Electronics-Y3.pdf
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Republic of the Philippines Department of Education PUBLIC TECHNICAL -VOCATIONAL HIGH SCHOOLS
Unit of Competency:
Module No:
1
ASSEMBLE AND DISASSEMBLE CONSUMER ELECTRONIC PRODUCTS AND SYSTEM Module Title:
ASSEMBLING AC-DC POWER SUPPLY
TABLE OF CONTENTS Page How to Use this Module ................................................................................... i Introduction .................................................................................................... ii Technical Terms ............................................................................................. iii Learning Outcome 1: Identify he parts and electronic components of AC-DC power supply…………… ................................... 1 Information Sheet 1.1 ............................................................................ 3 Self-Check 1.1 ..................................................................................... 11 Self-Check Key 1.1............................................................................... 12 Self-Check 1.2 ..................................................................................... 13 Self-Check Key 1.2.............................................................................. .14 Learning Outcome 2: Assembling AC-DC power supply…………...………………..16 Information Sheet 2.1…...……………………………………………………........18 Self-Check 2.1………………………………………………………………………...20 Self-Check Key 2.1…………………………………………………………..….……21 Operation Sheet 2.1………………………………………………….………………22 Performance Check 2.1………………………………..……………………………25 Information sheet 2.2………………………………………………………..….…..26 Job Sheet 2.1………………………………………………………….……….….…..27 Assessment Checklist 2.1…………………………………………..……………...31 Operation Sheet 2.3………………………………………………………………….33 Scoring Rubrics for Operation Sheet 2.3…………………………....…….…...36 Job Sheet 2.2…………………………………………………………………….……37 Assessment Checklist for Job Sheet 2.2…………………………..……………40 Assessment Plan……………………………………………………………………….……..41 Observation Checklist……………………………………………………….………42 Observation and Questioning Checklist……………………………….………..43 Demonstration Checklist…………………………………………………….……..44 Written Report………………………………………………………………….……..45 Performance Test…………………………………………………………….……….46 References …………………………………………………………………………………….47 Acknowledgment …………………………………………………………………………….48
HOW TO USE THIS MODULE Welcome to the Module “Assembling AC-DC Power Supply”. This module contains training materials and activities for you to complete. The unit of competency “Assemble and Disassemble Consumer Electronic Products and Systems” contains the knowledge, skills and desirable attitudes required for Consumer Electronic Servicing to obtain the National Certificate (NC) level II. You are required to go through a series of learning activities in order to complete each of the learning outcomes of the module. In each learning outcome, there are Information Sheets, Job Sheets and Operation Sheets. Do these activities on your own and answer the Self-Check at the end of each learning activity. If you have any question, don’t hesitate to ask your teacher for an assistance. Recognition of Prior Learning (RPL) You have already some basic knowledge and skills covered in this module because you have been working for some time; or have already completed training in this area. If you can demonstrate competence to your teacher in a particular skill, talk to your teacher so you don’t have to undergo the same training again. If you have a qualification or Certificate of Competency from previous trainings show it to him/her. If the skills you acquired are relevant to this module, they become part of the evidence. You can present these for RPL. If you are not sure about your competence skills, discuss this with your teacher. After completing this module, ask your teacher to assess your competence. Result of your assessment will be recorded in your competency profile. All the learning activities are designed for you to complete at your own pace. In this module, you will find the activities for you to complete and relevant information sheets for each learning outcome. Each learning outcome may have more than one learning activity. This module is prepared to help you achieve the required competency, in receiving and relaying information. This will be the source of information that will enable you to acquire the knowledge and skills in Assembling and Disassembling Consumer Electronic Products and Systems and independently at your own pace with minimum supervision from your teacher.
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Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
ASSEMBLE AND DISASSEMBLE CONSUMER ELECTRONIC PRODUCTS AND SYSTEMS
Module Title:
ASSEMBLING AC-DC POWER SUPPLY
INTRODUCTION: This module contains information and suggested learning activities on Assembling AC-DC Power Supply. It covers the knowledge, skills and desirable attitudes required in assembling consumer electronic products and systems. This module consists of two (2) learning outcomes. Each learning outcome contains learning activities supported by instructional sheets. Before you perform the instructions, read the information sheets and answer the self-check and activities provided to ascertain to yourself and your teacher that you have acquired the knowledge necessary to perform the skill portion of the particular learning outcome. Upon completing this module, report to your teacher for an assessment to check your achievement of knowledge and skills required in this module. If you pass the assessment, you will be given a certificate of completion. SUMMARY OF LEARNING OUTCOMES: Upon completion of the module, you should be able to: LO1. identify the parts and electronic components of AC-DC power supply; and LO2. assemble AC-DC power supply to the printed circuit board. ASSESSMENT CRITERIA: Refer to the assessment criteria of learning outcomes 1-2 of this module. PREREQUISITE:
Using hand tools Performing mensuration and calculation Preparing and interpreting Technical Drawing used in Electronics Applying Quality Standards
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TECHNICAL TERMS AC/DC. An equipment that operates on either an AC or DC power source. Anode. The positive electrode of a device. The “P” material of a diode. Bridge Rectifier. A circuit using four diodes that provides full wave rectification. Converts AC voltage to pulsating DC voltage. Calibration. To adjust the correct value of a reading by comparison with the Standard. Color Code. Set of colors used to indicate value of a component. Full Wave Rectifier. The rectifier that makes use of full AC wave in both Both positive and negative half cycles. Half Wave Rectifier. A diode rectifier that converts AC to pulsating DC by eliminating either the negative or positive alternation of each input AC cycle. Leakage. A small undesirable flow of current through an insulator. Output. A terminal at which a component, circuit or piece of equipment delivers current, voltage, or power. Primary winding. The first winding of a transformer. Winding that is connected to the source as opposed to secondary which is a winding connected to the load. Printed Circuit Board. An insulating board containing conductive parts for Circuit connections. Regulated Power Supply. A power supply where the output voltage is not affected by its loading factor. Schematic Diagram. An illustration of an electrical or electronic circuit with the components represented by symbols. Secondary Winding. An output winding of a transformer that is connected to the load. Short Circuit. A very low resistance between two points in a circuit causing excessive current.
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Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
ASSEMBLE AND DISASSEMBLE CONSUMER ELECTRONIC PRODUCTS AND SYSTEM
Module Title:
ASSEMBLING AC-DC POWER SUPPLY
Learning Outcome 1: Identify the parts and the electronic components of an AC-DC power supply.
Assessment Criteria 1. The types of AC-DC power supply are enumerated. 2. The parts of an AC-DC power supply are identified. 3. The electronic components needed in assembling AC-DC power supply are listed and acquired.
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LEARNING EXPERIENCES/ACTIVITIES Learning Outcome 1: Identify the parts and electronic components of an AC-DC power supply. Learning Activities 1. Read the attached Information Sheet 1.1 on AC-DC Power supply. a. Types of AC-DC Power Supply b. Parts of AC-DC Power Supply
Special Instruction
Try to answer the Self-Check 1.1 without looking at the information sheet.
c. Electronic Components and Symbols used in ACDC Power Supply
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INFORMATION SHEET 1.1 AC-DC Power Supply A power supply is the heart of all electronics equipment. It converts AC input power line to DC output voltage. It is the one that supplies the desired voltage or current in a circuit. Without it, all of the electronic equipment will not function properly or will be a dead set.
AC-DC Power Supply
TYPES OF AC-DC POWER SUPPLY A basic power supply consists of three basic stages: the power transformer stage, rectifier stage, and filter stage. An additional stage is sometimes added if there is a need for regulation. This stage is called regulator.
AC Outp ut
Transformer Stage
Rectifier Stage
Filter Stage
Block Diagram of AC-DC Power Supply
DC Outp ut
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1. Half-Wave Rectifier Circuit One rectifier diode D1
and one load resistor RL are needed to
conduct one alteration in every cycle of small AC input.
Schematic Diagram of A Half-Wave Rectifier
2. Full-Wave Center-Tapped Rectifier Circuit Using this type of circuit, you’ll need a center-tapped transformer, two rectifier diodes and a load resistor (RL). Each of the diode supplies one-half the DC load current.
Schematic Diagram of A Full-Wave Center Tapped Rectifier circuit
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3. Full-Wave Bridge Type Rectifier Circuit
Schematic Diagram of A Full-Wave Power Supply The previous circuit illustration uses four rectifier diodes D1 D2 D3 D4 and a load resistor (RL). Bridge circuit makes it possible to remove the centertapped transformer. Among the types of power supply this circuit can deliver a higher current range to the load because all of cycles are consumed by the four diodes. The operation of this rectifier circuit is different from the half-wave and full-wave center tapped. The conduction of AC voltage starts from Line-A going to the Line-B. First Conduction The negative half-cycle will be going to conduct to the cathode of diode D1, thru the RL and going to conduct to the cathode of diode D4 then Line-B. In this case D1 and D4 are conducting.
First Conduction in a Full Wave Power Supply
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Second Conduction The positive half-cycle will be going to conduct to the anode of diode D2, thru the RL and going to conduct to the anode of diode D3 then Line-B. In this case D2 and D3 are conducting.
Second Conduction in a Full Wave Power Supply Characteristics of a Full Bridge Type Power Supply a. Expensive b. Needs a lower value of capacitance c. Needs four rectifier diodes Filter Stage The filtering stage is one of the stages of the power supply which filters the pulsating DC. Output of rectifier stage and make it a pure DC voltages. The main function of the filter circuit is to increase the DC output and to smoothen the pulsating DC.
Insufficient filtering This can cause distortion.
Rectifier Stage
Filter Stage
(+) (-)
Filter Stage
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Basic Methods of Filtering 1. Simple Capacitor in Parallel You can parallel as many electrolytic capacitors as you want. This will increase the amount of capacitance causing good filtering effects to DC output. This is used for high current applications. The only disadvantage is that it will occupy a bigger space.
Placing additional capacitor in the output. Filter Circuit
2. Filter with RC Circuit This circuit is actually a resistor in series with the positive line together with 2 bypass capacitor C1 & C2. It is good in lowering the DC voltage output.
Placing a resistor in series with the positive line can cause voltage drop.
Filter with RC Circuit
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3. Filter with Inductor This circuit has a good filtering effect to the pulsating DC output of the rectifier. It uses minimal value of capacitance and it is good in low current and high current application. The only disadvantage is that the inductor in series with the positive line takes up big space in mounting it in the PC.
Filter with Inductor External Parts of AC-DC Power Supply The external parts of an AC-DC power supply are as follows:
Front Pane. It contains the power switch, voltage selector switch, and the power indicator.
Front Panel
Rear Panel. It contains the fuse and the AC line cord.
Rear Panel
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Internal Parts of AC-DC Power Supply The internal parts of the AC-DC Power Supply are shown in the figure below.
Internal Parts of an AC-DC Power Supply Parts of AC-DC Power Supply Components Description Alligator Clip
A special type of connector used to connect the power supply to the electronic gadget.
Capacitor
A capacitor acts as the filter. The one that removes ripples from the output of the rectifier circuit. The type of capacitor used in this purpose is the electrolytic capacitor.
Case and Cover
It serves as the housing of an AC-DC power supply.
Diode
A device which only allows current to flow in only one direction.
Fuse
A protective device used to prevent the circuit from short circuit or damage
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LED A transducer which converts electrical energy to light. Light Emittin g Diode Line cord
A type of cord used to connect the unit to the voltage source.
On-Off switch
Used to switch on and off the circuit.
Printed Circuit Board
PCB – a conductive pattern formed on one or both sides of an
Resistor
A resistor restricts the flow of current (eg. to limit the current
insulating base by etching, plating or stamping.
passing through an LED). A resistor is used with a capacitor in a timing circuit. Some publications still use the old resistor symbol. Rotary Switch
A switch that is operated by a rotating shaft.
Transformer A component that consist of two or more coils which are coupled together by magnetic induction.
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SELF-CHECK 1.1 AC-DC Power Supply GENERAL DIRECTION: Write all your answers in separate sheets of paper. Do not write anything in this module. Direction: Answer the following questions below. 1. How many stages do basic power supplies have? 2. What component do we need to use in a simple basic filtering stage? 3. Why is a bridge type rectifier the most expensive type rectifier stage? 4. What stage of the power supply step-down the high AC voltage to lower AC voltage? 5. What stage of the power supply converts small AC voltage to pulsating DC voltage? 6. How many basic methods of filtering do the filtering stages have? 7. How many types of rectifier circuits do basic power supplies have? 8. What stage of the power supply smoothens the pulsating DC into pure DC output voltages? 9. How many diodes full-wave center tapped power supplies have? 10. Why is a half-wave rectifier the cheapest type rectifier stage?
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SELF-CHECK KEY 1.1 AC-DC Power Supply
1. Three 2. Filter Capacitor / Electrolytic Capacitor 3. It uses four rectifier diodes 4. Transformer stage 5. Rectifier stage 6. Three 7. Three 8. Filter Stage 9. Two 10. It uses one diode
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SELF-CHECK 1.2 Assembling AC-DC Power Supply I. Direction: Fill in the blank with the names of the parts indicated in the diagram. (1-9). Write the answer in your test notebook. _________2. __________1. _________3.
_______4.
________7. _________8.
________5. ________6.
_________9. __________10. Based on the given circuit, what type of power supply is this?
II. Direction: Draw the schematic diagram of the following circuit: a. Half-wave power supply
b. Full-wave conventional
c. Full-wave bridge type
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SELF-CHECK KEY 1.2 I. 1. Transformer 2. AC plug 3. LED 4. Rotary Switch knob 5. Alligator Clip 6. Rubber Grommet 7. Rotary Switch 8. Printed Circuit Board 9. Fuse Holder 10. Full-wave Bridge Type Power Supply II.
a. Half-wave power supply
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b. Full-wave conventional
Primary Windings
c. Full-wave bridge type
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Program/Course
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency
ASSEMBLE AND DISASEMBLE CONSUMER ELECTRONIC PRODUCTS AND SYSTEMS
Module Title
ASSEMBLING AC-DC POWER SUPPLY
Learning Outcome 2: Assemble AC-DC power supply to the printed circuit board. Assessment Criteria 1. Printed Circuit Board design and etching for AC-DC power supply are prepared. 2. Electronic components are mounted and soldered at the appropriate location on the Printed Circuit Board. 3. All auxiliary components, including the transformer are interconnected to the Printed Circuit Board. 4. Assembled AC-DC power supply is tested and defects are corrected.
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LEARNING EXPERIENCES/ACTIVITIES Learning Outcome 2: Assemble AC-DC power supply to the Printed Circuit Board. Learning Activities 1. Read the attached Information Sheet 2.1 about the Preparation of PCB of an AC-DC Power Supply. 2. Answer the Self-Check 2.1. 3. Compare your answers with the Self Check Key 2.1. 4. If you missed some of the questions, go over the Information Sheet again.
Special Instructions
Try to answer the Self-Check 2.1 without looking at the information sheet. Mount and solder components in the PCB. Connect all the auxiliary components of an AC-DC Power Supply.
5. Read the attached Operation Sheet 2.1 on mounting and soldering electronic components.
Power on the AC-DC power supply.
6. Read the Information Sheet 2.2 on:
Mount and solder electronic components.
a. Interconnecting all auxiliary components
Prepare and design the Printed Circuit Board.
Test voltage.
b. Components including the transformer interconnecting all auxiliary Electronic Components and Symbols of AC-DC Power Supply 7. Perform the Job Sheet 2.1. 8. Do the assessment check list 2.1 and 2.2. 9. Read the Information sheet 2.3. 10. Perform the Job sheet 2.2.
Refer to the teacher’s Assessment Check list 2.1 and 2.2. Refer to the teacher’s Assessment Check list 2.3. Refer to the teacher’s Assessment Check list 2.4.
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INFORMATION SHEET 2.1 Designing and Etching
PCB of AC-DC Power Supply
A printed circuit board (PCB) has components inserted into the hole and soldered to form its circuit connection. Its main purpose is to reduce the space and to troubleshoot easily when problem arises. The printed circuit board (PCB) has conductors that are thin strip of copper, usually bonded to a baseboard called substrate. There are two very common substrate materials used in printed circuit, the phenolic and epoxy plastic.
Copper
Substrate
on
Printed Circuit Board
Printed Circuit Board Etching is where the excess copper is removed to leave the individual tracks or traces as they are sometimes called. Buckets, bubble tanks, and spray machines are tools to do different ways of etching but most firms currently use high pressure conveyors spray equipment. Spray etching is fast Ammoniacal etching solutions when sprayed can etch 55 microns of copper a minute. Less than 40 seconds to etch a standard 1 oz, 35 micron circuit board.
Printed Circuit Board Etching Many different chemical solutions can be used to etch circuit boards ranging from slow controlled speed etches used for surface preparation to the faster etches used for etching the tracks. Some are best used in horizontal spray process equipment while others are best used in tanks. Enchants for PTH work have to be selective and be non aggressive to tin / tin lead plating, which is used as the etch resists. Copper etching is normally exothermic where high
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speed etching is carried out solution cooling is normally required. This is normally done by placing titanium water cooling coils into the enchant. Almost all etching solutions liberate toxic corrosive fumes. Extraction is highly recommended. All enchants are corrosive and toxic mainly due to the high metal content. P.P.E. Personal Protection Equipment must always be used. Spent solutions should always be disposed properly and not to be spilled down local drains where they can pollute local sewage works and rivers. Manufacturing of Printed Circuits in the Copper Clad Board In PCB designing, we should not focus only on the size of the pathways linking to the other component, but also on the types, kinds, and characteristics of component. Here are the other design factors needed: 1. PCB size and shape. The PCB must be big enough for the entire component to be mounted where it is anticipated. 2. Position of the Terminal. Input, output and supply voltage if possible should be placed near the border for easier way during troubleshooting or minor repair. 3. High Temperature Dissipation. Too much heat is the number one problem of all components. Bigger space is needed so that heat sink can be provided to the component. This will protect the component from burning up. 4. Accessibility of Components. This component that is adjustable or variable (example: potentiometer, trimmer resistor or capacitor) should be placed near the border to make the troubleshooting or minor repair easier. 5. Space for Bolt and Nut. The designer should place an allowance for mounting the PCB with bolt and nut in securing the entire board to the chassis. 6. Different Types of Circuit Should be Grouped according to its Application. This will enhance the circuit operation and will prevent it from distortion generated by other circuit. This is the reason why the circuit of the power supply is far from the audio circuit.
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SELF-CHECK 2.1 Designing and Preparing PCB of AC-DC Power Supply
Direction: Identify the following items.
1.
A board that is open with electronic components is mounted and soldered.
2.
A conductor where the component’s terminal lead is soldered.
3.
It consists of a thin copper layer which is firmly bonded to an insulating base material. It is sometimes called as a component side.
4 -5. The two types of substrate materials used in a present circuit.
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SELF-CHECK KEY 2.1 Designing and Preparing PCB of AC-DC Power Supply
1.
PCB
2.
Substrate
3.
Copper foil side
4.
Epoxy
5.
Phenolic
Note: If you got all the answers right, that is an excellent mark. But if you missed one or more, go back to the questions and study them more closely before you proceed to the next lesson .
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OPERATION SHEET 2.1 Designing and Preparing PCB of AC-DC Power Supply Direction: Given the resources needed, perform the procedure in designing and preparing a PCB of AC-DC Power Supply. Conditions The following resources are needed: - Electronic tools and equipment Soldering Iron Desoldering tool Screwdriver (Flat / and Philip) Wire stripper / Utility knife Pliers Diagonal cutter long nose plier High grade magnifying glass with lamp Cleaning brush Soldering lead Cleaning agent Wires Stranded Solid Pre-design Printed Circuit Boards (PCB) Mini drill with drill bit ) with adaptor (+12VDC supply) Sand paper Metal polish or eraser Ruler AC-DC power supply kit (1.5 – 12 volts variable power supply) Analog multi tester (voltmeter / VOM) Procedure in Preparing the Layout Diagram in the PCB 1. Prepare the schematic diagram of the circuit.
Circuit Schematic Diagram
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2. Arrange the component circuit in a graphing paper to show/illustrate the same design factor in PCB lay outing. Note: Actual size of the component should be adapted for component arrangement and mounting. Capacitor Four Diodes
ccc
Resistor Led
AC Input DC Output Hole for Bolt & Nut
PCB Layout
3. Interconnect each component by copying the connection in the schematic diagram.
Schematic Diagram 4. Double-check the connection. 5. Trace the designed PCB by using a carbon paper and mark it on the copper side of the clad board. 6. And use a high point permanent marker for marking. Do the marking three times and be careful not to shorten each line marking.
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Characteristics of Good PCB Design – 4C’s 1. Clean. It should be clean so that the representation of the schematic diagram is easy to mark and troubleshoot the PCB. 2. Compressed. Reducing the size for space saving in chassis. 3. Creative in Design. There is a pattern or image when it is created. 4. Consistency in Component. The components should be well arranged in group.
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PERFORMANCE CHECK 2.1 Designing and Preparing PCB of AC-DC Power Supply Direction: Answer the following by putting a check mark in the appropriate box. Did you:
YES
NO
1. Prepare the schematic diagram of the circuit? 2. Arrange the components in the circuit in graphic paper to follow the design factor in PCB layout? 3. Interconnect each component? 4. Trace the design? 5. Produce a good characteristics PCB design (clean, compressed, creative and consistent with the component size?
5 Yes Remarks Excellent
3 Yes Remarks Satisfactory
4 Yes Remarks Very Satisfactory
1-2 Yes Remarks Needs Improvement
Student’s Signature______________________
Date
______________
Teacher’s Signature______________________
Date
_________________
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INFORMATION SHEET 2.2
Printed Circuit Board Etching It is the removal of unwanted portion or layer of conductive materials (that is copper) bonded to an insulating base called substrate. By using a chemical reaction to the copper called ferric chloride, it liquefies the uncovered surfaces of the designed copper clad board that creates a PCB. Cover Surface Copper Conductor
Printed Circuit Board
Substrate
Cover Surface Copper Conductor
Printed Circuit Board
Substrate
Tools and Materials Needed In PCB Etching 1. Designed PCB 2. A bottle of the Ferric Chloride. (The quantity of bottle will depend upon the area of the PCB). 3. Plastic Basin. It is the medium of ferric chloride 4. Popsicle sticks (2 pieces). It is used for hauling the designed PCB. 5. Old newspaper. It is placed under the plastic basin for the prevention of accidental spill of chemical over the table. 6. Apron 7. Piece of Cloth 8. Plastic Varnish 1 bottle 9. Lacquer Thinner 10. Surgical Gloves 11. Knife or Cutter JOB SHEET 2.1
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Printed Circuit Board Etching Direction: Given the resources needed, perform the procedure in PCB Etching to produce a PCB. Conditions The following resources are needed: Electronic tools and equipment Soldering Iron Desoldering tool Screwdriver (Flat / and Philip) Wire stripper / Utility knife Pliers Diagonal cutter long nose plier - High grade magnifying glass with lamp - Cleaning brush - Soldering lead 60/40 - Cleaning agent - Wires Stranded Solid - Pre-design Printed Circuit Board (PCB) - Mini drill with drill bit ( .9mm and 3mm ) with adaptor (+12VDC supply) - PCB copper foil cleaning agent ( metal polish/Eraser ) - Pencil - Ruler - AC-DC power supply kit (1.5 – 12 volts variable power supply) - Analog multi tester (voltmeter / VOM) -
Steps in PCB Etching 1. Prepare the necessary tools and materials needed in PCB etching. 2. Wear your apron and surgical gloves in order to prevent accidental splash of the solution on your clothes or on your skin.
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3. Pour the ferric chloride in the plastic basin.
Ferric
Chloride Plastic Basin 4. Etch the PCB by immersing it in a basin filled with ferric chloride until the uncovered part of the copper clad is totally etched.
Immerse PCB in plastic basin filled with ferric chloride
5. After 10 - 15 minutes, check the PCB if all the parts needed to be removed are totally etched (using the two popsicle sticks in hauling). If not yet, return it into the plastic basin filled with ferric chloride. After 3 – 5 minutes check it again. 6. Haul the PCB from the plastic basin and wash it in a free flowing water to remove the remaining residue in the PCB. PCB basin
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7. With a clean and dry piece of cloth, wipe the wet PCB. 8. Pour a little amount of lacquer thinner on a clean dry piece of cloth and wipe the markings of the permanent marker pen in the copper clad. (Note: In doing this, you should wear your surgical gloves.) 9. Aided by bright light, inspect the PCB for possible hairline break or short. If there is a hairline path between the copper conductors, cut it by a knife or cutter. And if there is a break between the copper conductors, solder it.
PCB
light
Designed
10.
Apply plastic varnish to the newly etched PCB to prevent corrosion
or rust, and let it dry before touching it.
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Techniques to correct PCB Hairline Break or Short A.
Hairline Break.
It is an open copper foil in the Printed Circuit Board.
Most of the time this is due to improper PCB designing or etching. To eliminate the hairline break, just place a hook up wire and solder it.
Hairline Break B.
Hairline Short in the PCB Conductor. It arises if the printed circuit board designing or etching is done improperly. To eliminate the hairline short, you should cut it with a knife.
Hairline Short
Hairline Short in the PCB Conductor
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ASSESSMENT CHECKLIST 2.1 PCB Etching Direction: Encircle the number which will show how competent you have applied the skill using the criteria below. Compute for the total result.
Criteria
Points
Final
Workmanship Use of Tools Use Personal Protective Equipment SPEED House Keeping Finished Design Total
Assessment Criteria 2.1 Score
Descriptive Grade
96-100
Excellent
86-95
Very good
81-85
Good
75-80
Fair
70-74
Poor
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ASSESSMENT GUIDE FOR JOB SHEET 2.1 Direction: Encircle the number which shows how competent you have applied the skills according to the criteria given below.
The evidence shows that you have performed
Points
the following:
Final Score
1. Prepared Printed Circuit Board design and etch AC-DC power supply . 2. Mounted and soldered electronic components at the appropriate location on the Printed Circuit Board. 3. Interconnected all auxiliary components including the transformer on the Printed Circuit Board. TOTAL
Rating System 2.1 Score
Descriptive Grade
15
Excellent
12-14
Very good
10-11
Good
7-9
Fair
6 and below
Reread the information sheet 2.2 on PCB Etching
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OPERATION SHEET 2.3
Boring Direction: Given the resources needed, perform the procedure in designing and preparing a PCB of AC-DC power supply. Conditions
Tools and Materials - Mini Drill - PCB - Piece of wood - Drill bit - Varnish
Procedure
Mini Drill Setup 1. Loosen the chuck by using a long metal tool and change the drill bit. This is done in a counter clockwise movement.
Drill Bit
Long Metal Tool Mini Drill
2. Insert the drill bit 1mm diameter in size and attach it to the chuck of the unit.
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3. Turn the long metal tool clockwise to tighten the jaw of the unit. Be sure that the drill bit is well secured on the chuck. 4. Before inserting the 12 volts adaptor, you should turn off the unit. 5. Test the rotation of the unit if it is well aligned. If not, align it following the steps no. 1 and 2.
How to Use a Mini Drill? To control the unit, hold the mini - drill at the lower part and firmly position your arm. Then with the mini drill held perpendicularly to your work surface, lightly press downward to the holes to be drilled in the PCB but be sure that the PCB has a piece of wood under it to avoid damaging the table. With practice, you will be able to get the procedure correctly.
Mini Drill PCB
Piece of Wood
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Boring Procedure 1.
Prepare all the materials needed. - Mini drill -
Designed PCB
2. Mark where the holes are to be drilled. 3. Using the mini drill, bore hole perpendicularly to the surface of the PCB. 4. Clean the surface of the PCB and look for open line or short circuit. 5. Apply varnish on the clad surface to prevent it from corrosion.
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SCORING RUBRICS FOR OPERATION SHEET 2.3 Boring Note: You should read the following before and after performing the process. Workmanship 55% 1. Tools were properly used according to its function. 2. PPE was observed completely while working. 3. Proper tools were used and PPE were observed while working. Speed 5% Finished task before time frame Finished task within the time frame Finished task 15 minutes after the time frame Finished task 30 minutes after the time frame Finished task 31 minutes and more Housekeeping 5% 1. The whole area was cleaned after the assembly 2. The whole area was dirty after the assembly Finished Design 35% Finished design based from the given schematic diagram Finished design was correct but with access copper clad on the finished design Finished design was correct but with cut on the line Finished design was with shorted line that will cause a short circuit Finished design was incorrect
25 25 5 5 4 3 2 1 5 1 35 30 25 10 2
Total 100%
Rating System Score in Percent Descriptive Grade 95% - 100% Outstanding 80% - 94% Very Satisfactory 75% - 79% Satisfactory 74% and below Needs Improvement Note: If you got 74 and below, you need to go over the procedures and ask assistance from your classmates who passed this activity or from your teacher.
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JOB SHEET 2.2 Mounting and Soldering AC-DC Power Supply Project Direction: Using the given tools, supplies and materials, mount the electronic components to the PCB and perform soldering procedure to assemble an AC-DC power supply project. Conditions o
Supplies and Materials -
o
Designed PCB Soldering Lead, 60/40 AC cord with plug Toggle Switch (on/off) Fuse and fuse holder (1A) Selector switch – 2 poles 6 positions 4 pcs. Rectifier diode Electrolytic capacitor – 3,300 uF/25V Jumbo LED with holder Transformer, Primary voltage 0-220 volts; Secondary voltage (0V, 3V, 4.5V, 6V, 9V, 12V; current rating 750mA)
Tools and Equipment - Long nose pliers - Soldering iron
Simple Power Supply Project In all the basic electronic theories, power supply assembling is the most common application needed by the students. In this project, they will be able to apply all the knowledge they have learned since the very start of their lessons. This project will enable them to practice the five characteristics of a good assembler. These are the planning, assembling, testing, troubleshooting and appreciating the work.
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Schematic Diagram of a Multi-Volts Unregulated Power Supply
Auxiliary Components of Power Supply There are some minor components needed to be familiarized with and their uses. These are the AC plug with cord, power switch, fuse holder and fuse, selector switch, selector knob, indicator lamp and alligator clips.
-
AC Plug with Cord is used for connecting the 220V input voltage of the power supply.
-
Power Switch is used to control the flow of 220VAC to the power supply by turning off or on.
-
Fuse Holder & Fuse is used to protect the unit from any sudden short from the load or too much rising of power from the line source.
-
Selector Switch is used to select the output voltage of the power supply from 3V to 12V DC
-
Selector Knob is a plastic holder of the selector switch.
-
Indicator Lamp is used to show if there is a presence of power in the circuit. Neon Lamp is for 220V AC monitoring lamp. Led is for output monitoring lamp
-
Alligator Clips are used to connect the two-line output to the load. Red clip for positive. Black clip for negative
38
Sample Components Placement Guide Four Diodes
ccCapacitor
Resistor
Led AC Input
c
DC Output
Hole for Bolt & Nut
Top View of PCB Layout
PCB LAYOUT Procedure: 1. Prepare all the materials needed. 2. Clean the terminals of the components to be soldered and the PCB copper side. 3. Mount the components in the PCB. 4. Solder components. 5. Cut the excess terminals of the component. 6. Test the circuit using the multi-tester.
39
ASSESSMENT CHECKLIST FOR JOB SHEET 2.2 Mounting and Soldering AC-DC Power Supply Project Direction: Encircle the number which will show how competent you have applied the skill using the criteria given below. Compute for the total result.
Criteria
Points
Final
Workmanship Use of Tools Use PPE SPEED House Keeping Finished Design Total
Assessment Criteria 2.3 Score
Descriptive Grade
96-100
Excellent
86-95
Very good
81-85
Good
75-80
Fair
70-74
Poor
40
ASSESSMENT PLAN
Title of Module
ASSEMBLING AC-DC POWER SUPPLY
Observation
Ways on how evidences will be collected [tick the column]
The evidence shows that the student can…
identify types of power supply
identify parts of AC-DC power supply
identify electronic components needed in assembling AC- DC power supply
prepare, design and etch printed circuit board of an AC-DC power supply.
mount and solder electronic components at the appropriate location on the printed circuit board.
interconnect the PCB with all the auxiliary components.
securely mount all the components at the chassis
correct all defects of an AC-DC power supply .
