporator) The refrigerant changes from liquid to gas (superheated vapor) in the evaporator. The refrigerant mist in the evaporator evaporates actively. At this time, the refrigerant evaporates quickly, absorbing heat necessary for evaporation (latent heat of vaporization) from the air around the cooling fins (air in the operator's cab). The cooled air is spread in the operator's cab by the fan to lower the temperature in the operator's cab.

Reference: The pressure varies with the type of the refrigerant and condensation temperature.

71-4 (6)

Air conditioner

STRUCTURE AND FUNCTION

The refrigerating cycle performs theOF following 4 actions and the OUTLINE REFRIGERATING CYCLE

The refrigerant mist sent through the expansion valve and the evaporated refrigerant are mixed together in the evaporator. While the refrigerant liquid changes to the refrigerant gas, the relationship between the pressure (evaporation pressure) and temperature (evaporation temperature) is kept constant. If the pressure is set, the temperature is decided automatically. That is, the relationship between the above pressure and temperature is equal to the relationship between saturation pressure and saturation temperature. To evaporate the refrigerant at lower temperature, the pressure in the evaporator must be kept lower. Accordingly, the evaporated refrigerant is sucked in the compressor. The refrigerant circulates in the refrigerating cycle, repeating the above 4 actions, to move the heat from the operator's cab where the temperature is low to the outside where the temperature is high.

Air conditioner

71-5 (6)

STRUCTURE AND FUNCTION

OUTLINE OF MAIN PARTS

OUTLINE OF MAIN PARTS 1. Compressor assembly 1) Compressor The compressor is of swash plate type. The swash plate is installed to the shaft. The rotary motion of the shaft is converted into the reciprocating motion to suck, compress, and discharge the refrigerant. 2) Magnet clutch The magnet clutch is used to drive or stop the compressor while the engine is running. While the compressor is not driven, only the pulley is revolving. When the compressor is driven, a current flows in the field coil to make a strong electromagnet, which attracts the drive plate to rotate the compressor shaft and the pulley together. 3) Relief valve (Installed to only PC1238US-2) When the pressure in the compressor exceeds the set pressure of the relief pressure, the relief valve opens to discharge the refrigerant. If the pressure lowers, the relief valve closes.

9JS01940

2. Condenser The condenser is of parallel flow type. The refrigerant gas of high temperature and high pressure sent from the compressor is cooled to be liquefied with the cooling fan of the engine. a PC128US-2 has a sub-cool condenser made one with the receiver drier.

9JS01941

3. Receiver drier The receiver drier is of aluminum flat head type. The receiver drier has the following functions. q The receiver drier stores the refrigerant to operate the cooling cycle smoothly. q The receiver drier removes dirt and water from the refrigerant. q Flowing condition of the refrigerant is seen through the sight glass. q If the temperature of the cycle rises for some reason, the lead at the center of the fusible plug melts and the refrigerant is discharged out to secure the safety.

71-6 (6)

6250

Air conditioner

STRUCTURE AND FUNCTION

•

OUTLINE OF MAIN PARTS

The main parts under the operator's seat are roughly classified into air conditioner unit (1), intake duct (2), and mode duct (3).

9JS01943

4. Intake duct (2) The intake duct selects the external air or internal air to be sucked in the fan motor of the air conditioner unit. Filter (4) is installed to the air outlet side of the intake box to remove dust from the external air and internal air and supply clean air to the air conditioner unit. The intake duct includes the intake actuator and intake door.

5. Mode duct (3) The mode duct changes the flow of the air cooled with the evaporator of the air conditioner unit, air heated with the heater core, or mixture of the cooled air and heated air to each air outlet. There are 3 selectable positions and the operator can select a favorite flow with the control panel. The mode duct includes the mode actuator and mode door.

6. Air conditioner unit (1) The air conditioner unit includes the blower motor, evaporator, heater core, mix door, and internal air filter (5). Its piping has the pressure switch for protection and the sight glass to check the refrigerant. It is thin and compact and has a connecting hole to take in external air. Air conditioner

71-7 (6)

STRUCTURE AND FUNCTION

1) Expansion valve The expansion valve is of internal equal pressure type. The expansion valve converts the high pressure refrigerant liquid sent from the receiver drier into low pressure refrigerant mist by restricting action and sends it to the evaporator. The expansion valve also adjusts the refrigerant flow rate automatically according to the variable thermal load. 2) Evaporator The evaporator is of serpentine type. The refrigerant mist made by the expansion valve evaporates actively in the evaporator and its temperature lowers. The air in the operator's cab is sucked in the fan and passed and cooled through the evaporator. 3) Thermostat The thermostat senses the temperature of the cooled air just after it is blown out of the evaporator and turns the compressor OFF before the evaporator is frozen. a If the thermostat does not touch the evaporator, it cannot sense the temperature and cooling does not stop. As a result, evaporator is frosted and air flow rate is lowered.

OUTLINE OF MAIN PARTS

6251

6252

4) Pressure switch The pressure switch senses abnormally low or high pressure and turns the compressor OFF. k When replacing the pressure switch, collect the refrigerant in advance.

6253

71-8 (6)

Air conditioner

STRUCTURE AND FUNCTION

Pressure

OUTLINE OF MAIN PARTS

Between terminals

Max. approx. 0.177 MPa {1.8 kg/cm2}, Min. approx. There is not continuity 2.65 MPa {27 kg/cm2} Between approx. 0.177 and 2.65 MPa {1.8 - 27 kg/cm2}

There is continuity

5) Fan motor A sirocco fan is used to lower the noise.

9JS01947

6) Heater core The hot water from the engine cooling water (hot) outlet flows in the heater core, where it heats the air sent by the fan motor.

9JS01948

Air conditioner

71-9 (6)

STRUCTURE AND FUNCTION

OUTLINE OF CONTROL SYSTEM

OUTLINE OF CONTROL SYSTEM The control panel is installed to the top of the control unit. It receives various signals and indicates them with the LED and controls the air conditioner unit, actuators of 3 types, and compressor.

9JS02164

71-10 (6)

Air conditioner

STRUCTURE AND FUNCTION

• •

OUTLINE OF CONTROL SYSTEM

Configuration of control panel and air conditioner unit The relationship between the switches on the control panel (top of the control unit) and the actuators of the air conditioner unit is shown by [1] - [5] in the following figures. Control panel a The control panel shown below is for the automatic air conditioner.

6254

•

Configuration of air conditioner unit

6255

Air conditioner

71-11 (6)

TESTING AND ADJUSTING

TESTING AND ADJUSTING ZEXEL VALEO (NEW REFRIGERANT (R134a) TYPE) List of tools for testing, adjusting, and trouble shooting ......................................................................... 72-

2

Inspection and maintenance table for air conditioner ............................................................................ 72-

3

Inspection and maintenance table for heater ........................................................................................ 72-

4

Inspection with self-diagnosis function .................................................................................................. 72-

5

Outline ....................................................................................................................................... 72-

5

Self-diagnosis procedure ........................................................................................................... 72-

6

Step 1 inspection of display unit and display led ...................................................................... 72-

7

Step 2 inspection of each sensor and actuator ........................................................................ 72-

8

Step 3 display of past troubles ................................................................................................. 72-

9

Step 4 inspection of each output device ................................................................................... 72- 10 Step 5 set temperature correcting function .............................................................................. 72- 11 Inspecting temperature adjustment (air mix door and mix actuator) ..................................................... 72- 12 Inspecting selection of air outlet (mode door and mode actuator) ......................................................... 72- 13 Inspecting selection of intake (intake door and intake actuator) ............................................................ 72- 13 Inspecting relays .................................................................................................................................... 72- 14 Checking for refrigerant leakage ........................................................................................................... 72- 15 Charging with refrigerant ....................................................................................................................... 72- 18 Handling refrigerant can and compressor oil ......................................................................................... 72- 19 Precautions for connecting air conditioner piping .................................................................................. 72- 22

Air conditioner

72-1 (6)

LIST OF TOOLS FOR TESTING, ADJUSTING, AND TROUBLELIST OF TOOLS FOR TESTING, ADJUSTING, AND TROUBLESHOOTING SHOOTING

TESTING AND ADJUSTING

LIST OF TOOLS FOR TESTING, ADJUSTING, AND TROUBLESHOOTING Testing and adjusting item

Symbol

Part No.

Part name

1 799-703-1200 Service tool kit Measuring refrigerant pressure in air conditioner, charging with refrigerant, and discharging refrigerant

799-703-1100 Vacuum pump N 2 799-703-1111 Vacuum pump 799-703-1121 Vacuum pump

Leakage of refrigerant

72-2 (6)

O

799-703-1400 Gas leak tester

Remarks For new refrigerant R134a For new refrigerant R134a in Japan (100 V) For new refrigerant R134a in overseas countries (220 V) For new refrigerant R134a in overseas countries (240 V) For countries other than USA

Air conditioner

TESTING AND ADJUSTING

INSPECTION AND MAINTENANCE TABLE FOR AIR INSPECTION AND MAINTENANCE TABLE FOR AIR CONDITIONER CONDITIONER

The air conditioner (cooler/heater) needs "periodic inspection and maintenance" (there is a charge for it) for constant use under the best condition.

