Application Manual Transformer

1ZVN460100 – A

Application manual

1ZVN460100 – A

2/3

Table of contents 1 2 3 4

Rating Plate .................................................................................................................. Tapchanger .................................................................................................................. Bushing ........................................................................................................................ Cooling Equiptment.....................................................................................................

5 6 7 8

Current Transformer.................................................................................................... Other Acessories ......................................................................................................... Drawings ...................................................................................................................... Final Test Reports .......................................................................................................

9 Assemblies and Oil Filling at Site............................................................................... 10 Site Test and Commissioning..................................................................................... 11 Maintenance .................................................................................................................

1ZVN460100-A

1

Rating Plate

1ZVN460100-A

2

Tapchanger Ref to 1ZVN460100-C_Operation Manual

1ZSE 5492-104 Language en Rev. 4, 1997-03-30

On-Load Tap-Changers Type UZ Technical Guide

L37034

ABB Components

Manufacturer’s declaration The manufacturer

ABB Components AB SE-771 80 LUDVIKA Sweden

Hereby declares that The products

On-load tap-changers types UZE and UZF with motor-drive mechanism type BUF 3

comply with the following requirements: By design, the machine, considered as component on a mineral oil filled power transformer, complies with the requirements of •

Machinery Directive 89/392/EEC (amended 91/368/EEC and 93/44/EEC) and 93/68/EEC (marking) provided that the installation and the electrical connection be correctly realized by the manufacturer of the transformer (e.g. in compliance with our Installation Instructions) and

•

EMC Directive 89/336/EEC regarding the intrinsic characteristics to emission and immunity levels and

•

Low Voltage Directive 73/23/EEC (modified by Directive 93/68/EEC) concerning the built-in motor and apparatus in the control circuits.

Certificate of Incorporation: The machines above must not be put into service until the machinery into which they have been incorporated have been declared in conformity with the Machinery Directive. Date

1997-02-10

Signed by

......................................................................... Olof Heyman

Title

Manager of Division for Tap-Changers

This Technical Guide has been produced to allow transformer manufacturers, and their designers and engineers, access to all the technical information required to assist them in their selection of the appropriate on-load tap-changer and motor-drive mechanism. The guide should be used in conjunction with the Selection Guide and the Design Guides, to allow the optimum selection to be made. The technical information pertaining to on-load tap-changers and motor-drive mechanisms manufactured by ABB Components has been divided and is contained in separate documents, with one document for each type. The information provided in this document is intended to be general and does not cover all possible applications. Any specific application not covered should be referred directly to ABB Components AB, or its authorized representative. ABB Components AB makes no warranty or representation and assumes no liability for the accuracy of the information in this document or for the use of such information. All information in this document is subject to change without notice. ABB Components also manufactures the following products: De-energized tap-changers Transformer bushings Wall bushings GIS bushings Transformer cooling equipment

Table of Contents General Information ___________

4

Design Principles _____________

6

On-Load Tap-Changer _____________________ Epoxy-Resin Moulding __________________ Selector Switch ________________________ Transition Resistors ____________________ Change-over Selector __________________ Geneva Gear _________________________ Tap-Changer Tank _____________________ Oil Conservator _______________________ Accessories for the Tap-Changer __________ Special Applications ____________________ Motor-Drive Mechanism ____________________ Accessories for the Motor-Drive Mechanism _ Motor-Drive Mechanism Cubicle __________ Degree of Protection ___________________

Principles of Operation _________ On-Load Tap-Changer _____________________ Switching Sequence ____________________ Selector Switch ________________________ Change-over Selector for Plus/Minus Switching ___________________ Change-over Selector for Coarse/Fine Switching __________________ Through Positions _____________________ Motor-Drive Mechanism ____________________ Operational Description _________________ Local Control _________________________ Remote Control _______________________ Through Positions _____________________ Step-by-Step-Operation _________________ Protection against Running-Through _______ Contact Timing ________________________

Characteristics and Technical Data ________________ On-Load Tap-Changer _____________________ Type Designation ______________________ Rated Phase Step Voltage _______________ Standards and Testing __________________ Rating Plate __________________________ Mechanical Life _______________________ Insulation Levels _______________________ Sound Level __________________________ Contact Life __________________________