Did the student’s overall performance meet the standard? Prepared by:
Date:
Checked by:
Date:
Yes
Portfolio
ASSEMBLE AND DISASSEMBLE CONSUMER ELECTRONIC PRODUCTS AND SYSTEMS
Demonstration
Unit of competency
Third party Report
CONSUMER ELECTRONIC SERVICING NC II
Oral Questioning
Competency standard
Written
Evidence Checklist
No
41
OBSERVATION CHECKLIST Student’s name: Teacher’s name: Name of School Competency standards Unit of competency: Instructions for the teacher: 1. Observe the student in Assembling AC-DC power supply 2. Describe the assessment activity and the dates when it will be undertaken 3. Place a tick in the box to show that the student has completed each aspect of the activity according to the standard expected in the enterprise. 4. Complete the feedback sections of the form. Date of observation Description of assessment activity Location of assessment activity The student has:
Identified types of power supply
Identified parts of AC-DC power supply
Known the electronic components in assembling AC-DC power supply.
Prepared, designed and etched printed circuit board of an AC-DC power supply.
Mounted and soldered electronic components at the appropriate location on the printed circuit board.
Interconnected the PCB with all auxiliary components.
Securely mounted all components at the chassis.
Corrected all defects of an AC-DC power supply.
Did the student’s overall performance meet the standard?
If yes, tick the box
Yes
No
Teacher’s Feedback Teacher’s signature
Date:
42
OBSERVATION AND QUESTIONING CHECKLIST Student’s name Teacher’s name Name of School Competency standards Unit of competency Instructions for the teacher: 1. Observe the candidate in Assembling AC-DC power supply 2. Describe the assessment activity and the date when it will be undertaken. 3. Place a tick in the box to show that the student has completed each aspect of the activity according to the standard expected in the enterprise. 4. Ask the student based on the questions in the list to confirm his/her underpinning knowledge 5. Place a tick in the box to show that the student has answered the questions correctly. 6. Complete the feedback sections of the form. Date of observation Description of assessment activity Location of assessment activity The student has
Identified types of power supply.
Identified parts of AC-DC power supply
Known electronic components needed in assembling ACDC power supply.
Prepared, designed, and etched Printed Circuit Board of an AC-DC power supply.
Mounted and soldered electronic components at the appropriate location on the printed circuit board.
Interconnected the PCB with all the auxiliary components.
Securely mounted all the components at the chassis.
Corrected all defects of an AC-DC power supply
If yes, tick the box
Yes
No
Did the student’s overall performance meet the standard?
43
DEMONSTRATION Student’s name: Teacher’s name: Unit of competency: Competency standards: Date of assessment: Time of assessment: Instructions for demonstration Given the necessary materials the trainee/student must be able to:
Materials and equipment:
to show if the skill has demonstrated
During the demonstration of skills, did the student:
Yes
No
N/A
Identify types of power supply?
Identify parts of AC-DC power supply?
Know the electronic components needed in assembling AC-DC power supply?
Prepare, design and etch printed circuit board of an AC-DC power supply?
Mount and solder electronic components at the appropriate location on the printed circuit board?
Interconnect the PCB to all the auxiliary components?
Securely mount all components at the chassis?
Correct all defects of an AC-DC power supply ?
The student’s demonstration was: Satisfactory
Not Satisfactory
44
WRITTEN REPORT Student’s name: Teacher’s name: Name of School Competency standards Unit of competency: Task: Your task is to: Assemble AC-DC power supply Submission date: Use the checklist below as the basis for judging whether the student’s report has met the required competency standards. The student’s report states that
The types of power supply were identified.
The parts of AC-DC power supply were identified.
The electronic components needed in assembling AC-DC power supply were identified.
The printed circuit board of an AC – DC power supply was prepared, designed and etched.
The electronic components mounted and soldered at the appropriate location on the printed circuit board.
The PCB was interconnected to all auxiliary components.
All the components were securely mounted at the chassis.
All defects of an AC-DC power supply were connected.
Generally, did the student’s report meet the standard?
If yes, tick the box
Yes
No
Comments:
Student’s signature:
Date:
Teacher’s signature:
Date:
45
PERFORMANCE TEST Student's Name
Date
Competency:
Directions: Ask your teacher to assess your performance in the following critical tasks using the performance criteria below. You will be rated based on the overall evaluation at the right side.
Test Attempt 1st 2nd 3rd OVERALL EVALUATION Level Achieved
PERFORMANCE LEVELS 4 - Can perform this skill without direct supervision and with initiative and adaptability to problem situations. 3 - Can perform this skill satisfactorily without direct assistance or supervision. 2 - Can perform this skill satisfactorily but requires some assistance and/or supervision. 1 - Can perform parts of this skill satisfactorily, but requires considerable assistance and/or supervision. Teacher will put initial at level achieved.
PERFORMANCE STANDARDS For acceptable achievement, all items should receive a "Yes" or "N/A" response.
Yes
No
N/A
Types of power supply were identified.
Parts of AC-DC power supply were identified.
Electronic components needed in assembling AC-DC power supply were identified.
Printed Circuit Board of an AC – DC power supply was prepared, designed and etched.
Electronic components were mounted and soldered at the
Appropriate location on the Printed Circuit Board
The PCB was interconnected with all the auxiliary components.
All components were securely mounted at the chassis.
All defects of an AC-DC power supply were corrected.
46
REFERENCES
1. Tan, Michael Q., Gantalao, Fred T., Lasala, Rommel M. Simple Electronics; Andes Mountain Printers: 2004 2. Enriquez, Marcelo T. Electronics Technology IV; Souvenir Publications, Inc.: 2003
ACKNOWLEDGMENT Copyright Department of Education 2008 First Published JUNE 2008 This module is based on the Competency-Based Curriculum-Contextual Learning Matrix (CBC-CLM) and finalized on the Instructional Modules Finalization Development Workshop conducted at the Finalization Workshop conducted at the Development Academy of the Philippines, Tagaytay City on May 6 -10, 2008 This learning instrument was developed by the following personnel: Technology Teachers:
Mr. Vic P. Diola – Group Leader Bauan Technical High School
Dr. Gilbert M. Castor Don Alejandro Roces Sr. Science-Technology High School
Mr. Eddielou L. Dayao Sanchez Mira School of Arts and Trades
Mr. Rufo G. Malla Eulogio Rodriguez Vocational High School
Mr. Sherwin P. Medrano San Pedro Relocation Center National High School
Mr. Remar C. Pinsoy Baguio National School of Arts and Trades
Contextual Teacher: Mrs. Daisy Carousel P. Cervantes Don Alejandro Roces Sr. Science-Technology High School
Facilitators:
Dr. Edward M. Dela Rosa
Dr. Corazon L. Echano TEC-VOC Task Force
Encoders:
Mrs. Rosario D. Briones Mr. Mhariel L. Echano Mr. Jason O. Villena
Funding: Department of Education
ACKNOWLEDGEMENT Copyright: Department of Education 2009 This module is based on Competency-based Curriculum- Contextual Learning Matrix ( CBC-CLM ) refined during the Writeshop on the Refinement and Enrichment of Competency-Based Curriculum and Contextual Learning Matrix of ARTS and TRADES Specializations at Marikina Hotel, Marikina City on April 20 – 25,2009. This learning instrument was refined and enriched by the following educators: Technology Teachers ( Electronics ) VICTORINO P. DIOLA – Group Leader TVE Coordinator, Bauan Technical High School Bauan, Batangas GIGI C. CORPUZ Teacher III, Malvar National High School Malvar, Batangas ISMAEL G. GALLARDO Teacher I, Community Vocational High School Masipit, Calapan City, Oriental Mindoro REYNALDO C. CUNANAN Head Teacher VI, EARIST Voc. High School Nagtahan, Sampaloc, Manila GEORGE B. FUASO Teacher II, Gen. Mariano Alvarez Technical High School GMA, Cavite RUFO G. MALLA Teacher II, EARIST Voc. High School Nagtaha, Sampaloc, Manila Contextual Teachers: English TERESITA P. TANAEL Teacher III, Gen. Mariano Alvarez High School GMA, Cavite CHARLIE I. SORIANO Teacher I, Don Alejandro Roces, Sr. Science-Technology H.S.
Mathematics ANALISA ROSA P. LIBRADA Teacher I, Mathematics Coordinator San Pedro Relocation Center National High School San Pedro, Laguna Science GEMMA G. VALLARTA Teacher III, Science Coordinator San Pedro Relocation Center National High School San Pedro, Laguna
LENALYN N. MANZANO Teacher I, Physics E. Rodriguez Vocational High School Nagtahan, Sampaloc, Manila Facilitators: Dr. CORAZON L. ECHANO Tech-Voc Task Force Dr. VICTORIO N. MEDRANO Tech-Voc Task Force Dr. ORLANDO E. MANUEL Tech-Voc Task Force Encoder: MARISOL E. SALDIVAR Teacher I, Sta. Lucia High School Pasig City
Republic of the Philippines Department of Education PUBLIC TECHNICAL -VOCATIONAL HIGH SCHOOLS
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module No. 2
MAINTAINING AND REPAIRING AN ELECTRIC FAN
Table of Content How to Use this Module ................................................................................... 2 Introduction ..................................................................................................... 3 Technical Terms ............................................................................................... 4 Learning Outcome 1: Identify the parts and functions of an electric fan ............................................. 6
Learning Experience / Activities …………………………………………………..7 Information Sheet 1.1 ............................................................................. 8
Student-Check 1.1................................................................................ 11
Answer Key 1.1 ..................................................................................... 12
Learning Outcome 2: Diagnose an electric fan and troubleshoot the defects found........................... 13
Learning Experience / Activities ………………………………………………...14 Operation Sheet 2.1 .............................................................................. 15
Performance Test 2.1 ............................................................................ 23
Student Write-up A ........................................................................... 23
Student Write-up A ………………………………………………………………….24 Learning Outcome 3:
Maintain and repair an electric fan................................................................. 25
Learning Experience/Activity ……………………………………………………..26 Information Sheet 3.1 ........................................................................... 27
Student Check 3.1 ............................................................................... 31
Student Check Key 3.1 ......................................................................... 32
Job Sheet 3.1 ....................................................................................... 33
Performance Test ........................................................................................... 35 Assessment Plan ............................................................................................ 36 Observation Checklist for Performance test .................................................... 37 Questionnaire Checklist ................................................................................ 38 Observation Checklist 3.1 …………………………………………………………………39 Questioning Checklist ………………………………………………………………………40 Acknowledgement…………………………………………………………………………….42
HOW TO USE THIS MODULE Welcome to the Module “Maintaining And Repairing An Electric Fan”. This module contains training materials and activities for you to complete. The unit of competency “Maintain & Repair Electronically-Controlled Domestic Appliances” contains the knowledge, skills and attitudes required for Consumer Electronics Servicing required to obtain the National Certificate (NC) level II. You are required to go through a series of learning activities in order to complete each of the learning outcomes of the module. In each learning outcome there are Information Sheets and Activity Sheets. Do these activities on your own and answer the Self-Check at the end of each learning activity. If you have questions, don’t hesitate to ask your teacher for assistance. Recognition of Prior Learning (RPL) You have already some basic knowledge and skills covered in this module because you have been working for some time; and have already completed training in this area. If you can demonstrate competence to your teacher in a particular skill, talk to him/her so you don’t have to undergo the same training again. If you have a qualification or Certificate of Competency from previous trainings show it to him/her. If the skills you acquired are consistent with and relevant to this module, they become part of the evidence. You can present these for RPL. If you are not sure about your competence skills, discuss this with your teacher. After completing this module, ask your teacher to assess your competence. Result of your assessment will be recorded in your competency profile. All the learning activities are designed for you to complete at your own pace. In this module, you will find the activities for you to complete and relevant information sheets for each learning outcome. Each learning outcome may have more than one learning activity. This module is prepared to help you achieve the required competency, in receiving and relaying information. This will be the source of information that will enable you to acquire the knowledge and skills in Maintaining and Repairing an Electric Fan independently at your own pace with minimum supervision from your teacher.
2
Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING AN ELECTRIC FAN
INTRODUCTION: This module contains information and suggested learning activities in maintaining and repairing an electric fan. It covers the knowledge, skills and attitudes required to maintain and repair an electric fan. Completion of this module will help you better understand the succeeding module on maintaining and repairing electronically-controlled domestic appliances. This module consists of three (3) learning outcomes. Each learning outcome contains learning activities supported by instructional sheets. Before you perform the instructions, read the information sheets and answer the self-check and activities provided to ascertain to yourself and your teacher that you have acquired the knowledge necessary to perform the skill portion of the particular learning outcome. Upon completing this module, report to your teacher for an assessment to check your achievement of knowledge and skills required this module. If you pass the assessment, you will be given a certificate of completion. SUMMARY OF LEARNING OUTCOMES: Upon completion of the module, you should be able to:
LO1. identify the parts and functions of an electric fan;
LO2. diagnose and troubleshoot an electric fan; and
LO3. maintain and repair an electric fan.
3
TECHNICAL TERMS AC Motor. It converts AC electrical energy into mechanical energy producing a mechanical rotary action that performs some kind of work. Antistatic. It is a container which resists generation of triboelectric charge (frictionally generated ) as the device is inserted into, removed from , or allowed to slide around it. Bushing. It is a sleeve protecting a conductor where it passes through a hole in motor. Capacitor. It is a device used to boost the voltage to a motor. Running capacitors are used in the starting winding to increase the running torque of the motor. Starting capacitors are used in the starting winding to increase the starting torque of the motor. Capacitor for Start Motor. It is a low reactance non-polar electrolytic capacitor connected in series with the start winding. Motor. It is a rotating electric machine which changes applied electrical energy or power into mechanical output energy or power. Rotor. It is the part of an electric motor that turns or rotates. Run Winding. It is the winding in an electric motor provides the power for turning the rotor during operation. It has the larger wire of the two windings. The main winding of the motor is comparatively low resistance and high inductance. Rectifier. It is a diode circuit that converts AC to pulsating DC. Resistor. It is a component made of material that opposes the flow of current and therefore has some value of resistance. Rotary Switch. It is an electromechanical device that has a rotating shaft connected to one terminal capable of making, breaking a connection to one or more other terminals. Shaft. It is the part of a rotor that carries other rotating members and that is supported by bearings in which it can rotate. Start Winding. It is the auxiliary winding of the motor with comparatively high resistance and lower inductance. Stator. It is the stationary part of the motor which the field windings are placed.
4
System Control Microprocessor. It is an integrated circuit that can recognize and respond to commands from the operator by monitoring the DC voltages at the output terminals. Schematic Diagram. It is an illustration of an electrical or electronic circuit with the components represented by their symbol. Short Circuit. It is also called as short. It is low resistance connection between two points in a circuit typically causing excessive current. Solder. It is a metallic alloy used to join two metal surfaces. Soldering. It is a process of joining two metallic surfaces to make an electrical contact by melting solder (tin and lead) across them. Substrate. It is a mechanical insulating support upon which a device is fabricated. Switch. It is an electrical device having two states, ON (closed) or OFF (open). Thermal cutout. It is an over current device that contains a heater element in addition to and affecting a renewable fusible member which opens the circuit. It is not designed to interrupt short-circuit currents. Transformer. It is an inductor with two or more windings. Troubleshooting. It is a systematic approach to locate the cause of a fault in an electronic circuit or system. Winding. It is an assembly of coils designed to act in consort to produce a magnetic flux field or to link a flux field.
5
Program/Course
CONSUMER ELECTRONIC MECHANIC NCII
Unit of Competency
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title
MAINTAINING AND REPAIRING AN ELECTRIC FAN
Learning Outcome 1: Identify the parts and functions of an electric fan. Assessment Criteria: 1. The operation of an electric fan is explained. 2. The parts of an electric fan are identified. 3. The functions of its parts are explained.
6
LEARNING EXPERIENCE / ACTIVITIES Learning Outcome 1 : Identify the functions of the parts of an electric fan. Learning Activities Special Instructions Read the Information Sheet You can ask assistance from 1.1 on Operation of an electric your teacher to show you and fan, parts and its functions. explain to you further by the topics you don’t understand Do the Self-Check No. 1.1 to well. check your knowledge on the Operation of an electric fan, Try to answer the Self-Check parts and its functions. without looking at the Information Sheet. Check your answers using the Answer Key. If you were not able to answer all the questions, go over again to the Information Sheet. If you have answered all the questions, you can proceed to the next learning outcome.
7
INFORMATION SHEET 1.1 Operation of an Electric Fan, Parts and Functions OPERATION OF AN ELECTRIC FAN Electric Fan is an air moving machine used to cool with an AC Motor connected to the 60 Hz power source which converts electrical energy to mechanical energy in order to generate a moving air. It is a power driven machine capable of providing high air flow parallel to the axis of the motor shaft where an axially mounted impeller or fan blade agitates the air. The air velocity/delivery of the electric fan is controlled by a mechanical speed selector switch for old models and electronically controlled speed selector switch for new models. Timer is also included for fully automatic operations. PARTS OF AN ELECTRIC FAN
Front Guard.
It is a protective metal mesh wire used to prevent the fan blade from any physical contact with foreign objects.
Guard Mark.
It is a logo of the manufacturer of the electric fan which is mounted at the center of the front guard.
8
Switch Box .
It is a panel board for the controls of the electric fan.
Inner Pipe.
It is a metal tube inserted into the outer tube intended for the proper height adjustment of the electric fan.
Outer Pipe.
It is a metal tube attached to the base stand of the Electric fan.
Base Stand.
It is the bottom or lowest part of the electric fan where it stands on as a foundation.
Blade.
It is a propeller made out of plastic or metal attached to the motor shaft and agitates air when the motor rotates.
Remote Control. It is a transmitter device used to control the electric fan from a distance.
Block Diagram of Electronically-Controlled Electric Fan (ECEF)
Power Controller. It is a circuit that controls the amount of power Supplied to the motor.
9
Sensor
Manual Control.
Non-polarized Capacitor. A low reactance non-polar capacitor connected in series with the start winding of an electric fan.
Timer.
It is used to switch on or switch off automatically with predetermined time.
Comparator.
It is a processing circuit that accepts the input input signal coming from remote control, manual switch or timer switch. This circuit provides the triggering voltage to the power controller.
AC Motor.
AC Plug.
It is the input receiver that detects input signal coming from remote control. It is a push button switch that controls manually operation of the electric fan.
It is rotating electric machine which changes applied electrical energy or power into mechanical output energy or power. It is a connector intended for connecting to the main source 220 V.
10
SELF-CHECK 1.1 Direction: Label the different blocks that resemble an electronicallycontrolled electric fan. Write your answer in piece of paper. Do not write anything in this module. I
II
11
ANSWER KEY TO SELF-CHECK 1.1 I 1. Blade 2. Front Guard 3. Switch Box 4. Inner pipe 5. Base stand II 1. Comparator 2. Power Controller 3. AC Motor 4. Sensor 5. Manual Switch
12
Program/Course
CONSUMER ELECTRONIC MECHANIC NCII
Unit of Competency
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title
MAINTAINING AND REPAIRING AN ELECTRIC FAN
Learning Outcome 2: Diagnose an electric fan and troubleshoot the defects found. ASSESSMENT CRITERIA: 1. Pre-testing
procedure
is
followed
in
accordance
with
the
manufacturer’s manual. 2. System defects/fault symptoms are identified using appropriate tools and equipment. 3. Identified defects and faults are explained to the responsible person. 4. Results of diagnosis and testing are documented. 5. Troubleshooting is performed in accordance with the service manual.
13
LEARNING EXPERIENCE / ACTIVITIES Learning Outcome 2 Diagnose an electric fan and troubleshoot the defects found. Learning Activities Special Instruction Perform the Operation Sheet 2.1 You can ask assistance from on procedure and technique in your teacher to show you and pre-testing and troubleshooting explain to you further the topic/s an electric fan. you don’t understand well. Do the Performance Test to test your skills on procedure and technique in pre-testing and troubleshooting an electric fan.
Try to perform the Performance Test within the time allotment.
Refer to your Performance Output to the Observation and Questioning Checklist. If you missed some of the items in the Observation and Questioning Checklist, go over again to the Operation Sheet. If you did get all the items in the Observation and Questioning Checklist, you can proceed to the next learning outcome.
14
OPERATION SHEET 2.1 Procedure and Techniques In Pre-Testing An ElectronicallyControlled Electric Fan (ECEF) PROCEDURE IN PERFORMING PRE-TESTING OF AN ELECTRIC FAN 1. Determine what the problem really is. a. Ask questions to the owner/operator of the electric fan to identify the problem to you. b. Ask for the detail about the problem and how long it has been happening. 2. Be sure that you understand how the electric fan is going to be operated. a. If you have worked on it before, check it out to see if it still operates in the same way. b. Try to determine the last time it has been modified/repaired prior to you. c. Review the operating manual if you are not familiar with the model of the electric fan. d. Review the service manual for the unit prior to any testing. 3. Perform closer inspection into the suspected defective parts or components. a. Prepare the tools needed and remove the cover ready for inspection. b. Apply careful physical inspection of the suspected parts/components. c. Look for burned and broken components. d. Inspect for loose connections or broken wires. e. Modify
15
TECHNIQUES IN PERFORMING PRE-TESTING OF AN ELECTRIC FAN 1. Conduct a prompt diagnosis of the trouble symptom and repair the defective set in the shortest possible time. Do not troubleshoot an electric fan unless you have determined what the fault is. Locate the fault from the mechanical section or electrical circuit section. 2. Wear cotton gloves while troubleshooting to avoid the electrical shock. Also note that, especially in tropical countries, sweat on hands may cause accident. 3. When troubleshooting in the electrical circuit section, never remove a component for testing. Before doing this, first measure the voltage. If the reading is abnormal, analyze the circuit and check which component may be causing the trouble and should be tested. 4. Discharge large capacitors by connecting a jumper wire across their two conducting terminals. 5. If the trouble symptom is caused by aging components, the defective component is usually one of them. But in some cases, especially in highpower-handling circuits, a defective component may cause other components to malfunction. 6. Know the usual defects of components. For example, capacitors usually become leaky, shorted or open. Resistor increase their resistance when they become defective. Semi-conductors such as transistors usually become open or shorted. 7. When troubleshooting integrated circuits (ICs) in the electrical circuit section of an electric fan, do not remove the IC from the PCB just simply suspecting that it is defective. To help you diagnose the function of the IC, secure a circuit diagram from the manufacturer. It will be even better if you have available diagram showing the internal connection of the IC. 8. Always be careful about the polarity of the components when replacing them. Electrolytic capacitors used in transistors or integrated circuits have only low voltages. 9. Do not remove components from the PCB. Every component has a specific function in the circuit. Always analyze the specific function of every component in the circuit. 10. Don’t replace an opened fuse or burned resistor unless, you have corrected the trouble or have detected. 11. Always suspect a faulty contact on mechanical switch circuit rather than defective electronic components. 12. When replacing the resistor (SCR/TRIAC), the replacement should have the same current rating. 13. Use needle-pointed probes for better contact and to avoid short circuiting nearby components. 14. When measuring resistance in the circuit, make sure that the power is not being supplied on the circuit, and that stored charges in capacitors are properly discharged. Failure to do so can damage the volt-ohmmilliameter (VOM) and the circuit due to the low resistance of the ohmmeter.
16
15. The functions and the characteristics of the VOM should be wisely used. 16. While using a VOM for in-circuit resistance measurement, always exchange the setting of positive and negative probes. Take the higher meter reading with the approximate resistance. 17. Use soldering irons with the proper power rating to prevent the components and the circuit board from being overheated and damaged. The soldering iron tips should be cleaned and preferably slim. Soldering guns are not recommended for beginners, since it is difficult to keep their temperature constant. 18. Use proper tools and soldering aids when troubleshooting printed circuit boards. Ground the soldering iron to avoid damaging ICs and transistors. 19. Dry solder joints are hard to detect. However, when they are found or suspected, remove the components from the PCB; then file or clean the leads and solder the joints back. Reheating dry joints with a new soldering lead is another remedy. When re-soldering, make sure you do not overheat the components. Overheating the PCB may cause the copper layer on it to warp and peel off. 20. Select a soldering iron with the rating appropriate for the particular application.
17
TROUBLESHOOTING PROCEDURE A. MECHANICAL FAULTS PROBLEM/SYMPTOMS 1. Doesn’t rotate 2. Can’t rotate automatically. 3. Rotation is slow.
CHECKS TO MADE A. Check the bent shaft. B. Verify if the shaft is seized. A. Check if the motor is binding up. A. Check if the shaft is slightly bent. B. Check for an oiling and dirt build up. C. Verify if oil is sufficient.
4. Noisy operation.
A. Check for any worn bearing. B. Check for a loose guard mark . C. Check loose guard fitter. D. Check for an improperly balanced blade or broken blade.
5. No oscillation or unsteady oscillation.
E. Check for a loose spinner F. Check if there is too much front to back play in the motor shaft. G. Check for an oil and dirt build up. H. Check if oil is sufficient. I. Check for any improper mounting of the front and/or rear guard. J. Check if there are loose screws. K. Check for rotor rubbing against housing insulation or wiring. A. Check for a broken, stripped or bent part in the clutch or knee joint system.
SYSTEM DEFECTS/FAULTS Defective rotor Defective rotor and end belts Defective motor Defective rotor Defective rotor Inadequate lubricant with accumulated dirt Poor lubrication Defective yoke or motor metal cover Loose guard mark screw Untighten guard mark fitter Effective fan blade
Untighten spinner Worn out shaft washers Poor lubrication with accumulated dirt Inadequate lubricant Misaligned front and rear guards Untighten screws Misaligned and dirt build-up in the rotor Defective clutch assembly or knee joint system
18
6. Imperfect oscillation (clutch lever system).
7. Unsteady oscillation.
8. Unsteady or imperfect vertical movement.
B. Check for a slippage or wear of worm wheel. C. Check for a disengagement of clutch cover. D. Check for a disengaged oscillating rod set screw. E. Check for a broken oscillating rod pin. F. Check for a disengaged and loose gear set screw. G. Check for a bent oscillating rod. H. Check for a disengaged and loose clutch ball. I. Check for a bent yoke (frame) shaft. J. Check for a worn rotor shaft worm. A. Check for a tight operation of oscillation switch. B. Check for an excessively high outer wire position. C. Check for a loosen outer wire set screw. A. Check for a worm wheel. B. Check for an excessive thrust. C. Check for a bent yoke (frame) shaft. D. Check for a loosen oscillating rod set pin. E. Check for a loosen oscillating rod screw. F. Check for an excessive oscillating rod bore. G. Check for a worm gear shaft metal. H. Check for a disengaged gear set screws. I. Check for an excessive gear thrust A. Check for a clogging of free stop bushing.
Defective worm wheel Untighten clutch cover Untighten oscillating rod set screw Defective knee joint upper part assembly Untighten gear set screw Defective oscillating rod Defective clutch shaft Defective yoke shaft Defective rotor Defective oscillating switch Misaligned fitting in the high outlet wire position Untighten outlet wire set screw Defective worm gear Misaligned thrust Defective shaft Untighten set pin and calk pin Untighten rod set screws calk screws Defective oscillating rod Defective cover Untighten gear set screws Misaligned thrust Misaligned bushing
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B. ELECTRICAL FAULTS PROBLEM/SYMPTOMS 1. Doesn’t rotate
2. Starts to rotate only by manual turning of the shaft.
CHECKS TO MADE A. Check for an open stator B. Check for an open AC cord or wiring C. Check for an open AC line fuse D. Check for an open thermal cut-off (inside the motor) E. Check for an open speed selector switch F. Check for a defective system control A. Check for a shorted capacitor B. Check for an open start winding
SYSTEM DEFECTS/FAULTS Defective stator Defective wiring/AC cord Defective fuse Defective thermal cut-off Defective switch/electronic system control Defective module(system control) Defective capacitor Defective stator
TOOLS AND EQUIPMENT NEEDED IN TROUBLESHOOTING 1. 2. 3. 4. 5. 6.
Mechanical Pliers Long nose pliers Side-cutting pliers Set of Philip Screw Drivers Set of standard Screw driver Volt-Ohm milliammeter
POSSIBLE FAULTS AND CORRESPONDING REMEDIES TROUBLE
Doesn’t Rotate Rotation
POSSIBLE FAULTS Bent shaft Open switch Shaft is seized Open stator
Starts to rotate only by manual turning
Open AC cord or wiring Start winding is open
CORRESPONDING REMEDIES Replace the motor assembly. Replace the switch, Replace rotor and end bell. Replace the motor assembly. Repair or replace the defective component. Repair the lead wire to winding or replace stator.
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of the shaft.
Rotation is slow
Noise
Noisy
Shorted capacitor Motor is binding up Bent shaft Oil and dirt buildup Lack of oil Worn bearing Loose guard mark Loose guard fitter Imbalanced or broken blade Loose spinner
Oscillation No oscillation or Unsteady oscillation
Too much front to back play in the motor shaft Oil and dirt buildup Lack of oil Improper mounting of the front and/or rear guard Loose screws Rotor rubbing against housing insulation or wiring Broken, stripped or bent part in clutch or knee joint system
Replace the capacitor. Replace the motor assembly. Clean and lubricate. Lubricate Replace the yoke or its cover. Fasten the guard mark screw. Tighten the guard filter. Replace the blade. Tighten the loosen spinner. Adjust by adding shaft washers. Clean and lubricate. Lubricate the screws. Re – adjust the screws. Tighten the screw. Disassemble, clean and adjust the rotor if necessary. Inspect, repair and replace parts if necessary.
Note 1: If the shaft of model C30TK is bent, replace the rotor. 2: If the stator of model C30TK is opened, replace the stator. 3: Experience has shown that tapping the end bells and motor housing with a wooden or plastic mallet will free up motors of this design. If this step fails to free up the motor replace it. 4: Replace the motor assembly.
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TROUBLE
Automatic oscillation system
Non-oscillation
POSSIBLE FAULTS Slippage or wear of the worn wheel Disengagement of the clutch cover Disengaged rod set screw Broken rod set pin Disengaged and loose gear set screw Bent rod Disengaged and loose clutch ball Bent yoke (frame) shaft Poor gear rotation
Imperfect oscillation (clutch lever system)
Unsteady oscillation
Height
Unsteady or
Worn rotor shaft worm Tight operation of oscillation switch Excessively high outer-wire position Loose outer-wire set screw Worn worm wheel Excessive thrust Bent yoke (frame) shaft Loosen rod set pin Loosen rod set screw Excessive rod bore Worm gear shaft metal Disengaged gear set screw Excessive gear thrust Clogging of free
CORRESPONDING REMEDIES Replace the worm wheel. Tighten the clutch cover. Tighten the screw. Replace the kneejoint upper part assembly. Tighten the screw. Adjust or replace the rod. Replace the clutch shaft. Adjust or replace the shaft. Adjust or disassemble and clean. Replace the rotor. Replace the oscillation switch. Adjust fitting. Tighten the screw. Replace the worn wheel. Adjust the thrust. Adjust the shaft. Tighten the pin. Tighten the screw. Replace the rod. Replace the cover. Tighten the screw. Adjust the thrust with the washer. Adjust the bushing.
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adjustment of standing fan External appearance
imperfect vertical movement
stop bushing
Scratch, stain or breakage
Scratch Dirt
Touch up with a lacquer. Wipe off with a cloth, soap and water.
PERFORMANCE TEST 2.1 Direction: Given a set of hand tools, multi-tester and defective electric fan with the manufacturer’s service manual, perform the procedure and techniques in pre-testing and troubleshooting an electric fan. Provide a work report/write-up after completing the task. Write your answer in a separate sheet of paper. STUDENT WRITE-UP A Common Symptoms / Defects of an Electric fan Student : _________________________________ Date: ________________________ Year & Section: _________________________ Teacher: _______________________ UNIT BRAND : _________________________ Unit Model: ______________________ Owner: ______________________ Address: _________________________________ 1. PROBLEM/S & SYMPTOM/S : ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________
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STUDENT WRITE UP B Diagnosing Faults and Remedies in ECEF Note: Write your answer in sheet of paper. Do not write anything in this module. Student : _________________________________ Date: ________________________ Year & Section: _________________________ Teacher: _______________________ UNIT BRAND : _________________________ Unit Model: ______________________ Owner: ______________________ Address: _________________________________ 2. POSSIBLE CAUSE/S: ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________ Teacher’s Initial: ___________
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Program/Course
CONSUMER ELECTRONIC MECHANIC NCII
Unit of Competency
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module
MAINTAINING AND REPAIRING AN ELECTRIC FAN
Lesson Outcome 3:
Maintain and repair an electric fan.