If the air conditioner has a trouble, much repair cost is required. Accordingly, recommend that the customer should take periodic inspection and maintenance.

INSPECTION AND MAINTENANCE TABLE FOR AIR CONDITIONER No.

Inspection item

Contents of inspection

Maintenance

Inspection/Maintenance period (interval) 6 12 24 36 months months months months

1 Start and stop

Flow of cold air

Q

2 Refrigerant and pressure

Quantity of refrigerant and gauge pressure

Q

3 Condenser

Stain and clogging

4 Condenser fan motor

Operating condition

5 Belt

Tension, flaw, and deterioration Adjust or replace

Q

6 Air filter

Stain, clogging, and removal Adjust or replace

aQ

7 Clean or replace

Stain, clogging, and removal Adjust or replace

aQ

8 Piping and its connections

Refrigerant leakage

Clean

Q

Q

leakage, loose9 Cycle parts and their mounting parts Refrigerant ness, and breakage between cycle parts Clearance 10 Clearance and machine parts

aQ

Q Secure clearance

Q

If defective, replace

Q

11 Pressure switch

OFF when high pressure is above 2,648 kPa {27 kg/cm2G} OFF when high pressure is below 176 kPa {1.8 kg/cm2G}

12 Compressor

Operating condition

Q

w

13 Valve of compressor

Breakage

Q

w

14 Bearing of compressor

Q

w

15

Q

16 17 18

Operating condition (Abnormal sound) Operating condition and wear Magnet clutch of attracting surface Operating condition (AbnorBearing of magnet clutch mal sound) Operating condition (AbnorTension pulley mal sound) High pressure and low pressure hoses Flaw, deterioration, and breakage

Q Q Q

19 Air conditioner unit (Evaporator) Stain, clogging, and breakage If clogged, disassemble

Q

20 Electric parts and their wiring Operating condition and breakage

Q

21 Receiver drier

Clogging and breakage

22 Expansion valve

Operating condition

Q

q Q w

23 Compressor assembly a Daily inspection. Q Inspection. w Disassembly. q Replacement

Advice qInspect the belt at intervals of 6 months or about 50 operating hours. qDirect the customer to inspect the items marked with a every day.

Air conditioner

72-3 (6)

TESTING AND ADJUSTING

INSPECTION AND MAINTENANCE TABLE FOR HEATER

INSPECTION AND MAINTENANCE TABLE FOR HEATER No.

Inspection item

Contents of inspection

Maintenance

Inspection/Maintenance period (interval) 6 months

1

Start and stop

Flow of hot air

Q

2

Engine coolant

Coolant level

Q

3

Piping and its connections

Water leakage and clamping condition Water leakage, looseness, and breakage

Q

4 5

Cycle parts and their mounting parts Clearance between cycle parts and machine parts

12 months

Q Q

Clearance

6

Heater hose

Flaw, deterioration, and breakage

Q

7

Fan motor

Operating condition

Q

8

Air conditioner unit (Heater core) Stain and clogging

9

Electric parts and their wiring

Operating condition and breakage

If clogged, disassemble

Q Q Q Inspection

72-4 (6)

Air conditioner

TESTING AND ADJUSTING

INSPECTION WITH SELF-DIAGNOSIS FUNCTION

INSPECTION WITH SELF-DIAGNOSIS FUNCTION 1. Outline •

There are steps 1 - 5 in the self-diagnosis. You can check each sensor (which is not installed to the air conditioner having only the manual mode) for trouble according to those steps. You can also output control signals specified for each output device and inspect the operation of the device (excluding the intake actuator). If a troubled section is detected, every part of that section must be inspected. Step 1 Step 2 Step 3 Step 4 Step 5

•

Starting self-diagnosis mode 1) Turn the air conditioner OFF. 2) While pressing the air conditioner switch and foot switch, turn the key switch from the OFF position to the START position to start the engine, and the self-diagnosis (step 1) starts. Note:

•

Inspection of display unit and display LED Inspection of each sensor and actuator (excluding intake actuator) Each sensor, mix actuator, and mode actuator are inspected in real time. Display of past troubles The recorded past troubles of each sensor, mix actuator, and mode actuator are displayed. Inspection of each output device The pattern operation of each output device is performed. Set temperature correcting function

If the battery voltage lowers below 24V during step 4, the operating speed of the actuator lowers. As a result, the actuator may be judged NG, even if it is operating normally. Accordingly, start the engine when performing the self-diagnosis.

Finishing self-diagnosis 1) Turn the key switch OFF. 2) Hold the OFF switch for 3 seconds.

a Selecting a step • Select step 1 - 5 with the fan switch.

6256(6)

Air conditioner

72-5 (6)

TESTING AND ADJUSTING

INSPECTION WITH SELF-DIAGNOSIS FUNCTION

2. Self-diagnosis procedure Outline

6257(7)

72-6 (6)

Air conditioner

TESTING AND ADJUSTING

INSPECTION WITH SELF-DIAGNOSIS FUNCTION

3. Step 1 Inspection of display unit and display LED The display LED of each switch on the panel is inspected. All of the LEDs flash in the following order. (Up to 6 LEDs flash simultaneously.) If normal, each LED is turned ON and OFF twice at intervals of 0.5 seconds in the flashing period. Display order of LED Note) -- means that LED is turned OFF. Display

Same operation is repeated

STEP 1

STEP 2

STEP 3

STEP 4

STEP 1

•••

A/C

Flashing

Flashing

Flashing

Flashing

Flashing

Flashing

Front/Rear vent

Flashing

--

--

--

Flashing

--

Rear vent

--

Flashing

--

--

--

Flashing

Foot

--

--

Flashing

--

--

--

AUTO

Flashing

Flashing

Flashing

Flashing

Flashing

Flashing

LO

Flashing

--

--

--

--

Flashing

ML

--

Flashing

--

--

--

--

MH

--

--

Flashing

--

--

--

HI

--

--

--

Flashing

--

--

TEMP 1

Flashing

--

--

--

Flashing

--

TEMP 2

--

Flashing

--

--

--

Flashing

TEMP 3

--

--

Flashing

--

--

--

TEMP 4

--

--

--

Flashing

--

--

TEMP 5

Flashing

--

--

--

Flashing

--

TEMP 6

--

Flashing

--

--

--

Flashing

TEMP 7

--

--

Flashing

--

--

--

TEMP 8

--

--

--

Flashing

--

--

LED

When normal:

All the display LEDs light up.

When abnormal:

The LED of a troubled section does not light up.

Is the display LED normal? YES > Go to step 2 NO

> Replace the control unit.

Air conditioner

72-7 (6)

TESTING AND ADJUSTING

INSPECTION WITH SELF-DIAGNOSIS FUNCTION

4. Step 2 Inspection of each sensor and actuator 1. Press the fan UP switch to select step 2. 2. During step 2, the front/rear vent LED flashes. After the inspection is finished, the front/rear vent LED lights up. When normal: Only front/rear vent LEDs lights up. When abnormal: Front/rear vent LEDs lights up and TEMP LED flashes. After operation is confirmed, each output returns to the initial position. How is the inspection result? OK

> Go to step 3

NG

> See the following

Inspection of troubled sensor and actuator If a sensor or an actuator is troubled, the TEMP LED corresponding to it flashes. If multiple sensors or actuators are troubled, the LED flashes twice at intervals of 0.5 seconds, and then the next trouble is displayed. Contents of display by LED Object of diagnosis

Location of display LED

Reference section

Mix actuator

TEMP 1

Inspecting temperature adjustment (Air mix door and mix actuator) (Page 72-12)

Mode actuator

TEMP 2

Inspecting selection of air outlet (Mode door and mode actuator) (Page 72-13)

Internal air sensor (* 1)

TEMP 3

Troubleshooting, How to inspect electric parts, internal air sensor (Page 73-8)

External air sensor (* 1)

TEMP 4

Troubleshooting, How to inspect electric parts, external air sensor (Page 73-8)

Water temperature sensor (* 1)

TEMP 5

Troubleshooting, How to inspect electric parts, water temperature sensor (Page 73-8)

Sunlight sensor (* 1)

TEMP 6

Troubleshooting, How to inspect electric parts, sunlight sensor (Page 73-8)

Caution: While the sunlight sensor is not exposed to the sunlight, a trouble is displayed. • Not installed to the air conditioner having only manual mode. (* 1) • The external air sensor is not installed to the automatic air conditioner of PC78US-6, either.