6 6 6 7 7 7 8 8 9 9 9 9 9 9 10 10 10 10 11 11 11 12 12 14 14 14 14 14 14

15 15 15 15 15 15 16 16 16 16

Short-circuit Current Strength _____________ Highest Phase Service Voltage Across the Regulating Winding _________________ Rated Through-Current _________________ Maximum Rated Through-Current _________ Occasional Overloading _________________ Oil Temperature _______________________ Motor-Drive Ambient Air Temperature ______ Tie-in Resistors _______________________ Conductors from the Windings ____________ Cable Lugs ___________________________ Standard Version of Motor-Drive Mechanism ___ Control ______________________________ Wiring Connection _____________________ Protection ____________________________ Indication ____________________________ Optional Accessories ______________________ Anti-Condensation Coverage _____________ Outlet _______________________________ Extra Heater __________________________ Hygrostat ____________________________ Tropical Version _______________________ Extra Multi-Position Switches _______________

Design, Installation and Maintenance______________ On-Load Tap-Changer with Motor-Drive Mechanism _____________________________ Design Differences between the UZE and UZF On-Load Tap-Changers _____________ Schematic Diagrams ___________________ Drying _______________________________ Painting _____________________________ Weights _____________________________ Oil Filling _____________________________ Installation ___________________________ Maintenance __________________________ Pressure Relay ________________________ General Description _________________ Design ____________________________ Operation _________________________ Function Pressure ___________________ Testing ___________________________ Dimensions, On-Load Tap-Changer Type UZE ____________________________ Dimensions, On-Load Tap-Changer Type UZF ____________________________ On-Load Tap-Changers Types UZE and UZF with Accessories _______________________ Oil Conservator for UZF _________________

17 17 17 17 17 17 18 18 18 18 19 19 19 19 19 20 20 20 20 20 20 20

21 21 21 22 26 26 26 26 26 26 27 27 27 27 27 27 28 29 30 31

General Information The UZ types of on-load tap-changers operates according to the selector switch principle, that is, the tap selector and diverter switch functions are combined in one.

Standard tanks are designed for the UZ types. The standard tanks have a number of standard flanges to get great flexibility for accessories. Standard accessories are pressure relay and oil valve. See Figs. 1a and 1b. A great number of extra accessories can be ordered. See Figs. 2a and 2b.

The UZ types of on-load tap-changers are mounted on the outside of the transformer tank. All of the equipment necessary to operate the tap-changer is contained in a single compartment, with the motor-drive mechanism attached to the outside.

As a design option, the UZ types can be supplied without the tank. This gives the transformer manufacturer the flexibility to design the tap-changer tank as an integral part of the transformer tank.

Because the UZ types are designed for mounting on the outside of the transformer tank installation procedures are simplified and the overall size of the transformer tank can be reduced.

Fig. 1a. On-load tap-changer type UZE with standard accessories.

L37037

Fig. 1b. On-load tap-changer type UZF with standard accessories.

L37023

Fig. 2a. On-load tap-changer type UZE with extra accessories.

L37036

Fig. 2b. On-load tap-changer type UZF with extra accessories.

L37024

4

Connection to oil conservator

Cover for access to conductors

Lifting eye

Motor-drive mechanism

Connection for oil filter unit

Attachment flange to transformer tank

Gasket Terminal

Front cover

Geneva gear

Selector switch unit

Insulating shaft Change-over selector

Pressure relay Fixed contact Moving contact system

Test valve

Test connection Shielding-ring Oil valve On-load tap-changer tank

Transition resistor

Fig. 3. Design principle of on-load tap-changer type UZF 5

Design Principles On-Load Tap-Changer

Selector Switch

The tap-changer is built-up by using single-phase units, each identical, mounted in the openings on the rear of the compartment. Each single-phase unit consists of an epoxy-resin moulding, a selector switch, transition resistors and, in most cases, a change-over selector.

The selector switch consists of fixed contacts and a moving contact system. The fixed contacts are mounted onto a bracket which is screwed onto the terminals previously moulded into the epoxy-resin moulding. Each fixed contact has two contact paths, one for the main moving contact and one for the moving switching contacts.

Epoxy-Resin Moulding

The moving contact system consists of the main contact, the main switching contact and two transition contacts. The system is built as a rigid unit rotated by a common drive-shaft. In the service position the load current is carried by the moving main contact, which consists of two contact fingers, pressed onto the fixed contact by springs. The moving switching contacts and the transition contacts are made as rollers, see Fig. 5, which move over the knife-like fixed contacts. The making and breaking takes place between the fixed and moving switching contacts.