ASSESSMENT CRITERIA: 1. Personal Protective Equipment are used in accordance with the Occupational Health and Safety practices. 2. Electro-static discharge (ESD) protection procedure is followed. 3. Defective parts/components are replaced with identical equivalent ratings and repaired at the specified location. 4. Control settings/adjustments are performed in conformity with the service-manual specifications. 5. The unit is cleaned after the maintenance and repair activity.
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LEARNING EXPERIENCE / ACTIVITIES Learning Outcome 3: Maintain and repair an electric fan. Learning Activities Special Instruction Read the Information Sheet No. You can ask assistance from 3.1 on Personal Protective your teacher to show you and Equipment and Electrostatic explain to you further the topic Discharge protection procedure. you don’t understand well. Do Self-Check No. 3.1 to test your knowledge on Personal Protective Equipment and Electro-static Discharge protection procedure.
Try to answer the Self-Check without looking at the Information Sheet.
Check your answers with the Answer Key. If you were not able to answer all the questions, go over again to the Information Sheet. If you have answered all the questions, perform Job Sheet No. 3.1 on Maintaining and Repairing an Electric Fan. Do the Performance Test No. 3.1 on Maintain and Repair an Electric Fan. Refer to your performance output to the Observation and Questioning Checklist. If you missed some of the items in the Observation and Questioning Checklist, go over again to the Operation Sheet.
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INFORMATION SHEET 3.1 PERSONAL PROTECTIVE EQUIPMENT: It is the employer’s responsibility to provide protective clothing and equipment. Work clothes and specially designed protective clothing designed for your protection. Wear the correct clothing and equipment to protect yourself from possible serious injury. Do not interfere with or misuse any item provided by your employer for health and safety.
Wear plain, tough clothes that are closefitting and keep them buttoned up. - Loose sleeves, unbuttoned or torn shirts or sweaters, ties or loose belts can easily be caught in revolving machinery. - Your work clothes should be cleaned regularly. Wear cuff less trousers. - Trouser cuffs may cause you to trip or they may catch sparks or harmful substances. - Wear suitable footwear and keep it in good repair. - Wear safety shoes or boots with insulated sole for electrical work. - Good uppers protect against burning from hot turning, drops of molten metal, etc. Safety shoes and boots will reinforce toecaps to protect against heavy falling objects. Keep long hair under a tight fitting cap or net, as required by the regulations. It is your employer’s duty to ensure that machineries have guards to protect employees who work closely to the machine. More so, if your hair is long, it can be easily caught by the machinery, like the frilling machine. Many people have been scalped in this type of accident. Do not wear rings or wrist watches while on the job. - Such item can be caught by a moving machinery. It is extremely dangerous to wear them in certain types of work. You may lose your fingers. Do not wear earrings, neck chains, pendants and bracelets. 27
All items or personal jewelry worn at work have the potential to cause an accident or aggravate an injury sustained by an accident. Wear personal protective equipment suitable to the kind of work to be done. - Learn the purpose of each item from the wide range of protective devices available. -
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A. HOW IS ESD GENERATED Static charge is a form of electricity at rest. It can be generated by simple friction that is, rubbing two objects together. A simple method of generating a static charge is to rub a plastic ballpen case on a nylon cloth. Once generated, the static electricity will remain on the ballpen for as long as it is not placed on any other charged materials. If ever the ballpen comes in contact with another object, the static electricity can move to or from the ballpen to equalize the charge between the two objects. The transfer of static electricity from any of the two objects is called electro-static discharge. One inexhaustible source of electrons that can supply or can accept them without any effect is the earth. Whatever charged object brought into it is immediately discharged. This simple illustration does not necessarily mean that static electricity can be generated intentionally. The truth is that static electricity can be generated in a multitude of possible ways. Rubbing of hands or arms on a table can result in the generation of up to about 3000 volts of static electricity. Sliding of the IC pins in a plastic box can result in the generation of up to 12000 volts of static electricity. A person walking across a vinyl floor can generate about 13000 volts of static electricity. The amount of static electricity varies within the environment and it depends primarily on the prevailing relative humidity. The moisture in the air offers a readily present conductive path to ground from static electricity and hence avoiding any static build-up. B. ESD wrist straps ESD wrist straps are also called conductive wrist straps or bands. They are usually made of elastic cloth but contain conductive strands that touch your skin and so bleed off any static electricity on your body. Some straps are made of conductive rubber. The wire attached to the strap contains a large value resistor usually one mega ohm (1,000,000 ohms) allows any charge on your body to be slowly transferred to an electric fan ground point. This build in resistor also limits the amount of current to a safe level in case the other end of the wire touches a power supply voltage. Some ESD kits also contain a conductive pad on which you can place components, like circuit boards and ICs, when they’re out of the switch box of an electric fan. Often there’s an additional clip on the wire leading from the wrist strap that you can attach to this conductive pad, so that any charge on the pad will also flow to the electric fan ground point. C. ELECTRO-STATIC DISCHARGE (ESD) PROTECTION PROCEDURE 1. Purchase an antistatic kit from a computer or electronics supply store. Kits vary, but the main component is an ESD wrist strap with a wire several feet long having an alligator clip at the other end.
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2. So to start troubleshooting an electric fan, get an ESD wrist strap and wear it wherever you go under the covers or handle ICs and circuit boards. 3. Put the adjustable strap around your wrist (usually the left wrist if you’re right handed). Wearing an ESD wrist strap connected to frame or chassis ground drains static charges off your body, preventing damaging ESD. 4. Attach the clip at the end of the wire to an electrical ground connection or metal framework of the electric fan. 5. If you work on an electric fan without a conductive wrist strap, touch an electrical appliance such as a lamp or the screw in a wall outlet cover plate before touching the PCB circuit. An electrostatic discharge of just a few hundred volts is too small to feel in most cases, but can be usually deadly to ESD sensitive devices. 6. When you are working with a switch box of an electric fan, touch a ground point, like the metal extension pole before touching anything else. This should ground out any static charge your body. Also avoid wearing clothes that easily produce a static charge, such as, knits and wools and limit your movements as much as possible, especially on carpets while working on electronic circuits of an electric fan.
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SELF - CHECK 3.1 I. Direction: Identify the different personal protective equipment as illustrated. Write your answer in sheet of paper.
II. Direction: Write TRUE if the statement is correct or FALSE if it is wrong. Write your answer in another sheet of paper. 1. Static charge is a form of electricity at rest. 2. ESD wrist straps are also called conductive wrist straps or bands. 3. When working with the electronic system control of an electric fan, it is a safety practice to touch a round point like the metal extension pole before touching anything else. 4. An electrostatic discharge of just a few hundred volts is too small to fill in but can be usually deadly to ESD sensitive devices. 5. An ESD wrist strap is connected to the frame or chassis ground which drains static charges off your body preventing damaging ESD-sensitive devices.
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SELF-CHECK KEY 3.1 I. 1. Head Protection 2. Ear Protection 3. Tidy Hair Style 4. Close –fitting high buttoned overall 5. Close fitting cuff 6. No rings or watch 7. eye protection 8. cuffless trousers 9. Insulated soles 10. Reinforced footwear II 1. True 2. True 3. True 4. True 5. True
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JOB SHEET 3.1 COMPONENT REPLACEMENT 1. Determine the description of the values and ratings of the individual defective parts from the manufacturer’s service manual. 2. Identify the sources of the replacement components/parts. Original replacement components from the original factory sources. Universal replacement components from independent factory sources. (Note: Always consider the physical size of the replacement part). 3. Consider some factors in the selection of specific part. Quality . Is the ability to provide exact value or specification to replacement part Tolerance. Is the ability to provide exact value or acceptable parameters to replacement parts. Availability. Is the local access to parts and whether the parts are available . Price. It refers to the affordability of the replacement parts at a reasonable price. 4. Disconnect or remove properly the electrical/mechanical parts of an electric fan 5. Install correctly the replacement parts/components in the existing electric fan MAINTENANCE OF AN ELECTRIC FAN 1. Turn off the electric fan and remove the cord from the source of voltage. 2. Apply lubricant to the mechanical parts of the electric fan that requires lubrication for a smooth operation without grinding or squeaking. 3. Replace the bushings or end bells that squeak with the use of appropriate tools if squeaking cannot be corrected by applying lubricants. 4. Apply or spray anti-rust lubricants to all mechanical parts of the electric fan to drive out moisture, to protect corrosion, to loosen rusted metal parts and to even free if from sticky elements. 5. Clean and check cooling louvers for any obstructions to avoid cutting off the air flow. 6. Clean or wipe dust and foreign particles at the PC Board and metal parts of the motor. 7. Replace worn or frayed AC cord and electrical wires. SOLVENTS FOR CLEANING 1. Use a mild soap with a damp cloth or rug when cleaning plastic front panel and cover. They are susceptible to immediate and long term damage from solvents. 2. Apply denatured alcohol as the safest solvent to use for plastic front panel and cover with heavy stain. It should be used only as a last resort and applied to areas with heavy stain.
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PROCEDURE IN REPAIRING AN ELECTRIC FAN 1. Once the specific electrical/mechanical problem is located: Consider the techniques for the proper removal of the defective component or parts. Anticipate what to do if the replacement part does not correct the problem. Check the installation of the replacement or original part for any improper mounting in the mechanical assembly or circuit board. 2. Examine carefully the mounting of the replacement of original parts of the system. Check the placement of the wires or leads of the replacement component. Consider significant factors used in the original installation such as insulating washer, silicon grease and locating mark for pin connections. Observe proper placement of the component leads for electrical parts. 3. Perform the techniques for the proper soldering of the electrical parts. Be careful not to damage adjacent components Be careful not to lift the copper conductive path from circuit board base material. Avoid any solder bridges between board path. Do not destroy the component being removed if it is still functional and be careful not to damage the component being installed. 4. Verify all connections and harness. Be sure that all components are pre-positioned in a manner that will avoid the possibility of adjacent component short circuit conditions. Be sure to check or inspect all insulators and barriers between sections after working on any model/brand of electric fan. Check for frayed or broken insulation in all wiring including the AC line cord. Be sure to replace fuses, resistors and capacitors with special designation such as flame proof to components equal to the original value for both safety and liability purposes. 5. Once the repair is completed, perform an AC leakage test on all exposed metal parts of an electric fan to eliminate the possibility of electric shock. Perform complete retesting of the electric fan to ensure the correctness of the actual repair. Connect the electric fan into the 60Hz power to allow the time period required to let the new parts settle in and operate as they are designed to work with each other. Recheck or inspect if the repair was done correctly and the unit functions properly to ensure successful completion of the repair. 6. Clean the electric fan before returning it to the customer. Be sure that the blade, front and rear guards of the electric fan are properly cleaned. Be sure that proper cleaning is given to the control panel or switch box of the electric fan.
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PERFORMANCE TEST Direction: Given a set of hand tools, multi-tester and defective electric fan with identified faults or defect, perform preventive maintenance and repair procedure. Provide a work report/write-up after completing the task. Write your answer on a separate sheet of paper. STUDENT WRITE-UP A Maintaining an Electric fan Student : _________________________________ Date: ________________________ Year & Section: _________________________ Teacher: _______________________ UNIT BRAND : _________________________ Unit Model: ______________________ Owner: ______________________ Address: _________________________________ SYMPTOMS
DEFECTIVE COMPONENT/PARTS
REMEDY
STUDENT WRITE UP B Repairing an Electric Fan Student : _________________________________ Date: ________________________ Year & Section: _________________________ Teacher: _______________________ UNIT BRAND : _________________________ Unit Model: ______________________ Owner: ______________________ Address: _________________________________ SYMPTOMS DEFECTIVE REMEDY COMPONENT/PARTS
Teacher’s Initial: ___________
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Maintain and Repair Electronically-Controlled Domestic Appliances
Title of Module
Maintaining and Repairing an Electric Fan
The evidences must show that the student can…
explain the operation of an electric fan
identify the parts of an electric fan.
explain the functions of its parts.
perform pre-testing procedure manufacturer’s manual.
identify the system defects/fault symptoms using appropriate tools and equipment.
explain Identified defects and faults responsible person.
document the results of diagnosis and testing .
perform troubleshooting service manual.
use Personal Protective Equipment in accordance with Occupational Health and Safety practices.
follow Electro-Static Discharge (ESD) protection procedure.
replace defective parts/components with identical or recommended appropriate equivalent ratings.
solder/mount repaired or replaced parts/components at the specified location.
based
on
Questioning
Observation
Ways in which evidence will be collected: [tick the column]
Portfolio
Unit of competency:
Demonstration
NC II
Third party Report
Competency standard:
Written
ASSESSMENT PLAN
the
to the
in accordance with the
Clean the unit after the maintenance and repair activity. NOTE: *Critical aspects of competency Prepared by:
Date:
Checked by:
Date:
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OBSERVATION CHECKLIST FOR PERFORMANCE TEST Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the assessor: 1. Observe the students in Maintaining and Repairing an Electric Fan 2. Describe the assessment activity and the date when it has been undertaken. 3. Place a tick in the box to show that the candidate has completed each aspect of the activity to the standard expected in the enterprise. 4. Complete the feedback sections of the form. Date of observation Description of assessment activity Location of assessment activity The student’s can
If yes, tick the box
determine what the problems really is
obtain a description of the problem and how long it has been going on
trace out how long the electric fan is operating at present time
inquire whether the electric fan has done this in the past and how it is supposed to operate.
make follow-up on how the electric fan is supposed to operate.
perform preliminary inspection to locate where the problem originated
perform closer inspection into the suspected parts or components.
look for burned and broken components.
inspect for loose connections or broken wires
plan an approach to the repair problem
use appropriate tools and equipment in performing troubleshooting.
trace out the different symptoms/problems of an electric fan
verify the system defects or faults of an electric fan
pinpoint accurately the defective component or part of an electric fan
perform correctly the pre-testing troubleshooting procedures.
document the results of diagnosis and testing an electric fan
Did the student’s overall performance meet the standard?
Yes
No
Teacher’s Feedback: Teacher Signature:
Date:
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QUESTIONING CHECKLIST FOR PERFORMANCE TEST Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the teacher: 1. Observe the candidate in Maintaining and Repairing an Electric Fan 2. Describe the assessment activity and the date on which it was undertaken. 3. Place a tick in the box to show that the student completed each aspect of the activity to the standard expected in the enterprise. 4. Ask the student a selection of questions from the attached list to confirm his/her underpinning knowledge 5. Place a tick in the box to show that the student answered the questions correctly. 6. Complete the feedback sections of the form Date of observation Description of assessment activity Location of assessment activity The candidate’s report….
If yes, tick the box
What precautions must you take in performing pre-testing? How would you determine the defective parts for an intermittent problem? Why do you need to ask questions to the owner/operator of the electric fan in performing pre-testing? Why do you need to use sense of smell and sight in performing pretesting? Why is it, if possible, you need to attempt to operate an electric fan in performing pre-testing? What would you do in the event that you are not overly familiar with the model of the electric fan? What should you do if you found out that someone modified the circuit of the electric fan before performing pre-testing? Why is it necessary to conduct closer inspection to suspected part of the electric fan? Did the student’s overall performance meet the standard?
Yes
No
Feedback to student: Teacher signature:
Date:
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OBSERVATION CHECKLIST 3.2 Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency:
1. 1. 2. 3. 4.
Instructions for the teacher: Observe the candidate in Maintaining And Repairing An Electric Fan Describe the assessment activity and the date on which it was undertaken. Place a tick in the box to show that the student completed each aspect of the activity to the standard expected in the enterprise. Complete the feedback sections of the form
Date of observation Description of assessment activity Location of assessment activity The student’s can….
remove properly the identified defective parts.
verify carefully the mounting of the identical or replacement part. perform proper placement of component/part in the installation process perform the proper techniques in soldering electronic parts
perform the proper techniques in soldering electrical component/part perform the proper techniques in the installation of mechanical components/part handle properly the component/part being removed or installed
perform accurate connections and harness
observe proper use of tools and measuring instruments
perform completer re-testing of the unit once the repair is completed apply lubricant to moving mechanical parts that requires lubrication perform preventive check to rotating or moving parts that squeaks apply or spray anti-rust lubricant to all mechanical and metal parts clean and check cooling louvers for any obstructions
clean sticky rotating mechanisms
wipe dust and foreign particles at the PC board and metal parts of the unit replace worn or frayed AC cord and electric wires
If yes, tick the box
use mild soap with damp cloth or rags when cleaning plastic front panel and cover 39
apply appropriate solvent when cleaning plastic front panel and cover with heavy stain follow ESD protection procedure in accordance with current industry standard Did the student’s overall performance meet the standard?
Yes
No
Feedback to student: Teacher signature:
Date:
QUESTIONING CHECKLIST Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the teacher: 1. Observe the candidate in maintaining and repairing electric fan. 2. Describe the assessment activity and the date on which it was undertaken. 3. Place a tick in the box to show that the student completed each aspect of the activity to the standard expected in the enterprise. 4. Ask the student a selection of the questions from the attached list to confirm his/her underpinning knowledge 5. Place a tick in the box to show that the student answered the questions correctly 6. Complete the feedback sections of the form
Date of observation Description of assessment activity Location of assessment activity The student’s report answers the following questions…. What would you do if there is no available service manual or schematic diagram for the defective unit? Why do you need to discharge all capacitors mounted in the circuit before you start the maintenance and repair jobs? What would you do in the event that the replacement part does not correct the problem? Why is it necessary to perform an AC leakage test on all exposed metal parts of an electric fan?
If yes, tick the box
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What safety precaution must you take before applying to the repaired electric fan? What would you do in the event when the previous problem of the electric fan occurred again while performing the pre-testing? Why is it necessary to perform complete retesting one the repair of the electric fan is completed? Why is it necessary to clean the electric fan before it would be returned to the customer? Did the student’s overall performance meet the standard?
Yes
No
Feedback to student: Teacher signature:
Date:
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ACKNOWLEDGMENT Copyright Department of Education 2008 First Published JUNE 2008 This module is based on the Competency-Based Curriculum-Contextual Learning Matrix (CBC-CLM) and finalized on the Instructional Modules Finalization Development Workshop conducted at the Development Academy of the Philippines, Tagaytay City on May 6 -10, 2008 This learning instrument was developed by the following personnel: Technology Teachers:
Mr. Vic P. Diola – Group Leader Bauan Technical High School
Dr. Gilbert M. Castor Don Alejandro Roses Sr. Science-Technology High School
Mr. Eddielou L. Dayao Sanchez Mira School of Arts and Trade
Mr. Rufo G. Malla E. Rodriguez Vocational High School
Mr. Sherwin P. Medrano San. Pedro Relocation Center National High School
Mr. Remar C. Pinsoy Baguio National School of Arts and Trade
Contextual Teacher:
Mrs. Daisy Carousel P. Cervantes Don Alejandro Roses Sr. Science-Technology High School
Facilitators:
Dr. Edward dela Rosa TEC-VOC Task Force
Dr. Corazon L. Echano TEC-VOC Task Force
Encoders:
Mrs. Rosario D. Briones Mr. Mhariel L. Echano Mr. Jason O. Villena 42
Funding: Department of Education
ACKNOWLEDGMENT Copyright Department of Education 2009 First Published JUNE 2008 This module is based on the Competency-Based Curriculum-Contextual Learning Matrix (CBC-CLM) refined during the Writeshop on the Refinement and Enrichment of Competency-Based Curriculum and Contextual Learning Matrix of ARTS abd TRADES Specializations at Marikina Hotel, Marikina City on April 20 – 25, 2009. This learning instrument was refined and enriched by the following educators: Technology Teachers:
Mr. Victorino P. Diola – Group Leader TVE Coordinator, Bauan Technical High School Bauan, Batangas
Mr. Reynaldo C. Cunanan Head Teacher VI, E. A. Rodriguez Vocational High School Nagtahan, Sampaloc, Manila
Mrs. Gigi C. Corpuz Teacher III, Malvar National High School Malvar, Batangas
Mr. Ismael G. Gallardo Teacher I, Community Vocational High School Masipit, Calapan City, Oriental Mindoro
Mr. Rufo G. Malla Teacher II, E. A. Rodriguez Vocational High School Nagtahan, Sampaloc, Manila
Mr. George B. Fuazo Teacher II, Gen. Mariano Alvarez Technical High School GMA, Cavite
Contextual Teacher: English
Mrs. Teresita P. Tanael Teacher III, Gen. Mariano Alvarez Technical High School GMA, Cavite
o Mrs. Charlie I. Soriano Teacher I, Don Alejandro Roces Sr. Science-Technology HS Quezon City
Mathematics 43
o
Mrs. Analiza Rosa P. Librada Teacher I,-Mathematics Coordinator, San Pedro Relocation Center Nat’l. HS San Pedro, Laguna
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Republic of the Philippines Department of Education PUBLIC TECHNICAL -VOCATIONAL HIGH SCHOOLS
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module No. 3
MAINTAINING AND REPAIRING A MICROWAVE OVEN
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Table of Contents How to Use this Module ................................................................................... 1 Introduction ..................................................................................................... 2 Technical Terms ............................................................................................... 3 Learning Outcome 1: Identify the Parts and Functions of a Microwave Oven ...................................... 4
Learning Experience/Activities ............................................................... 5
Information Sheet 1.1 ............................................................................. 6
Self-Check 1.1 ........................................................................................ 9
Self-Check Key 1.1................................................................................ 11
Learning Outcome 2: Diagnose a microwave oven and analyze defects found ................................... 12
Learning Experience/Activities ............................................................. 13
Information Sheet 2.1 ........................................................................... 14
Operation Sheet 2.1............................................................................ 16
Job Sheet 2.1 ....................................................................................... 18
Learning Outcome 3: Maintain and repair a microwave oven ........................................................... 19
Learning Experience/Activities ............................................................. 20
Information Sheet 3.1 ........................................................................... 21
Operation Sheet 3.1 .............................................................................. 23
Operation Sheet 3.2 .............................................................................. 26
Job Sheet 3.1 ....................................................................................... 29
Assessment Plan ............................................................................................ 30 Observation Checklist .................................................................................... 31 Observation and Questioning Checklist .......................................................... 32 Demonstration ............................................................................................... 33 Written Report ............................................................................................... 34 Performance test ............................................................................................ 35 Acknowledgement .......................................................................................... 36
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HOW TO USE THIS MODULE Welcome to the Module “Maintaining and Repairing a Microwave Oven”. This module contains training materials and activities for you to complete. The unit of competency “Maintain and Repair Electronically-Controlled Domestic Appliances” contains the knowledge, skills and desired attitudes required for Consumer Electronics Servicing required to obtain the National Certificate (NC) level II. You are required to go through a series of learning activities in order to complete each of the learning outcomes of the module. In each learning outcome there are Information Sheets, Job Sheets, and Operation Sheets. Do these activities on your own and answer the Self-Check at the end of each learning activity. If you have questions, don’t hesitate to ask your teacher for assistance. Recognition of Prior Learning (RPL) You have already some basic knowledge and skills covered in this module because you have been working for some time; and already completed training in this area. If you can demonstrate competence to your teacher in a particular skill, talk to your teacher so you don’t have to undergo the same training again. If you have a qualification or Certificate of Competency from previous trainings show it to him/her. If the skills you acquired are consistent with and relevant to this module, they become part of the evidence. You can present these for RPL. If you are not sure about your competence skills, discuss this with your teacher. After completing this module, ask your teacher to assess your competence. Result of your assessment will be recorded in your competency profile. All the learning activities are designed for you to complete at your own pace. In this module, you will find the activities for you to complete and relevant information sheets for each learning outcome. Each learning outcome may have more than one learning activity. This module is prepared to help you achieve the required competency, in receiving and relaying information. This will be the source of information that will enable you to acquire the knowledge and skills in “Maintain and Repair Electronically-Controlled Domestic Appliances” independently at your own pace with minimum supervision from your teacher.
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Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A MICROWAVE OVEN
INTRODUCTION: This module contains information and suggested learning activities on Maintaining and Repairing a Microwave Oven. It covers the knowledge, skills and attitudes required to maintain and repair this home appliance. Completion of this module will help you better understand the succeeding module on maintaining and repairing electronically-controlled domestic appliances. This module consists of three (3) learning outcomes. Each learning outcome contains learning activities supported by instructional sheets. Before you perform the instructions, read the information sheets and answer the self-check and activities provided to ascertain to yourself and your teacher that you have acquired the knowledge necessary to perform the skill portion of the particular learning outcome. Upon completing this module, report to your teacher for assessment to check your achievement of knowledge and skills requirements of this module. If you pass the assessment, you will be given a certificate of completion. SUMMARY OF LEARNING OUTCOMES: Upon completion of the module, you should be able to: LO1 identify the parts and functions of a microwave oven; LO2 diagnose a microwave oven and analyze defects found; and LO3 maintain and repair a microwave oven. ASSESSMENT CRITERIA: Refer to the assessment criteria of learning outcomes 1-3 of this module. PREREQUISITES: Using Hand Tools Preparing and Interpreting Technical Drawing Used in Electronics Connecting and Terminating Electronics Circuit Applying Quality Standards
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TECHNICAL TERMS Domestic appliances. They are appliances like microwave oven, blender, washing machine, flat iron, etc. Resistance heating appliance. It is an appliance that uses resistive load for its main part which produces heat when current passes through it. Thermostat. It is a type of switching system that is being controlled by temperature. Heating element. It is a part of a resistance heating appliance that gets hot when operated. Electrical components. They are devices that perform electrical activities when current is applied to the circuit. Mica insulator. It is a transparent material that splits readily into thin sheets which have excellent insulating and heat resisting qualities. Non - electrical components. They are parts of an appliance that performs designated function other than electrical application. ON / Off switch. It is used to designate the operating and the inoperative state of a device or unit. Timer. It is a device that opens the electrical circuit after a predetermined period of time elapses. Thermistor. It is a device with high negative temperature coefficient or resistance, so its resistance decreases as temperature rises. Power. It is the rate at which electric energy is fed to or taken from a device measured in watts. Watt. It is the basic unit of power which in one second gives rise to energy of one joule. Fluro pan. It is an aluminum pan that is used to store food stuff like rice, corn, etc. Troubleshooting. It is a problem solving process with the goal of returning an item to its operational state.
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Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLY CONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A MICROWAVE OVEN
Learning Outcome 1: Identify the parts and functions of a microwave oven.
Assessment Criteria 1.
The operation of microwave oven is explained.
2.
The parts of a microwave oven are identified.
3.
The functions of its parts are discussed.
References: 1. Tan, Michael Q., Gantalao, Fred T., Lasala, Rommel M. Simple Electronics; Andes Mountain Printers: 2004 2. Enriquez, Marcelo T. Electronics Technology IV; Souvenir Publications, Inc.: 2003
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LEARNING EXPERIENCES/ACTIVITIES Learning Outcome 1: Identify the parts and functions of a microwave oven. Learning Activities
Special Instruction
1. Read the attached Information Sheet 1.1 on microwave oven. 2. Answer the Self Check 1.1. 3. Compare your answer with the model answer. Self-Check key1.1.
Try to answer the Self-Check 1.1 without looking at the Information Sheet.
4. If you missed some of the questions, go back again to Information Sheet 1.1. 5. If you have answered the questions, you are ready to proceed to learning outcome 2.
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INFORMATION SHEET 1.1 Operation of Microwave Oven Microwave oven Is a kitchen appliance that can come in many different sizes and styles employing microwave radiation primarily to cook or to heat food. This is made possible by using microwaves emitted from a magnetron to excite water (primarily) and other polarized molecules within the food to be heated.
Microwave Oven
How the microwave operates? Microwave ovens are generally used for time efficiency in both industrial applications such as restaurants and at home, rather than for cooking quality, although some modern recipes using microwave ovens rival recipes using traditional ovens and stoves. They have a central heated anode which is the source of electrons. These are several identical tuned cavities a very strong magnet, and a small antenna to extract the energy. They are usually made of metal but operate on the same principles that glass thermionic valves do.
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Major Parts and its Functions
Magnetron The magnetron is a device for producing microwave radiation from electricity. A variation on this device, called the cavity magnetron is usually used as the microwave energy source in your microwave oven. It can also be used as the microwave source in a pulsed radar.
High voltage transformer It is the "muscle" of the microwave oven. With an input of 120 VAC (or 240 VAC in many commercial models) applied to the primary winding, the high-voltage transformer (also referred to as power or plate transformer) steps up that primary voltage to a very high voltage. This high voltage is then boosted even higher by the voltage-doubling action of the capacitor and diode.
Varistor It is a type of resistor with a significantly non-ohmic current-voltage characteristic. The name is a portmanteau of variable resistor which is misleading since it is not continuously user-variable like a potentiometer or rheostat, and is not a resistor but in fact a capacitor. Varistor is often used to protect circuits against excessive voltage by arching.
Fuse It is a wire, bar, or strip of fusible metal inserted for safety in an electric circuit. When the current increases beyond a certain safe strength, the metal melts, interrupting the circuit and thereby preventing possibility of damage.
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High voltage diode It is a high voltage diode has a lamellar structured body of semiconductor material. The lamellar structure is produced by the thermal gradient zone melting process method of migrating metal "wires" through the body to form a plurality of spaced regions of conductivity opposite to that of the body.
Latch switch It is a switch having a bimetal latch for locking a resilient contact in a closed circuit position and a heating coil for activation of the latch to release the contact.
Oven lamp It is a lamp which indicates that the unit has a power.
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SELF-CHECK 1.1 Direction: Label the parts of the microwave oven based from the given Description. Write your answer in another sheet of paper.
Part name
Description
Picture
has a lamellar
1.__________________
structured body of semiconductor material.
is the "muscle" of the
2.__________________
microwave oven.
is a device used for producing microwave
3.__________________
4.__________________
radiation from electricity.
It is a lamp which indicates that the unit has a power.
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A wire, bar, or strip of
5.__________________
fusible metal inserted for safety in an electric circuit.
A type of resistor with a
6._________________
significantly non-ohmic current-voltage characteristic.
A switch having a
7._________________
bimetal latch for locking a resilient contact in a closed circuit position,
8-10. Given an actual microwave oven, identify at least three (3) major parts of it.
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SELF CHECK KEY 1.1
1. High voltage diode 2. High voltage transformer 3. Magnetron 4. High voltage capacitor 5. Fuse 6. Varistor 7. Latch switch
8-10. High voltage transformer High voltage diode High voltage capacitor Magnetron Fuse Varistor Latch switch Oven lamp
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Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLY CONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A MICROWAVE OVEN
Learning Outcome 2: Diagnose a microwave oven and analyze the defects found. Assessment Criteria: 1. 2. 3. 4. 5. 6.
Pre-testing procedure is performed in accordance with the manufacturer’s instruction. System defects/fault symptoms are identified using the appropriate tools and equipment. Identified defects and faults are explained to the responsible person. Results of diagnosis and testing are documented. Troubleshooting is performed based on the service manual. Safety practices are observed during troubleshooting of microwave oven.
References: 1. Tan, Michael Q., Gantalao, Fred T., Lasala, Rommel M. Simple Electronics; Andes Mountain Printers: 2004 2. Enriquez, Marcelo T. Electronics Technology IV; Souvenir Publications, Inc.: 2003
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LEARNING EXPERIENCES/ACTIVITIES Learning Outcome 2: Diagnose a microwave oven and analyze the defects found. Learning Activities
Read the information Sheet 2.1 on microwave oven.
Read the Operation sheet 2.1.
Perform the Job Sheet 2.1.
Read the Operation sheet 2.1.
Answer the Assessment Plan.
If you have answered the questions correctly, you are ready to proceed to learning outcome number 3.
Special Instruction
Try to answer the Self-Check materials without looking at the information sheet.