72-8 (6)

Air conditioner

TESTING AND ADJUSTING

INSPECTION WITH SELF-DIAGNOSIS FUNCTION

5. Step 3 Display of past troubles 1) Press the fan UP switch to select step 3. 2) During step 3, the front/rear vent LED flashes. After the inspection is finished, the front/rear vent LED lights up. If there is not a past trouble: Only front/rear vent LEDs lights up. If there is any past trouble: Front/rear vent LEDs lights up and TEMP LED flashes. How is the inspection result? OK

> Go to step 4

NG

> See the following

Inspection of past trouble of sensor and actuator If a sensor or an actuator has been troubled, the TEMP LED corresponding to it flashes. If multiple sensors or actuators have been troubled, the LED flashes twice at intervals of 0.5 seconds, and then the next trouble is displayed. Contents of display by LED Object of diagnosis

Location of display LED

Mix actuator

TEMP 1

Mode actuator

TEMP 2

Internal air sensor ( * 1 )

TEMP 3

External air sensor ( * 1 )

TEMP 4

Water temperature sensor ( * 1 )

TEMP 5

Sunlight sensor ( * 1 )

TEMP 6

Caution: As trouble of the sunlight sensor, only short circuit is recorded. • Not installed to the air conditioner having only manual mode. ( * 1 ) • The external air sensor is not installed to the automatic air conditioner of PC78US-6, either. How to delete past trouble record Hold the air conditioner switch for 3 seconds in step 3, and the past trouble record is deleted. At this time, the air conditioner LED flashes 5 times, and then it returns to the normal control mode. Each switch is initialized.

Air conditioner

72-9 (6)

TESTING AND ADJUSTING

INSPECTION WITH SELF-DIAGNOSIS FUNCTION

6. Step 4 Inspection of each output device 1) Press the fan UP switch to select step 4. 2) Each time the foot switch is pressed, TEMP LEDs light up one by one from the left to the right. 3) Inspect the air outlet, spurting air temperature, voltage applied to the blower fan motor, and operation of the compressor (magnet clutch). Same operation is repeated

STEP Objective device 1

2

3

4

TEMP 1

TEMP 2

TEMP 3

TEMP 4

Front/Rear vent

Rear vent

Rear vent

Foot

Opening ratio of air mix door

Full cool

50%

50%

Full heat

Voltage applied to blower fan motor

10V

14.5

19.5

Source voltage

Compressor (Magnet clutch)

ON

ON

ON

OFF

Lighting of LED Mode door

1 ••••

How is the inspection result? OK

> Finish self-diagnosis

NG

> • The air outlet does not change: See Inspecting selection of air outlet. (Mode door and mode actuator) • The spurting air temperature does not change: See Inspecting temperature adjustment. (Air mix door and mix actuator) • Defective operation of blower fan motor: See Troubleshooting table • Defective operation of compressor: See Troubleshooting table

72-10 (6)

Air conditioner

TESTING AND ADJUSTING

INSPECTION WITH SELF-DIAGNOSIS FUNCTION

7. Step 5 Set temperature correcting function (Function of setting difference between set temperature and control temperature) Outline When the set spurting air temperature is different from the sensory temperature, you can change the control temperature of the control unit from the set (displayed) temperature. Method 1) Select the self-diagnosis mode. 2) In self-diagnosis step 4, press the fan UP switch and AUTO switch simultaneously. 3) The temperature setting LEDs (2 pieces at the center) light up. 4) Each time the temperature setting switch (UP or DOWN) is pressed, a different temperature setting LED lights up and you can set the correction temperature freely between +2 °C and -2 °C.

6258(3)

Reference: If the correction temperature is set while the leftmost temperature setting LED (-2 °C) is lighting, the control unit controls the temperature to 25 °C - 2 °C = 23 °C. Accordingly, the actual temperature is controlled below the displayed temperature. Caution: If the negative terminal of the battery is disconnected or the battery voltage lowers below 20V, the difference between the set (displayed) temperature and control temperature is cancelled.

Air conditioner

72-11 (6)

INSPECTING TEMPERATURE ADJUSTMENT (AIR MIX DOOR TESTING AND ADJUSTING INSPECTING TEMPERATURE ADJUSTMENT (AIR MIX DOOR AND MIX ACAND MIX ACTUATOR)

INSPECTING TEMPERATURE ADJUSTMENT (AIR MIX DOOR AND MIX ACTUATOR) •

If a mix actuator error is detected by the self-diagnosis, inspect the mix actuator visually.

1. Remove operator's seat undercover (1). 2. Turn the starting switch ON (and start the engine) and operate the temperature setting switch of the control panel from the left end (FC) to the right end (FH) to see if levers 1 and 2 operate in 8 steps.

AJS01467

a If the result is NG, see Troubleshooting, E-4 Temperature cannot be adjusted

6254

•

Front side of air conditioner unit under operator's seat

9JS02169

72-12 (6)

Air conditioner

INSPECTING SELECTION OF AIR OUTLET (MODE DOOR AND MODE ACTUATOR)

TESTING AND ADJUSTINGINSPECTING SELECTION OFOFAIR OUTLET (MODE DOOR AND MODE ACTUINSPECTING SELECTION INTAKE (INTAKE DOOR AND INTAKE ACTUATOR)

INSPECTING SELECTION OF AIR OUTLET (MODE DOOR AND MODE ACTUATOR) • 1. 2. 3.

4. 5. a

If a mode actuator error is detected by the selfdiagnosis, inspect the mode actuator visually. Remove monitor panel under cover (1). Loosen right console (2) and move it inward, and then remove cover (3). Disconnect connector M88, move duct joint A in the direction of the arrow, and then remove mode duct (5) toward you (so that you can see inside) Connect connector M88 and turn the starting switch ON (and start the engine). Operate the mode switch of the control panel to see if mode door (4) operates normally. If the result is NG, see Troubleshooting, Troubleshooting for selection of air outlet (Mode door and mode actuator)

AJS01468

INSPECTING SELECTION OF INTAKE (INTAKE DOOR AND INTAKE ACTUATOR) •

Since selection of the intake cannot be inspected by the self-diagnosis, inspect it according to the following procedure. 1. Disconnect M83 from under the rear left of the operator's seat and remove intake duct (1). 2. Make the internal intake door visible, connect connector M83, and turn the starting switch ON (and start the engine). 3. Operate the intake switch of the control panel to see if the intake door operates normally. a If the result is NG, see Troubleshooting, Troubleshooting for selection of intake (intake door and intake actuator)

AJS01469

6254

Air conditioner

72-13 (6)

TESTING AND ADJUSTING

INSPECTING RELAYS

INSPECTING RELAYS a If the compressor revolves and air spurts to the maximum level, the relays are normal. Omit the following inspection, in this case. Inspect the relays of 3 types by sound. (If each relay is normal, it clicks when it is turned ON and OFF.) a Bring your ear close to each relay and hear it clicks. • • •

AJS01467

Air conditioner relay: Turning ON/OFF of compressor OFF relay: Turning ON/OFF of fan motor MAX HI relay: Turning ON when air flow is at maximum

1. Remove operator's seat undercover (1).

9JS02180

2. While the starting switch is turned OFF, disconnect pressure switch connector (I) and fan motor connector (O) (to prevent the compressor and fan motor from starting) 3. Turn the starting switch ON (Do not start the engine, however) and turned the air conditioner switch of the control panel ON/OFF to check that the relays make sound. a The air conditioner relay and OFF relay sounds independently, thus the sound is made twice. If the sound is made only once, turn the starting switch OFF and remove either relay to see with relay is broken. 4. Set the fan motor speed between the maximum and medium to check that the MAX HI relay makes sound.

72-14 (6)

Air conditioner

TESTING AND ADJUSTING

CHECKING FOR REFRIGERANT LEAKAGE

CHECKING FOR REFRIGERANT LEAKAGE Since refrigerant leakage has bad effects on the performance and durability of the air conditioner and global environment, it must be stopped immediately, if detected. Flow of checking for refrigerant leakage

6259(26)

1. Checking for refrigerant leakage Using a special gas leak detector for HFC-134a, check for refrigerant leakage. If any troubled part is found, repair it. In this case, repeat the procedure from the first step. k Caution Never use a CFC-12R (R-12) leak detector of halide torch type to check for refrigerant leakage. The leak detector of halide torch type detects CFC-12 leakage by reacting on chlorine contained in CFC-12. Since HFC-134a does not contain chlorine, the leak detector of halide type cannot detect it. In addition, if HFC-134a come in contact with flame, it is decomposed and poisonous gas is produced.

Air conditioner

6260(3)

72-15 (6)

TESTING AND ADJUSTING

Check for refrigerant leakage according to the following procedure. a Before starting the check, confirm that there is no refrigerant or smoke around the machine to prevent misjudgment of refrigerant leakage. Perform the check in a place where leaking refrigerant will not be blown off by wind. a Perform the check mainly on pipe joints and parts which are stained oil remarkably. If refrigerant leaks, internal oil always leaks, too.

CHECKING FOR REFRIGERANT LEAKAGE

•

When leakage is not detected by the ordinary check, operate the compressor for at least 5 minutes and then check the high pressure side similarly. a After the compressor is stopped, the high pressure lowers gradually. Refrigerant leakage from the high pressure side can be detected easily while the pressure is higher. Accordingly, operate the compressor. Immediately after stopping the engine, check the highpressure parts immediately for refrigerant leakage with the gas leak detector.