The one-piece moulding provides a bushing between the transformer and the tap-changer. The conductors are moulded into position to connect the fixed contacts to the terminals for connection to the transformer windings. Also moulded into the unit are bearings for the selector switch and the change-over selector. The terminals on the moulding are numbered according to the schematic diagrams, see the section ”Design, Installation, and Maintenance” contained in this Guide.

The switching contacts are made of copper/tungsten, or in the case of tap-changers for lower currents, the contacts are made of copper.

Fig. 4. One phase of an on-load tap-changer type UZ

L036257

Fig. 5. Moving contact system

6

Transition Resistors

Change-over Selector

The resistors are made from spirally wound wire mounted on insulating bobbins. They are connected between the moving main contact and the transition contacts.

The change-over selector is used for reversing the regulating winding or for changing connection in the coarse/fine regulation. The selector consists of a moving contact and two fixed contacts. The moving contact is fixed to a shaft and is supported by a bearing in the moulding. The current is carried by the four contact fingers of the moving arm, and transferred to the fixed contacts. The change-over selector does not make or break the current during operation.

Fig. 6. Selector switch

Geneva Gear The Geneva gear principle is used to change a rotary motion into a stepping motion. Drive is transmitted directly from the motor-drive mechanism to the Geneva gear. The Geneva gear operates the selector switch and the change-over selector. The Geneva gear is also used to lock the moving contact system when it is in position.

Fig. 7. 7

Tap-Changer Tank A standard tank is designed for each size of UZE and UZF. The standard tanks have a number of standard flanges intended for a great variety of accessories. Flanges that are not used are mounted with greyblue covers. Adapter flanges can be bolted on if the sizes of the standard flanges not are suitable.

When the on-load tap-changer operates, arcing occurs in the tap-changer. To avoid contamination of the transformer oil, the tap-changer is housed in its own tank separated from the transformer oil. All components that make and break the current during the operation of the tap-changer are located in the tap-changer tank.

Standard accessories are pressure relay and oil valve. A great number of extra accessories can be ordered. Dimensions and accessories for the tap-changer tanks are shown on pages 28 to 31.

The tap-changer tank is separated from the transformer tank by a vacuum-proof barrier, designed to withstand a maximum test pressure of 100 kPa, at a maximum of 60 oC. The barrier and the gasket are oil-tight, which means that they are designed and routinely tested for a permissible air leak at each leak location of 0.0001 cm3/s, at a pressure difference of 100 kPa and a temperature of 20 oC. This safely guarantees the contaminated tapchanger oil to remain separated from the transformer oil. It should be noted that the barrier has not been designed to allow for a simultaneous over-pressure on one side, and vacuum on the other. All models are supplied with an oil valve, for filling and draining.

The tap-changer tank can be bolted (standard) or welded to the transformer tank. A non-standard tank can also be ordered, but to a higher price and a longer delivery time than the standard tank.

Fig. 8a. UZE standard tank

TC_00267

Fig. 8b. UZF standard tank

TC_00267

Oil Conservator Normally the oil compartment of the tap-changer shall be connected to a conservator, separated from the oil of the transformer. If the transformer oil is to be supervised by gas-in-oil analyses, the conservator for the tap-changer oil should have no connection to the conservator of the transformer on either the oil or the air side.

The oil pressure difference between the transformer and the tap-changer should not exceed 10 kPa or 1.2 metres oil column. If the pressure difference is between 10 and 70 kPa a reinforced barrier should be ordered. For the version for sealed tank transformers the pressure difference is allowed to be up to 70 kPa (10 Psi) and for that version the reinforced barrier is delivered.

For use on a sealed tank transformer a special version can be supplied, in which UZE includes the volume needed for oil expansion, an oil level indicator and a breather. UZF needs an own conservator, which can be supplied mounted on the top of the tap-changer tank.

The set point for the pressure relay connected to the UZ tank is 50 kPa (7 Psi). For further information, see page 27 or pamphlet 1ZSE 5492-151.

8

Accessories for the Tap-Changer

Special Applications

Accessories for the tap-changer are shown on dimension prints on pages 30 and 31.

ABB Components should be consulted for all special application tap-changers, such as sealed tank transformers or transformers for use with arc-furnaces and converters.

For a list of accessories see the Selection Guide or consult ABB Components.