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INFORMATION SHEET 2.1 Faults and Troubles of a Microwave oven
Trouble No power
Cause
Inspection
Remedy
Overload
Using multi-
High voltage
tester, check
component
transformer is
continuity of the
testing
continuously
ff. parts
operated for
a. fuse
defective parts,
more than 3 hrs.
b. diode
Refer to the
c. high voltage
next Learning
capacitor.
outcome on the
Refer to the
Replace
repairing procedure.
Doesn’t light
Oven lamp is
Check oven
continuously
lamp.
Replaced busted oven
operated for
lamp.
more than 3hrs.
With power
but no display With power but doesn’t heat
Foreign materials
Check
Replaced digital
short the circuit
Using multi-
programmer
board.
tester .
circuit assembly.
Defective
Using multi-
magnetron.
tester, check
component
continuity of
testing
magnetron.
procedure.
Refer to the
Explain to customer the microwave magnetron is defective.
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Tools Used in pre-testing a microwave oven
VOM (multi-tester)
Instructional/Operational Manual
Screw Driver
Pliers
Side cutting pliers
Long nose pliers
Pre-testing procedure of a microwave oven Trouble/Problem Unit cannot be turned on
Possible Cause
How to fix?
Is AC power cord properly
Visual check on AC
Plugged in?
power cord if there is a loose in the connection.
Unit does not operate When turned on
Is the plug properly
Secure the connection
connected?
of the plug
Is the front cover properly closed?
Push front cover/ front lid properly
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OPERATION SHEET 2.1 PRECAUTIONS AND WARNINGS IN HANDLING A MICROWAVE OVEN Unlike many other appliances, the microwave oven has high voltage and high-current characteristics. Though it is free from danger in ordinary use, extreme care should be taken during repair. Precautions to be observed in handling a microwave oven: 1. Serviceman must remove his watches whenever working close to or replacing the magnetron. 2. Do not operate on a two-wire extension cord. The microwave is designed to be used in a completely earthed condition. It is imperative, therefore, to make sure it is properly earthed before beginning the repair work. 3. If the door locks, or if the door switch or the door seal malfunctions, be sure not to operate the oven until total repair is done. 4. Avoid inserting nails, wires, etc. through any holes in the unit during operation because such worsen the problem. 5. Make sure that all electrical connections are tight before inserting the plug into the wall outlet and check energy leakage of the microwave. Warnings to pay attention to when dealing with the microwave oven: 1. Never operate the oven until the following are confirmed: The door is tightly closed. There is no broken hinge or door arm. The door seal is not damaged. The door is not bent or warped. There is no other visible damage. 2. Warning about the electric charge in the high voltage capacitor for about 30 seconds after the oven is turned-off, an electric charge remains in the high voltage capacitor. When replacing or checking parts, remove the power plug from the outlet and the short terminal of the high voltage capacitor terminal of lead wire from diode to chassis ground with an insulated handle screwdriver to discharge. 3.Never touch any circuit wiring with your hand nor with an insulated tool during operation.
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4.Touch chassis side first then short to the high voltage capacitor terminal.
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JOB SHEET 2.1 Result of Diagnosis and Testing Direction: Fill in the table with technical data that will correspond to microwave diagnosis and testing. Brand: ___________________ Model #:__________________ Serial#:___________________
Trouble
Possible
Possible affected
Possible
cause of
components/parts
remedy
trouble
1._______________
2._______________
3._______________
4._______________
5._______________
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Program/Course: Unit of Competency: Module Title:
-
CONSUMER ELECTRONIC SERVICING NC II
-
MAINTAIN AND REPAIR ELECTRONICALLY CONTROLLED DOMESTIC APPLIANCES
-
MAINTAINING AND REPAIRING A MICROWAVE OVEN
Learning Outcome 3: Maintain and repair a microwave oven. Assessment Criteria 1. Personal Protective Equipment is used in accordance with the occupational health and safety practices. 2. Defective parts/ components are replaced with the identical equivalent ratings and repaired at the specified location. 3. Control settings/adjustments are performed in conformity with the service manual specifications. 4. Repaired activity is performed within the required time frame.
References: Tan, Michael Q., Gantalao, Fred T., Lasala, Rommel M. Simple Electronics; Andes Mountain Printers: 2004 Enriquez, Marcelo T. Electronics Technology IV; Souvenir Publications, Inc.: 2003
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LEARNING EXPERIENCES/ACTIVITIES
Learning Outcome 3: Maintain and repair a microwave oven. Learning Activities
Special Instruction
1. Read the Operation Sheet 3.1 on microwave oven. 2. Read the Information Sheet 3.1.
Try to answer all the Self Check 3.1 without looking at the Information sheet.
3. Read the Operation Sheet 3.1.
4. Perform the Job Sheet 3.1.
5. Answer the Assessment Plan. If you missed some of the question, go back again. 6. If you have answered the assessment plan with accuracy, you are ready to proceed to the next module.
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INFORMATION SHEET 3.1 SPECIFICATION OF REPLACEMENT PARTS
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OPERATION SHEET 3.1 COMPONENT CHECKING AND REPLACEMENT
1.)PRIMARY LATCH SWITCH, (DOOR SWITCH AND POWER RELAY B INTERLOCKS. Unplug lead connectors to primary latch switch and door switch Test the continuity of the circuit of door opened and closed position Normal continuity readings should be as follows Door open Door closed Primary latch switch ∞ Ω (open) 0 Ω (close) Door switch ∞ Ω (open) 0 Ω (close) Power relay b ∞ Ω (open) ∞ Ω (open) 2.) SHORT SWITCH AND MONITOR Test continuity of switches at door opened and closed positions using the lowest scale of the ohmmeter. Normal continuity readings should be as follows Door opened Door closed 0Ω 0Ω 3.)HIGH VOLTAGE TRANSFORMER Normal resistance readings should be as follows: Secondary winding Approx. 60 Ω-120 Ω Filament winding Approx. 0 Ω Primary winding Approx. 0 Ω - 2 Ω
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4.) HIGH VOLTAGE CAPACITOR Normal capacitor will show continuity for a short time, and then will indicate 9MΩ once the capacitor is charged.
5.) MAGNETRON A continuity check across magnetron filament terminals should indicate one ohm or less. A continuity check between each filament terminal and magnetron case should read open.
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6.) DIODE Disconnect the two leads connected to the diode terminal and a normal diode’s resistance will be infinite in one direction and several hundreds kΩ in the other direction.
7.) PROTECTOR DIODE A normal protector diode’s resistance will be infinite in both directions. If it is faulty, it shows continuity in one or both directions.
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OPERATION SHEET 3.2 Maintain and Repair a Microwave Oven MAGNETRON After replacement of the magnetron, tighten mounting screws properly making sure that there is no gap between the waveguide and the magnetron to prevent microwave leakage.
DIGITAL PROGRAMMER CIRCUIT (D.P.C) AND MEMBRANE KEYBOARD The membrane key board is attached to the escutcheon base with double faced adhesive tape. Therefore, applying hot air such as using a hair dryer is recommended for smoother removal. When installing new membrane keyboard, make sure that the surface of escutcheon base is cleaned sufficiently so that any problem can be avoided. Alignment position of membrane key board; membrane keyboard; right and upper edges Escutcheon sheet: right and upper edges. LOW VOLTAGE TRANSFORMER Be sure to ground any static electric charge built up on your body before handling the D.P.C. Do not use soldering iron or disordering tool of more the than 30watts on D.P.C contacts.
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TEMPERATURE SENSOR (thermal protector) Remove 1 screw holding the temperature sensor and replace with new one. Solder the lead wires securely to the sensor terminals.
FAN MOTOR Remove 5 screws holding fan motor shaft by pulling it straight out. Separate the fan motor from the orifice.
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DOOR ASSEMBLY After replacement of defective component parts of the door, be sure that the door assembly is properly mounted. Microwave power may leak from the clearance between the door and oven if the door assembly is not mounted properly.
STIRRER MOTOR Remove and reinstall the motor cover Use 4x6 screw.
FLOR SHELF AND/OR MOVING ANTENNA When replacing the moving antenna, make sure the plastic stirrer spacers are correctly placed. They are necessary to stabilize the antenna by gliding around the oven bottom as the antenna turns.
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JOB SHEET 3.1 Repairing a Microwave Oven Direction: By using a defective microwave oven, fill-out the following table. Student Name: ______________________________ Blender model: _____________________________ Serial no: __________________________________
Trouble
Cause of trouble
Affected components
Description of Components
Possible Remedy
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ASSESSMENT PLAN Evidence Checklist
MAINTAINING AND REPAIRING A MICROWAVE OVEN
Observation
Ways in which evidence will be collected: [tick the column]
The evidence must show that the student can
Written
Title of Module
Portfolio
MAINTAIN AND REPAIR ELECTRONICALLY CONTROLLED DOMESTIC APPLIANCES
Demonstration
Unit of competency:
Third party Report
CONSUMER ELECTRONIC SERVICING NC II
Oral Questioning
Competency standard:
operate a microwave oven. distinguish parts of a microwave oven. determine the functions of its parts. perform pre-testing procedure in accordance with manufacturer’s instruction. identify system defects/fault symptoms using appropriate tools and equipment. explain identified defects and faults to the responsible person. document results of diagnosis and testing. perform troubleshooting in accordance with the service manual. use Personal Protective Equipment in accordance with occupational health and safety practices. . replace defective Parts/components with identical or recommended appropriate equivalents ratings. solder/mount repair or replace parts/ components are soldered /mounted in specified location. perform control setting/adjustment in conformity with service manual specification. perform repaired activity within the required time frame. NOTE: Critical aspects of competency Prepared by:
Date:
Checked by:
Date:
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Observation Checklist Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the assessor: 1. Observe the candidate in Maintain and Repair Microwave oven. describe the assessment activity and the date on which it was undertaken. 2. Place a tick in the box to show that the candidate completed each aspect of the activity to the standard expected in the enterprise. 3. Complete the feedback sections of the form. Date of observation Description of assessment activity Location of assessment activity The student can distinguish operation of microwave oven.
determine parts of a microwave oven.
identify functions of its parts.
If yes, tick the box
perform pre-testing procedure in accordance with manufacturer’s instruction. identify system defects/fault symptoms using appropriate tools and equipment. explain identified defects and faults to the responsible person. document results of diagnosis and testing.
perform troubleshooting in accordance with the service manual use Personal Protective Equipment in accordance with occupational health and safety practices. . replace defective parts/components with identical or recommended appropriate equivalents ratings. solder/mount repair or replace parts/ components in specified location. perform control setting/adjustment in conformity with service manual specification. perform repair activity within the required time frame. Did the candidate’s overall performance meet the standard?
Yes
No
Feedback to student’s: Teacher’s signature:
Date: 31
Observation and Questioning Checklist Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the assessor: 1. Observe the candidate in Maintain and Repair Microwave oven 2. Describe the assessment activity and the date on which it was undertaken. 3. Place a tick in the box to show that the candidate completed each aspect of the activity to the standard expected in the enterprise. 4. Ask the candidate a selection of the questions from the attached list to confirm his/her underpinning knowledge 5. Place a tick in the box to show that the candidate answered the questions correctly. 6. Complete the feedback sections of the form. Date of observation Description of assessment activity Location of assessment activity The student can..
operate a microwave oven.
identify parts of a microwave oven.
determine functions of its parts.
If yes, tick the box
perform pre-testing procedure in accordance with manufacturer’s instruction. identify system defects/fault symptoms a using appropriate tools and equipment. explain identified defects and faults to the responsible person. document results of diagnosis and testing.
perform troubleshooting in accordance with the service manual use Personal Protective Equipment in accordance with Occupational Health and Safety practices. . replace defective parts/ components with identical or recommended appropriate equivalents ratings. Can solder/mount repair or replace parts/ components in specified location. Can perform control setting/adjustment in conformity with service manual specification. Can perform repaired activity within the required time frame. Did the student’s overall performance meet the standard?
Yes
No
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Demonstration Candidate’s name: Assessor’s name: Unit of competency: Competency standards: Date of assessment: Time of assessment: Instructions for demonstration Given the necessary materials the trainee/student must be able to:
Materials and equipment: Multitester Screw Driver Set Microwave Oven Service Manual Soldering Iron Soldering Stand
Set of Pliers Soldering Lead Desoldering Tool to show if evidence is demonstrated
During the demonstration of skills, did the candidate:
Yes
No
N/A
operate the microwave oven?
identify the parts of a microwave oven?
determine the functions of its parts?
perform pre-testing procedure in accordance with manufacturer’s instruction? identify system defects/fault symptoms using appropriate tools and equipment? explain identified defects and faults to responsible person? document results of diagnosis and testing? perform troubleshooting in accordance with the service manual? use Personal Protective Equipment in accordance with occupational health and safety practices? replace defective parts/ components with identical or recommended appropriate equivalents ratings. replace parts/ components in specified location. perform control setting/adjustment in conformity with service manual specification. perform repaired activity within the required time frame. The student’s demonstration was: Satisfactory Not Satisfactory
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Written report Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Task: Your task is to: Maintaining and repairing microwave oven Submission date: Use the checklist below as a basis for judging whether the student’s report meets the required competency standards. The student can… operate a microwave oven.
If yes, tick the box
determine the parts of a microwave oven. Explain the functions of its parts.
perform pre-testing procedure in accordance with manufacturer’s instruction. identify system defects/fault symptoms using appropriate tools and equipment. explain identified defects and faults to the responsible person. Document results of diagnosis and testing. Perform troubleshooting in accordance with the service manual use Personal Protective Equipment in accordance with occupational health and safety practices. . replace defective parts/ components with identical or recommended appropriate equivalents ratings. solder/mount replacement parts/ components in specified location. perform control setting/adjustment in conformity with service manual specification. perform repaired activity within the required time frame. Overall did the Student’s report meet the standard?
Yes
No
Comments: Student’s signature:
Date:
Teacher’s signature:
Date: 34
PERFORMANCE TEST Student's Name
Date
Competency:
Directions: Ask your teacher to assess your performance in the following critical task and performance criteria below You will be rated based on the overall evaluation on the right side.
Test Attempt 1st 2nd 3rd OVERALL EVALUATION Level Achieved
PERFORMANCE LEVELS 4 - Can perform this skill without direct supervision and with initiative and adaptability to problem situations. 3 - Can perform this skill satisfactorily without direct assistance or supervision. 2 - Can perform this skill satisfactorily but requires some assistance and/or supervision. 1 - Can perform parts of this skill satisfactorily, but requires considerable assistance and/or supervision.
Teacher will put the initial at level achieved.
PERFORMANCE STANDARDS For acceptable achievement, all items should receive a "Yes" or "N/A" response. A microwave oven was operated
Parts of a microwave oven were distinguished.
The functions of its parts were determined.
pre-testing procedure in accordance with manufacturer’s instruction were performed. system defects/fault symptoms using appropriate tools and equipment were identified. identified defects and faults were explained to the responsible person. results of diagnosis and testing were documented. troubleshooting in accordance with the service manual was performed Personal Protective Equipment in accordance with occupational health and safety practices were observed defective parts/ components were replaced with appropriate equivalent ratings. repaired or replaced parts/ components were soldered/ mounted in specified location. control setting/adjustment in conformity with service manual specification was performed. repair activity within the required time frame was performed.
Yes
No
N/A
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ACKNOWLEDGMENT Copyright Department of Education 2008 First Published JUNE 2008 This module was based on the Competency-Based Curriculum-Contextual Learning Matrix (CBC-CLM) and finalized on the Instructional Modules Finalization Development Workshop conducted at the Finalization Workshop conducted at the Development Academy of the Philippines, Tagaytay City on May 6 -10, 2008 This learning instrument was developed by the following personnel: Technology Teachers:
Mr. Vic P. Diola Bauan Technical High School
Dr. Gilbert M. Castor Don Alejandro Roces Sr. Science-Technology High School
Mr. Eddielou L. Dayao Sanchez Mira School of Arts and Trades
Mr. Rufo G. Malla Eulogio Rodriguez Vocational High School
Mr. Sherwin P. Medrano San Pedro Relocation Center National High School
Mr. Remar C. Pinsoy Baguio National School of Arts and Trades
Contextual Teacher:
Mrs. Daisy Carousel P. Cervantes Don Alejandro Roces Sr. Science-Technology High School
Facilitators:
Dr. Edward M. Dela Rosa Dr. Corazon L. Echano TEC-VOC Task Force
Encoders:
Mrs. Rosario D. Briones Mr. Mhariel L. Echano Mr. Jason O. Villena
Funding: Department of Education
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ACKNOWLEDGEMENT Copyright: Department of Education 2009 This module is based on Competency-based Curriculum- Contextual Learning Matrix ( CBC-CLM ) refined during the Writeshop on the Refinement and Enrichment of Competency-Based Curriculum and Contextual Learning Matrix of ARTS and TRADES Specializations at Marikina Hotel, Marikina City on April 20 – 25,2009. This learning instrument was refined and enriched by the following educators: Technology Teachers ( Electronics ) VICTORINO P. DIOLA – Group Leader TVE Coordinator, Bauan Technical High School Bauan, Batangas
GIGI C. CORPUZ Teacher III, Malvar National High School Malvar, Batangas
ISMAEL G. GALLARDO Teacher I, Community Vocational High School Masipit, Calapan City, Oriental Mindoro
REYNALDO C. CUNANAN Head Teacher VI, EARIST Voc. High School Nagtahan, Sampaloc, Manila
GEORGE B. FUASO Teacher II, Gen. Mariano Alvarez Technical High School GMA, Cavite
RUFO G. MALLA Teacher II, EARIST Voc. High School Nagtaha, Sampaloc, Manila Contextual Teachers: English
TERESITA P. TANAEL Teacher III, Gen. Mariano Alvarez High School GMA, Cavite
CHARLIE I. SORIANO Teacher I, Don Alejandro Roces, Sr. Science-Technology H.S. Quezon City Mathematics
ANALISA ROSA P. LIBRADA Teacher I, Mathematics Coordinator San Pedro Relocation Center National High School San Pedro, Laguna 37
Science
LENALYN N. MANZANO Teacher I, EARVHS Nagtahan, Sampaloc manila
GEMMA G. VALLARTA Teacher III, Science Coordinator San Pedro Relocation Center National High School San Pedro, Laguna Facilitators:
Dr. CORAZON L. ECHANO Tech-Voc Task Force
Dr. VICTORIO N. MEDRANO Tech-Voc Task Force
Dr. ORLANDO E. MANUEL Tech-Voc Task Force Encoder:
MARISOL E. SALDIVAR
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Table of Content How to Use this Module ................................................................................... 1 Introduction ..................................................................................................... 2 Technical Terms ............................................................................................... 3 Learning Outcome 1: Identify the function of the parts of a blender ................................................... 4
Learning Experience…………………………………………………………………..5 Information Sheet 1.1 ............................................................................. 6
Self-Check 1.1 ........................................................................................ 9
Self-Check Key 1.1................................................................................ 10
Learning Outcome 2: Diagnose a blender and troubleshoot the defect found.................................... 11
Learning Experience ……………………………………………………………….12 Operation Sheet 2.1 .............................................................................. 13
Information Sheet 2.1 ........................................................................... 14
Operation Sheet 2.2 .................................................................................... 16
Job Sheet 2.1 ....................................................................................... 18
Check List for Job Sheet 2.1 ................................................................. 19
Learning Outcome 3: Maintain and repair a blender ........................................................................ 20
Learning Experience…………………………………………………………………21 Operation Sheet 3.1 .............................................................................. 22
Information Sheet 3.1 ........................................................................... 29
Operation Sheet 3.2 .............................................................................. 30
Job Sheet 3.1 ....................................................................................... 32
Assessment Plan ............................................................................................ 33 Observation Checklist……………………………………………………………………….34 Observation and Questioning Checklist ……………………………………………….36 Demonstration ……………………………………………………………………………….39 Written Report ……………………………………………………………………………….39 Performance Test …………………………………………………………………………....40 Performance Standards .................................................................................. 40 Acknowledgement…………………………………………………………………………….41
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HOW TO USE THIS MODULE Welcome to the Module “Maintaining and Repairing a Blender”. This module contains training materials and activities for you to complete. The unit of competency “Maintain and Repair Electronically-Controlled Domestic Appliances” contains the knowledge, skills and desirable attitudes required for Consumer Electronic Servicing to obtain the National Certificate (NC) level II. You are required to go through a series of learning activities in order to complete each of the learning outcomes of the module. In each learning outcome there are Information Sheets, Job Sheets, Operation Sheets and Activity Sheets. Do these activities on your own and answer the Self-Check at the end of each learning activity. If you have questions, don’t hesitate to ask your teacher for assistance. Recognition of Prior Learning (RPL) You have already some basic knowledge and skills covered in this module because you have been working for some time. If you can demonstrate competence to your teacher in a particular skill, talk to him/her so you don’t have to undergo the same training again. If you have a qualification or Certificate of Competency from previous trainings show it to him/her. If the skills you acquired are consistent with and relevant to this module, they become part of the evidence. You can present these for RPL. If you are not sure about your competence skills, discuss this with your teacher. After completing this module, ask your teacher to assess your competence. Result of your assessment will be recorded in your competency profile. All the learning activities are designed for you to complete at your own pace. In this module, you will find the activities for you to complete and relevant information sheets for each learning outcome. Each learning outcome may have more than one learning activity. This module is prepared to help you achieve the required competency, in receiving and relaying information. This will be the source of information that will enable you to acquire the knowledge and skills in Maintain and Repair Electronically-Controlled Domestic Appliances maintain and repair electronically controlled domestic appliances independently at your own pace with minimum supervision from your teacher.
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Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLY CONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A BLENDER
INTRODUCTION: This module contains information and suggested learning activities on Maintaining and Repairing a Blender. It covers the knowledge, skills and attitudes required to maintain and repair a blender. Completion of this module will help you better understand the succeeding module on maintaining and repairing electronically-controlled domestic appliances. This module consists of three (3) learning outcomes. Each learning outcome contains learning activities supported by instructional sheets. Before you perform the instructions, read the information sheets and answer the self-check and activities provided to ascertain to yourself and your teacher that you have acquired the knowledge necessary to perform the skill portion of the particular learning outcome. Upon completing this module, report to your teacher for assessment to check your achievement of knowledge and skills requirements of this module. If you pass the assessment, you will be given a certificate of completion. SUMMARY OF LEARNING OUTCOMES: Upon completion of the module, you should be able to: LO1. identify the parts and function of a blender; LO2. diagnose/troubleshoot blender defects; and LO3. maintain and repair a blender. ASSESSMENT CRITERIA: Refer to assessment criteria of learning outcomes 1-3 of this module. PREREQUISITES: Using hand tools Preparing and interpreting technical drawing Connecting and terminating electronics circuit Applying Quality Standards
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TECHNICAL TERMS Blender. It is a motorized small appliance that blends, chops, and grates food. Domestic appliances. They are household appliances like rice cooker, blender, washing machine, flat iron, etc. Electrical components. They are devices that performs electrical activities when current is applied to the circuit. Heating element. It is a part of a resistance heating appliance that get hot when operated. Jar. It is made of glass, plastic, or stainless steel and often has graduated markings for approximate measuring purposes. Mica insulator. It is a transparent material that splits readily into thin sheets which have excellent insulating and heat resisting qualities. Non - electrical components. They are parts of an appliance that performs designated function other than electrical application. ON / Off switch. It is used to designate the operating and the inoperative state of a device or unit. Power. Is the rate at which electric energy is fed to or taken from a device measured in watts. Resistance heating appliance. It is a type of appliance that use resistive load for its main part. The part that produced heat when current passes through it. Selector Switch. It is used to control the speed of a motor. Thermistor. It is a device with high negative temperature coefficient or resistance, so its resistance decreases as temperature rises. Thermostat It is a type of switching system that is being controlled by temperature Timer. It is a device that opens the electrical circuit after a predetermined period of the time elapses. Troubleshooting. It is a problem solving process with the goal of returning an item to its operational state.
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Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLY CONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A BLENDER
Learning Outcome 1: Identify the parts and functions of a blender. Assessment Criteria 1.
The parts and their functions are identified based on the manufacturer’s service manual.
2.
The parts are handled in accordance with the manufacturer’s service manual.
References: 1. Tan, Michael Q., Gantalao, Fred T., Lasala, Rommel M. Simple Electronics; Andes Mountain Printers: 2004 2. Enriquez, Marcelo T. Electronics Technology IV; Souvenir Publications, Inc.: 2003
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LEARNING EXPERIENCES/ACTIVITIES Learning Outcome 1: Identify the parts and functions of a blender. Learning Activities
Special Instruction
1. Read the Information Sheet 1.1 on Food Blender. 2. Answer Self -Check 1.1. 3. Compare your answer with the model answers.
Try to answer all the Self Check materials without looking at the information sheet.
4. If you missed some of the questions, go back again to Information Sheet 1.1. 5. If you have answered all the questions correctly, you can proceed to the next Learning Outcome.
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INFORMATION SHEET 1.1 Blender What is a blender? A blender is…
a motorized small appliance that blends, chops, and grates food. a handy electrical gadget that makes chopping and mixing food easier. a liquidizer or kitchen appliance used to mix ingredients or make puree. a stationary, upright electrical device which is distinguished from a hand-powered or electric mixer that may be used for similar purposes.
How a blender operates? A blade inside a jar is connected to a motor shaft inside the unit. The blade speed is controlled by varying electric current to the motor using one or more switches. The motor is operated by supplying electric current to the motor. Applications and uses of a blender Blenders are used both at home and commercial kitchens for various purposes:
to crush ice in drinks;
to make smooth purées of semi-solid ingredients, such as cooked vegetables and meat;
to reduce small solids such as spices and seeds to powder or nut butters;
to blend mixtures of powders, granules, and/or liquids thoroughly; and
to help dissolve solid into liquid.
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Parts of a blender
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Parts and Functions of a Blender
Blending container (jar) is made of glass, plastic, or stainless steel, and often has graduated markings for approximate measuring purposes.
At the top of the container is a lid to prevent ingredients from escaping during operation.
At the bottom is a blade assembly, sometimes removable for cleaning purposes. In cases where the blades are removable, the container should have an o-ring between the body of the container and the base to seal the container and prevent the contents from leaking.
The container rests upon a base that contains a motor for turning the blade assembly and has controls on its surface. Most modern blenders offer a number of possible speeds.
Selector switch is used to control the speed of the motor. It comes in different speed.
The power train of a blender (motor). A fan-cooled electric motor is secured into the housing by way of vibration dampeners and a small output shaft penetrates the upper housing and meshes with the blade assembly.
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SELF CHECK 1.1 Parts of a Blender A. Identify what is being asked. Write your answer in a separate sheet of paper. Do not write anything in this module. ____________________1. A handy electrical gadget that makes chopping and mixing food easier. ____________________2. A part of a blender which is made of glass or plastic with graduated marking for approximate measuring process. ____________________3. It is secured into the housing by way of vibrating dampeners, a small output shaft penetrating the upper housing and meshing with the blade assembly. ____________________4. It is a part of a blender which prevents ingredients from escaping during operation. ____________________5. It contains a motor for turning the blade assembly and has controls on its surface. ____________________6-7 Two applications and uses of a blender. ____________________ ____________________8-10 How the blender operates? ____________________ ____________________
B. Given an actual blender, identify its parts. Ask your teacher to provide you with a blender.
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. SELF CHECK KEY 1.1 1. 2. 3. 4. 5.
Blender Jar or container Motor Lid or cap Base
6-7
to crush ice in drinks
to make smooth purées of semi-solid ingredients, such as cooked vegetables and meat
to reduce small solids such as spices and seeds to powder or nut butters
to blend mixtures of powders, granules, and/or liquids thoroughly
to help dissolve solids into liquids
8-10. A blender is handy electrical gadget and a motorized small appliance. A blade inside a jar is connected to a motor shaft inside the unit. The blade speed is controlled by varying electric current to the motor using one or more switches. The blender operates when supplied by an electric current.
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Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLY CONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A BLENDER
Learning Outcome 2: Diagnose/troubleshoot the defect found Assessment Criteria: 1. 2. 3. 4. 5.
Pre-testing procedure is observed in accordance with the manufacturer’s instruction. System defects/faults symptoms are identified using appropriate tools and equipment and in accordance with the safety procedure. Identified defects/faults are explained to the responsible person ( the teacher) in accordance with the enterprise or company policy. Results of diagnosis and testing are documented accurately and completely within the specified time frame. Customers ( assessors/teachers ) are advised/informed regarding the status and serviceability of the unit as per procedure.
References: 1. Tan, Michael Q., Gantalao, Fred T., Lasala, Rommel M. Simple Electronics; Andes Mountain Printers: 2004 2. Enriquez, Marcelo T. Electronics Technology IV; Souvenir Publications, Inc.: 2003
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LEARNING EXPERIENCES/ACTIVITIES Learning Outcome 2: Diagnose/troubleshoot blender Learning Activities
Special Instruction
1. Read the Operation Sheet 2.1 on Pre-Testing a Food Blender. 2. Read the Information Sheet 2.1.
Try to answer all the Self- Check materials without looking at the information sheet.
3. Read the Operation Sheet 2.2. 4. Perform the Job Sheet 2.1. 5. Answer the Assessment Plan 6. If you have answered the questions perfectly, you can proceed to the Learning Outcome 3.
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OPERATION SHEET 2.1 Pre-Testing Procedure of Blender Table for pre-testing a blender
Proper Handling of a Blender How to use a blender? Before using any other accessory, make sure that the power unit is turned off and placed on a suitable work surface. Put the protective cover over the drive that you will not be using. 1. Before using the blender for the first time, wash the blender bowl, and cover funnel and blade assembly and gasket in warm soapy water. After washing, rinse well and dry before using. Your blender is now ready for use. 2. To assemble the blender, press the gasket into the recess in the blade assembly base. 3. Then, insert the blade assembly into the blender bowl from below. Using the lid as a wrench, tighten the blade assembly into place. The blade assembly must be tightened firmly to the bowl/jar to prevent leakage. 4. Place the blender on the high-speed (upper) drive and turn to the left (counter-clockwise) to lock the blender in place.
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INFORMATION SHEET 2.1 Faults and Trouble of a Blender Possible Faults and Corresponding Remedies of the Blender
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B. Tools used in pre-testing a blender 1. 2. 3. 4. 5.
VOM (multi-tester) Instructional/ operational manual Screw driver Soldering Iron Pliers Diagonal pliers Long nose Pliers
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OPERATION SHEET 2.2 Troubleshooting Procedure of a Blender PROCEDURE: 1. Prepare all the tools and materials needed. 2. Unplug the blender and remove the jar. Undo the screw securing the base plate. Separate the base plate and attached motor collar from the base housing. 3. Remove the switch housing; remove the decorative facing to get at the top screws. Remove the lower screws from inside the blender base. 4. Hold the fan to keep the motor shaft from turning as you unscrew the drive stud. Remove the shield and any washers. Unscrew the fan nut to remove the fan. 5. Disengage the strain-relief fitting from the housing. Remove the wire connector joining the power cord and the lead to the brush housing. Trouble shooting
6. Label and disconnect the lead wires from the switch block. Remove the motor mounting bolts and lift out the motor if necessary. 7. To free brushes, remove the leads attached to the brush housing. Use a screw driver to press lead terminal through the slot. 8. Conduct the following: Servicing the Multi-speed Switch. It's easy to see why the multispeed switch is a critical component to the operation of your food blender. Because of its high use and complexity, it is a frequent culprit when things go wrong.
Multi-speed switch
Servicing a fuse. Fortunately, most blenders include an in-line fuse that protects the motor from overload. If excessive current is sent to the motor, the fuse will blow.
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Motor servicing is easy to test. Because there is a circuit running from the appliance cord, through the multispeed controls, to the motor, and back to the cord, an ohmmeter (part of your multitester) can test the circuit.
Tightening the Drive Stud. If the motor operates well, but the blade in the blender jar doesn't turn as it should, the problem may be the drive stud. The most frequent cause is a loose drive stud.
Service the Blade Assembly. The blender's blade assembly is simple in its function. It is rotated by the drive stud, which blends or chops food within the jar. The most common problem is caused by the jar leaking liquids. The solution is to tighten the base. If this doesn't solve the problem, inspect and if necessary, replace the gasket.