6261(2)

•

72-16 (6)

6262(2)

Air conditioner

TESTING AND ADJUSTING

•

CHECKING FOR REFRIGERANT LEAKAGE

Important parts to be checked for refrigerant leakage Part name

Check point

Compressor

Pipe joints Shaft seals Cylinder fitting parts

Condenser

Pipe joints Welded parts of body

Receiver drier

Pipe joints Dual pressure switch Fusible plug Around sight glass

Air conditioner unit

Pipe joints Expansion valve joints Brazed parts of evaporator

Remarks Check through clearance of magnet clutch

Check through hole for drain hose

Pipe joints Piping (Hoses and pipes) Caulked parts of hoses Hoses and pipes Service valve

Around service valve

Install a cap when checking

2. Adding refrigerant • Referring to 42-11, Connecting service tool prepared by DENSO CO., LTD. (New refrigerant specifica tion), connect the gauge manifold. • To make sure, perform 42-19, Checking with gauge manifold. • Add refrigerant. See 42-38, Charging with (Adding) refrigerant from low pressure side. kSince refrigerant is high-pressure gas, it must be handled by only designated persons. kIf refrigerant gets in your eyes, you may lose your sight. (Put on protective goggles.)

3. After adding refrigerant, perform the final refrigerant leakage test.

Air conditioner

72-17 (6)

TESTING AND ADJUSTING

CHARGING WITH REFRIGERANT

CHARGING WITH REFRIGERANT See 42-32, Charging with refrigerant (New refrigerant specification) prepared by DENSO CO., LTD k Since refrigerant is high-pressure gas, it must be handled by only designated persons.

k If refrigerant gets in your eyes, you may lose your sight. (Put on protective goggles.)

72-18 (6)

Air conditioner

TESTING AND ADJUSTING

HANDLING REFRIGERANT CAN AND COMPRESSOR OIL

HANDLING REFRIGERANT CAN AND COMPRESSOR OIL 1. Refrigerant can (HFC-134a) (For repair) a HFC-134a and R134a are the same material. Quantity of refrigerant

Part No.

200g

583200-0600

a The label and the adapter thread size of the refrigerant can valve are different from those of the CFC-12 can for distinction. 2. Precautions for storing and handling refrigerant can When handling the refrigerant can, observe the precautions printed on it. q Do not store the refrigerant can in place where the temperature is heightened above 40°C by the direct sunlight, fire, etc. q Be sure to store the refrigerant can in a dark and cool place. Do not corrode it. q Carry the minimum necessary quantity of refrigerant cans and keep them in a place where the temperature does not rise above 40°C.

9JS02187

kThe high-pressure gas is in the refrigerant can. If the can is stored in a hot place, its inside pressure rises and it may burst and can cause injury, frostbite, loss of sight, etc. q Never throw or hit the refrigerant can. (Do not roughly handle the package of the refrigerant can, either.) q If the refrigerant can has a flow, bruise, etc., do not use it.

kThe high-pressure gas is in the refrigerant can. If the can is handled wrongly, it may burst or the refrigerant may leak, and that can cause injury, frostbite, loss of sight, etc. q Do not put the refrigerant can in fire.

kDo not bring refrigerant in contact with flame. If refrigerant touches flame, it will be decomposed and poisonous gas will be produced. q Keep the refrigerant can off children.

Air conditioner

72-19 (6)

TESTING AND ADJUSTING

HANDLING REFRIGERANT CAN AND COMPRESSOR OIL

3. Control of compressor oil (ZXL-100PG: For HFC134a) Compressor oil does not need to be checked or added so frequently as engine oil. Insufficiency or excess of compressor oil can cause the following troubles, however. Accordingly, compressor oil must be supplied to the specified level, similarly to refrigerant. Check compressor oil in the following cases, and then add new oil if necessary. q At the beginning of the 2nd season. q When much refrigerant is discharged because of leakage. q When the compressor is troubled and replaced. q When a cycle parts such as the condenser, receiver drier, evaporator unit, etc. is replaced.

Condition Insufficiency of oil Excess of oil •

added Air conditioner part Quantity to be (cm3) Evaporator

Approx. 50

Condenser

Approx. 30

Receiver drier

Approx. 50

Hose/Pipe

Approx. 10

Item

5. Oil return operation Compressor oil is circulated in the air conditioner cycle together with refrigerant while the air conditioner is in operation. When checking the oil level or replacing a cycle part, you are required to return compressor oil in the piping and each component part to the compressor to minimize the quantity of oil lost during the replacement work. For this purpose, perform the "oil return operation" shown at right. a If it is impossible to perform the oil return operation (because of seizure, breakage, etc.), install a new compressor (link part, etc.) and perform the oil return operation. Then, remove the compressor again and drain the excessive oil.

72-20 (6)

Lubrication trouble and seizure of compressor Cooling trouble (Excessive oil stick to parts and lower heat exchange performance)

Quantity of oil to be added when cycle part is replaced

4. Procedure for checking (adding, replacing) oil level 1) Perform the oil return operation. 2) Collect refrigerant in the air conditioner cycle. [* 1] 3) Remove the compressor. 4) Check the oil level. 5) Add or replace oil. 6) Install the compressor. 7) Charge the air conditioner cycle with refrigerant. [* 2] [* 1] [* 2] TAKAHASHI WORKS CO., LTD., see page 52 - 3 to 15. kSince refrigerant is high-pressure gas, it must be handled by only designated persons. kIf refrigerant gets in your eyes, you may lose your sight. (Put on protective goggles.)

Contents

Condition value

Doors

Open all doors (OPEN)

Engine speed

Approx. 1,000 rpm

Blower fan motor

HI (Max. speed)

Air conditioner switch

ON (Operate compressor)

Operating time

Approx. 20 min

Air conditioner

TESTING AND ADJUSTING

HANDLING REFRIGERANT CAN AND COMPRESSOR OIL

6. Draining and adding compressor oil 1) Draining oil. Prepare an oil pan and drain oil. Measure the quantity of the drained oil with a measuring cylinder and set it as the 16quantity to be added. a The type (ZXL-100PG) and additional quantity of compressor oil are printed on the label stuck to the compressor.

2186(2)

2) Adding oil Add oil of the specified quantity (quantity measured with the measuring cylinder) through the port in the reverse order to draining. a If oil for CFC-12 (R-12) is used, lubrication trouble will occur and the compressor may be broken or seized. Be sure to use the specified oil (ZXL-100PG). a Oil for HFC-134a absorbs moisture very easily. Accordingly, fit the cap immediately after using oil to stop the atmosphere. Store the oil can in a dry and ventilated place.

2187(2)

a Precautions for using oil Oil for HFC-134a (ZXL-100PG in particular) may dissolve acrylic resin and polystyrene (excluding baked polystyrene paint film). Accordingly, do not stick oil to those plastics.

2188(2)

7. Compressor oil for applying piping When connecting a pipe or hose, apply oil (ZXL100PG) to its O-ring to prevent refrigerant leakage.

kWhen discarding a can which still has some oil in it, make a hole on it to discharge gas and oil.

Air conditioner

2189(2)

72-21 (6)

TESTING AND ADJUSTING

PRECAUTIONS FOR CONNECTING AIR CONDITIONER PIPING

PRECAUTIONS FOR CONNECTING AIR CONDITIONER PIPING q When connecting the piping, apply compressor oil to the O-rings. (See the previous page.) Do not apply oil to the threads of a nut or union, however. q Once an O-ring is used, it is deformed and deteriorated. Accordingly, do not reuse it. When removing it, use a soft tool (such as a toothpick) so that the piping will not be damaged. q Push in each pipe to the stopper (until it clicks) and tighten the nut fully with your fingers. q Be sure to use 2 wrenches to tighten each nut (Apply a torque wrench to the tightening side). Fix 1 wrench and tighten the nut with another wrench to the specified torque. a Tightening torque for pipes of O-ring type (Standard value) Tightening torque Outside Nm {kgm} diameter of pipe Cylindrical (mm) End face seal face seal

72-22 (6)

ø 8, ø 9

9.8 – 20 {1.0 – 2.0}

9.8 – 20 {1.0 – 2.0}

ø 12

15 – 25 {1.5 – 2.5}

15 – 25 {1.5 – 2.5}

ø 16

20 – 29 {2.0 – 3.0}

29 – 34 {3.0 – 3.5}

ø 19

25 – 34 {2.5 – 3.5}

34 – 49 {3.5 – 4.0}

Air conditioner

TROUBLESHOOTING ZEXEL VALEO (NEW REFRIGERANT (R134a) TYPE) Troubleshooting procedure...................................................................................................................... 73-

2

Block diagram and circuit diagram of control system .............................................................................. 73-

3

Detail of air conditioner unit ..................................................................................................................... 73-

5

Arrangement of connector pins ............................................................................................................... 73-

6

Arrangement of connectors and how to disconnect control unit connectors ........................................... 73-

7

How to inspect electric parts.................................................................................................................... 73-

8

Troubleshooting chart .............................................................................................................................. 73- 10 Troubleshooting table ...............................................................................................................................73- 11 Troubleshooting for electrical system (E mode) ...................................................................................... 73- 13 E-1 Air conditioner does not operate............................................................................................ 73- 14 E-2 Air is not cooled ..................................................................................................................... 73- 16 E-3 Air does not come out or air flow is abnormal........................................................................ 73- 18 E-4 Temperature cannot be adjusted ........................................................................................... 73- 20 E-5 Air outlet cannot be changed ................................................................................................. 73- 22 E-6 Intake cannot be changed ..................................................................................................... 73- 25 Troubleshooting with gauge pressure...................................................................................................... 73- 26

Air conditioner

73-1 (6)

TROUBLESHOOTING

TROUBLESHOOTING PROCEDURE

The air conditioner has a self-diagnosis function for inspecting the main component parts. With this function, you can inspect the operations of each sensor (which is not installed to the air conditioner having only the manual mode), each actuator, and fan motor system. If a troubled section is detected, every part of that section must be inspected.