Fig. 9. Motor-drive mechanism

Motor-Drive Mechanism

Motor-Drive Mechanism Cubicle

The motor-drive mechanism provides the drive to allow the tap-changer to operate. As the name implies, drive is provided from a motor through a series of gears and on to a spring energy storage device, which when fully charged, operates the tap-changer via a drive shaft. Several features are incorporated within the mechanism to promote long service intervals and reliability.

The cubicle is manufactured from steel and is welded to the outside of the tap-changer tank. The door, which can be padlocked, forms a cap around the mechanism to allow easy access to all the working parts. Vents, with filters, and a heater are fitted to ensure that the mechanism remains operative in varied climates.

Degree of Protection

For a detailed operating description, see the section ”Principles of Operation” contained in this guide.

The motor-drive mechanism has passed a test for IP 54 according to IEC 529.

Accessories for the Motor-Drive Mechanism Accessories for the motor-drive mechanism are described on page 20. For a list of accessories see the Selection Guide or consult ABB Components. 9

Principles of Operation On-Load Tap-Changer Switching Sequence The switching sequence is designated the symmetrical flag cycle. This means that the main switching contact of the selector switch breaks before the transition resistors are connected across the regulating step. This ensures maximum reliability when the switch operates with overloads. At rated load the breaking takes place at the first current zero after contact separation, which means an average arcing time of approximately 6 milliseconds at 50 Hz. The total time for a complete sequence is approximately 50 milliseconds. The tap change operation time of the motor-drive mechanism is approximately 3 seconds per step.

Fig. 10c. The transition contact M1 has made on the fixed contact 2. The load current is divided between the transition contacts M1 and M2. The circulating current is limited by the resistors.

Selector Switch The switching sequence when switching from position 1 to position 2 is shown in the diagrams of Figs. 10a-e below. The moving contact H is shown as one contact but consists in fact of two, the main contact and the main switching contact. The main contact opens before and closes after the main switching contact.

Fig. 10d. The transition contact M2 has broken at the fixed contact 1. The transition resistor and the transition contact M1 carry the load current.

Fig. 10a. Position 1. The main contact H is carrying the load current. The transition contacts M1 and M2 are open, resting in the spaces between the fixed contacts.

Fig. 10e. Fig. 10b.

Position 2. The main switching contact H has made on the fixed contact 2. The transition contact M1 has opened at the fixed contact 2. The main contact H is carrying the load current.

The transition contact M2 has made on the fixed contact 1, and the main switching contact H has broken. The transition resistor and the transition contact M2 carry the load current.

For plus/minus and coarse/fine switching, the changeover selector is used.

10

Change-over Selector for Plus/Minus Switching The switching sequence, when the change-over selector R changes over for plus/minus switching, is shown in the diagrams of Figs. 11a and 11b. The contact arm of the selector switch has reached the fixed contact 12 after switching from the fixed contact 11. The fixed contact 12 is wide enough to cover the whole distance between two positions of the selector switch. It is connected to the end of the main winding. The contact arm of the selector switch has travelled on to the contact 12, and the change-over selector R is in offload condition. The load current goes directly from the main winding through the contact 12 and out through the current collector at the centre of the contact arm. The upper end of the regulating winding is still connected to the main winding. This is the service position.

Fig. 11a. Service position

The contact arm of the selector switch has travelled further on the contact 12 without any breaking or making of the current. At the same time the contact arm of the change-over selector R, has travelled from contact B to contact C, through which the lower end of the regulating winding has been connected to the main winding. This is called a through position, see Through Positions.

Fig. 11b. Through position

Change-over Selector for Coarse/Fine Switching

Through Positions A so called ”Through Position” is a position the tapchanger has to pass without changing the ratio of the transformer. Figs. 11a-b shows how the change-over selector is operated, while the selector moves over the double fixed contact. The extra position has the same number on the scale of the position indicator, together with a letter, e.g. 12A. There might be need for more through positions over the operating range if the number of taps of the winding is less than the number of mechanical positions of the selector. The motor-drive will automatically pass the through positions.

The mechanical switching is exactly the same as for the plus/minus switching, the electrical switching is different however. The change-over selector connects or disconnects the coarse winding.

11

Motor-Drive Mechanism

Indicating device Outgoing drive shaft

Spring energy storage device

Driving disc

Mechanical limit stop

Disc brake

Flywheel Cam wheel Drive pin Spur gears Motor

V-belt

Limit switch

Maintaining contact

Fig. 12.

Operational Description Drive is via a V-belt from the motor transmitted through a system of spur gears to the drive pin of the cam wheel. The spring energy storage device is charged by this pin.