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JOB SHEET 2.1 Results of Diagnosis and Testing a Blender Direction: With the used of actual blender, diagnose its trouble and fill out the following table. Write your answer on a separate sheet of paper. Do not write anything on this module.
Blender model:_____________________________ Serial no: ___________________________________
Possible trouble
Cause of trouble
Affected components
Possible Remedy
1. ______________________
2. ______________________
3. ______________________
4. ______________________
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CHECKLIST FOR JOB SHEET 2.1 Diagnosis and Testing a Blender Directions: Put a check on designated box if you perform the following criteria.
The students must….. Perform pre-testing procedure in accordance with the manufacturers instruction Identify system defects/ faults system using the appropriate tools and equipment Explain identified defects and faults to the responsible person. Document results of diagnosis and testing.
YES
NO
Perform troubleshooting in accordance with the service manual.
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Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLY CONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A BLENDER
Learning Outcome 3: Maintain and repair a blender. Assessment Criteria: 1. Personal Protective Equipment is used in accordance with the Occupational Health and Safety Practices. 2. Defective parts/components are replaced with identical equivalent ratings and repaired in accordance with the current industry standard. 3. Control settings/adjustments are performed in conformity with the service manual specification. 4. Repair activity is performed within the required time frame. 5. Cleaning of unit is performed procedures.
in accordance with the standard
References: 1. Tan, Michael Q., Gantalao, Fred T., Lasala, Rommel M. Simple Electronics; Andes Mountain Printers: 2004 2. Enriquez, Marcelo T. Electronics Technology IV; Souvenir Publications, Inc.: 2003
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LEARNING EXPERIENCES/ACTIVITIES Learning Outcome 3: Maintain and repair a blender. Learning Activities
Special Instruction
1. Read the Operation Sheet 3.1 on food blender. 2. Read information Sheet 3.1. 3. Read Operation Sheet 3.2.
Try to answer all the Self Check materials without looking at the information sheet.
4. Perform the Job Sheet 3.1.
5. Answer assessment plan if you missed some of the question, go back to LO2. 6. If you have answered the assessment plan perfectly, you can proceed to the next module.
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OPERATION SHEET 3.1 Components Checking and Replacement
Exploded View and Replacement Part list
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Replacement Part List
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Components Checking
Rubber Cap, Connector U (lower)
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25
26
27
INF
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INFORMATION SHEET 3.1 Specifications of the parts of a blender
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OPERATION SHEET 3.2 Procedure in Maintaining and Repairing a Blender Servicing the Multispeed Switch: Step 1: Remove the blender base. Step 2: Attach the multi-speed switch to the base with clips or screws accessed from underneath the base's faceplate or from inside the base. Visually inspect the switch before removing it. In many cases, the problem is a loose terminal. Otherwise, a blackened terminal or wire may identify where the problem has occurred. Step 3: To check the multispeed switch use a continuity tester or multitester. Step 4: Because of its exposed location in front of the blender, the switch is susceptible to damage from liquids. Use a can of compressed air or an electrical contact cleaner to clean the switch. (Note: Before testing the switch, make sure to remove it from the blender)
Servicing a fuse: Step 1: Remove the blender base and locate the fuse in the wire from the multispeed switch to the motor. Step 2: Disconnect the wire and use a continuity tester or multitester to check the fuse. If the circuit is open, the fuse is blown. Step 3: Replace the faulty in-line fuse with one of identical rating.
Servicing the Motor: Step 1: Place a probe on each cord prong. Step 2: Select a speed-control button or turn the speed controller slightly, then read the resistance on the meter. Step 3: Next, rotate the drive stud clockwise by turning it once. If the resistance reading (in ohms) changes, the motor needs service. Take it to an appliance-repair service or replace the appliance with a good one depending on cost.
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Tightening the Drive Stud Step 1: Remove the base and turn the blender over. The other end of the drive shaft will protrude from the bottom side of the motor. Step 2: Grip the drive shaft with a wrench or pliers, and then turn the blender on its side to attach a wrench to the drive stud. Step 3: Hold the drive shaft steady as you turn the drive stud clockwise. The other cause of drive stud problems is the rounding of its corners, requiring a new drive stud. To replace a worn drive stud, reverse the instructions for tightening a drive stud, install the new part, and tighten it.
Service the Blade Assembly The blender's blade assembly is simple in its function. It is rotated by the drive stud which blends or chops food within the jar. The most common problem is leaking liquids in the jar. The solution is to tighten the base. If this doesn't solve the problem, inspect and if necessary, replace the gasket.
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JOB SHEET 3.1 Repairing a Blender Directions: With the use of actual blender, fill out the following table. Write your answer on a separate sheet of paper. Do not write anything in this module. Blender model:_____________________________ Serial no: ___________________________________
Trouble
Cause Affected Description Possible Repairing of components of Remedy procedure trouble Components
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ASSESSMENT PLAN
Title of Module
MAINTAINING AND REPAIRING A BLENDER
The evidence must show that the student can …
explain the operation of a blender.
identify the parts of the blender.
explain the functions of its parts.
Observation
Ways in which evidence will be collected: [tick the column]
Portfolio
MAINTAIN AND REPAIR ELECTRONICALLY CONTROLLED DOMESTIC APPLIANCES
Demonstration
Unit of competency:
Third party Report
CONSUMER ELECTRONIC SERVICING NC II
Oral Questioning
Competency standard:
Written
Evidence Checklist
perform pre-testing procedure in accordance with the manufacturer’s instruction. identify system defects/faults symptoms using appropriate tools and equipment. explain identified defects and faults to the responsible person. document results of diagnosis and testing. perform troubleshooting in accordance with the service manual.
use Personal Protective Equipment in accordance with Occupational Health and Safety Practices
follow Electro-static protection procedure.
replace defective parts/components with identical or recommended appropriate equivalents ratings.
solder/mount repaired or replaced parts /components in specified location.
Discharge
(ESD)
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perform control setting/ adjustment in conformity with service-manual specification.
perform repair activity required time frame.
clean the unit is cleaned after the maintenance and repair activity in accordance with standard procedures.
within
the
NOTE: Critical aspects of competency Prepared by:
Date:
Checked by:
Date:
Observation Checklist Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the teacher: 1. Can observe the student in Maintain and Repair a blender. 2. Can describe the assessment activity and the date on which it was undertaken. 3. Can place a tick in the box to show that the student completed each aspect of the activity to the standard expected in the enterprise. 3. Can complete the feedback sections of the form. Date of observation Description of assessment activity Location of assessment activity The student can...
Explain the operation of a blender.
Identify the parts of the blender. Explain the functions of its parts. performpre-testing procedure in accordance with the manufacturer’s instruction. identify system defects/faults symptoms using appropriate tools and equipment. identify defects and faults to the responsible person. document the results of diagnosis and testing.
If yes, tick the box
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perform troubleshooting in accordance with the service manual.
use Personal Protective Equipment in accordance with Occupational Health and Safety Practices
follow Electro-static protection procedure.
replace defective parts/components with identical or recommended appropriate equivalents ratings.
solder/mount and repair or replace parts /components in specified location.
perform control setting/ adjustment in conformity with service-manual specification.
perform repair activity within the required time frame.
clean the unit after the maintenance and repair activity performed in accordance with standard procedures.
Discharge
Did the candidate’s overall performance meet the standard?
(ESD)
Yes
No
Feedback to student’s: Teacher’s signature:
Date:
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Observation and Questioning Checklist Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the assessor:
1. Observe the candidate in Maintain and Repair a Blender 2. Describe the assessment activity and the date on which it was undertaken. 3. Place a tick in the box to show that the candidate completed each aspect of the activity to the standard expected in the enterprise. 4. Ask the candidate a selection of the questions from the attached list to confirm his/her underpinning knowledge 5. Place a tick in the box to show that the candidate answered the questions correctly. 6. Complete the feedback sections of the form. Date of observation Description of assessment activity Location of assessment activity The student can…
If yes, tick the box
Explain The operation of a blender.
Identify the parts of the blender. Explain the functions of its parts.
Perform pre-testing procedure in accordance with the manufacturer’s instruction. Identify system defects/faults symptoms using appropriate tools and equipment. Explain identified defects and faults to the responsible person. Document results of diagnosis and testing. Perform troubleshooting in accordance with the service manual.
Use Personal Protective Equipment in accordance with Occupational Health and Safety Practices.
Follow Electro-static protection procedure.
replace
defective
Discharge
(ESD)
parts/components
with 36
identical or recommended equivalents ratings.
appropriate
solder replacement parts/components specified location.
perform control setting/ adjustment in conformity with service-manual specification.
perform repair activity time frame.
clean the unit after the maintenance and repair activity in accordance with standard procedures.
in
within the required
YES
Did the student’s overall performance meet the standard?
NO
Demonstration Candidate’s name: Assessor’s name: Unit of competency: Competency standards: Date of assessment: Time of assessment: Instructions for demonstration Given the necessary materials the trainee/student must be able to:
Materials and equipment: VOM (Multitester) Instructional Operational Manual Screw Driver Soldering Iron Pliers: Diagonal pliers, Long nose pliers to show if evidence is demonstrated
During the demonstration of skills, did the student:
explain the operation of a blender?
identify the parts of the blender ? explain the functions of its parts ?
perform pre-testing procedure in accordance with the manufacturer’s instruction? identify system defects/faults symptoms using appropriate tools and
Yes
No
N/A
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equipment? explain identified defects and faults to the responsible person? document results of diagnosis and testing ? perform troubleshooting in accordance with the service manual?
use Personal Protective Equipment in accordance with Occupational Health and Safety Practices?
follow Electro-Static Discharge (ESD) protection procedure?
replace defective parts/components with identical or recommended appropriate equivalents ratings?
solder/mount repair or replace parts /components in specified location?
perform control setting/ adjustment in conformity with service-manual specification?
perform repair activity required time frame?
within the
clean the unit after the maintenance and repair activity performed in accordance with standard procedures?
The student’s demonstration was: Satisfactory
Not Satisfactory
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Written report Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Task: Your task is to: Maintaining and Repairing a Blender Submission date: Use the checklist below for judging the student’s report based on the competency standards. The student has: explained the operation of a blender . identified the parts of the blender . explained the functions of its parts.
performed the procedure manufacturer’s instruction.
identified system defects/faults symptoms appropriate tools and equipment.
explained identified responsible person.
documented the results of diagnosis and testing.
performed troubleshooting in accordance with the service manual.
used the Personal Protective Equipment in accordance with Occupational Health and Safety Practices.
followed Electro-Static procedure.
replaced defective parts/components with identical or recommended appropriate equivalents ratings.
soldered/mounted repaired or /components in specified location.
performed control setting/ adjustment in conformity with service-manual specification.
performed repair activity within the required time frame.
in accordance with the
defects
and
Discharge
faults
(ESD)
using to
the
protection
replaced
parts
clean the unit after the maintenance and repair activity performed in accordance with standard procedures. Overall did the Student’s report meet the standard?
Yes
No
Comments:
Student’s signature:
Date:
Teacher’s signature:
Date:
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PERFORMANCE TEST Student's Name
Date
Competency:
Test Attempt 2nd 3rd
1st Directions: Ask your teacher to assess your performance in the following critical task and performance criteria below
OVERALL EVALUATION Level Achiev PERFORMANCE LEVELS ed 4 - Can perform this skill without supervision and with initiative and adaptability to problem situations.
You will be rated based on the overall evaluation on the right side.
3 - Can perform this skill satisfactorily without assistance or supervision. 2 - Can perform this skill satisfactorily but requires some assistance and/or supervision. 1 - Can perform parts of this skill satisfactorily, but requires considerable assistance and/or supervision. Teacher will put his/her initial at level achieved.
PERFORMANCE STANDARDS For acceptable achievement, all items should receive a "Yes" or "N/A" response.
Ye s
No
N/ A
The operation of a blender is explained.
The parts of the blender are identified. The functions of its parts are explained. Pre-testing procedure is performed manufacturer’s instruction.
System defects/faults symptoms are identified using the appropriate tools and equipment.
Identified defects and faults are explained to the responsible person.
Results of diagnosis and testing are documented.
Troubleshooting is performed in accordance with the service manual.
Personal Protective Equipment is used in accordance with the Occupational Health and Safety Practices.
Electro-static Discharge (ESD) protection procedure is followed.
Defective parts/components are replaced recommended appropriate equivalents ratings.
or
Repaired or replaced parts /components are soldered/mounted in specified location.
Control setting/ adjustment are performed in conformity with servicemanual specification.
Repair activity is performed within the required time frame.
The unit is cleaned after the maintenance and repair activity performed in accordance with standard procedures.
in
accordance
with
with
identical
the
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ACKNOWLEDGMENT Copyright Department of Education 2008 First Published JUNE 2008 This module is based on the Competency-Based Curriculum-Contextual Learning Matrix (CBC-CLM) and finalized on the Instructional Modules Finalization Development Workshop conducted at the Development Academy of the Philippines, Tagaytay City on May 6 -10, 2008 This learning instrument was developed by the following personnel: Technology Teachers:
Mr. Vic P. Diola – Group Leader Bauan Technical High School
Dr. Gilbert M. Castor Don Alejandro Roses Sr. Science-Technology High School
Mr. Eddielou L. Dayao Sanchez Mira School of Arts and Trade
Mr. Rufo G. Malla E. Rodriguez Vocational High School
Mr. Sherwin P. Medrano San. Pedro Relocation Center National High School
Mr. Remar C. Pinsoy Baguio National School of Arts and Trade
Contextual Teacher:
Mrs. Daisy Carousel P. Cervantes Don Alejandro Roses Sr. Science-Technology High School
Facilitators:
Dr. Edward dela Rosa TEC-VOC Task Force
Dr. Corazon L. Echano TEC-VOC Task Force
Encoders:
Mrs. Rosario D. Briones Mr. Mhariel L. Echano Mr. Jason O. Villena
Funding: Department of Education
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ACKNOWLEDGMENT Copyright Department of Education 2009 First Published JUNE 2008 This module is based on the Competency-Based Curriculum-Contextual Learning Matrix (CBC-CLM) refined during the Writeshop on the Refinement and Enrichment of Competency-Based Curriculum and Contextual Learning Matrix of ARTS abd TRADES Specializations at Marikina Hotel, Marikina City on April 20 – 25, 2009. This learning instrument was refined and enriched by the following educators: Technology Teachers:
Mr. Victorino P. Diola – Group Leader TVE Coordinator, Bauan Technical High School Bauan, Batangas
Mr. Reynaldo C. Cunanan Head Teacher VI, E. A. Rodriguez Vocational High School Nagtahan, Sampaloc, Manila
Mrs. Gigi C. Corpuz Teacher III, Malvar National High School Malvar, Batangas
Mr. Ismael G. Gallardo Teacher I, Community Vocational High School Masipit, Calapan City, Oriental Mindoro
Mr. Rufo G. Malla Teacher II, E. A. Rodriguez Vocational High School Nagtahan, Sampaloc, Manila
Mr. George B. Fuazo Teacher II, Gen. Mariano Alvarez Technical High School GMA, Cavite
Contextual Teacher: English
Mrs. Teresita P. Tanael Teacher III, Gen. Mariano Alvarez Technical High School GMA, Cavite
o Mrs. Charlie I. Soriano Teacher I, Don Alejandro Roces Sr. Science-Technology HS Quezon City
Mathematics o Mrs. Analiza Rosa P. Librada Teacher I,-Mathematics Coordinator, San Pedro Relocation Center Nat’l. HS San Pedro, Laguna
Science 42
o
Mrs. Gemma G. Vallarta Teacher III Science Coordinator, San Pedro Relocation Center Nat’l. HS San Pedro, Laguna
Mrs. Lenalyn Manzano
o
Teacher I, E A. Rodriguez Vocational High School Nagtahan, Sampaloc, Manila
Facilitators:
Dr. Corazon L. Echano TEC-VOC Task Force
Dr. Victorio N. Medrano TEC-VOC Task Force
o Dr. Orlando E. Manuel TEC-VOC Task Force
Encoders: o Marisol E. Saldivar
Funding: Department of Education
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Republic of the Philippines Department of Education PUBLIC TECHNICAL -VOCATIONAL HIGH SCHOOLS
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLY CONTROLLED DOMESTIC APPLIANCES
Module No. 4
MAINTAINING AND REPAIRING A BLENDER
TABLE OF CONTENTS Page How to Use this Module ................................................................................... i Introduction .................................................................................................... ii Technical Terms ............................................................................................. iii Learning Outcome 1: Identify the Parts and Functions of a Washing Machine ......................................................................... 1 Learning Experience 1.1 ........................................................................ 2 Information Sheet 1.1 ............................................................................ 3 Self-Check 1.1 ....................................................................................... 5 Self-Check Key 1.1................................................................................. 6
Learning Outcome 2: Diagnose and troubleshoot Washing Machine
Defects ......................................................................................... 7 Learning Experience 1.1 ........................................................................ 8 Operation Sheet 2.1 ............................................................................... 9 Performance Test 2.1 ........................................................................... 28 Observation Check List 2.1 .................................................................. 29 Questioning Check List 2.1 .................................................................. 31
Learning Outcome 3: Maintain and repair a washing machine....................... 32 Learning Experience 1.1 ...................................................................... 33 Information Sheet 3.1 .......................................................................... 34 Self-Check 3.1 ..................................................................................... 38 Self-Check Key 3.1............................................................................... 39 Job Sheet 3.1 ...................................................................................... 40 Information Sheet 3.1 .......................................................................... 41 Performance Test 3.1 ........................................................................... 43 Observation Checklist 3.1 .................................................................... 44 Questioning Checklist 3.1 .................................................................... 46 Evidence Checklist 3.1......................................................................... 47 Acknowledgement ................................................................................ 48
HOW TO USE THIS MODULE Welcome to the Module “Maintaining and Repairing a Washing Machine”. This module contains training materials and activities for you to complete. The unit of competency “Maintain and Repair Electronically-Controlled Domestic Appliances” contains the knowledge, skills and desirable attitudes required for Consumer Electronics Servicing required to obtain the National Certificate (NC) level II. You are required to go through a series of learning activities in order to complete each of the learning outcomes of the module. In each learning outcome there are Information Sheets, Activity Sheets Operation Sheet, and Student Write-Up. Do these activities on your own and answer the SelfCheck at the end of each learning activity. If you have questions, don’t hesitate to ask your teacher for assistance.
Recognition of Prior Learning (RPL) You have already some basic knowledge and skills covered in this module because you have been working for some time; and already completed training in this area. If you can demonstrate competence to your teacher in a particular skill, talk to him/her so you don’t have to undergo the same training again. If you have a qualification or Certificate of Competency from previous trainings show it to him/her. If the skills you acquired are consistent with and relevant to this module, they become part of the evidence. You can present these for RPL. If you are not sure about your competence skills, discuss this with your teacher. After completing this module, ask your teacher to assess your competence. Result of your assessment will be recorded in your competency profile. All the learning activities are designed for you to complete at your own pace. In this module, you will find the activities for you to complete and relevant information sheets for each learning outcome. Each learning outcome may have more than one learning activity. This module is prepared to help you achieve the required competency, in receiving and relaying information. This will be the source of information that will enable you to acquire the knowledge and skills in Maintaining and Repairing a Washing Machine independently at your own pace with minimum supervision from your teacher. i
Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A WASHING MACHINE
INTRODUCTION: This module contains information and suggested learning activities on Maintaining and Repairing a Washing Machine. It covers the knowledge, skills and attitudes required in maintaining and repairing washing machine. Completion of this module will help you better understand the succeeding module on maintaining and repairing electronically-controlled domestic appliances. This module consists of three (3) learning outcomes. Each learning outcome contains learning activities supported by instructional sheets. Before you perform the instructions, read the information sheets and answer the selfcheck and activities provided to ascertain to yourself and your teacher that you have acquired the knowledge necessary to perform the skill portion of the particular learning outcome. Upon completing this module, report to your teacher for assessment to check your achievement of knowledge and skills required in this module. If you pass the assessment, you will be given a certificate of completion. SUMMARY OF LEARNING OUTCOMES: Upon completion of the module, you should be able to: LO1. identify the parts and functions of a washing machine; LO2. diagnose and troubleshoot washing machine defects; and LO3. maintain and repair a washing machine.
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TECHNICAL TERMS AC Motor. It converts AC electrical energy into mechanical energy, producing a mechanical rotary action that performs some type of work. Antistatic. It is a container which resists generation of triboelectric charge (frictionally generated) as the device is inserted into, removed from, or allowed to slide around in it. Bushing. It is a sleeve protecting a conductor where it passes through a hole in motor. Capacitor. It is a device used to boost the voltage to a motor. Running capacitors are used in the starting winding to increase the running torque of the motor. Starting capacitors are used in the starting winding to increase the starting torque of the motor. Capacitor for Start Motor. It is a low reactance non-polar electrolytic capacitor connected in series with the start winding. Motor. It is a rotating electric machine which changes applied electrical energy or power into mechanical output energy or power. Rotor. A part of an electric motor that turns or rotates. Run Winding. The winding in an electric motor that provides the power for turning the rotor during operation. It has the larger wire of the two windings. The main winding of the motor with comparatively low resistance and high inductance. Resistor. It is a component made of material that opposes the flow of current and therefore has some value of resistance. Rotary Switch. It is an electromechanical device that has a rotating shaft connected to one terminal capable of making, breaking a connection to one or more other terminals. Shaft. It is a part of a rotor that carries other rotating members and that is supported by bearings in which it can rotate. Start Winding. It is an auxiliary winding of the motor with comparatively high resistance and lower inductance. Stator. It is a stationary part of the motor which the field windings are placed. System Control Microprocessor. It is an integrated circuit that can recognizes and responds to commands from the operator by monitoring the DC voltages at the output terminals. iii
Schematic Diagram. It is an illustration of an electrical or electronic circuit with the components represented by their symbol. Short Circuit. It is also called a short. A low resistance connection between two points in a circuit typically causing excessive current. Solder. It is a metallic alloy used to join two metal surfaces. Soldering. It is a process of joining two metallic surfaces to make an electrical contact by melting solder (tin and lead) across them. Substrate. It is a mechanical insulating support upon which a device is fabricated. Switch. It is an electrical device having two states, ON (closed) or OFF (open). Test. It is a sequence of operations intended to verify the correct operation or malfunctioning of a piece of equipment or system. Thermal cutout. It is an over current device that contains a heater element in addition to and affecting a renewable fusible member which opens the circuit. It is not designed to interrupt short circuit currents. Transformer. It is an inductor with two or more windings. Troubleshooting. It is a systematic approach to locate the cause of a fault in an electronic circuit or system. Winding. It is an assembly of coils designed to act in consort to produce a magnetic flux field or to link a flux field.
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Program/Course
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title
MAINTAINING AND REPAIRING A WASHING MACHINE
Learning Outcome 1: Identify the parts and functions of a washing machine.
Assessment Criteria: 1. The parts and their functions are identified based on the manufacturer’s service manual. 2. The parts are handled in accordance with the manufacturer’s service manual. REFERENCES AND FURTHER READING 1. Goldberg, Joel. Troubleshooting Electronic Devices; Delmar Publishers, Inc:1994. 2. Mukay, Masaaki, Kobayashi, Ryozzo. TV Troubleshooting Manual. Pictorial Printers, Ltd: 1988. 3. Perozzo, James. Practical Electronics Troubleshooting: Delmar Publishers, Inc: 1992. 4. Ronan, David T. Practical VCR Repair; Delmar Publishers, Inc: 1995. 5. www.google.com 6. www.yahoo.com
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LEARNING EXPERIENCE / ACTIVITIES Learning Outcome 1 Identify the functions of the parts of a washing machine. Learning Activities Special Instructions You can ask the assistance of Read the Information Sheet your teacher to show you and No. 1.1 on operation of a explain further the topic you washing machine, parts and don’t understand. its functions.
Do the Self-Check No. 1.1 to check your knowledge on the operation of a washing machine, parts and its functions.
Compare your answers to the Answer Key.
If you were not able to answer all the questions, go over again the Information Sheet.
If you have answered all the questions, you can proceed to the next learning outcome.
Try to answer Self-Check without looking at the Information Sheet.
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INFORMATION SHEET 1.1 OPERATION OF A WASHING MACHINE Washing Machine . It is a domestic appliance that washes clothes and linens. It is a power driven machine with an AC motors connected to the 60 Hz power source so that the electrical energy can be converted into mechanical energy in order to facilitate an act of washing rinsing and spinning. It also includes wash and spin timers for automatic operations. PARTS OF WASHING MACHINE AND ITS FUNCTIONS
TOP COVER
PROGRAM SELECTION CONTROL
PULSATOR
WATER SUPPLY HOSE AC CORD
DRUM
SIDE COVER TUB
DRAIN HOSE Function of its Parts: Top Cover is used to cover the tub. Pulsator is a rotating part inside the tub and responsible in making the water spin. Drain Hose serves as a passage way out. Side Cover Tub is the main housing of the unit. Drum serves as a washing tub. Water Supply Hose serves as an inlet of water.
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Block Diagram of Electronically-Controlled Washing Machine
Power Controller. It is a circuit that controls the amount of power supplied to the motor. Sensor. It is the input receiver that detects input signal coming from forward and reverse motor. It detects any abnormality of the operation for automatic shut off. Program Selection Control. It is a push button switch that controls the operation of the washing machine. This circuit has a timing sequence for low,medium or high. Comparator. It is a processing circuit that accepts the input signal coming from sensor, program selection control. This circuit provides the triggering voltage to the power controller. Forward/Reverse Motor. A rotating electric machine which changes applied electrical energy or power into mechanical output energy or power. Buzzer. It is a device used to generate sound, once the program operation is completed or problem occurred. Input Command. It is a setting period of the user. AC Plug. It is a connector intended for connecting to the main source of 220V
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SELF-CHECK 1.1 A. Direction: Label the different blocks that resemble an electronicallycontrolled washing machine. Write your answer in another sheet of paper. Do not write anything in this module.
B. Direction: Define the following words below. Write your answer on a sheet of paper. Do not write anything in this module. 1. Pulsator - _______________________________________________________________ 2. Drain Hose - ____________________________________________________________ 3. Buzzer - ________________________________________________________________ 4. Program Selection Control - _____________________________________________ 5. Power Control - _________________________________________________________
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ANSWER KEY TO SELF-CHECK 1.1 A. Label the different blocks. 1.
AC Plug
2.
Buzzer
3.
Forward/Reverse Motor
4.
Input Command
5.
Comparator
B. Define the following words. 1. Pulsator. It is a rotating part inside the tub. Responsible in making the water spin. 2. Drain Hose. It serves as a passage way out. 3. Buzzer. It is a device used to generate sound once the program operation is completed or problem occurred. 4. Program Selection Control. It is a push button switch that controls the operation of the washing machine. This circuit has a low, medium or high timing sequence. 5. Power Control. It is a circuit that controls the amount of power supplied to the motor.
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Program / Course
CONSUMER ELECTRONIC SERVICING NCII
Unit of Competency
MAINTAIN AND REPAIR ELECTRONICALLY - CONTROLLED DOMESTIC APPLIANCES
Module Title
MAINTAINING AND REPAIRING A WASHING MACHINE
LO 2:
Diagnose/troubleshoot washing machine.
ASSESSMENT CRITERIA: 1. Pre-testing procedure is observed in accordance with the manufacturer’s instructions. 2. System defects/fault symptoms are identified using the appropriate tools and equipment and in accordance with the safety procedures. 3. Identified defects and faults are explained to the responsible person (the teacher) in accordance with the enterprise or company policy and procedures. 4. Results of diagnosis and testing are documented accurately and completely with the specified time frame. 5. Customers (assessors/teachers) are advised/ informed regarding the status and serviceability of the unit as per procedure. CONTENTS:
Procedure and Techniques in Pre-Testing a Washing Machine Troubleshooting Procedure Tools for Testing Possible Faults and Corresponding Remedies
REFERENCES AND FURTHER READING 7. Goldberg, Joel. Troubleshooting Electronic Devices; Delmar Publishers, Inc:1994. 8. Mukay, Masaaki, Kobayashi, Ryozzo. TV Troubleshooting Manual. Pictorial Printers, Ltd: 1988. 9. Perozzo, James. Practical Electronics Troubleshooting: Delmar Publishers, Inc: 1992. 10.Ronan, David T. Practical VCR Repair; Delmar Publishers, Inc
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LEARNING EXPERIENCE / ACTIVITIES Learning Outcome 2 Diagnose a washing machine and troubleshoot defects / faults found. Learning Activities Special Instruction Perform Operation Sheet No. You can ask the assistance of 2.1 on procedure and your teacher to show you and technique in pre-testing and explain further the topic you troubleshooting a washing don’t understand. machine.
Do Performance Test to test your skills on procedure and technique in pre-testing and troubleshooting a washing machine.
Refer your Performance Output to the Observation and Questioning Checklist.
If you missed some of the items in the Observation and Questioning Checklist, go over again the Operation Sheet.
If you did get all the items in the Observation and Questioning Checklist, you could proceed to the next learning outcome.
Try to perform the Performance Test within the least possible time allotment.
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OPERATION SHEET 2.1 PROCEDURE AND TECHNIQUES IN PRE-TESTING AN ELECTRONICALLYCONTROLLED WASHING MACHINE: 1. Determine what the problem really is. 2. Be sure you understand how the washing machine operates. 3. Perform preliminary inspection to locate where the problem has originated. 4. Perform closer inspection into the suspected parts or components. 5. Plan your approach to the repair problem. TROUBLESHOOTING PROCEDURE: ELECTRICAL FAULTS 1. Washer is not energized. Checks to be made
Household Power Supply 1. Check whether connection between the plug and the electrical outlet has poor contact. 2. Measure voltage of the electrical.
Result of the Check
Possible Cause
Remedy
Poor contact.
Defect on the electrical outlet.
Change the electrical outlet.
Approximate voltage rating.
No defect.
No Voltage.
Defects on the Fix the 60 Hz AC 60 Hz power supply household power line. supply.
Less than 1 Ω ∞ Ω.
No defect.
Wiring of the Washer 1. Measure the resistance between both end of the power supply cord with both the plug pins shortcircuited. 2. Check whether every connector in the bundle of connectors has a
Open circuit of the power supply cord. Male and female connectors are separated.
Poor connection.
Change the power supply cord.
Remove the cause to give strain and reconnect them. 9
good connection 3. Check the resistance of every wire to find out an open wire. Electrical Component
Change the lead wire.
∞Ω Wire is opened.
1. Check the resistance with power relay switch turned on.
Less than 0.5 Ω More than 1.0 Ω.
No defect Poor contact.
Change the auto off switch.
2. Check the secondary voltage of the transformer.
10~14 V OV.
No defect.
Change the transformer.
Coil is open.
3. Measure the ∞ Ω and motor resistance to is hot. check whether testing point of the motor is blown out. Open. 4. Check whether the fuse is open. Controller 1. If there are no defects as mentioned above, it is the controller that is defective.
Over 120% voltage than rating check.
Testing Point blown out.
Remove causes to overload the motor.
Change the fuse. Defect on the fuse. Change the controller if all the electrical parts have no defects.
2. If supply voltage is 120% higher than rating, the varistor in the controller may be broken. Check the supply voltage.
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2. Defects on Displaying Function. Checks to be made
Main Voltage 1. Measure the main voltage at the wall outlet.
Result of Check
Less than 85% of the rating.
Possible Cause
Low voltage.
Remedy
To explain that it is caused by low voltage in electric supply and to recommend use of a transformer if voltage has been continuously low.
2. Measure the voltage at the Less than extended outlet 85% of the where the washer rating. is plugged in. If the extended outlet is used and voltage at the electrical outlet is normal in the above, then the extended outlet is defective. Transformer
The diameter of the lead wire is smaller or many loads are connected at the same outlet.
1. Measure the secondary voltage of the transformer.
Defect on the transformer.
Change the controller.
Defect on the controller.
Change the controller.
Less than AC 10V.
To use a transformer having enough capacity.
Controller 1. Defect on LED 2. Defect on LED driving circuit 3. Defect on micon 3. Reset during Operation. Checks to be made
Result of Check
Possible Cause
Remedy
Main Voltage 1.Measure the Less than voltage of the outlet 80% of the where the washer is rating.