TROUBLESHOOTING PROCEDURE 1. Find out the troubled section according to the detected trouble of the air conditioner. 2. Find out the troubled section with the self-diagnosis function (See TESTING AND ADJUSTING, Inspection with self-diagnosis). If the air conditioner unit or control unit does not operate at all, however, check that the power supply up to the control unit is normal. If any part of the air conditioner unit or control unit operates, the power supply does not need to be checked. 3. After finding out the troubled section, inspect the component parts in that section and repair the troubled part. Basic flow of troubleshooting Occurrence of trouble

Check of battery voltage (24 V)

Does any part of air conditioner unit or control unit operate?

No

E-1 Air conditioner does not operate

Repair

Inspection of troubled part

Repair

Inspection with troubleshooting table

Repair

Inspection of troubled part

Repair

YES Inspection with self-diagnosis function (* 1)

No

OK Troubleshooting with troubleshooting chart

No

OK Troubleshooting with gauge pressure

No

OK End * 1: See TESTING AND ADJUSTING

73-2 (6)

Air conditioner

TROUBLESHOOTING

BLOCK DIAGRAM AND CIRCUIT DIAGRAM OF CONTROL SYSTEM

BLOCK DIAGRAM AND CIRCUIT DIAGRAM OF CONTROL SYSTEM

6267

* 1. The internal air sensor, water temperature sensor, external air sensor, and AUTO SW AUTO LED are not installed to the air conditioner having only the manual mode. The external air sensor is not installed to the automatic air conditioner of PC78US-6, either. Air conditioner

73-3 (6)

TROUBLESHOOTING

BLOCK DIAGRAM AND CIRCUIT DIAGRAM OF CONTROL SYSTEM

6268

73-4 (6)

Air conditioner

TROUBLESHOOTING

DETAIL OF AIR CONDITIONER UNIT

DETAIL OF AIR CONDITIONER UNIT

6269

* 1. The internal air sensor and external air sensor are not installed to the air conditioner having only the manual mode. Air conditioner

73-5 (6)

TROUBLESHOOTING

ARRANGEMENT OF CONNECTOR PINS

ARRANGEMENT OF CONNECTOR PINS * 1. The water temperature sensor, internal air sensor, sunlight sensor, and external air sensor are not installed to the air conditioner having only the manual mode. The external air sensor is not installed to the automatic air conditioner of PC78US-6, either. a For the wiring harness connectors of M26, M84, and M85 on the air conditioner unit side, see Detail of air conditioner unit

6270

6271

73-6 (6)

Air conditioner

TROUBLESHOOTING

ARRANGEMENT OF CONNECTORS AND HOW TO DISCONNECT CONTROL UNIT CONNECTORS

ARRANGEMENT OF CONNECTORS AND HOW TO DISCONNECT CONTROL UNIT CONNECTORS a The following is the explanation for PC78US-6 and PC128/138US-2. 1. Arrangement of connector 1) Connectors M26, M84, and M85 are installed under the rear part of the operator's seat.

AJS01466

2) Connector M87 is in cover (1) under the right rear part of the operator's cab. a Connector M88 of the mode duct is described in the text (See TESTING AND ADJUSTING, Inspecting selection of air outlet (Mode door and mode actuator)).

AJS01477

2. How to disconnect control unit connectors 1) Unhook claw (N) under left console bellows (B) and remove plate (P). 2) Remove tray (T) and screw (S), and then lift up cover (C) and control unit and disconnect connectors M80 and M81.

9JS02170

Air conditioner

73-7 (6)

TROUBLESHOOTING

HOW TO INSPECT ELECTRIC PARTS

HOW TO INSPECT ELECTRIC PARTS kWhen removing each electric part, turn the starting switch OFF. a See Detail of air conditioner unit a Even if the water temperature sensor, internal air sensor, and thermostat are normal, if a clip is removed by vibration and the sensor is separated from the object, the system does not work. 1. Water temperature sensor and internal air sensor * Not installed to the air conditioner having only manual mode. a Remove the air conditioner unit to inspect these sensors. • Measure the resistance between the terminals. 2.

6272

External air sensor * Not installed to the air conditioner having only manual mode. Not installed to the automatic air conditioner of PC78US-6, either. a On PC128/138US-2, this sensor is installed to the battery relay bracket. • Measure the resistance between the terminals. (The characteristics of this sensor are the same as those of the internal air sensor.)

3. Sunlight sensor (1) * Not installed to the air conditioner having only manual mode a Since the current is small (several 10 µA), it cannot be checked with a circuit tester. a On PC78US-6 and PC128/138US-2, this sensor is installed on the monitor panel.

6273

4. Thermostat a The thermostat unit cannot be inspected in the field (since 24V power source is necessary and the ON/OFF range is 1.5 - 6 °C) a Inspect the thermostat without removing it from the machine (See E-2 Air is not cooled) a Removal: Remove the air conditioner unit, and then remove the thermostat 5. Pressure switch (See STRUCTURE AND OPERATION, Outline of main parts, 6.4)

73-8 (6)

9JS02205

Air conditioner

TROUBLESHOOTING

HOW TO INSPECT ELECTRIC PARTS

a Before performing the following work (6. - 10.), remove the cover under the seat. 6. Resistor (1) Remove connector [N] from the resistor. (2) Measure the resistance between terminal L and terminal Mo. Resistance between L and Mo: 7.3 z a The resistance has effects on the operation when the fan speed (air flow) is at the minimum. a Before performing the following work, remove the cover under the seat. 7. Power transistor (1) Disconnect connector [L] of the power transistor. (2) Check the continuity between the terminals on the power transistor. a The power transistor has effects on the lowest 3 levels of the fan speed (air flow) control.

8. MAX HI relay (1) Disconnect connector [M] from the MAX HI relay. (2) Check the continuity between the terminals on the MAX HI relay side. a This relay is turned ON when the fan speed (air flow) is set to the maximum (MAX HI).

6274

6275

6276

9. A/C (Air conditioner) relay (1) Disconnect connector [H] from the air conditioner relay. (2) Check the continuity between the terminals on the air conditioner relay. a Turn the compressor OFF. 10. OFF relay (1) Disconnect connector [K] from the OFF relay. (2) Check the continuity between the terminals on the OFF relay side. a This relay is used to turn the fan (all airflow) OFF.

Air conditioner

6277

73-9 (6)

TROUBLESHOOTING

TROUBLESHOOTING CHART

TROUBLESHOOTING CHART The numbers in the boxes are the item Nos. in the troubleshooting table. 1. Cooling trouble

Cooling trouble Check of spurting air temperature

Air flow is insufficient or air does not come out

Air flow is normal

Check of operation of blower fan motor

1 Blower fan motor does not revolve or its speed is different from set value

Both high pressure and low pressure are low

Check or revolution of compressor

2 Blower fan motor is normal but air flow is insufficient

3 Compressor operates normally

Both high pressure and low pressure are high

High pressure is high and low pressure is low

4 Compressor does not revolve at all or its speed is low

High pressure is low and low pressure is high

2. Heating trouble

Heating trouble Check of spurting air temperature

Air flow is insufficient or air does not come out

Air flow is normal but air temperature is low

Check of operation of blower fan motor

1 Blower fan motor does not revolve or its speed is different from set value

73-10 (6)

5 Blower fan motor is normal but air flow is insufficient

6 Check of hot water

Air conditioner

TROUBLESHOOTING

TROUBLESHOOTING TABLE

TROUBLESHOOTING TABLE 1. Blower fan motor does not revolve or its speed is different from set value. a See the troubleshooting for the electrical system "E-3 Air does not come out or air flow is abnormal" Possible cause

Check method

Remedy

Defective OFF relay

See check of relay

Replace

Disconnection of wire or defective connection

Check ground wire and connector of blower fan motor for disconnection

Repair broken parts and connect correctly

Defective blower motor

Check 2 lead wires of motor with circuit tester. If there is not continuity, motor is defective

Replace

Resistor trouble

Check continuity with circuit tester (If there is not Replace continuity, resistor is defective)

Defective power transistor or defective MAX HI relay

Move fan switches in order and check fan speed. Replace See section of check of relay