The driving disc operates the Geneva gear within the tap-changer. The flywheel is stopped by a disc brake, which also operates the starting contact.

During the rotation the cam wheel drive pin tensions the springs. When the drive pin reaches its lowest position on the cam wheel the springs are released, and with the assistance of the flywheel, the drive is transmitted to the outgoing drive shaft and the driving disc.

The outgoing drive shaft, via a chain, drives the Geneva gear of the indicating device. The indicating device consists of the mechanical position indicator, the mechanism for operating the electrical and mechanical limit stop, and the position transmitter. The maintaining contact is operated by the cam wheel. 12

Fig. 13. Circuit diagram The following is a detail list for the circuit diagram in Fig. 13 and the contact timing diagram in Fig. 14. 1 2 3 4 5 6 7 8

11 12 14 15 19 21 36 37 43 51

Control selector switch, local/remote Control switch, raise/lower Contactor, raise Contactor, lower Starting contact Maintaining, interlocking and auxiliary contact Motor Limit switch: 8.1 Lower tap position 8.2 Upper tap position Interlocking switch, open when hand crank is fitted Anti-condensation heater Position transmitter, potentiometer Continuation contact Protective motor switch Contactor, step-by-step operation Cabinet light Switch, door operated Time relay, running-through protection Emergency stop push button

Remote control Local control Protective earth Raise operation Lower operation Crank

13

Contact

Tap pos

Raise operation

Tap pos

Tap pos

Lower operation

Upper limit pos

T1 T2 T3 T4 T5

Tap pos

Lower limit pos

Starting range Spring charging starts Spring release Selector switch operates Stopping range

Fig. 14. Contact timing diagram Note: The numbered references under the following sections are to the circuit diagram in Fig. 13 and the contact timing diagram in Fig. 14.

Through Positions A so called ”Through position”, is a position the tapchanger has to pass without changing the ratio of the transformer. These positions are passed automatically. The continuation contact (15) bridges the maintaining contacts (6:3-4 and 6:1-2) via auxiliary contacts on raise contactor (3) at through positions. In this way the contactor (3) raise, or (4) lower, is kept energized and the motor will automatically make another operation.

Local Control Control selector switch (1) in position LOCAL. Raise impulse is given by control switch (2). Contactor (3) is thereby energized and will remain so by starting contact (5:1-2) and its own holding contact. The motor (7) starts running and soon the maintaining contact (6:3-4) closes and takes over control of the motor contactor (3). The brake is released and the starting contact (5:1-2) opens. The springs are set and will be released when fully charged, and operate the tap-changer. Maintaining contact (6:3-4) opens and the contactor disconnects the motor. The brake is applied, the starting contact (5:1-2) closes and the tap change operation is completed. The lowering operation is carried out in a similar manner.

Step-by-Step-Operation Step-by-step relay (21) connected so that only one tap change operation is obtained each time the raise/lower switch is operated.

Protection against Running-Through A relay (43) stopping the motor-drive mechanism in case of a a failure of the step-by-step control circuit which would cause a running-through of the motor-drive mechanism. The relay energizes the trip coil in the protective motor switch (19).

Remote Control Control selector switch (1) in position REMOTE. The signal for the operation is then received from the control circuits for raise and lower impulses connected to terminals as shown in Fig. 13. Local operation is not possible when switch (1) is in position REMOTE, and remote operation is not possible in position LOCAL.

Contact Timing The contact timing diagram, Fig. 14, shows the contact sequences for one change of tap position for raise and lower directions. 14

Characteristics and Technical Data On-Load Tap-Changer

Standards and Testing

Type Designation

The UZ types of on-load tap-changers fulfill the requirements according to IEC standard, publication 214.

UZ . . .

XXX/YYY

The type tests include: The routine tests include: Contact temp. rise test Check of assembly Switching tests Mechanical test Short-circuit current test Sequence test Transition impedance Auxiliary circuits test insulation test Mechanical tests Vaccum test Dielectric test Final inspection

Type E Insert upright F Insert inclined Type of switching L Linear R Plus/Minus D Coarse/Fine Type of connection N Three-phase star point T Three-phase fully insulated E Single-phase (option)

Rating Plate

Impulse withstand voltage 200 kV, 250 kV, 380 kV, 550 kV, 650 kV Maximum rated through-current 150 A, 300 A, 600 A Number of positions Linear switching: Plus/Minus switching: Coarse/Fine switching:

max 17 positions max 33 positions max 29 positions

Rated Phase Step Voltage The maximum allowable step voltage is limited by the electrical strength and the switching capacity of the selector switch. It is therefore a function of the rated through-current as shown in Figs. 16 and 17 below.