Explain that it is The main voltage caused by a low is too low or size voltage supply in of a lead wire is the locality. 11
plugged into during wash and spin.
too small. Recommend the use of regulated power supply.
2. Reset symptom happens at specific time zone repeatedly.
Explain that it is a problem of electric supply in the locality.
4. Water does not drain. Checks to be made
Result of Check
Possible Cause
Remedy
Ball Pressure Sensor 1. Is there a PE error on the display known as the means Ball Pressure Sensor Error?
PE error displayed.
2. Check frequency of the Ball Pressure Sensor without load if wash is proceeding without filling. Controller
Less than 26.2 Defect on the kHz. Ball Pressure Sensor.
1. Defect on the controller is highly possible if inlet valve and Ball Pressure Sensor have no defects in the above.
Connector is taken off or lead or the coil is open.
Reconnect the connector or change leads. Change the Ball Pressure Sensor if the coil is open. Change the pressure switch.
Change the controller.
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5. Pulsator doesn’t rotate normally. Checks to be made
Result of Check
Possible Cause
Remedy
Pulsator weakly rotates 1. Check the Less than 85% voltage at the of rating. power outlet where the washer is plugged into. Indicating 2. Check the needle rises capacitance of the and capacitor. immediately indicates ∞. The needle is stopped after it has been raised. The needle doesn’t move.
Lower voltage.
Capacitor is normal.
Lack of capacitance of the capacitor.
Explain the causes and recommend that a transformer should be used if necessary.
Change the capacitor.
Capacitor is fully Change the discharged. capacitor.
6. Drain error happens while water drains normally. Checks to be made
Result of Check
Possible Cause
Remedy
Ball Pressure Sensor 1. Check the Less than 26.3 generation kHz. frequency of the Ball Pressure Sensor without 26.3~27.1 water. kHz. 7. Spin extraction is not proceeded. Checks to be made
Result of Check
Defect on the ball pressure sensor.
Change the Ball Pressure Sensor.
Defect of the controller.
Change the controller.
Possible Cause
Remedy
Motor 1. The wash motor does not spin during spin extraction.
There is a motor working sound.
Defect on the capacitor or mechanically locked.
Change the capacitor after checking the defect of capacitor. 13
a. Check if there is motor working sound.
Check whether the washing tub is blocked if the motor rotates after removing the V-belt. Check if the motor is locked when it does not rotate even though the Vbelt is removed.
2. If there is no motor – working sound. a. Check the frequency of the Ball Pressure Sensor under no load condition. b. Place the magnetic in Lid-B.
Defect on the Less than 26.3 Ball Pressure kHz . Sensor.
The lid is open.
Misuse of the machine.
Defect of magnetic in lid-B. c. Check the resistance of the motor.
Change the Ball Pressure Sensor.
Explain that the lid is close during operation. Change the LidB.
Coil is open. Contact defect of the Ball Pressure Sensor ∞ Ω.
Change the Ball Pressure Sensor. Change the motor.
Drain Motor/Clutch 1. In case the motor rotates but the inner tub does not rotate. a. Check the resistance of the drain motor if the drain motor does
∞Ω Resistance is normal.
Coil is open. Defect on the connection part
Change the drain motor. Change the 14
not work.
or defect on the controller.
controller after checking connection parts.
8. Spinning is going on even though the lid is open. Checks to be made
Result of Check
Possible Cause
Remedy
Ball Pressure Sensor 1. The magnetic is placed on the wash.
Yes
No
Read S/W is short by magnetic on the washer.
Keep magnet away from the washer.
Read Switch.
Change the controller.
9. Spin basket does not reach to full speed (normal rpm). Checks to be made
Result of Check
Possible Cause
Remedy
Main Voltage 1. Check voltage Less than 85% at the power outlet of rating. where the washer is plugged into.
Too low voltage.
Explain the cause and recommend using a transformer if necessary.
Starting Capacitor 1. Check the capacitance of the starting capacitor.
Insufficient capacitance of the capacitor.
Defect on the capacitor.
Change the capacitor.
10. Power is not automatically turned off. Checks to be made
Result of Check
Possible Cause
Remedy
Auto Off Switch 1. Check whether There is there is something something that pushes on the press on it. power button.
Remove it.
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11. Power automatically turns on and off during operation. Checks to be made
Result of Check
Possible Cause
Remedy
Main Voltage 1. It is mostly caused by noise from main source of power. Auto Off switch or Controller 1. Check whether power is automatically turned off when turning on the auto off switch after unplugging the power cord from the outlet.
Automatically turned off.
Defect on the main power source.
Explain the cause.
Mechanical defect on the auto off switch.
Change the auto off switch.
Change the controller.
2. It would be a defect of the controller if the power is automatically turned off immediately when turning on the power switch even though there is no defect in the auto off switch. MECHANICAL FAULTS 1. Water doesn’t come into the wash tub. Checks to be made
Result of Check
Possible Cause
Remedy
Inlet Valve 1. If water doesn’t come through the inlet valve works, electric sound occurs. 16
a. Check whether water main is cut.
Water main is cut.
Main is cut.
Explain.
b. Check whether tubs are turned on.
Doesn’t turn on.
Misuse.
Turn on the tap.
Wrong installation.
Correct their locations and turn on the tap.
Misuse.
Explain how to use the machine properly.
c. Hot and cold Connected tubs are oppositely oppositely. connected. d. If there are no problems as mentioned, check the inlet valve filters after disconnecting the water supply hose. f. If there are no problems as mentioned, a diaphragm hole in the valve is blocked by foreign substance or the plunger in it is locked.
Selected oppositely. Filter is blocked by foreign substance .
Uncleaned. Defect on the inlet valve.
Clean them by a brush and explain to clean them regularly. Change the inlet valve.
2. Water fills continuously or intermittently. Checks to be made
Result of Check
Possible Cause
Remedy
Wrong Installation/Leakage 1.Check whether the drain hose is laying down on the floor.
Drain hose is not in its proper position.
2. Check where is the leak.
Wrong Installation.
Water leaks.
Defect on the part.
It doesn’t rotate.
Water pressure is not sensed.
The drain hose should be hanged on the stand-pipe or the tub. Change the part. Repair it.
Ball Pressure Sensor 1. Check the pulsator if it is rotating when
Check the tube of the Ball 17
water is filled continuously. 2. If there is no defect in the Ball Pressure Sensor, check whether the air hole of the outer tub is blocked.
Pressure Sensor. Repair it.
Blocked.
Air hole is blocked.
Water fills.
Defect on the inlet valve.
Repair the blocked hole.
Inlet Valve 1. The water fills even though it is not energized.
Change the inlet valve.
3. Pulsator doesn’t rotate normally. Checks to be made
Result of Check
Possible Cause
Remedy
Pulsator rotates at one direction 1. The Pulsator rotates normally at the beginning of wash cycle, but does not rotate at clockwise direction (locked) after some wash cycles though there is motorworking sound.
Clockwise rotation is locked.
Unusual operation.
Turn the power off and on again until that symptoms disappear.
Defect on the controller or poor contact of connectors of motor leads.
Change the controller if there are no contact defects in the leads of the motor.
2. In the case that the pulsator doesn’t rotate either clockwise or counter-clockwise from the beginning of wash cycle. a. Check the resistance of the wash motor. If there is no motor working sound.
Resistance is normal.
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b. Check the belt tension whether clutch rotates normally.
V-belt is loose. Clutch is locked.
Loose belt.
Defect on the clutch.
Adjust belt tension by changing motor fixing location. Change the belt if it is impossible to adjust the belt tension. Change the clutch if the clutch pulley is locked.
3. The pulsator doesn’t rotate at both directions. a. Check whether Motor rotates the motor rotates at both both direction when directions. it’s energized .
Loose belt.
Change the clutch. The pulsator is locked. Defect on the clutch.
Motor doesn’t rotate at both directions.
Adjust belt tension or change the belt if it is impossible to adjust. . Remove the cause of locking the pulsator.
Change the motor if the motor is locked when having its shaft rotated by hand.
Defect on the capacitor (check the capacitor’s capacitance).
Change the capacitor if there is no contact defect in the capacitor’s lead.
Defect on the motor.
Change the motor. Remove the causes.
2. Check resistance 19
of the motor if there is no motor∞Ω working sound. Normal resistance.
Motor coil is open. Defect on the leads.
4. Water does not drain. Checks to be made
Result of Check
Possible Cause
Remedy
Drain Pump 1. Check if the drain pump is working soundly.
There is a pump working sound.
Drain pump is blocked by foreign objects.
Disassemble the drain pump cap and remove the foreign objects in the pump casing.
Its coil is open.
Change the drain pump.
Defect on connection part.
Defect on connection part.
Repair defective connection.
Connection part has no defects.
Defect on the controller.
Change the controller.
2. Check the resistance between terminals if there ∞Ω is no working sound at the drain pump. 3. Check connection parts of the leads if there is no working sound and its resistance is normal.
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Drain Hose 1. Check whether the drain hose is put in a narrow space and kinked. 2. Check whether the internal drain rubber assembly is bent (for nonpump model). 3. Check whether the end of the drain hose is submerged into water or higher than required (for non-pump model). 4. Check whether the drain hose is blocked by foreign objects. It may happen in case that the hose is a little kinked.
Kinked.
Defect on the installation.
Reinstall.
Bent .
Defect on the drain rubber assembly.
Change the drain rubber assembly.
Submerged or higher than required.
Defect on installation.
Reinstall .
Blocked.
Blocked hose.
Remove the objects and reinstall so that it will not be kinked.
PV Case (for non-pump model only) 1. Check whether the PV assembly is blocked by foreign objects.
Blocked.
Separate the drain motor from the PV link; disassemble PV cover; and remove the foreign objects within the PV case. Check the washer works normally after repair and reassemble them. 21
Drain Motor (for non- pump model only) 1. Check the resistance of the drain motor if it cannot pull the PV link.
∞ Ω
Drain motor coil is open.
Change the drain motor. Check the washer if it works normally after reassembling.
Resistance is normal.
Contact defect in connection parts or defect of the controller .
Change the controller if there is no defects in the connection parts.
5. Water drains though it is not yet the time of draining. Checks to be made
Result of Check
Possible Cause
Remedy
Drain Motor (for non-pump model only) 1. Check whether the drain motor is normally returned after turning power off. It is considered normal if the lever of the drain motor is fully pulled out by the PV spring. PV Case
Blocked.
1. If water drains though the drain motor is normally returned, check whether PV assembly is blocked by foreign
Blocked.
Bellows are deformed.
Defect on the drain motor.
Change the drain motor.
Remove the objects from the PV assembly. Defect on PV Bellows.
Change the PV bellows. The bellows may 22
objects or the bellows in the PV assembly is deformed.
swell up if it contact petroleum or petrochemical substance because it is made of rubber.
Controller 1. Check whether the drain motor or the drain part works immediately after power is turned on.
Works.
Defect on the controller (Triac defect).
Change the controller.
6. Spin extraction is not proceeded. Checks to be made
Result of Check
Possible Cause
Remedy
Drain Motor/Clutch 1. In case motor rotates but the inner tub doesn’t rotate: a. Check resistance of the drain motor if the drain motor does not work.
b. Check gaps between PV link and the break lever if the inner tub does not rotate while the drain motor works.
∞ Ω
Coil is open.
Change the drain motor.
Resistance is normal.
Defect on connection part or defect of the controller.
Change the controller after checking connection parts.
The clearance is less than 2.0 mm or more than 3.5 mm.
Assembling defect onthe drain motor or the clutch
The gap is normal (2.03.5 mm).
Defect on the clutch.
Reassemble the drain motor or the clutch to keep the clearance. Change the clutch.
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7. Spin basket doesn’t reach to full speed (normal rpm). Checks to be made
Result of Check
Possible Cause
Remedy
Clutch Assembling 1. Check the clearance between the PV link and the break lever and clearance between the clutch lever and the adjustment bolt.
The clearance is less than 2.0 mm or more than 3.5 mm.
Adjust the PV lever bolt and paint it red. Reassemble the drain motor or the clutch.
Bolt clearance Defect on the is out of range. clutch.
Adjust the bolt clearance.
Blocked by foreign objects 1. Check whether the PV assembly, the drain pump and drain hose are blocked by foreign objects that makes water splashing noise in the tub.
Remove the foreign objects.
8. Vibration, Noise or Unbalance Error happens during spin. Checks to be made
Result of Check
Possible Cause
Remedy
Using conditions such as installation etc. 1. Check whether Not leveled. the washer is leveled check clearance without tub and out case the left gap is the same as the right and the rear gap is 1.5~2 time bigger than the front gap between the
Defect on installation.
Level the washer.
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cabinet and the wash bowl, when it is leveled. 2. Check whether the laundry in the wash bowl is out of balance that can cause severe vibration and noise. 3. Check whether the pulsator doesn’t rotate during spin
Laundry is unbalanced.
The pulsator rotates initially then the inner tub rotates.
Defect on the clutch.
Explain that it is not out of order and it may happen when big and long laundry is washed. Change the clutch spring-B or the clutch assembly.
Damper 1. Check whether the outer tub cover hits the top cover without load during spin.
Hit.
Defect of the damper
Change damper simultaneously. In assembling, check the position of the damper assembly.
Possible faults and corresponding remedies. TROUBLESHOOTING GUIDE SYSTEM SYMPTOM/ DEFECTS/ PROBLEM FAULTS Water Water level does supply and not rise to the inlet valve. set level in 40 minutes. Wash and rinse LED blink.
(ELECTRONICALLY CONTROLLED) POSSIBLE CAUSE Water faucet is closed. Water supply is interrupted Inlet V/V is clogged with dirts. Connector has bad contact to the inlet valve. Yellow (YL) 2 pin connector has bad contact to the P.W.B.ASM.
REMEDY Open the water faucet. Wait until water supply is resumed. Clean or replace filter. Correct the connector contact. Same as above. 25
Drainage.
Water is not completely drained in ten minutes. Rinse and spin LED blink.
Unbalanced.
Laundry is unbalanced during spin. Wash, Rinse and Spin LED blink.
Over flooding error.
Door open.
In a second QC Mode the following message is displayed. All of process LED blink. LID is opened in the course of intermittent spin, normal spin or processing reservation. Wash and spin LED blink.
Is the drain hose located properly? Drain hose is not lowered. Drain hose is folded or clogged due to freeze or dirts. Bad Drain Motor part or GRAY(GY) 2 pin connector to the P.W.B ASM has bad connection. Laundry in the INNER TUB is filled unevenly. Water tank is tilted. Connector or Ball pressure sensor is disconnected or badly touched.
Check INLET valve.
Lid is opened during intermittent spin or normal spin. Lid is opened while processing reservation. Is placed magnetic in Lid-B.
Hung up drain hose at 0.9~1.3m high. (For pump) Put the hose lower. (For: Non-pump) Unclog the drain hose. Replace drain motor or correct the connector contact. Try to fill laundry uniformly in the inner tub. Adjust the leg. Check B.P SENSOR CONNECTOR or replace B.P sensor. Make adjustment if inlet valve is defective.
Close the lid.
Close the lid. Change the Lid-B.
Signal is continuously ringing. 26
Ball pressure sensor.
Ball pressure sensor is off. All water level LED blink.
Auto off.
Connect the BALL PRESSURE .SENSOR or BLUE (BL) 3 pin connector to P.W.B ASM has bad connection. PRESSURE S/W is bad. In the initial state of QC TEST MODE, the number of the DISPLAY is less than 63 or more than 70.
Auto off relay S/W BLUE(BL) 1pin is out of order. connector to P.W.B ASM has bad connection.
Correct the connector contact.
Replace ball pressure sensor.
Correct the connector contact. Change auto off switch ASM.
TROUBLESHOOTING GUIDE (MECHANICALLY CONTROLLED) PROBLEM
Pulsator
POSSIBLE CAUSE
REMEDY
Power failure or plug dropped off.
Insert the plug well.
V-belt dropped off.
Put on the V-belt properly.
Pulley loosened.
Tighten the pulley screw.
Ceased Running.
Abnormal Noise and
Foreign matter jammed pulsator. Friction between pulsator and wash tub. Pulsator is jammed by foreign matter.
Vibration.
Over tightened V-belt.
Pulsator Runs at Low speed.
Stackened V-belt . Motor fixing screws loosened.
Take it away. Adjust the gap between them. Take it away. Adjust properly. Adjust properly or replace it with a new one. Tighten V-belt and the screws. 27
PERFORMANCE TEST 2.1 Direction: Given a set of hand tools, multi-tester and defective washing machine with manufacturer’s service manual perform the procedure and techniques in pre-testing and troubleshooting a washing machine. Provide a work report/write-up after completing the task. Write your answer on a separate sheet of paper. STUDENT WRITE-UP A Common Symptoms / Defects of a Washing Machine Student : _________________________________ Date: ________________________ Year & Section: _________________________ Teacher: _______________________ UNIT BRAND : _________________________ Unit Model: ______________________ Owner: ______________________ Address: _________________________________ 1. PROBLEM/S & SYMPTOM/S : ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________ STUDENT WRITE UP B Diagnosing Faults in ECEF Student : _________________________________ Date: ________________________ Year & Section: _________________________ Teacher: _______________________ UNIT BRAND : _________________________ Unit Model: ______________________ Owner: ______________________ Address: _________________________________ 2. POSSIBLE CAUSE/S: ______________________________________________________________________________ ______________________________________________________________________________ Teacher’s Initial: ___________
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OBSERVATION CHECKLIST FOR PERFORMANCE TEST 2.1 Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the Teacher: 1. Observe the Student [insert description of activity being observed] 2. Describe the assessment activity and the date on which it was undertaken. 3. Place a tick in the box to show that the student completed each aspect of the activity to the standard expected in the enterprise. 4. Complete the feedback sections of the form Date of observation Description of assessment activity Location of assessment activity The Student’s report can…
determine what is the real problem.
obtain a description of the problem and how long it has been going on.
trace out how long the washing machine is being operated.
inquire whether the washing machine has been in this condition.
make follow-up on how the washing machine is supposed to operate.
perform preliminary inspection to locate where the problem originated.
perform closer inspection into the suspected parts or components.
look for burned and broken components.
inspect for loose connections or broken wires.
plan an approach to the repair problem.
use appropriate tools and equipment in performing troubleshooting.
trace out the different symptoms/problems of a washing machine.
If yes, tick the box
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verify the system defects or faults of a washing machine.
pinpoint accurately the defective component or part on a washing machine.
perform correctly the pre-testing troubleshooting procedures.
document the results of diagnosis and testing a washing machine.
Did the student’s overall performance meet the standard?
Yes
No
Feedback to student: Teacher signature:
Date:
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QUESTIONING CHECKLIST FOR PERFORMANCE TEST 2.1 Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the Teacher: 1. Observe the Student [insert description of activity being observed] 2. Describe the assessment activity and the date on which it was undertaken. 3. Place a tick in the box to show that the Student completed each aspect of the activity to the standard expected in the enterprise. 4. Ask the Student a selection of questions from the attached list to confirm his/her underpinning knowledge 5. Place a tick in the box to show that the Student answered the questions correctly. 6. Complete the feedback sections of the form
Date of observation Description of assessment activity Location of assessment activity The Student’s report will answer the following questions…
What precautions must you take in performing pretesting procedure in a washing machine?
How would you determine the defective parts for an intermittent operation problem?
Why do you need to ask questions to the owner/operator of the washing machine in performing pre-testing?
Why do you need to use sense of smell and sight in performing pre-testing?
Why is it you need to operate a washing machine in performing pre-testing?
What would you do in the event that you are not familiar with the model of the washing machine?
What should you do if you found out that someone modified the circuit of the washing machine?
Why is it necessary to conduct closer inspection to suspected part / parts of the washing machine?
Did the Student’s overall performance meet the standard?
If yes, tick the box
Yes
No
Feedback to Student: Teacher signature:
Date:
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Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A WASHING MACHINE
LO3:
Maintain and repair a washing machine.
ASSESSMENT CRITERIA: 1.Personal Protective Equipment is used in accordance with the Occupational Health and Safety Practices. 2.Electro-Static Discharge (ESD) protection procedures are followed. 3.Defective parts/components are replaced with equivalent ratings and repaired in accordance with the current industry standards. 4.Control settings/adjustments are performed in conformity with the service manual specifications 5. Repair activity is performed within the required time frame. 6. Cleaning of unit is performed in accordance with standard procedure.
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LEARNING EXPERIENCE / ACTIVITIES Learning Outcome 3
Maintain and repair a washing machine.
Learning Activities Read the Information Sheet 3.1 on personal protective equipment and electrostatic discharge protection procedure. Do the Self-Check 3.1 to test your knowledge on personal protective equipment and electro-static discharge protection procedure.
Special Instructions You can ask the assistance of your teacher to show you and explain further the topic you don’t understand.
Try to answer the Self-Check without looking at the Information Sheet.
Compare your answers to the Answer Key. If you were not able to answer all the questions, go over again the Information Sheet. If you have answered all the questions, perform Job Sheet No. 3.1 on maintain and repair a washing machine. Do the Performance Test No. 3.1 on maintain and repair a washing machine. Refer your performance output to the Observation and Questioning Checklist. If you missed some of the items in the Observation and Questioning Checklist, go over again the Operation Sheet. If you did get all the items in the Observation and Questioning Checklist, you can proceed to the next module. 33
INFORMATION SHEET 3.1 PERSONAL PROTECTIVE EQUIPMENT: It is the employer’s responsibility to provide protective clothing and equipment. Work clothes and specially designed protective clothing are designed for your protection. Wear the correct clothing and equipment to protect yourself from possible serious injury. Do not interfere with or misuse any item provided by your employer for health and safety. Wear plain, tough clothes that are closefitting and keep them buttoned up. Loose sleeves, unbuttoned or torn shirts or sweaters, ties or loose belts can easily be caught in revolving machinery. Your work clothes should be cleaned regularly. Wear cuff less trousers. Trouser cuffs may cause you to trip or they may catch sparks or harmful substances. Wear suitable footwear and keep it in good repair. Wear safety shoes or boots with insulated sole for electrical work. Good uppers protect against burning from hot turning, drops of molten metal, etc. safety shoes and boots have reinforced toecaps to protect against heavy falling objects. Keep long hair under a tight fitting cap or net, as required by regulations. It is your employer’s duty to ensure that machineries have guards to protect employees who work closely to machine. Even, so, if your hair is long, it could be easily caught in machinery, such as a frilling machine. Many people have been scalped in this type of accident. Do not wear rings or wrist watches on the job. Because such item can be caught on moving machinery. It is extremely dangerous to wear them in certain types of work. You could lose fingers. Do not wear earrings, neck chains, pendants and bracelets. All items or personal jewelry worn at work have the potential to cause an accident or aggravate an injury sustained in an accident. Wear personal protective equipment suited to the work to be done. Learn the purpose of each item in the wide range of protective devices available.
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A. HOW IS ESD GENERATED Static charge is a form of electricity at rest. It can be generated by simple friction, that is, rubbing two objects together. A simple method of generating a static charge is to rub a plastic ballpen case on a nylon cloth. Once generated, the static electricity will remain on the ballpen for as long as it is not placed on any other charged materials. If ever the ballpen comes in contact with another object, the static electricity can move to or from the ballpen to equalize the charge between the two objects. The transfer of static electricity from any of the two objects is called electro-static discharge. One inexhaustible source of electrons that can supply or accept them without any effect is the earth. Whatever charged object brought into it is immediately discharged. This simple illustration does not necessarily mean that static electricity can be generated intentionally. The truth is that static electricity can be generated in a multitude of possible ways. Rubbing of hands or arms on a table can result to the generation of up to about 3000 volts of static electricity. Sliding of the IC pins in a plastic box can result to the generation of up to 12000 volts of static electricity. A person walking across a vinyl floor can generate about 13,000 volts of static electricity. The amount of static electricity varies with the environment and it depends primarily on the prevailing relative humidity. The moisture in the air offers a readily present conductive path to ground fro static electricity and hence avoiding any static build-up.
B. ESD WRIST STRAPS ESD wrist straps are also called conductive wrist straps or bands. They are usually made of elastic cloth but contain conductive strands that touch your skin and so bleed off any static electricity on your body. Some straps are made of conductive rubber. The wire attached to the strap contains a large value resistor, usually one mega-ohm (1,000,000 ohms) that allows any charge on your body to be slowly transferred to a washing machine ground point. This build in resistor also limits the amount of current to a safe level in case the other end of the wire touches a power supply voltage. Some ESD kits also contain a conductive pad on which you can place components, like circuit boards and ICs, when they’re out of the switch box of an washing machine. Often there’s an additional clip on the wire leading from the wrist strap that you can attach to this conductive pad, so that any charge on the pad will also flow to the washing machine ground point.
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C. ELECTRO-STATIC DISCHARGE (ESD) PROTECTION PROCEDURE 1. Purchase an antistatic kit from a computer or electronics supply store. Kits vary, but the main component is an ESD wrist strap with a wire several feet long having an alligator clip at the other end. 2. So to start off when troubleshooting washing machine, get an ESD wrist strap and wear it wherever you go under the covers or handle ICs and circuit boards. 3. Put the adjustable strap around your wrist (usually the left wrist if you’re right handed). Wearing an ESD wrist strap connected to frame or chassis ground drains static charges off your body, preventing damaging ESD. 4. Attach the clip at the end of the wire to an electrical ground connection or metal framework of the washing machine. 5. If you work on a washing machine without a conductive wrist strap, touch an electrical appliance such as a lamp or the screw in a wall outlet cover plate, before touching the PCB circuit. An electrostatic discharge of just a few hundred volts is too small to feel in most cases, but can be usually deadly to ESD sensitive devices. 6. When you are working with a switch box of a washing machine, touch a ground point, like the metal extension pole, before touching anything else. This should ground out any static charge on your body. Also, avoid wearing clothes that easily produce a static charge, such as, knits and wools and limit your movements as much as possible, especially on carpets, while working on electronic circuits of a washing machine.
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SELF – CHECK 3.1 I. Direction: Identify the different personal protective equipment as illustrated. Write your answer in another sheet of paper.
II. Direction: Write True if the statement is correct or False if it is wrong. Write your answer in another sheet of paper. 1. Static charge is a form of electricity at rest. 2. ESD wrist straps are also called conductive wrist straps or bands. 3. When working with the electronic system control of a washing machine, it is a safety practice to touch a round point like the metal extension pole before touching anything else. 4. An electrostatic discharge of just a few hundred volts is too small to fill in but can be usually deadly to ESD sensitive devices. 5. An ESD wrist strap is connected to the frame or chassis ground which drains static charges off your body preventing damaging ESD-sensitive devices. 38
ANSWER KEY TO SELF – CHECK 3.1 I. 1. Head Protection 2. Ear Protection 3. Tidy Hair Style 4. Close –fitting high buttoned overall 5. Close fitting cuff 6. No rings or watch 7. eye protection 8. cuff-less trousers 9. Insulated soles 10. Reinforced footwear
II 1. True 2. True 3. True 4. True 5. True
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JOB SHEET 3.1 COMPONENT REPLACEMENT 1. Determine the description of the values and ratings of the individual defective parts from the manufacturer’s service manual. 2. Identify the sources of replacement components/parts . Original replacement components from the original factory sources Universal replacement components from independent factory sources Always consider the physical size of the replacement part 3. Consider the factors in the selection of specific part. Quality. The ability to provide exact value or specification to replacement part. Tolerance. The ability to provide exact value or acceptable parameters to replacement parts. Availability. Local access to parts and whether the parts are available. Price. It refers to the affordability of the replacement parts at a reasonable price. 4. Disconnect or remove properly the electrical/mechanical parts of a washing machine. 5. Install correctly replacement part/components in existing washing machine. MAINTENANCE OF WASHING MACHINE 1. Turn off the washing machine and remove the cord from the source of voltage. 2. Apply lubricant to mechanical parts of the washing machine that requires lubrication through a drop of oil or grease to assure smooth operation without grinding or squeaks. 3. Replace the bushings or end bells for squeaks with the use of appropriate tools if squeaks cannot be corrected by applying lubricants. 4. Apply or spray anti-rust lubricants to all mechanical parts of the washing machine to drive out moisture, protect corrosion, loosen rusted metal parts and even frees sticky mechanism. 5. Clean and check cooling louvers for any obstructions to avoid cutting off the air flow. 6. Clean or wipe dust and foreign particles at the PC Board and metal parts of the motor. 7. Replace worn or frayed AC cord and electrical wires.
SOLVENTS FOR CLEANING 1. Use mild soap and damp cloth or rug when cleaning plastic front panel and cover. They are susceptible to immediate and long term damage from solvents. 2. Apply denatured alcohol as the safest solvent to use for plastic front panel and cover with heavy stain. It should be used only as a last resort and applied to areas with heavy stain. 40
INFORMATION SHEET 3.1 PROCEDURE IN REPAIRING A WASHING MACHINE 1. Once the specific electrical/mechanical problem is located: consider the techniques for the proper removal of the defective component or parts; anticipate what to do if the replacement part does not correct the problem; and check the installation of the replacement or original part for any improper mounting in the mechanical assembly or circuit board. 2. Examine carefully the mounting of the replacement of original parts of the system. Check the placement of the wires or leads of the replacement component. Consider significant factors used in the original installation such as insulating washer, silicon grease and locating mark for pin connections. Observe proper placement of the component leads for electrical parts. 3. Perform the techniques for the proper soldering of electrical parts. Be careful not to damage adjacent components. Be careful not to lift the copper conductive path from circuit board base material. Avoid any solder bridges between board paths. Do not destroy the component being removed in case it is still functional and be careful not to damage the component being installed. 4. Verify all connections and harness.
Be sure that all components pre-positioned in a manner that will avoid the possibility of having adjacent components short circuited.
Be sure to check or inspect all insulators and barriers between sections after working on any model/brand of washing machine.
Check for frayed or broken insulation on all wiring including the AC line cord.
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Be sure to replace fuses, resistors and capacitors with special designation such as flame proof to components equal to the original value for both safety and liability purposes.
5. Once the repair is completed, perform an AC leakage test on all exposed metal parts of an washing machine to eliminate the possibility of electric shock.
Perform complete retesting of the washing machine to ensure the correctness of the actual repair. Connect the washing machine into the 60Hz power to allow the time period required to let the new parts settle in and operate as they are designed to work with each other. Recheck or inspect if the repair was done correctly and the unit functions properly to ensure successful completion of the repair.
6. Clean the washing machine before it would be returned to the customer.
Be sure that the blade, front and rear guards of the washing machine are properly cleaned. Be sure that proper cleaning is given to the control panel or switch box of the washing machine.
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PERFORMANCE TEST 3.1 Direction: Given a set of hand tools, multi-tester and defective washing machine with identified faults or defect, perform preventive maintenance and repair procedure. Provide a work report/write-up after completing the task. Write your answer on a separate sheet of paper. STUDENT WRITE-UP A Common Symptoms / Defects of a Washing machine Student : _________________________________ Date: ________________________ Year & Section: _________________________ Teacher: _______________________ UNIT BRAND : _________________________ Unit Model: ______________________ Owner: ______________________ Address: _________________________________ SYMPTOMS
DEFECTIVE COMPONENT/PARTS
REMEDY
STUDENT WRITE UP B Diagnosing Faults in ECEF Student : _________________________________ Date: ________________________ Year & Section: _________________________ Teacher: _______________________ UNIT BRAND : _________________________ Unit Model: ______________________ Owner: ______________________ Address: _________________________________ SYMPTOMS
DEFECTIVE COMPONENT/PARTS
REMEDY
Teacher’s Initial: __________
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OBSERVATION CHECKLIST 3.1 Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the Teacher: 1. Observe the Student [insert description of activity being observed] 2. Describe the assessment activity and the date on which it was undertaken. 3. Place a tick in the box to show that the Student completed each aspect of the activity to the standard expected in the enterprise. 4. Complete the feedback sections of the form Date of observation Description of assessment activity Location of assessment activity
The Student’s report can reveal that the student can…
If yes, tick the box
properly identify the defective parts. verify carefully the mounting of the identical or replacement part. perform proper placement of component/part in the installation process. perform the proper techniques in soldering electronic parts. perform the proper techniques in soldering electrical component/part. perform the proper techniques in the installation of mechanical components/part. handle properly the component/part being removed or installed. perform accurate connections and harness . observe proper use of tools and measuring instruments . perform completer re-testing of the unit once the repair is completed. apply lubricant to moving mechanical parts that requires lubrication. 44
perform preventive check to rotating or moving parts that squeaks. apply or spray anti-rust lubricant to all mechanical and metal parts.
clean and check cooling louvers for any obstructions.
clean sticky rotating mechanisms .
wipe dust and foreign particles at the PC board and metal parts of the unit.
replace worn or frayed AC cord and electric wires.
use mild soap with damp cloth or rags when cleaning plastic front panel and cover. apply appropriate solvent when cleaning plastic front panel and cover with heavy stain. follow ESD protection procedure in accordance with current industry standard
Did the Student’s overall performance meet the standard?