2. Blower fan motor is normal but air flow is insufficient. Possible cause

Check method

Remedy

Air leakage

Check fitting condition of air conditioner unit case Replace

Obstacle on suction side of evaporator

Check evaporator for stain and obstacle

Remove obstacle and clean

Defective amplifier of electronic thermostat or defective contact of electronic thermostat sensor

Evaporator is frozen. Check sensor clip. Check sensor for dirt

Repair or replace

3. Air flow is normal or compressor operates normally. Possible cause

Check method

Excessive or insufficient refrigerant Insufficient refrigerant

Overcharge with refrigerant

Judgment by pressure at inlet/outlet of compressor

Air conditioner

If HFC-134a is used as refrigerant, its quantity cannot be checked through sight glass. Accordingly, check by connecting gauge manifold. Purpose of sight glass is to check refrigerant flow

Remedy Collect refrigerant, then charge with proper quantity of refrigerant again Repair leaking part, then charge with proper quantity of refrigerant again Collect refrigerant, then charge with proper quantity of refrigerant again

Normal pressure range Low pressure: Approx. 0.13 - 0.2 MPa {1.3 - 2.0 kg/cm2} See Troubleshooting with High pressure: Approx. 1.5 - 1.7 MPa gauge pressure {15 - 17 kg/cm2} These values are for following condition, however. Temperature in cab: 30 - 35 °C Engine speed: Approx. 1500 r/min

73-11 (6)

TROUBLESHOOTING

TROUBLESHOOTING TABLE

4. Compressor does not revolve at all or its speed is low. a

See "E-2 Air is not cooled"

Troubled part

Possible cause

Check method

Remedy

Belt

Loosened belt

Vibration amplitude of belt is large

Adjust tension

Compressor

Trouble in compressor

Slip of belt

Repair or replace

Low battery voltage

Slip of clutch

Charge battery

Layer short circuit in coil

Slip of clutch

Replace magnet clutch

Oil on clutch surface

Magnet clutch is dirty and slips

Clean clutch surface or replace clutch

Measure clearance between clutch plate and clutch wheel with feeler gauge Proper clearance: (0.3 - 0.6 mm)

Repair

Inspect with circuit tester

Replace

Magnet clutch Too large clearance between drive plate and pulley Disconnection of coil

Disconnection in wiring or When clutch is turned ON, magnet defective connection of ground does not attract. Check ground wire wire and connections

Repair

5. Blower fan motor is normal but air flow is insufficient. Possible cause Large duct resistance

Check method Check duct for crushing and clogging

Remedy Repair

duct joints for defective duct seal and disconAir leakage through duct joints Check nection of duct

Repair

Clogging of heat core fins

Repair

Check heater core fins for clogging

6. Check of hot water Possible cause

Check method

Remedy

Low engine coolant tempera- Warm up engine, and then check engine coolant tem- Find out cause ture perature Low engine coolant level

Check coolant level in radiator

Add coolant

Insufficient circulation of engine coolant

Check engine coolant piping for clogging (Hose, pipe, Bleed air and repair and core)

7. Other items Possible cause

Check method

Temperature cannot be adjusted

See Troubleshooting for electrical system, E-4

Air outlet cannot be changed

See Troubleshooting for electrical system, E-5

Intake cannot be changed

See Troubleshooting for electrical system, E-6

73-12 (6)

Air conditioner

TROUBLESHOOTING

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE) Information in troubleshooting table a The following information is summarized in the troubleshooting table and the related electrical circuit diagram.Before carrying out troubleshooting, understand that information fully. Trouble

Phenomenon that appears on machine

Related information Information related to the detected trouble or troubleshooting Cause

1

Standard value in normal state/Remarks on troubleshooting • Standard value in normal state to judge possible causes • Remarks on judgment

Possible causes of trouble • Disconnection (Given numbers are referConnector is connected imperfectly or wiring harence numbers, which do ness is disconnected not indicate priority. Possible causes and Perform troubleshooting standard value in noraccording to these num(1) Entry order of pin Nos. and handling of circuit mal state bers, however.) tester leads Connect positive (+) lead and negative (-) lead of 2 circuit tester as explained below for troubleshooting, unless otherwise specified • Connect positive (+) lead to pin No. or wiring harness entered on front side • Connect negative (-) lead to pin No. or wiring harness entered on rear side (2) Example of troubleshooting by inspection of multiple items 3 - defective a Normal in 1 but abnormal in 2 At this time "- defective" shown at left is applied a Grounding fault, short circuit with power source, and short circuit are not described since they are common to all items. After checking all of the shown possible causes, if you still cannot detect the cause, check for the above troubles. a If a wiring harness is burnt, replace it. • Grounding fault Wiring harness which is not connected to chassis ground circuit is in contact with chassis ground circuit. • Short circuit with power source Wiring harness which is not connected to power source (24V) circuit is in contact with power source (24V) circuit. • Short circuit Independent wiring harnesses are in contact with each other abnormally. Related circuit diagram This is a circuit diagram of the part related to troubleshooting • The circuit diagram shows the connector Nos. and pin Nos. • See "Arrangement of connector pins" and "Arrangement of connectors and how to disconnect control unit" • The circuit diagram shows the size and colors of wires. W: White, B: Black, R: Red, G: Green, Y: Yellow, L: Blue, V: Purple, P: Pink, O: Orange, Br: Brown, Gr: Gray, Sb: Sky blue, Lg: Light green, Dg: Dark green, Ch: Dark brown a When there are 2 colors Example: WY: Yellow line on white background a The number before the wire color indicates the wire size. • N.C.: Normally closed (Normally turned ON) a Sockets (of relays, resistors, power transistors, etc.) are omitted. Air conditioner

73-13 (6)

TROUBLESHOOTING

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

E-1 Air conditioner does not operate Trouble

The air conditioner does not operate

Phenomenon that • The LED on the control panel does not light up appears on • The compressor and fan motor do not revolve, either machine Check that the fuse is not broken and the engine starts normally in advance Related information The ground wire of the air conditioner is connected to the chassis ground inside the chassis wiring harness together with other electric parts (relay, valve, etc.) Cause

Standard value in normal state/Remarks on troubleshooting

1) Turn starting switch OFF 2) Disconnectground terminal of battery 3) Lift up left console cover and control unit as 1 unit 1 Defective ground wire 4) Disconnect connector M80 Between terminal 10 of connector M80 and chassis Resisground tance 1) Turn starting switch OFF 2) Disconnect ground terminal of battery 3) Lift up left console cover and control unit as 1 unit 4) Disconnect connector M80 Defective wiring har- 5) Connect ground terminal of battery 2 ness or defective con- 6) Turn starting switch ON trol unit Between terminal 2 of connector M80 and chassis Voltage ground Possible 3 Defective control unit causes and standard Disconnection in wirvalue in ing harness 4 normal • Intermediate wiring state harness

Between terminal 11 of connector M80 and chassis ground

Voltage

Max.1 z

24V 24V

a Normal in 1 and 2 a When abnormal in 1 or 2, find out which wiring harness is disconnected (Perform after 2) 1) Turn starting switch OFF 2) Disconnect connector M85 (without connecting connector M80) Female terminal of connector M80 and female terContinuity Made minal of M85 (See circuit diagram)

a When abnormal in 1 or 2, find out which wiring harness is disconnected (Perform after 2 or 4) Disconnection in wir1) Turn starting switch OFF ing harness 5 • Attached to air condi- 2) Disconnect connector M26 and M85 (without connecting connector M80) tioner unit Male terminal of connector M26 and male terminal Continuity Made of M85 (See circuit diagram) a When (abnormal in 1 or 2) and normal in 4 and 5, perform following directly 1) Turn starting switch OFF Disconnection in wir- 2) Disconnect ground terminal of battery ing harness 3) Disconnect connector M26 6 • Wiring harness on Between female terminal of connector M26 and Continuity Made machine chassis ground Female terminal of connector M26 and fuse 25A terminal (See circuit diagram)

73-14 (6)

Continuity

Made

Air conditioner

TROUBLESHOOTING

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

Related circuit diagram

6278

Air conditioner

73-15 (6)

TROUBLESHOOTING

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

E-2 Air is not cooled Trouble

Air is not cooled

Phenomenon that appears on machine

The compressor does not operate

Related information

See TESTING AND ADJUSTING, Inspecting relay (Remove the cover under the seat for troubleshooting)

Cause

1 Defective compressor

Standard value in normal state/Remarks on troubleshooting 1) Turn starting switch OFF 2) Disconnect compressor connector 3) Turn starting switch ON 4) Turn air conditioner switch ON Between connector terminal (there is on 1 pin) and chassis ground

Voltage

24V

1) Turn starting switch ON 2) Turn air conditioner switch ON/OFF Defective air conditioner 2 relay Air conditioner relay makes ON/OFF sound a See TESTING AND ADJUSTING, Inspecting relay

pressure 3 Defective switch

Possible causes and standard value in normal state

1) Turn starting switch OFF 2) Disconnect connector I Between terminals of connector I on air conditioner Continuity Made unit side a While pressure switch operates normally, continuity is may not be made. Accordingly, measure gauge pressure. For pressure range, see STRUCTURE AND OPERATION. For connecting method, see 42-11 "Connecting service tool" kWhen replacing pressure switch, collect refrigerant gas in advance