Fig. 15. Example of rating plate

fm_00214

Step voltage 2000 Step voltage 1500

1500

1000

1000

500

500

0

0 0

100

Tap-changer with:

200

300

0

400 500 600 A Rated through-current

100

Tap-changer with:

max 11 positions, linear max 23 positions, plus/minus max 23 positions, coarse/fine

Fig. 16.

Fig. 17. 15

200

300

400 500 600 A Rated through-current 13–17 positions, linear 25–33 positions, plus/minus 25–29 positions, coarse/fine

Mechanical Life

Contact Life

The mechanical life of the tap-changer is based on an endurance test. The test showed that the mechanical wear was negligible, and that the tap-changer was still mechanically sound after one million operations.

The predicted contact life of the fixed and moving contacts of the selector switch, is shown as a function of the rated through-current in Fig. 18. The values are calculated from the results of the service duty tests. For step voltages equal to or below 40 V at 50 Hz and equal to or below 50 V at 60 Hz the predicted contact life is always 500 000 operations.

Insulation Levels Dielectric tests are carried out according to IEC 214, Clause 8.6. The test object was immersed in clean transformer oil with a withstand value of at least 160 kV/cm.

Number of Operations

150 A

300 A600 A

50 Hz 60 Hz

500 000

In table 1, withstand levels are indicated as lightning impulse – power frequency withstand voltages.

400 000 300 000 200 000

Sound Level

100 000

During tap-changing the equivalent continuous sound pressure level is about 65 dB (A) measured one metre from the tap-changer.

0 0

100

200

300

400 500 600A Rated through-current

Fig. 18. Predicted contact life UZE/F On-load tap-changer type

200/... 250/... 380/... 550/... 650/... 1)

Insulation levels kV to earth between phases fully insulated 1) 200–70 250–95 380–150 550–230 650–275

250–95 250–95 440–165 600–230 650–275

Permissible service voltage between phases for fully insulated design UZE.T and UZF.T 1) kV 38 52 80 123 145

Class II according to IEC 214. Clause 8.6.2

Number of positions

Between electrically adjacent contacts, a1 (Fig. 19)

Between the first and the last contacts, a2 (Figs. 19–21)

Between any electrically nonadjacent contacts, a3 (Fig. 19)

Linear

7–11 13–17

110–30 110–30

220–60 220–60

220–60 200–60

Plus/minus

11–23 25–33

110–30 110–30

220–60 220–60

220–60 200–60

220–60 220–60

Coarse/fine

13–23 25–29

110–30 110–30

220–60 220–60

220–60 200–60

220–60 220–60

Type of switching

Across change-over selector, c1 (Figs. 20 and 21)

Table 1. Insulating levels

Fig. 19. Linear switching

Fig. 20. Plus/minus switching 16

Fig. 21. Coarse/fine switching

Short-circuit Current Strength

Maximum Rated Through-Current

The short-circuit current strength is verified with three applications of 2 seconds duration, without moving the contacts between the three applications. Each application has an initial value of 2.5 times the rms value.

The UZ models are designed for maximum rated through-currents of 150 A, 300 A or 600 A.

Max rated through current A rms

If the rated through-current of the tap-changer is not less than the highest value of tapping current of the tapped winding of the transformer, the tap-changer will not restrict the occasional overloading of the transformer, according to IEC 354 (1991), ANSI/IEEE C57.92 and CAN/CSA-C88-M90.

150 300 600 600 1) 1)

Occasional Overloading

Three applications of 2 seconds duration A rms 7000 7000 8000 12000

To meet these requirements, the UZ models have been designed so that the contact temperature rise over the surrounding oil, never exceeds 20 K at a current of 1.2 times the maximum rated through-current of the tapchanger.

Reinforced performance

Table 2

Highest Phase Service Voltage Across the Regulating Winding

The contact life stated on the rating plate, and given in this guide, is given considering that overload currents of maximum 1.5 times the rated through-current occur during a maximum of 3% of the tap-changer operations.