Yes
No
Feedback to Student:
Teacher signature:
Date:
45
QUESTIONING CHECKLIST 3.1 Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the Teacher: 1. Observe the Student [insert description of activity being observed] 2. Describe the assessment activity and the date on which it was undertaken. 3. Place a tick in the box to show that the Student completed each aspect of the activity to the standard expected in the enterprise. 4. Ask the Student a selection of the questions from the attached list to confirm his/her underpinning knowledge 5. Place a tick in the box to show that the Student answered the questions correctly 6. Complete the feedback sections of the form Date of observation Description of assessment activity Location of assessment activity The Student’s report will answer the following questions: What would you do if there is no available service manual or schematic diagram for the defective unit? Why do you need to discharge all capacitors mounted in the circuit before you start the maintenance and repair jobs? What would you do in the event that the replacement part does not correct the problem? Why is it necessary to perform an AC leakage test on all exposed metal parts of an washing machine? What safety precaution must you take before applying to the repaired washing machine? What would you do in the event when the previous problem of the washing machine occurred again while performing the pre-testing? Why is it necessary to perform complete re-testing one the repair of the washing machine is completed? Why is it necessary to clean the washing machine before it would be returned to the customer? Did the Student’s overall performance meet the standard?
If yes, tick the box
Yes
No
Feedback to Student: Teacher signature:
Date:
46
Maintain and Repair Electronically-Controlled Domestic Appliances
Title of Module
Maintaining and Repairing a Washing Machine
The evidence must show that the student can... explain the operation of a washing machine.
Questioning
Observation
Ways in which evidence will be collected: [tick the column]
Written
Unit of competency:
Demonstration
NC II
Third party Report
Competency standard:
Portfolio
EVIDENCE CHECKLIST
X
identify the parts of a washing machine. explain the functions of its parts. perform pre-testing procedure based on the manufacturer’s manual. identify system defect/fault symptoms using appropriate tools and equipment. explain identified defects and faults to the responsible person. document results of diagnosis and testing. perform troubleshooting in accordance with the service manual. use Personal Protective Equipment in accordance with Occupational Health and Safety practices. follow Electro-Static Discharge (ESD) protection procedure is. replace defective parts/ components with identical or recommended appropriate equivalent ratings. solder/mount repaired or replaced parts/components at the specified location.
X
clean the unit after the maintenance and repair activity. NOTE: *Critical aspects of competency
X
Prepared by:
Date:
Checked by:
Date:
47
ACKNOWLEDGEMENT Copyright Department of Education 2008 First Published JUNE 2008 This module was based on the Competency-Based Curriculum-Contextual Learning Matrix (CBC-CLM) and finalized on the Instructional Modules Finalization Development Workshop conducted at the Finalization Workshop conducted at the Development Academy of the Philippines, Tagaytay City on May 6 -10, 2008 This learning instrument was developed by the following personnel: 1
Technology Teachers: Mr. Vic P. Diola Bauan Technical High School
Dr. Gilbert M. Castor Don Alejandro Roces Sr. Science-Technology High School
Mr. Eddielou L. Dayao Sanchez Mira School of Arts and Trades
Mr. Rufo G. Malla Eulogio Rodriguez Vocational High School
Mr. Sherwin P. Medrano San Pedro Relocation Center National High School
Mr. Remar C. Pinsoy Baguio National School of Arts and Trades
Contextual Teacher: Mrs. Daisy Carousel P. Cervantes Don Alejandro Roces Sr. Science-Technology High School
Facilitators: Dr. Edward M. Dela Rosa Dr. Corazon L. Echano TEC-VOC Task Force
Encoders: Mrs. Rosario D. Briones Mr. Mhariel L. Echano Mr. Jason O. Villena
Funding: Department of Education
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ACKNOWLEDGEMENT Copyright: Department of Education 2009 This module is based on Competency-based Curriculum- Contextual Learning Matrix ( CBC-CLM ) refined during the Writeshop on the Refinement and Enrichment of Competency-Based Curriculum and Contextual Learning Matrix of ARTS and TRADES Specializations at Marikina Hotel, Marikina City on April 20 – 25,2009. This learning instrument was refined and enriched by the following educators: Technology Teachers ( Electronics ) VICTORINO P. DIOLA – Group Leader TVE Coordinator, Bauan Technical High School Bauan, Batangas GIGI C. CORPUZ Teacher III, Malvar National High School Malvar, Batangas ISMAEL G. GALLARDO Teacher I, Community Vocational High School Masipit, Calapan City, Oriental Mindoro REYNALDO C. CUNANAN Head Teacher VI, EARIST Voc. High School Nagtahan, Sampaloc, Manila GEORGE B. FUASO Teacher II, Gen. Mariano Alvarez Technical High School GMA, Cavite RUFO G. MALLA Teacher II, EARIST Voc. High School Nagtaha, Sampaloc, Manila Contextual Teachers: English TERESITA P. TANAEL Teacher III, Gen. Mariano Alvarez High School GMA, Cavite CHARLIE I. SORIANO Teacher I, Don Alejandro Roces, Sr. Science-Technology H.S. 49
Quezon City Mathematics ANALISA ROSA P. LIBRADA Teacher I, Mathematics Coordinator San Pedro Relocation Center National High School San Pedro, Laguna Science
LENALYN N. MANZANO Teacher I, EARVHS Nagtahan, Sampaloc manila GEMMA G. VALLARTA Teacher III, Science Coordinator San Pedro Relocation Center National High School San Pedro, Laguna
Facilitators: Dr. CORAZON L. ECHANO Tech-Voc Task Force Dr. VICTORIO N. MEDRANO Tech-Voc Task Force Dr. ORLANDO E. MANUEL Tech-Voc Task Force Encoder: MARISOL E. SALDIVAR
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Republic of the Philippines Department of Education PUBLIC TECHNICAL -VOCATIONAL HIGH SCHOOLS
Unit of Competency: MAINTAIN AND REPAIR ELECTRONICALLY-
Module No.
5
CONTROLLED DOMESTIC APPLIANCES Module Title: Maintaining and Repairing Washing Machine 51
52
Republic of the Philippines Department of Education PUBLIC TECHNICAL -VOCATIONAL HIGH SCHOOLS
Unit of Competency: MAINTAIN AND REPAIR ELECTRONICALLY-
CONTROLLED DOMESTIC APPLIANCES Module No. 6
Module Title:
Maintaining and Repairing Flat Iron
TABLE OF CONTENTS Page How to Use this Module .................................................................................. ii Introduction ................................................................................................... iii Technical Terms.... ..........................................................................................iv Learning Outcome 1 Identify the parts and functions of electric flat iron……...……............................................................................ 1
Learning Experience/Activities……………………………………………….…2
Information Sheet 1.1.……………………………………………………..……..3
Self Check 1.1……………………………………………………………..………..5
Self-Check Key 1.1 ………………………………………………………………..6
Learning Outcome 2 Diagnose /troubleshoot Electric flat iron defects…………………………………………….…………….……….7
Learning Experience/Activities………………………………………………….8
Information Sheet 2.1 ……..…………………………………………..………..9
Information Sheet 2.2 ……………………………………………………..……10
Self Check 2.1………….……………………………………………………..……11
Self Check Key 2.1
Student Write – Up 2.1 ………………………………… .………………..……13
Job Sheet 2.1……………………………………………………………………….14
……………………………………………………..……12
Learning Outcome 3 Maintain and repair electric flat iron…………………….…..15
Learning Experience/Activities ………………………………………………..16
Information Sheet 3.1..…………………………………………………..……..17
Self-check 3.1………………………………………………………………………19
Activity Sheet 3.1
Assignment Sheet 3.1 ……………………………………………………..……21
Job Sheet 3.1..……………………………………………………………………..21
Teacher Check Sheet 3.1
……………………………………………………..…… 20
……………………………………………..……22
Assessment Plan …………………………………………………………………………….23 Observation Checklist ……………………………………………………………………..24 Observation & Question Checklist ……….………………………………………..…..25 Demonstration ………………………………………………………………….….………..26 Written Report……………………………………………………………………..…………27 Performance Test ……………………………………………………………………..…….28 Performance Standards ……………………………………………………………..…….29 Acknowledgement …………………………………………………………………………..30
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HOW TO USE THIS MODULE Welcome to the Module “Maintaining and Repairing a Flat Iron”. This module contains training materials and activities for you to complete. The unit of competency “Maintain and Repair Electronically Controlled Domestic Appliances” contains the knowledge, skills and attitudes required for a Consumer Electronic Servicing required to obtain the National Certificate (NC) level II. You are required to go through a series of learning activities in order to complete each of the learning outcomes of the module. In each learning outcome there are Information Sheets, Job Sheets, Assignment Sheets, and Activity Sheets. Follow these activities on your own and answer the Self-Check at the end of each learning activity. If you have questions, don’t hesitate to ask your facilitator for assistance. Recognition of Prior Learning (RPL) You may already have some basic knowledge and skills covered in this module because you have been working for sometime; or already completed training in this area. If you can demonstrate to your teacher in a particular skill, talk to him/her about having them formally recognized so you don’t have to do the same training again. If you have a qualification or Certificate of Competency from previous trainings, show it to him/her. If the skills you acquired are consistent with and relevant to this module, they become part of the evidence you can present for RPL. If you are not sure about your competence skills, discuss this with your teacher. After completing this module ask your teacher to assess your competence. Result of your assessment will be recorded in your competency profile. All the learning activities are designed for you to complete at your own pace. Inside this module you will find the activities for you to complete and followed by relevant information sheets for each learning outcome. Each learning outcome may have more than one learning activity. This module is prepared to help you achieve the required competency, in receiving and relaying information. This will be the source of information that will enable you to acquire the knowledge and skills in Maintaining and Repairing a Flat iron independently at your own pace or with minimum supervision or help from your teacher.
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Program/Course
CONSUMER ELECTRONIC SERVICING NCII
Unit of Competency
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title
MAINTAINING AND REPAIRING FLAT IRON
INTRODUCTION: This module contains information and suggested learning activities on Maintaining and Repairing Electronically Controlled Appliances. It covers the knowledge, skills and attitudes required to repair and maintenance of a flat iron. This module consists of three learning outcomes. Each learning outcome contains learning activities supported by instructional sheets. Before you perform the instructions, read the information sheets and answer the self-check and activities provided to ascertain to yourself and your teacher that you have acquired the knowledge necessary to perform the skill portion of the particular learning outcome. Upon completing this module, report to your teacher for assessment to check your achievement of knowledge and skills requirements of this module. If you pass the assessment, you will be given a certificate of completion.
SUMMARY OF LEARNING OUTCOMES: Upon completion of the module, you should be able to: LO1. identify the parts and functions of electric flat iron; LO2. diagnose/troubleshoot electric flat iron defects; and LO3. maintain and repair electric flat iron.
PREREQUISITES:
Using Hand Tools
Preparing and Interpreting Technical Drawing Used in Shop
Connecting and Interpreting Electronic Circuit
Applying Quality Standard
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TECHNICAL TERMS Flat iron. It is a domestic appliance used to press clothes Schematic Diagram. It is an illustration of an electrical or electronic circuit with the components represented by their symbol. Short Circuit. It is also called a short. Low resistance connection between two points in a circuit typically causing excessive current. Soldering. It is a process of joining two metallic surfaces to make an electrical contact by melting solder (tin and lead) across them. Soldering Iron. It is a tool with an internal heating element used to heat surfaces being soldered to the point where the solder becomes molten. Switch. It is an electrical device having two states, ON (closed) or OFF (open). Test. It is a sequence of operations intended to verify the correct operation or malfunctioning of a piece of equipment or system. Troubleshooting. It is systematic approach to locate the cause of a fault in an
electronic circuit or system. Volt-Ohm-Meter. It is known as a multitester. A test equipment used to check AC, DC voltages, current in a circuit and resistance of any components out of the circuit.
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Program/Course
CONSUMER ELECTRONIC SERVICING NCII
Unit of Competency
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title
MAINTAINING AND REPAIRING A FLAT IRON
Learning Outcome 1: Identify the parts and functions of electric flat iron. Assessment Criteria: 1. The parts of a flat iron and their functions are identified based on the manufacturer’s service manual. 2. Parts are handled in accordance with manufacturer’s service manual.
References
http;//e-service.panasonic.com
1
LEARNING EXPERIENCES/ACTIVITIES Learning Outcome 1: Identify parts and functions of electric flat iron. Learning Activities 1. Read the attached Information Sheet 1.1 on: a. Functions of the parts of a flat iron. b. Proper handling of flat iron c. Proper handling of electronic parts d. Proper handling of its parts in accordance with the manufacturer’s service manual 2. Answer the Self-Check 1.1 to test your knowledge on the functions of the parts of a flat iron.
Special Instructions Identify the functions of the parts of a flat iron. Show proper way of handling parts of a flat iron according to manufacturer’s service manual. Answer the Self-check without looking at the information sheet.
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INFORMATION SHEET 1.1 Maintaining and Repairing a Flat Iron
Parts of Flat Iron 1. AC line cord is used to connect the unit to power source.
2. Selector Switchis a type of switch used to select the amount of heat required in ironing different types of fabrics. It can be a rotary or slide type.
3. Thermal Fuse is a safety protective device used to protect the unit from damage when overheating and short circuit occurs.
4. Heating Element a form of nichrome wire that assembles properly inside the flat iron to provide heat.
3
5. Soleplate is a base metal that serves as fabric pressing part made of metal.
6. Handle is the part of a flat iron by which it is, carried or controlled.
7. Body/Case is used to protect the internal parts of the flat iron.
Specific instructions To avoid a circuit from overload, do not operate another high wattage appliance on the same circuit. If an extension cord is absolutely necessary a 10 A cord should be used with a 120V iron or a 16A cord should be used with a 220V iron. Cords rated for less amperage may overheat. Care should be taken to arrange the cord so that it cannot be pulled or rippled over.
4
SELF CHECK 1.1 Identifying the Functions of the Parts of a flat iron Direction: Name the parts of a flat iron and give their function. Write your answers to all the instructional materials on another sheet of paper. Do not write anything in this module. Picture
Parts
Function
1.
2.
3.
4.
5.
6.
7.
5
SELF CHECK KEY 1.1 Identifying the functions of the Parts of a flat iron. Parts 1.Ac line cord
Function Used to connect the unit to the power source.
2. Selector switch
Used to select the amount of heat required in ironing different types of fabrics.
3. Thermal fuse
A safety protective device used to protect the unit from damage when short circuit occurs.
4. Heating element
A form of special wire that assembles properly inside a flat iron to provide heat.
5. Soleplate
A base metal that serves as fabric pressing part made of metal.
6. Handle
The part of a flat iron by which it is held, carried or controlled.
7. Body/Case
Used to protect the internal parts of a flat iron.
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Program/Course
CONSUMER ELECTRONIC SERVICING NCII
Unit of Competency
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title
MAINTAINING AND REPAIRING A FLAT IRON
Learning Outcome 2: Diagnose/troubleshoot electric flat iron defects. Assessment Criteria: 1. Pre-testing procedure is observed in accordance with the manufacturer’s instructions. 2. System defects/fault symptoms are identified using appropriate tools and equipment and in accordance with safety procedures. 3. Identified defects and faults are explained to the responsible person (teacher as in the case of student) in accordance with enterprise or company policy and procedures. 4. Results of diagnosis and testing are documented accurately and completely within the specified time frame. 5. Customers (Teachers) are advised/informed regarding the status and serviceability of the unit based on the procedures. 6. Pre-testing procedure is followed according to the manufacturer’s specifications.
Reference: http;//e-service.panasonic.com
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LEARNING EXPERIENCES/ACTIVITIES Learning Outcome 2
Diagnose/troubleshoot electric flat iron defect.
Learning Activities
1. Read the attached Information
Special Instructions
Do the Job Sheet 2.1 and fill-up
Sheet 2.1 on Troubles, Possible
the table with the necessary
Causes and Remedies/Repair
information.
and Information Sheet 2.2 on Tools and Materials needed.
2. Perform Job Sheet #2.1on Diagnosing and troubleshooting
Perform the activity with the supervision of the teacher.
a flat iron.
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Information Sheet 2.1 Diagnosing and Troubleshooting a Flat Iron
Troubles
Possible Causes
1. Electric iron does not Open circuit/terminal connection heat. Short Circuit Terminal connections Heat controller-selector switch Blown fuse 2. Electric iron gives abnormal temperature.
Grounded wire Loose contacts between terminals Heating element
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INFORMATION SHEET 2.2 Diagnosing and Troubleshooting a Flat Iron. Tools and Materials: 8. 1. Flat iron 9. Volt-ohm-milliammeter
2. Set of screw drivers 10.
Wrench/Pliers
11.
Desoldering tool
12.
Cleaning brush
3. Set of pliers
4. Soldering iron
5. Soldering stand
6. Soldering lead
7. Wire stripper
10
SELF CHECK 2.1 Diagnosing/Troubleshooting a Flat Iron Direction: Identify the common tools used in diagnosing and troubleshooting a flat iron.
1. 2. 3. 4. 5. 6. 7. 8.
.
9.
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SELF CHECK KEY 2.1 Diagnosing and Troubleshoot a Flat Iron.
1. Wrench/Pliers 2. Soldering Stand 3. Desoldering Tool 4. Screw driver 5. Volt Ohm Milliameter 6. Long Nose Pliers 7. Wire Stripper 8. Soldering Iron 9. Set of Cleaning Brush
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STUDENT WRITE-UP 2.1 Diagnosing and Troubleshooting a Flat Iron Student: __________________________ ____
Date: _______________________
Year and Section: _____________________
Teacher: ____________________
ADMISSION SLIP UNIT BRAND: _______________________________
Unit Model: _________________
Owner: ______________________________________
Address: ____________________
Direction: interview the owner of the unit regarding their complaints. 1. PROBLEM/S & SYMPTOMS/S: ____________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________
Teacher’s Initial: ________________
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JOB SHEET 2.1 Diagnosing and Troubleshooting a Flat Iron Direction: From the given defective flat iron Fill-out the table with the necessary information. Trouble/s identified
Possible Causes
Remedies to be made
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Program/Course
CONSUMER ELECTRONIC SERVICING NCII
Unit of Competency
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title
MAINTAINING AND REPAIRING A FLAT IRON
Learning Outcome 3: Maintain and repair electric flat iron. Assessment Criteria: 1. Personal Protective Equipment is used in accordance with Occupational Health and Safety Practices. 2. Defective parts and components are replaced with identical recommended appropriate equivalent ratings. 3. Repaired or replaced parts/components are soldered/mounted at specified location. 4. Control settings/adjustments are performed in conformity with service manual specifications. 5. The unit is cleaned after the maintenance and repair activity.
the or the the
References http;//e-service.panasonic.com
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Learning Outcome 3 Maintain and repair electric flat iron. Learning Activities 1. Read the attached Information Sheet 3.1on the Proper Care of Flat iron. 2. Perform repairing and maintaining flat iron. 3. Personal protective equipment are used in accordance with OH&S policies 4. Electro-static discharge protection procedure is followed in accordance with current industry standards 5. Defective parts/components are replaced with identical or recommended appropriate equivalent ratings 6. Repaired or replaced parts/components are soldered/mounted in accordance with manufacturer’s standards 7. Control settings/adjustments are performed in conformity with service manual specification 8. Repair activity is performed within the required timeframe Cleaning of unit is performed in accordance with standards procedure.
Special Instructions Do the Self-check 3.1 without looking at the Information Sheet. Do the Activity Sheet 3.1, Assignment Sheet 3.1 and Job Sheet 3.1 Follow the procedures in repairing and maintaining flat iron Observe safety in working Perform the activity following the ESD with the supervision of a teacher Replace the defective components/parts with the same or allowed value Soldered/mounted the parts in accordance with the manufacturer’s standards Follow the instruction in manual Finish the activity within the time allotted Clean the unit properly
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INFORMATION SHEET 3.1 Maintain and Repair Flat Iron Proper care to a Flat Iron 1. Prevent the iron fro falling on heavily padded board. 2. Avoid excessive scratches on iron plate due to direct contact from buttons, hooks, zipper, etc. 3. Cool iron before storing. Do not wrap cord around iron especially when it is still hot. 4. Put iron on a safe place to cool. 5. Always store iron in an upright position, on its heel rest, so that soleplate will not be scratched. 6. Clean brown stains in soleplate by heating the iron to a high temperature and iron it over to salt in wax paper. A non-scratchy household cleaner may also be used. To use a flat iron 1. Adjust the temperature selector to a minimum position before plugging cord into electrical outlet. 2. Pre-heat the unit 2 minutes before using. 3. To improve dry ironing results, sprinkle garments evenly at least one hour before ironing. 4. Unplug iron by gripping plug and pulling it from the outlet. Never yank the cord! To clean polished aluminum soleplate 1. Unplug the iron. 2. Make a paste of mild scouring powder and a little amount of water. Apply a small amount to soleplate using a damp cloth and rub the soiled area. Wipe thoroughly. 3. Do not use metal scouring pads since they will scratch the soleplate. Store Iron After iron has cooled, wrap cord loosely. To protect soleplate, always store iron on heel rest. Mail/travel iron When iron is cool, pack it carefully in its box.
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Important: When using an iron, basic precautions should always be followed: 1. Read the instructions first. 2. Use the iron only for its intended use. 3. To protect against risk of electric shock, do not immerse any part of the iron in water or other liquid. 4. The iron should always be turned to MIN position before plugging or unplugging from the outlet. Never yank cord to disconnect from the outlet; instead grasp plug and pull it to disconnect. 5. Do not allow the cord to touch hot surfaces. Let iron cool completely. 6. Do not operate iron if it has been dropped or damaged in any manner, as such may cause temperature setting in occasion or electric shock. Do not assemble the iron; take it to the dealer from whom the product was purchased for examination or any professional technician. Incorrect assembly can cause electric shock when the iron is used. 7. Close supervision is necessary for any appliances being used by or near children. Do not leave the iron unattended when plugged into the outlet or in an ironing board. Always position the iron carefully to prevent it from falling if ironing board is accidentally knocked or if the cord is pulled. When not in use, always stand the iron on heel rest. 8. Burn can occur from touching hot metal parts. 9. The use of accessory attachment not recommended or sold by the appliance manufacturer may create hazards or damage your flat iron. 10. Do not use the iron outdoor. 11. Do not operate in the presence of explosive and/or flammable materials.
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SELF-CHECK 3.1 Maintaining and Repairing a Flat Iron Directions: Answer each of the following questions by enumerating the procedures being asked. To check your answers, refer to Information Sheet 3.1 1. How will you apply proper care to a flat iron? 2. How will you use a flat iron? 3. How will you clean and polish the aluminum soleplate? 4. How will you store a flat iron? 5. What are the basic precautionary measures to be followed when using a flat iron?
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ACTIVITY SHEET 3.1 Maintaining and Repairing a Flat Iron With an actual flat iron provided by the teachers identify and pinpoint the different parts in accordance with the manufacturer’s service manual.
Parts of Flat Iron 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
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ASSIGNMENT SHEET 3.1 Maintaining and Repairing a Flat Iron Instruction: Bring a defective flat iron. Any type/brand.
JOB SHEET 3.1 Maintaining and Repairing a Flat Iron Instructions: 1. 2. 3. 4.
Get the defective flat iron. Identify the condition/trouble of the flat iron. Identify the existing defect/s and their possible cause/s. Record the information on the table.
Trouble
Possible Causes
Remedies made
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TEACHER-CHECK SHEET 3.1 Maintaining and Repairing a Flat Iron Instructions: Tick in the box which indicates how competent you are in demonstrating the troubleshooting techniques FLAT IRON Item no. 1.
2.
3.
4.
5.
6.
7 8.
Troubleshooting Techniques
70
75
80
85
90
95
100
Scor e
Identify the problem/symptoms of a flat iron. Identify the possible cause/s of the problem. Defective parts and components are replaced with identical equivalent ratings. Components are soldered and mounted at the specified location Proper tools and materials are used in maintaining and repairing a flat iron. Control settings/adjustments are performed in conformity with service manual specifications. Work safely is observed. The area is cleaned after the activity. Average
Score 96-100 86-95 81-85 75-80 70-74
Assessment Criteria 3.1 Descriptive Grade Excellent Very Good Good Fair Poor
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ASSESSMENT PLAN Evidence Checklist Competency standard Unit of competency
CONSUMER ELECTRONIC SERVICING NCII MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Written
Portfolio
Demonstration
Third party Report
Questioning
The evidence must show that the student… explained the operation of a flat iron.
Observation
MAINTAINING AND REPAIRING A FLAT IRON Title of Module Ways in which evidence will be collected: [tick the column]
Identified the parts of a flat iron Explained the functions of its parts performed pre-testing procedure in accordance with the manufacturer’s instructions. identified system defects and fault symptoms using appropriate tools and equipment. identified defects and faults are explained to the responsible person. documented results of diagnosis and performed troubleshooting in accordance with the service manual. used Personal Protective Equipment in accordance with the Occupational Health and Safety Practices. replaced defective parts and component with identical or recommended appropriate equivalent ratings. soldered/mounted repaired or replaced parts/components in the specified location. performed control settings and adjustments in conformity with the service manual specifications. cleaned the unit after the maintenance and repair activity.
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OBSERVATION CHECKLIST Student’s name: Teacher’s name: Name of school Competency standards Unit of competency: Instructions for the teacher: 1. Observe the student maintaining and preparing a flat iron insert description of activity being observed. 2. Describe the assessment activity and the date on which it was undertaken. 3. Place a tick in the box to show that the student completed each aspect of the activity to the standard expected in the enterprise. 4. Complete the feedback sections of the form. Date of observation Description of assessment activity Location of assessment activity The student can….
If yes, tick the box
explain the operation of a flat iron. identify the parts of a flat iron. explain the functions of its parts. perform Pre-testing procedure in accordance with the manufacturer’s instructions. identify the system defects and fault symptoms using appropriate tools and equipment explain to the responsible person the identified defects and faults document the results of diagnosis and testing. advise customer regarding the status serviceability of the unit as per procedures.
and
perform troubleshooting in accordance with the service manual. use PPE in accordance with OH and SP. repair or replace parts/components. perform control settings and adjustments in conformity with the service manual specifications. clean the unit after the maintenance and repair activity. Did the student’s overall performance meet the standard?
Yes
No
Feedback to student: Teacher’s signature:
Date:
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OBSERVATION AND QUESTIONING CHECKLIST Student’s name: Teacher’s name: Name of School Competency standards Unit of competency: Instructions for the teacher: 1. Observe the student in Maintaining and Repairing Flat Iron. 2. Describe the assessment activity and the date on which it was undertaken. 3. Place a tick in the box to show that the student completed each aspect of the activity to the standard expected in the enterprise. 4. Ask the student a selection of the questions from the attached list to confirm his/her underpinning knowledge 5. Place a tick in the box to show that the student answered the questions correctly. 6. Complete the feedback sections of the form. Date of observation Description of assessment activity Location of assessment activity The student can….
If yes, tick the box
explain the operation of a flat iron. identify the parts of a flat iron. explain the functions of its parts. perform Pre-testing procedure in accordance with the manufacturer’s instructions. identify the system defects and fault symptoms using appropriate tools and equipment explain to the responsible person the identified defects and faults document the results of diagnosis and testing. advise customer regarding the status and serviceability of the unit as per procedures. perform troubleshooting in accordance with the service manual. use PPE in accordance with OH and SP. repair or replace parts/components. perform control settings and adjustments in conformity with the service manual specifications. clean the unit after the maintenance and repair activity. Did the student’s overall performance meet the standard?
Yes
No
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DEMONSTRATION Student’s name: Teacher’s name: Unit of competency: Competency standards: Date of assessment: Time of assessment: Instructions for demonstration Given the necessary materials the student must be able to: Materials and equipment: 1. Flat iron 2. Set of screw drivers 3. Set of pliers 4. Soldering iron 5. Soldering stand 6. Soldering lead 7. Wire stripper 8. Volt-ohm-milliammeter 9. Wrench/Pliers 10. Desoldering tool 11. Cleaning brush to show if evidence is demonstrated During the demonstration of skills, did the student:
Yes
No
N/A
Explained the operation of a flat iron is.
Identified the parts of a flat iron are.
Explained he functions of its parts are.
Performed the pre-testing procedure in accordance with the manufacturer’s instructions. Identified the system defects and fault symptoms are using appropriate tools and equipment. Identified defects and faults are explained to the responsible person. Documented results of diagnosis and testing are.
Performed troubleshooting in accordance with the service manual. Used Personal Protective Equipment in accordance with the Occupational Health and Safety Practices. Replaced defective parts and component with identical or recommended appropriate equivalent ratings. Soldered/mounted repaired or replaced parts/components in the specified location. Performed control settings and adjustments in conformity with the service manual specifications. Cleaned the unit after the maintenance and repair activity.
The student’s demonstration was: Satisfactory
Not Satisfactory 26
WRITTEN REPORT Student’s name: Teacher’s name: Name of the School Competency standards Unit of competency: Task: Your task is to: Maintain and Repair Flat Iron. Submission date: Use the checklist below as a basis for judging whether the student’s report meets the required competency standards. The student’s report can….
identify the parts and function of flat iron.
diagnose and troubleshoot defective flat iron.
apply PPE and OHS&P.
repair/replace parts and solder components and mount components to the specified location.
perform settings and adjustments in conformity with the service manual specifications.
maintain the area clean after the activity.
Overall did the student’s report meet the standard?
If yes, tick the box
Yes
No
Comments:
Student’s signature:
Date:
Teacher’s signature:
Date:
27
PERFORMANCE TEST Student’s Name
Date
Competency:
Directions: Ask your teacher to assess your performance in the following critical task and performance criteria below You will be rated based on the overall evaluation in the right side.
Test Attempt 1st 2nd 3rd OVERALL EVALUATION Level Achieved PERFORMANCE LEVELS 4 - Can perform this skill without supervision and with initiative and adaptability to problem situations. 3 - Can perform this skill satisfactorily without assistance or supervision. 2 - Can perform this skill satisfactorily but requires some assistance and/or supervision. 1 - Can perform parts of this skill satisfactorily, but requires considerable assistance and/or supervision. Teacher will put his/her achieved.
initial to the level
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PERFORMANCE STANDARDS For acceptable achievement, all items should receive a "Yes" or "N/A" response. Explained the operation of a flat iron.
Yes
No
N/A
Identified the parts of a flat iron Explained the functions of its parts Performed pre-testing procedure in accordance with the manufacturer’s instructions. Identified system defects and fault symptoms using appropriate tools and equipment. Identified defects and faults are explained to the responsible person. Documented results of diagnosis and Performed troubleshooting in accordance with the service manual. Used Personal Protective Equipment in accordance with the Occupational Health and Safety Practices. Replaced defective parts and component with identical or recommended appropriate equivalent ratings. Soldered/mounted repaired or replaced parts/components in the specified location. Performed control settings and adjustments in conformity with the service manual specifications. Cleaned the unit after the maintenance and repair activity.