Defective control unit or in inter4 disconnection mediate wiring harness (between M81 and M84)

1) Turn starting switch OFF 2) Disconnect connector M84 3) Turn starting switch ON 4) Turn air conditioner switch ON Between female terminal of connector M84 and chasResistance Max. 1z sis ground

1) Turn starting switch OFF Disconnection in wiring 2) Lift up left console cover and control unit as 1 unit 3) Disconnect connectors M81 and M84 5 harness • Intermediate wiring harFemale terminal of connector M81 and female terminess nal of M84 6 Defective control unit

Continuity

a Abnormal in 4 and normal in 5

–

1) Turn starting switch OFF Defective thermostat or 2) Disconnect connector I wiring harness 3) Disconnect connector M84 7 (Air conditioner unit Between 0.3GY on wiring harness side of connector and male pin does not need to be removed) 25 (0.3GW) of connector M84 Continuity Set cooling level to maximum to freeze evaporator (Set air flow to minimum) 8 Defective thermostat

Disconnection in wiring 9 harness • Attached to air conditioner unit

73-16 (6)

Made

Made

Turned Compressor OFF before freezing

a Protective circuit of thermostat turns operation OFF when temperature is 1.5 - 6°C. Accordingly, if protective circuit operates normally, compressor may not revolve. Check again before judging thermostat defective 1) Turn starting switch OFF 2) Disconnect connectors M84, M85, M26, and I and air conditioner relay Referring to circuit diagram, check continuity Continuity Made a To check around thermostat, air conditioner unit must be removed and disassembled

Air conditioner

TROUBLESHOOTING

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

Related circuit diagram

6279

9JS02181

Air conditioner

73-17 (6)

TROUBLESHOOTING

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

E-3 Air does not come out or air flow is abnormal Trouble

Air does not come out or air flow is abnormal

Phenomenon that appears on • The fan motor does not operate machine • Air flow is different from the setting of the control panel See TESTING AND ADJUSTING, Inspecting relay (Remove the cover under the seat for troubleshooting.) See How to inspect electric parts

Related information Cause

1 Defective OFF relay

Standard value in normal state/Remarks on troubleshooting 1) Turn starting switch ON 2) Turn air conditioner switch ON/OFF. OFF relay makes ON/OFF sound

When air does not come out at any of 4 levels

a See TESTING AND ADJUSTING, Inspecting relay 2 Defective fan motor

1) Turn starting switch OFF 2) Disconnect connector O Between terminals of connector O on air conditioner unit side

–

Continuity

Made

1) Turn starting switch ON 2) Turn air conditioner switch ON 3) Set air flow to MAX HI and medium alternately Defective MAX HI relay 3 Air flow changes (MAX HI relay makes ON/OFF sound) *1 a See TESTING AND ADJUSTING, Inspecting relay. If air flow cannot be set to maximum (relay is kept turned OFF) or it is kept at maximum regardless of setting of air flow (relay is kept turned ON), replace MAX HI relay 1) Turn starting switch ON 2) Turn air conditioner switch ON Defective power transis- 3) Set air flow to lower 3 levels 4 tor Air flow is increased as level is increase to 2 and 3 *1 a If air flow is kept at minimum (power transistor is kept turned OFF) or at level 3 (power transistor is kept turned ON) regardless of setting of air flow, replace power transistor 1) Turn starting switch ON 2) Turn air conditioner switch ON 3) Set air flow to minimum 5 Defective resister Possible causes and standard value in normal state

Air flows out a little (a If air does not flow out only when setting is at minimum, replace resistor) 1) Turn starting switch OFF 2) Disconnect connector N Resistance

Approx. 7z

Between female terminal 23 of connector M84 and chassis ground

Resistance

Max.1z

1) Turn starting switch OFF 2) Disconnect connector M84 Defective control unit or 3) Turn starting switch ON 6 intermediate wiring har- 4) Turn air conditioner switch ON ness (between M81 and 5) Set air flow to maximum M84) Between female terminal 31 of connector M84 and chassis ground

Resistance

Max.1z

Voltage

1 - 5V

Continuity

Made

Between resistor terminals MO and L (See 6. How to inspect electric parts) 1) Turn starting switch OFF 2) Disconnect connector M84 3) Turn starting switch ON 4) Turn air conditioner switch ON

1) Turn starting switch OFF 2) Disconnect connector M84 3) Turn starting switch ON 4) Turn air conditioner switch ON 5) Set air flow to intermediate level 2 Between female terminal 22 of connector M84 and chassis ground 1) Turn starting switch OFF Disconnection in wiring 2) Lift up left console cover and control unit as 1 unit harness 3) Disconnect connectors M81 and M84 7 • Intermediate wiring harFemale terminal of connector M81 and female terminal of connector ness M84 (See circuit diagram)

73-18 (6)

8 Defective control unit

a Abnormal in 6 and normal in 7

Disconnection in wiring harness 9 • Attached to air conditioner unit

1) Turn starting switch OFF 2) Disconnect connectors M84 M26, L, N, and O, OFF relay, and MAX HI relay Referring to circuit diagram, check continuity

–

Continuity

Made

Air conditioner

TROUBLESHOOTING

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

* 1. When either of the MAX HI relay (kept turned ON) or power transistor (kept turned ON) is broken, it is diffi cult to see which one is broken. In this case, check them according to the following procedure. 1) Turn the starting switch OFF and remove the MAX HI relay. 2) Turn the starting switch and air conditioner switch ON and set the air flow to lower 3 levels to see if the air flow is normal (changed). Normal o MAX HI relay is defective, Abnormal o Power transistor is defective Related circuit diagram

6280

9JS02180

Air conditioner

73-19 (6)

TROUBLESHOOTING

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

E-4 Temperature cannot be adjusted Trouble

Temperature cannot be adjusted

Phenomenon that appears The mix door does not move. (Normal: Operates to 8 levels according to setting of temperature) on machine Related information

See TESTING AND ADJUSTING, Inspecting temperature adjustment (Air mix door and mix actuator) (In air conditioner unit: Remove the cover under the seat for troubleshooting.)

Cause Defective link mechanism between mix 1 actuator and mix door (Removal of rod (3), etc.)

Standard value in normal state/Remarks on troubleshooting As temperature setting is changed from left end to right end, levers (1) and (2) operates in 3 levels. (Since there are 2 doors, there are 2 levers and 2 rods.)

Repair

Same as above Remove, disassemble, and • Mix actuator tries to move (motor sounds and repair vibrates) but cannot move 1) Turn starting switch OFF 2) Disconnect connector D Defective mix actuator Between terminals 19 and 20 and between 8 and 20 of Max.approx.4 Resistance • Potentiometer mix actuator connector on air conditioner unit side Kz • Motor coil Continuity Made Between terminals 27 and 35 of mix actuator connector D on air conditioner unit side Diode range 1) Turn starting switch OFF 2) Disconnect connector D 3) Turn starting switch ON 4) Turn air conditioner switch ON Between terminals 20 and 19 of mix actuator connecVoltage 5V Defective control unit tor D on wiring harness side (regardless of setting of – or wiring harness temperature control switch) • Potentiometer - 21 to + 21V Voltage • Motor drive Between terminals 27 and 35 of mix actuator connector D on wiring harness side (Change of setting of tem- a Several seconds after switch setting is perature control switch: Left end - Right end) changed a If abnormal in 4, perform 5 and 6 to see which of wiring harness andcontrol unit is defective 1) Turn starting switch OFF Disconnection in wir- 2) Disconnect connectors D, M84, and M85 Terminal of connector D on wiring harness side and ing harness Continuity Made male terminal of M84 (See circuit diagram) • Attached to air conditioner unit Terminal of connector D on wiring harness side and Continuity Made male terminal of M85 (See circuit diagram) 1) Turn starting switch OFF 2) Lift up left console cover and control unit as 1 unit 3) Disconnect connectors M81, M84, M80, and M85 Disconnection in wir- Female terminal of connector M81 and female termiContinuity Made nal of M84 (See circuit diagram) ing harness • Intermediate wiring Female terminal of connector M80 and female termiContinuity Made harness nal of M85 (See circuit diagram) a If M85 (or M80) is disconnected, power is not supplied to control unit. Accordingly, M85 and M80 cannot be inspected by checking voltage similarly to 4. Inspect them by checking continuity – Defective control unit a Abnormal in 4 and normal in 5 and 6

2 Locked air mix door

3

Possible causes and 4 standard value in normal state

5

6

7

73-20 (6)

Air conditioner

TROUBLESHOOTING

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

Related circuit diagram

6281

9JS02169

Air conditioner

73-21 (6)