The table below, Table 3, shows the highest permissible phase service voltage for different types of switching and different number of positions. Highest service voltage kV

Type of switching

Number of positions Insulation across

Linear

–17

Regulating winding

22

Plus/minus

–29 31–33

Regulating winding Regulating winding

22 15

Coarse/fine

–29 –29 –29

Fine regulating winding Coarse regulating winding Fine and coarse regulating winding

17.5 17.5 35 1)

1)

Overloading in excess of the above results in increased contact wear and shorter contact life.

Oil Temperature The temperature of the oil in the on-load tap-changer shall be between -25 and +80 oC for normal operation, as illustrated below. o

C

+90

1)

1) No operations allowed

2)

+80

For 3-phase star point design BIL 200 22 kV BIL 250 30 kV

Table 3

3)

Rated Through-Current

3) Normal operating range

0

The rated through-current of the tap-changer is the current which the tap-changer is capable of transferring from one tapping to the other at the relevant rated step voltage, and which can be carried continuously whilst meeting the technical data in this document.

2) Emergency overloading. The on-load tap-changer will not restrict the occasional overloading of the transformer according to the standards in section Occasional Overloading above.

4) For operation within this range, the viscosity shall be between 2-800 m2/s (=cst)

-25 4)

-40 5)

5) Operation with de-energized transformer only

The rated through-current determines the dimensioning of the transition resistors and the contact life. The rated through-current is stated on the rating plate, Fig. 15.

Fig. 22. On-load tap-changer oil temperature

17

fm_00215

Motor-Drive Ambient Air Temperature The ambient air temperature requirements for the motordrive mechanism are shown in Fig. 23. The normal ope-rating range is between -40 and +60 oC.

o

C 1) The motor-drive mechanism must be shaded from sun radiation by screens. It must be specially equipped if the ambient temperature exceeds +70 oC.

1)

Tie-in Resistors +60

If the service voltage and the winding capacitances are such that the recovery voltage of the change-over selector exceeds 40 kV, it must be limited to this value or lower, by means of a tie-in resistor. The tie-in resistors can be placed in the tap-changer tank for UZE and UZF models BIL 200, 250 and 380 kV. For UZE and UZF models BIL 550 and 650 kV the tie-in resistors are placed in the transformer tank. There is usually a need for tie-in resistors for UZ models, BIL 550 and 650 kV, when delta-connected and placed in the line ends of the windings.

2) Normal operating range. (Normal heater shall operate.) The temperature inside the cabinet must not exceed +75 oC.

2)

3) Extra 250 W heater should be used.

0 4) Extra 250 W heater and anticondensation coverage should be used.

-40 -45 -50

3)

5) ABB Components should be consulted.

4) 5)

Design information on tie-in resistors is provided in a separate document, On-Load Tap-Changer Tie-in Resistors, 5492 0030E-28.

fm_00216

Fig. 23. Motor-drive mechanism ambient air temperature

Conductors from the Windings The temperature of the conductors connected to the terminals on the back of the on-load tap-changer must not exceed 30 K over the surrounding oil.

Cable Lugs The Cat. No. and required quantity should be ordered separately according to the tables below.

Hole diam. Ø mm

For cable area mm2

11 13 15 17 19 21

50 70 95 120 150 185

Cat. No. LL114 003-A -B -C -D -E -F

Required quantity of cable lugs per tap-changer Linear

Plus/minus

Coarse/fine

Number of positions

3-phase star point

3-phase fully insulated

3-phase star point

3-phase fully insulated

3-phase star point

3-phase fully insulated

7 9 11 13 15 17 19 21 23 25 27 29 31 33

22 28 34 40 46 52 – – – – – – – –

24 30 36 42 48 54 – – – – – – – –

– – 22 25 28 31 37 37 43 43 46 52 52 58

– – 24 27 30 33 39 39 45 45 48 54 54 60

– – – 28 31 34 37 40 43 46 49 52 – –

– – – 30 33 36 39 42 45 48 51 54 – –

18

Mass kg 0.10 0.11 0.13 0.14 0.15 0.16

Protection

Standard Version of MotorDrive Mechanism

Protective switch for the motor with thermal overload release and magnetic overcurrent release. Limit switches – in both control and motor circuits. Mechanical end stops. Interlocking contact in the control circuit to prevent electrical operation during manual operation. Interlocking contacts in raise and lower control circuits to prevent operation in wrong direction of rotation (with wrong phase sequence). Motor contactors are electrically interlocked. Protection against running-through in case of a failure of the step-by step control circuit. Emergency stop push button.