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ACKNOWLEDGMENT Copyright Department of Education 2008 First Published JUNE 2008 This module is based on the Competency-Based Curriculum-Contextual Learning Matrix (CBC-CLM) and finalized on the Instructional Modules Finalization Development Workshop conducted at the Development Academy of the Philippines, Tagaytay City on May 6 -10, 2008 This learning instrument was developed by the following personnel: Technology Teachers:
Mr. Vic P. Diola – Group Leader Bauan Technical High School
Dr. Gilbert M. Castor Don Alejandro Roses Sr. Science-Technology High School
Mr. Eddielou L. Dayao Sanchez Mira School of Arts and Trade
Mr. Rufo G. Malla E. Rodriguez Vocational High School
Mr. Sherwin P. Medrano San. Pedro Relocation Center National High School
Mr. Remar C. Pinsoy Baguio National School of Arts and Trade
Contextual Teacher:
Mrs. Daisy Carousel P. Cervantes Don Alejandro Roses Sr. Science-Technology High School
Facilitators:
Dr. Edward dela Rosa TEC-VOC Task Force
Dr. Corazon L. Echano TEC-VOC Task Force
Encoders:
Mrs. Rosario D. Briones Mr. Mhariel L. Echano Mr. Jason O. Villena
Funding: Department of Education 30
ACKNOWLEDGMENT Copyright Department of Education 2009 First Published JUNE 2008 This module is based on the Competency-Based Curriculum-Contextual Learning Matrix (CBC-CLM) refined during the Writeshop on the Refinement and Enrichment of Competency-Based Curriculum and Contextual Learning Matrix of ARTS abd TRADES Specializations at Marikina Hotel, Marikina City on April 20 – 25, 2009. This learning instrument was refined and enriched by the following educators: Technology Teachers:
Mr. Victorino P. Diola – Group Leader TVE Coordinator, Bauan Technical High School Bauan, Batangas
Mr. Reynaldo C. Cunanan Head Teacher VI, E. A. Rodriguez Vocational High School Nagtahan, Sampaloc, Manila
Mrs. Gigi C. Corpuz Teacher III, Malvar National High School Malvar, Batangas
Mr. Ismael G. Gallardo Teacher I, Community Vocational High School Masipit, Calapan City, Oriental Mindoro
Mr. Rufo G. Malla Teacher II, E. A. Rodriguez Vocational High School Nagtahan, Sampaloc, Manila
Mr. George B. Fuazo Teacher II, Gen. Mariano Alvarez Technical High School GMA, Cavite
Contextual Teacher: English
Mrs. Teresita P. Tanael Teacher III, Gen. Mariano Alvarez Technical High School GMA, Cavite
Mrs. Charlie I. Soriano Teacher I, Don Alejandro Roces Sr. Science-Technology HS Quezon City
Mathematics Mrs. Analiza Rosa P. Librada Teacher I,-Mathematics Coordinator, San Pedro Relocation Center Nat’l. HS San Pedro, Laguna
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Science Mrs. Gemma G. Vallarta Teacher III Science Coordinator, San Pedro Relocation Center Nat’l. HS San Pedro, Laguna
Mrs. Lenalyn Manzano Teacher I, E A. Rodriguez Vocational High School Nagtahan, Sampaloc, Manila
Facilitators:
Dr. Corazon L. Echano TEC-VOC Task Force
Dr. Victorio N. Medrano TEC-VOC Task Force
Dr. Orlando E. Manuel TEC-VOC Task Force
Encoders:
Marisol E. Saldivar
Funding: Department of Education
32
Republic of the Philippines Department of Education PUBLIC TECHNICAL -VOCATIONAL HIGH SCHOOLS
Unit of Competency: MAINTAIN AND REPAIR ELECTRONICALLY-
CONTROLLED DOMESTIC APPLIANCES Module No. 7
Module Title:
Maintaining and Repairing a Rice Cooker
TABLE OF CONTENTS Page How to Use this Module ................................................................................... i Introduction .................................................................................................... ii Technical Terms ............................................................................................. iii Learning Outcome 1: Identifying the parts and functions of a rice cooker ..................................................................... 1 Learning Experiences/Activities ............................................................. 2 Information Sheet 1.1 ............................................................................ 3 Self-Check 1.1 ....................................................................................... 6 Answer key 1.1 ...................................................................................... 9 Learning outcomes 2: Diagnose and troubleshoot a rice cooker and analyze the defects found ....................................................................... 10 Learning Experiences/Activities ........................................................... 11 Operation sheet 2.1 ............................................................................. 12 Operation sheet 2.2 ............................................................................. 13 Job sheet 2.2 ....................................................................................... 14 Learning Outcomes 3: Maintain and repair a rice cooker ............................. 13 Learning Experiences/Activities ........................................................... 16 Operation sheet 3.1 ............................................................................. 17 Job sheet 3.1 ....................................................................................... 21 Job sheet key 3.1................................................................................. 22 Information sheet 3.2 .......................................................................... 23 Assessment Plan ........................................................................................... 26 Observation checklist .................................................................................... 27 Observation and Questioning checklist ......................................................... 28 Demonstration .............................................................................................. 29 Written Report .............................................................................................. 30 Performance test ........................................................................................... 31 Acknowledgement …………………………………………………………………………. 32
HOW TO USE THIS MODULE Welcome to the Module “Maintaining and Repairing a Rice cooker”. This module contains training materials and activities for you to complete. The unit of competency “Maintain and Repair Electronically-Controlled Domestic Appliances” contains the knowledge, skills and desirable attitudes required for Consumer Electronics Servicing to obtain the National Certificate (NC) level II. You are required to go through a series of learning activities in order to complete each of the learning outcomes of the module. In each learning outcome there are Information Sheets, Job Sheets, and Operation Sheets . Do these activities on your own and answer the Self-Check at the end of each learning activity. If you have questions, don’t hesitate to ask your teacher for assistance. Recognition of Prior Learning (RPL) You have already some basic knowledge and skills covered in this module because you have been working for some time; on already completed training in this area. If you can demonstrate competence to your teacher in a particular skill, talk to him/her so you don’t have to undergo the same training again. If you have a qualification or Certificate of Competency from previous trainings show it to him/her. If the skills you acquired are consistent with and relevant to this module, they become part of the evidence. You can present these for RPL. If you are not sure about your competence skills, discuss this with your teacher. After completing this module, ask your teacher to assess your competence. Result of your assessment will be recorded in your competency profile. All the learning activities are designed for you to complete at your own pace. In this module, you will find the activities for you to complete and relevant information sheets for each learning outcome. Each learning outcome may have more than one learning activity. This module is prepared to help you achieve the required competency, in receiving and relaying information. This will be the source of information that will enable you to acquire the knowledge and skills in “Maintaining and Repairing a Rice cooker” independently at your own pace with minimum supervision from your teacher.
i
Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A RICE COOKER
INTRODUCTION: This module contains information and suggested learning activities on Maintaining and Repairing a Rice Cooker. It covers the knowledge, skills and desirable attitudes required to maintain and repair this home appliance. Completion of this module will help you better understand the succeeding module on maintaining and repairing electronically-controlled domestic appliances. This module consists of three (3) learning outcomes. Each learning outcome contains learning activities supported by instructional sheets. Before you perform the instructions, read the information sheets and answer the self-check and activities provided to ascertain to yourself and your teacher that you have acquired the knowledge necessary to perform the skill portion of the particular learning outcome. Upon completing this module, report to your teacher for an assessment to check your achievement of knowledge and skills required in this module. If you pass the assessment, you will be given a certificate of completion. SUMMARY OF LEARNING OUTCOMES: Upon completion of the module, you should be able to: LO1. identify the parts and functions of a rice cooker; LO2. diagnose and troubleshoot the defects of a rice cooker and analyze the defects found; and LO3. maintain and repair a rice cooker. PREREQUISITES:
Using Hand Tools Preparing and Interpreting technical Drawing used in Shop Connecting and Terminating Electronic Circuit Applying Quality Standards
ii
TECHNICAL TERMS Domestic appliances. They are household appliances like rice cooker, blender, washing machine, flat iron, etc. Rice Cooker. It is a domestic appliance designed but not limited to rice cooking. It can also be used to cook other food stuff and can be used for other related purpose. Resistance heating appliance. It is an appliance that use resistive load for its main part. The part that produced heat when current passes through it. Thermostat. It is a type of switching system that is controlled by temperature. Heating element. It is a part of a resistance heating appliance that get hot when operated. Cast heater. It is a part of the rice cooker that delivers the heat to the fluro pan where the food stuff is located. Electrical components. They are the devices that performs electrical activities when current is applied to the circuit. Mica insulator. It is a transparent material that splits readily into thin sheets which has excellent insulating and heat resisting qualities. Non - electrical components. These are parts of an appliance that performs designated function other than electrical application. ON / Off switch. It is used to designate the operating and the inoperative state of a device or unit. Timer. It is a device that opens the electrical circuit after a predetermined period of time elapses. Thermistor. It is a device with high negative temperature coefficient or resistance so its resistance decreases as temperature rises. Power. It is the rate at which electric energy is fed to or taken from a device measured in watts. Watt. It is the basic unit of power which in one second gives rise to energy of one joule. Fluro pan. It is an aluminum pan that is used to store food stuff like rice, corn, etc.
iii
Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A RICE COOKER
Learning Outcome1: Identify the parts and functions of a rice cooker.
Assessment Criteria 1. Operation of a rice cooker is explained. 2. The parts of a rice cooker are identified based on the manufacturer’s manual. 3. Functions of each part are explained.
References: 1. Tan, Michael Q., Gantalao, Fred T., Lasala, Rommel M. Simple Electronics; Andes Mountain Printers: 2004 2. Enriquez, Marcelo T. Electronics Technology IV; Souvenir Publications, Inc.: 2003
1
LEARNING EXPERIENCES/ACTIVITIES Learning Outcome 1: Identify the parts and function of a rice cooker. Learning Activities
Special Instruction
1. Read the attached Information Sheet 1.1 on rice cooker. 2. Answer the Self Check 1.1. 3. Check your answers with the model answers.
Try to answer the Self-Check without looking at the information sheet.
4. If you missed some of the questions, go back to the information sheet 1.1. 5. If you have answered all the questions correctly, you can proceed to the next Learning Outcome 2.
2
INFORMATION SHEET 1.1 Rice Cooker Rice Cooker
This self-contained kitchen appliance is used primarily for cooking rice. It is used to prepare steamed rice and keep them warm after cooking. It consists of an insulated case containing a removable cooking pot. A heating element is located between the two Containers which is usually controlled by a thermostat. The cooking pot is usually calibrated to ensure proper proportions of the rice and water.
Application and Uses of Rice Cooker Rice cooker is used both in home and commercial kitchens for various purposes: To cook rice To keep rice warm To steam fish or vegetables
PROPER HANDLING OF A RICE COOKER How to use a rice cooker? Before using any other accessory, make sure that the power unit is on a suitable work surface and switch it to off position. Put the protective cover over the drive when you are not using the rice cooker.
How does the rice cooker operate? In most rice cooker, the rice and the water are poured in at the start of cooking. The heater then brings the water to its boiling point during which the rice absorbs the water and expands. While cooking the rest of the water boil away and the machine either shuts off or switches to “keep warm” mode.
3
Major Parts of a Rice Cooker and their Functions:
Power Cord is a cord that temporarily connects an electrical appliance to an electrical power source. The term is generally used for cables using a power plug to connect to a single-phase.
. Cast Heater is a part of a rice cooker that produces heat to the aluminum pan which serves as a heating element of the rice cooker.
Mica heater is consists of an etched-foil sandwiched between layers of mica. Installed by clamping to heat sinks, mica heater provides the ultimate temperature and wattage capability for fast warm-up.
Thermal fuse is a cut-off device which uses a one-time fuse link. Unlike the thermostat which automatically resets itself when temperature drops, the thermal fuse is more like an electrical fuse.
Thermostat assembly is a device, as in a home heating system that automatically responds to temperature changes and activates switches controlling the equipment.
4
Fluro pan is a part of a rice cooker where the rice is placed.
Outer Lid assembly is one of the major parts of a rice cooker and which serves as a wife of an aluminum pan, because this part is responsible to cover the bowl or an aluminum pan.
Body assembly is a part of a rice cooker in which the label is usually found and the holder of the outer lid assembly.
Switch assembly is a part of a rice cooker that controls the whole operation automatically.
5
SELF CHECK 1.1 Direction: Fill in the blanks with what is being referred to by each of the items below.
Part name
Description
Picture
A part of a rice cooker
1.__________________
where the rice is placed.
Consist of an etched-
2.__________________
foil sandwiched between layers of mica.
A device that automatically
3._________________
responds to the temperature changes and activates switches controlling the equipment.
4.____________________
It Is a cutoff switch that uses a one-time fusible link.
6
A part of a rice cooker 5.______________________ that controls the whole operation automatically.
A part of a rice cooker in which the label is 6.______________________ usually found and is considered the holder of the outer lid assembly. One of the major 7.______________________ parts of a rice cooker and serves as a partner of the aluminum pan.
8.______________________
9._____________________
A part of a rice cooker that produces heat to the aluminum pan.
A cord that temporarily connects an electrical appliances.
7
10.____________________
A self-contained kitchen appliance used primarily for cooking rice.
8
Self Check Key 1.1
1. Fluro pan 2. Mica heater 3. Thermostat assembly 4. Thermal fuse 5. Switch assy. 6. Body assy. 7. Outer lid assy. 8. Cast heater assy. 9. Power cord 10. Rice cooker
9
Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLYCONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A RICE COOKER
Learning Outcome 2: Diagnose and troubleshoot the defects of a rice cooker and analyze the defects found. Assessment Criteria 1. Pre-testing procedure is performed in accordance with the manufacturer’s instructions. 2.System defects/fault symptoms are identified using the appropriate tools and equipment. 3.Identified defects and faults are explained to the person in authority. 4.Results of diagnosis and testing are documented. 5. Troubleshooting is performed in accordance with the service manual.
References: 1. Tan, Michael Q., Gantalao, Fred T., Lasala, Rommel M. Simple Electronics; Andes Mountain Printers: 2004 2. Enriquez, Marcelo T. Electronics Technology IV; Souvenir Publications, Inc.: 2003
10
LEARNING EXPERIENCES/ACTIVITIES Learning Outcome 2: Diagnose and troubleshoot the defects of rice cooker and analyze the defects found. Learning Activities
Special Instruction
Read the attached Operation Sheet 2.1 on pre-testing a rice cooker. Read the Operation Sheet 2.2.
Try to answer the job sheet with out looking at the operation sheet.
Perform the Job Sheet 2.2. Answer assessment plan If you have answered perfectly the test, you can proceed to the next Learning Outcome 3.
11
OPERATION SHEET 2.1 Pre-Testing Procedure of a Rice Cooker If a …
Possible cause
How to fix Check AC power
Unit cannot be turned on.
AC power cord is not
cord if there is loose
properly plugged in.
connection in the
The plug is not connected
power plug.
properly. Unit does not operate
The front cover is not
Plug-in properly.
when turned on.
properly closed.
Unit has light indicator
The cast heater doesn’t
Push front cover/
ON but the cast heater
functions well.
front lid properly.
Unit has bogs down
The thermal fuse is not
Check and
during operation.
active.
continuously check
doesn’t function.
the cast heater. Unit has poor boiling
The pan bottom is not
Follow the instruction
condition.
properly brought into
for the thermal fuse
contact with the cast
protection.
heater. Unit has excessive burning period.
The relay doesn’t operate.
Replace the inner pan or the cast heater. Replace the relay and replace the PCB completely.
12
OPERATION SHEET NO. 2.2 Faults and Trouble of a Rice Cooker Trouble No power
Cause Overloading
Inspection
Remedy
Use the multi-
Refer to the
tasked check
component
Rice cooker is
continuity of the
testing.
continuously
ff. parts:
Replace defective
operated for more
a.) fuse
parts.
than 3 hrs. without b.) power cord
Refer to the next
rest.
Learning outcome repairing procedure.
Doesn’t light
Rice cooker lamp is continuously
Check the rice
Replace the
operated for more
cooker lamp.
busted lamp.
than 3hrs. With power but
Foreign materials
doesn’t heat
are shorted to the circuit board.
Check it by using the VOM
Replace the switch assembly.
for continuity test. With power but
Refer to the
doesn’t heat
component Defective
Use the multi -
cast heater
tester to check
testing procedure.
continuity of
Explain to the
cast heater
customer that the
filament.
cast heater is defective.
13
Tools Used in Pre-Testing a Rice Cooker
VOM (multitester)
Instructional/Operational Manual
Screw Driver
Pliers
Side cutting pliers
Long nose pliers
JOB SHEET 2.2 Faults and Trouble of a Rice Cooker Instruction: Fill out the table with the data corresponding to the trouble, causes, inspection procedure and remedy when troubleshooting a rice cooker. Write your answers on a separate sheet of paper. Do not write anything in this module. Trouble
Cause
Inspection
Remedy
No power
Doesn’t light
W/power won’t heat
W/power doesn’t heat
14
Program/Course:
CONSUMER ELECTRONIC SERVICING NC II
Unit of Competency:
MAINTAIN AND REPAIR ELECTRONICALLY CONTROLLED DOMESTIC APPLIANCES
Module Title:
MAINTAINING AND REPAIRING A RICE COOKER
Learning Outcome 3: Maintain and repair a rice cooker. Assessment Criteria; 1. Personal protective equipment are used in accordance with the occupational health and safety practices. 2. Defective parts/components are replaced with the appropriate equivalent ratings. 3. Control settings/adjustments are performed in conformity with the service manual specifications. 4. Repair activity is performed within the required time frame. 5. The unit is cleaned after the maintenance and repair activity.
References: Tan, Michael Q., Gantalao, Fred T., Lasala, Rommel M. Simple Electronics; Andes Mountain Printers: 2004 Enriquez, Marcelo T. Electronics Technology IV; Souvenir Publications, Inc.:
15
LEARNING EXPERIENCES/ACTIVITIES Learning Outcome 3: Maintain and repair a rice cooker Learning Activities Read the attached Operation Sheet 3.1 component checking and replacement. Perform the job sheet 3.1.
Special Instruction
Try to answer the Self-Check without looking at the information sheet.
Read the Information sheet 3.2. If you have answered perfectly yes, you are ready to proceed to the next module.
16
OPERATION SHEET 3.1 COMPONENT CHECKING AND REPLACEMENT PROCEDURE:
Prepare all the tools and materials needed.
Bubbling test Fill water until the center area of the pan bottom is dipped and the lid is closed. When steam is produced while boiling, remove the lid immediately and check the bubbling condition on the pan bottom. See the figures at the right.
Evaporation Test Check if the water is boiling properly, then open the lid, place weight and find out what happens.
NOTE: 1. Be sure to open the lid fully to prevent plastic the part from deformation. 2. Be sure that water on the pan bottom evaporated completely a minute after the boiling switch is turned-off.
17
Heat reserving test Put approximately 1 liter of water into the pan. Close the lid and turn on the switch to 70 degrees Celcius. After the warming heater is activated, check the heat-serving temperature after I hour or more. When it reaches 70 degrees Celcius, close the lid after the warming heater is activated. Check the heat-serving temperature after one hour or more.
Hinge cover removal (Hinge cover) Remove the hinge cover with a mounting screw. As shown in the figure, insert a narrow flat screw driver just below and pry off the hinge cover.
Inner enclosure and upper frame removal As shown in the figure, pry up three fastening hooks. Fixing the upper frame, turn the inner enclosure in the arrow direction. The upper frame will be separate the upper frame from the inner enclosure.
18
Disassembling a control unit Pull out the hinge shaft. Pull out wiring fir lid heater and then the outer lid assembly.
Loosen the screw from the button frame. Loosen the screw (2pieces) from the P.C.B base.
Use a screwdriver to pry the bottom frame. Pull out the body from the upper frame.
Pull out the switch assembly.
Loosen the screw to disassemble electronic parts.
19
Disassembling Cast Heater and Thermostat Case Assembly.
Loosen the screw from the cast heater. Bend the leg of the thermostat.
Lift the thermostat.
Pull out a side heater.
20
JOB SHEET 3.1 Troubleshooting Procedure of a Rice Cooker Direction: Select the right illustration shown below to describe the a given procedure. Write your answer in a separate sheet of paper. Do not write anything in this module. __________1.) Loosen the a screw for a cast heater and bend the leg of the thermostat. __________2.) Pulling out the side heater. __________3.) Lift the thermostat. __________4.) Loosen the screw from the P.C.B Base. __________5.) Pulling out the switch assembly. __________6.) Loosen the screw from the button frame. __________7.) Pull out the hinge shaft. __________8.) Loosen the screw for disassembling electronic parts. __________9.) Use a screw driver to pry bottom frame. __________10.) Remove the hinge cover with a mounting screw.
A
F
B
G
C
H
D
I
E
J
21
JOB SHEET KEY 3.1 Troubleshooting Procedure of a Rice Cooker
1. C 2. A 3. B 4. D 5. F 6. H 7. I 8. E 9. G 10. J
22
INFORMATION SHEET 3.2 IDENTIFYING THE SPECIFICATION OF REPLACEMENT PARTS
23
PARTS LIST OF THE RICE COOKER
Ref. no.
Part name
Part no.
1
OUTER LID ASSY.
ARBO111935W9U
2
STEAM DOME
ARB19T920-W9
3
STEAM VENT
ARC00T920-W9
4
STEAM VENT HOLDING PACKING
ARB82T920
5
HOOK LEVER
ARE05H617-W9
6
HOOK LEVER SPRING
ARE06H6167
7
HOOK LEVER BASE
ARC31H617
8
HANDLE COVER
ARB15T920-W9
9
HANDLE
ARB10920W-9
10
LID CAUTION LEVEL
ARB32H920
11
OUTER LID COMP
ARB01T935-WU
12
FLIRO PAN
ARE50T935
13
CAST HEATER ASSY.
ARL20909-0U
14
THERMOSTAT CASE ASSY.
ARS24T908-OU
15
OUTER SPRING
ARS62H616
16
UPPER FRAME
ARE00A6171W-9
17
HINGE SHAFT
ARB74H616
18
PROTECTING FRAME
ARE20T935
19
SIDE HEATER ASSY.
ARL10P75200U
20
BODY ASSY.
ARE10Y929Z3U
21
SWITCH ASSY.
ARN01H935UHU
22
DECORATIVE PANEL
ARN21H935-UH
23
HINGE COVER
ARE40H6262W9
24
DEW COLLECTOR
ARK20H616-0C
25
BOTTOM FRAME ASSY.
ARH30T935W9U
26
FOOT RUBBER
ARH90H66327
27
NAME PLATE
ARY30H935-CS
24
28
POWER CORD ASSY
ARQ14509943
29
INLET
ARG10T9200U
30
STEAMING BASKET
ARK53H617-W9
31
MEASURING CUP
ASR7234R0-454BK
32
SCOOP
ASR79WE281AK
A
TAPPING SCREW
XTB4+10GPJ
B
SEMS SCREW
XYN4+C10FNS
C
SEMS SCREW
XYM4+C7FNS
D
SPRING WASTLE
XWA4BPW
E
TAPPING SCREW
XTN4+8FFJ
F
TAPPING SCREW
ASR118-972-W
G
TAPPING SCREW
XTN4+16AZW
H
TAPPING SCREW
XPB4+25CFJ
25
ASSESSMENT PLAN Repairing a Rice Cooker
Direction: Put a check on the designated box if you perform the following skills.
YES
The operation of a rice cooker was explained.
The parts of the rice cooker were identified
The function of its parts was explained.
Pre- testing procedure was performed in accordance with the manufacturers instruction System defects/ faults system were identified using appropriate tools and equipment Identified defect and faults were explained to the responsible person. Results of diagnosis and testing were documented
NO
Troubleshooting was performed in accordance with the service manual. Personal protective equipment were used in accordance with Occupational Health and Safety Policies.
Prepared by:
Date:
Checked by:
Date:
26
Observation Checklist Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the teacher: 1. Observe the student in Maintaining and repairing a rice cooker. 2. Describe the assessment activity and the date on which it was undertaken. 3. Place a tick in the box to show that the student completed each aspect of the activity to the standard expected in the enterprise. 4. Complete the feedback sections of the form. Date of observation Description of assessment activity Location of assessment activity The student can… explain the operation of a rice cooker..
identify the parts of the rice cooker.
explain the function of the parts of a rice cooker.
perform the pre-testing procedure in accordance with the manufacturers instruction. identify the system defects/ faults system using appropriate tools and equipment. explain identified defects and faults to the responsible person.. document results of diagnosis and testing.
If yes, tick the box
perform troubleshooting in accordance with the service manual. use Personal protective equipment in accordance with Occupational Health and Safety Policies. Did the student’s overall performance meet the standard?
Yes
No
Feedback to student: Teacher signature:
Date:
27
Observation and Questioning Checklist Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Instructions for the teacher: 1. Observe the student in Maintaining and repairing a rice cooker 2. Describe the assessment activity and the date on which it was undertaken. 3. Place a tick in the box to show that the student completed each aspect of the activity to the standard expected in the enterprise. 4. Ask the student a selection of the questions from the attached list to confirm his/her underpinning knowledge 5. Place a tick in the box to show that the student answered the questions correctly. 6. Complete the feedback sections of the form. Date of observation Description of assessment activity Location of assessment activity The student can… Explain the operation of a rice cooker.
Identify the parts of a rice cooker.
Explain the function of the parts of rice cooker.
Perform the pre- testing procedure in accordance with the manufacturers instruction. Identify system defects/ faults using appropriate tools and equipment. Explain identified defect and faults to the responsible person. Document results of diagnosis and testing are documented.
If yes, tick the box
Troubleshooting in accordance with the service manual. Use Personal Protective Equipment in accordance with Occupational Health and Safety practices. Did the student’s overall performance meet the standard?
Yes
No
28
Demonstration Student’s name: Teacher’s name: Unit of competency: Competency standards: Date of assessment: Time of assessment: Instructions for demonstration Given the necessary materials the trainee/student must be able to:
Materials and equipment: Rice Cooker Basic electronic hand tools Multi tester Service Manual to show if evidence is demonstrated
During the demonstration of skills, did the student manifest that he/she can...
Explain the operation of a rice cooker.
Identify he parts of the rice cooker. .
Explain the function of its parts.
Perform pre- testing procedure in accordance with the manufacturers instruction. Identify system defects/ faults using appropriate tools and equipment. Explain identified defect and faults to the responsible person. Document results of diagnosis and testing.
Perform troubleshooting in accordance with the service manua.. Use Personal Protective Equipment in accordance with Occupational Health and Safety practices. The student’s demonstration was: Satisfactory
Yes
No
N/A
Not Satisfactory
29
Written report Student’s name: Teacher’s name: Assessment Center Competency standards Unit of competency: Task: Your task is to: Maintain and repair a rice cooker Submission date: Use the checklist below as a basis for judging whether the student’s report meets the required competency standards. The student’s report states that he/she can…
Explain the operation of a rice cooker.
Identify the parts of the rice cooker.
Explain the function of its parts.
Perform pre- testing procedure in accordance with the manufacturers instruction. Identify system defects/ faults using appropriate tools and equipment. Explain identified defects and faults to the responsible person. Document results of diagnosis and testing.
If yes, tick the box
Perform troubleshooting in accordance with the service manual. Used Personal Protective Equipment in accordance with Occupational Health and Safety practices.
Overall did the student’s report meet the standard?
Yes
No
Comments:
Student’s signature:
Date:
Teacher’s signature:
Date:
30
PERFORMANCE TEST Learner's Name
Date
Competency:
Directions: Ask your teacher to assess your performance in the following critical task and performance criteria below You will be rated based on the overall evaluation on the right side.
Test Attempt 1st 2nd 3rd OVERALL EVALUATION Level Achieved
PERFORMANCE LEVELS
4 - Can perform this skill without supervision and with initiative and adaptability to problem situations. 3 - Can perform this skill satisfactorily without assistance or supervision. 2 - Can perform this skill satisfactorily but requires some assistance and/or supervision. 1 - Can perform parts of this skill satisfactorily, but requires considerable assistance and/or supervision. Teacher will put his/her initial at the level achieved.
PERFORMANCE STANDARDS For acceptable achievement, all items should receive a "Yes" or "N/A" response.
The operation of a rice cooker is explained.
The parts of the rice cooker are identified. The function of its parts is explained. Pre- testing procedure is performed in accordance with the manufacturers instruction. System defects/ faults system are identified using appropriate tools and equipment. Identified defect and faults are explained to the responsible person. Results of diagnosis and testing are documented.
Yes
No
N/A
Troubleshooting is performed in accordance with the service manual. Personal protective equipment is used in accordance with Occupational Health and Safety practices.
31
ACKNOWLEDGMENT Copyright Department of Education 2008 First Published JUNE 2008 This module is based on the Competency-Based CurriculumContextual Learning Matrix (CBC-CLM) and finalized on the Instructional Modules Finalization Development Workshop conducted at the Development Academy of the Philippines, Tagaytay City on May 6 -10, 2008 This learning instrument was developed by the following personnel: Technology Teachers:
Mr. Vic P. Diola – Group Leader Bauan Technical High School
Dr. Gilbert M. Castor Don Alejandro Roses Sr. Science-Technology High School
Mr. Eddielou L. Dayao Sanchez Mira School of Arts and Trade
Mr. Rufo G. Malla E. Rodriguez Vocational High School
Mr. Sherwin P. Medrano San. Pedro Relocation Center National High School
Mr. Remar C. Pinsoy Baguio National School of Arts and Trade
Contextual Teacher:
Mrs. Daisy Carousel P. Cervantes Don Alejandro Roses Sr. Science-Technology High School
Facilitators:
Dr. Edward dela Rosa TEC-VOC Task Force
Dr. Corazon L. Echano TEC-VOC Task Force
Encoders:
Mrs. Rosario D. Briones Mr. Mhariel L. Echano Mr. Jason O. Villena
32
Funding: Department of Education
ACKNOWLEDGMENT Copyright Department of Education 2009 First Published JUNE 2008 This module is based on the Competency-Based CurriculumContextual Learning Matrix (CBC-CLM) refined during the Writeshop on the Refinement and Enrichment of Competency-Based Curriculum and Contextual Learning Matrix of ARTS abd TRADES Specializations at Marikina Hotel, Marikina City on April 20 – 25, 2009. This learning instrument was refined and enriched by the following educators: Technology Teachers:
Mr. Victorino P. Diola – Group Leader TVE Coordinator, Bauan Technical High School Bauan, Batangas
Mr. Reynaldo C. Cunanan Head Teacher VI, E. A. Rodriguez Vocational High School Nagtahan, Sampaloc, Manila
Mrs. Gigi C. Corpuz Teacher III, Malvar National High School Malvar, Batangas
Mr. Ismael G. Gallardo Teacher I, Community Vocational High School Masipit, Calapan City, Oriental Mindoro
Mr. Rufo G. Malla Teacher II, E. A. Rodriguez Vocational High School Nagtahan, Sampaloc, Manila
Mr. George B. Fuazo Teacher II, Gen. Mariano Alvarez Technical High School GMA, Cavite
Contextual Teacher: English
Mrs. Teresita P. Tanael Teacher III, Gen. Mariano Alvarez Technical High School GMA, Cavite
o Mrs. Charlie I. Soriano Teacher I, Don Alejandro Roces Sr. Science-Technology HS
33
Quezon City
Mathematics o Mrs. Analiza Rosa P. Librada Teacher I,-Mathematics Coordinator, San Pedro Relocation Center Nat’l. HS San Pedro, Laguna
Science o Mrs. Gemma G. Vallarta Teacher III Science Coordinator, San Pedro Relocation Center Nat’l. HS San Pedro, Laguna
Mrs. Lenalyn Manzano
o
Teacher I, E A. Rodriguez Vocational High School Nagtahan, Sampaloc, Manila
Facilitators:
Dr. Corazon L. Echano TEC-VOC Task Force
Dr. Victorio N. Medrano TEC-VOC Task Force
o Dr. Orlando E. Manuel TEC-VOC Task Force
Encoders: o Marisol E. Saldivar
Funding: Department of Education
34
Republic of the Philippines Department of Education PUBLIC TECHNICAL -VOCATIONAL HIGH SCHOOLS
`
Unit of Competency:
Module No. 7
MAINTAIN AND REPAIR ELECTRONICALLY CONTROLLED DOMESTIC APPLIANCES MAINTAINING AND REPAIRING A RICE COOKER
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