TROUBLESHOOTING

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

E-5 Air outlet cannot be changed Trouble

The air outlet cannot be changed

Phenomenon that appears on machine

Mode door (4) does not move

Related information

See TESTING AND ADJUSTING, Inspecting selection of air outlet (Mode door and mode actuator). (Carry out troubleshooting for mode duct (5).) Cause

Defective mode 1 actuator • Motor coil

2

Locked mode door (4)

Standard value in normal state/Remarks on troubleshooting 1) Turn starting switch OFF 2) Disconnect connector M88 Made Terminals 28 and 36 of mode actuator connector M88 on Continuity mode duct side a Diode range a Since direction troubleshooting for mode door position sensor is impossible, carry out troubleshooting indirectly by 3 and 4 Mode actuator tries to move (motor sounds and Mode door Revolution (Visual vibrates) but cannot move check) 1) Turn starting switch OFF 2) Disconnect connector M88 3) Turn starting switch ON 4) Turn air conditioner switch ON - 21 to + 21V Voltage Between terminals 28 and 36 of mode actuator connector M88 on wiring harness side (Change of setting of a Several seconds after switch setting is mode switch: Left end - Right end) changed 5) Mode switch position: Left (Vent/Def) Between terminals 4 and 20 of M88 on wiring harness Voltage 0V side

Possible causes and standard value in normal state

Defective control unit or wiring harness 3 • Motor drive • Mode door position sensor

Between terminals 14-A (14-B) and 20 of M88 on wiring harness side

Voltage

0V

Between terminals 5-A (5-B) and 20 of M88 on wiring harness side

Voltage

5V

Between terminals 4 and 20 of M88 on wiring harness side

Voltage

5V

Between terminals 14-A (14-B) and 20 of M88 on wiring harness side

Voltage

0V

6) Mode switch position: Center (Bi-level)

Between terminals 5-A (5-B) and 20 of M88 on wiring Voltage 0V harness side 7) Mode switch position: Right (Foot) Between terminals 4 and 20 of M88 on wiring harness Voltage 5V side Between terminals 14-A (14-B) and 20 of M88 on wiring Voltage 0V harness side Between terminals 5-A (5-B) and 20 of M88 on wiring Voltage 5V harness side a If abnormal in 3, perform 4 to see which of wiring harness and control unit is defective (Keep M88 disconnected.) 1) Turn starting switch OFF 2) Lift up left console cover and control unit as 1 unit 3) Disconnect connectors M81 and M80 Female terminal of connector M81 and female terminal Continuity Made Disconnection in wir- of M88 (See circuit diagram) harness Female terminal of connector M89 and female terminal Continuity 4 ing Made of M88 (See circuit diagram) (Inspect 3 pieces together) a If M85 (or M80) is disconnected, power is not supplied to control unit. Accordingly, wiring between M85 and M80 (wiring on position sensor side) cannot be inspected by checking voltage. Inspect it by checking continuity a If abnormal in 4, perform 5 to see which wiring harness is defective. (Keep M80, M81, and M88 disconnected.)

73-22 (6)

Air conditioner

TROUBLESHOOTING

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

1) Turn starting switch OFF 2) Disconnect connectors M84, M85, and M87 Disconnection in wiring Female terminal of connector M81 and Continuity female terminal of M84 (See circuit diagram) harness Female terminal of connector M80 and • Intermediate wiring Continuity female terminal of M85 (See circuit diagram) harness Possible 5 • Attached to air Male terminal of connector M84 and female causes and Continuity conditioner unit terminal of M87 (See circuit diagram) standard value • Wiring harness on Male terminal of connector M85 and female in normal state Continuity machine terminal of M87 (See circuit diagram) Male terminal of connector M87 and female Continuity terminal of M88 (See circuit diagram) 6 Defective control unit a Abnormal in 3 and normal in 4 7 Defective mode duct a Normal in 3 Move right console (2) inward, and then remove covers (1) and (3). a (4) is the mode door a There is the mode actuator in mode duct (5). a If duct joint A is moved, you can replace mode duct (5).

Made Made Made Made Made

•

AJS01468

Related circuit diagram

6282

Air conditioner

73-23 (6)

TROUBLESHOOTING

•

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

Connector M87: Remove cover (1) at the right rear of the operator's cab to find.

AJS01477

73-24 (6)

Air conditioner

TROUBLESHOOTING

TROUBLESHOOTING FOR ELECTRICAL SYSTEM (E MODE)

E-6 Intake cannot be changed Trouble The intake cannot be changed Phenomenon that The intake door does not move appears on machine Related information See TESTING AND ADJUSTING, Inspecting selection of intake (Intake door and intake actuator) (Remove the intake duct for troubleshooting) Cause intake 1 Locked door

Standard value in normal state/Remarks on troubleshooting • Intake actuator tries to move (motor sounds and Intake door Revolution (Visual vibrates) but cannot move check) 1) Turn starting switch OFF 2) Disconnect connector M83 3) Turn starting switch ON 4) Turn air conditioner switch ON 5) Press intake switch to select external/internal air

Defective intake control 2 actuator, unit, or wiring harness Between terminals 32 and 24 of intake actuator connector M83 on wiring harness side

Voltage ±21V a Reversal of polarity (Several seconds after switch setting is changed)

1) Turn starting switch OFF 2) Lift up left console cover and control unit as 1 unit Disconnection in 3) Disconnect connectors M81, M80, and M83 Possible causes and harness 3 wiring terminal of connector M81 and female standard value in • Intermediate wir- Female Continuity Made terminal of M83 (See circuit diagram) normal state ing harness Female terminal of connector M80 and female Continuity Made terminal of M83 (See circuit diagram) intake 4 Defective a Normal in 2 and 3 actuator a Abnormal in 2 and normal in 3, or perform following directly 1) Turn starting switch OFF 2) Lift up left console cover and control unit as 1 unit 3) Disconnect connectors M81 (Connect M80) 4) Turn starting switch ON 5) Turn air conditioner switch ON 5 Defective control unit 6) Press intake switch to select external/internal air Voltage ±21V a Reversal of polarity Between terminals 32 and 24 of (Several seconds after connector M81 on control unit side switch setting is changed)

Related circuit diagram

6283

Air conditioner

73-25 (6)

TROUBLESHOOTING

TROUBLESHOOTING WITH GAUGE PRESSURE

TROUBLESHOOTING WITH GAUGE PRESSURE Connect the gauge manifold ( * 1) and carry out troubleshooting by reading the high and low gauge pressures of the cooling cycle. a The gauge pressure varies largely with the weather condition and operating condition of the machine. Take care.

Indicated gauge pressure

Item Atmospheric tempera ture Engine speed Air conditioner switch Fan switch Set temperature

Condition value 30 - 35 °C 1500rpm ON HI Full cool

Cause Check method Air conditioner cycle is operating normally If there is any trouble (cooling trouble), there is another 2cause High pressure: Approx. 1.5 -1.7 MPa {15 -17 kg/cm } 2 Low pressure: Approx. 0.13 - 0.2 MPa {1.3 - 2.0 kg/cm } Insufficient refrigerant

Clogging of receiver drier



Clogging of expansion valve

Refrigerant leakage through tube of expansion Low pressure becomes thermometer valve (Blocking of valve vacuum passage)

Remedy

Collect refrigerant, then charge with proper quantity of refrigerant again Connect gauge manifold (* 1) (* 2) There is temperature difference between inlet and outlet pipes of receiver drier Replace Tank is frosty (* 2) Clean or replace Expansion valve is frosty (* 2) Opening side of expansion valve is not cold (• Low gauge pressure becomes vacuum)

Replace

(* 2) Defective electronic thermometer (thermometer Adjust or replace amplifier) or defective contact of Evaporator is frozen sensor (removal of fixing clip) Piping between receiver drier and compressor is clogged or Clogging or flattening of flattened. If clogged comClean or replace piping pletely, low gauge pressure becomes vacuum (* 2) Collect refrigerant, then charge with Overcharging with refrigerant proper quantity of Connect gauge manifold refrigerant again (* 1) (* 2) Clean, repair fins, Stain of condenser, clogging repair or replace or Defective cooling of condenser or crushing of fins, or defec- condenser tive revolution of cooling fan (* 2) Defective adjustment of expan- Defective adjustment of sion valve or defective installa- refrigerant flow rate tion of thermometer tube (Valve Thermometer tube is not in Repair or replace is opened too wide) contact with evaporator pipe (* 2) Evacuate and then charge with proper Air in cycle – quantity of refrigerant again (* 2) or flattening of piping There is remarkable temper- Clean inside of cycle between denser before and after clogged part (* 2) Defective compressor valve or Both high pressure and low gasket compressor) compressor is in operation (* 2) * 1. See page 42-11 "Connecting service tool" * 2. kWhen replacing a cooling cycle part, collect refrigerant, and then charge the air conditioner system with refrigerant again. See page 52-14 "Procedure for collecting refrigerant gas" and page 42-32 "Charging with refrigerant"

73-26 (6)

Air conditioner

DISASSEMBLY AND ASSEMBLY

63-12 (5)

DISASSEMBLY, ASSEMBLY OF CONTROL PANEL

Air conditioner