Control Control selector switch, local/remote Control switch, raise/lower Handcrank for manual operation

Wiring Connection The wiring is of grey polyvinylchloride-insulated, stranded wire. Type and data see table below. Every wire is marked with figures corresponding to terminal numbers. All external connections are made to disconnectible terminals of thermosetting resin. Type and data see table below. Short circuit protection (fuses) for motor, control and heater supplies, if required, should be installed in the control cabinet or other separate compartment.

Indication Mechanical position indicator Drag hands for max. and min. position indication Tap change in progress indicating red flag Operation counter Position transmitter (potentiometer) for remote position indication, 10 or 50 ohms per step.

Subject

Standard version

Alternative version

Special version at an additional price

Motor voltage

220-240/380-420 V, 3-phase, 50 Hz

208/360 V, 3-phase, 60 Hz 220-240/380-420 V, 3-phase, 60 Hz 440-480 V, 3-phase, 60 Hz

120 V, 240 V, 1-phase, 60 Hz 110 V, 220 V d.c. Optional

Current Rated output Speed

1.2/0.7 0.18 kW 1370 rev/min

Voltage for control circuit

220-230 V, 50 Hz 220-240 V, 60 Hz

110 V, 120 V, 240 V, 50 Hz 110 V, 120 V, 208 V, 60 Hz

110 V, 220 V, d.c. Optional

Voltage for heater

220-240 V

110-127 V, 260 V

Optional

Mechanical position indicator

lowest position marked 1

middle position marked N (Normal position)

Optional

Terminal blocks Number of terminals supplied

33-Phönix URTK/S Ben 61 A, 500 V, A.C.acc. to VDE Cross sectional area: 0.5-6 sqmm

Max. number that can be accomodated

130 - Phönix UK 4 120 - Weidmüller SAK 4 100 - Phönix URTK/S Ben 48 - General Electric EB-25 48 - Critchley S 300 (OBA)

Cabling

Type H07V2-K, 1.5 sq mm, 750 V 90 oC

Test voltage on control circuits

2 kV (50 Hz, 1 min)

Anti-condensation heater (Functions without extra heater down to -40 oC)

50 W

Operating time

approx. 3 seconds

Number of turns per operation of the handcrank

20

Degree of protection of cabinet

IEC 529, IP 54

Optional

Additional 250 W

19

Optional Accessories Anti-Condensation Coverage

Extra Heater

The motor-drive cabinet inside can be supplied with an anti-condensation coverage.

Extra heater, 250 W, with thermostat and switch for e.g. use in arctic climate.

Outlet

Hygrostat For tropical climate the heater can be controlled by a hygrostat.

Socket outlet according to DIN or ANSI. Prepared for socket outlet, i.e. holes are cut out in the panel and cables are wired to the panel for the outlet.

Tropical Version The motor-drive mechanism can be equipped to meet the requirements for humid tropical climate and desert conditions.

Extra Multi-Position Switches Type

Symbol

Number of contact rows

1 Extra position transmitter

1

2 Break before make

1

3 Make before break

1

4 Voltage transformer switch (Furnace)

1

5 Step switch for parallel control

2

6 Follower switch for parallel control

2

Note: Master switch for parallel control is a break before make multi-position switch. Maximum 10 extra contact rows can be accomodated. If more than 4 extra contact rows are ordered a special drive system for the switches is required (extra price). 20

Design, Installation and Maintenance On-Load Tap-Changer with Motor-Drive Mechanism Design differences between the UZE and UZF On-Load Tap-Changers

the UZF tank to allow easier access to the terminals. Access to the terminals is via a connection cover on the top of the tank. Both UZE and UZF are completely filled with oil and have no gas/air cushion.

The basic design difference between the UZE model and the UZF model is the inclining of the active part within

Fig. 24. UZFRT 650/600 seen from the connection side

L037022

Fig. 25. The UZF-design makes the connection of the transformer leads to the TapChanger easy

Intermediate flange

Connection cover

Connection cover

Transformer winding

Transformer leads Transformer tank

UZF

UZE

Fig. 26. 21

L034275

Schematic Diagrams connections with the maximum number of turns in the transformer winding connected in position 1. The tapchanger can be connected in such a way that position1 gives a minimum effective number of turns in the transformer winding with the tap-changer in position 1.

Table 4 shows all the basic connection diagrams for the UZE and UZF series of on-load tap-changers. The basic connection diagrams illustrate the different types of switching and the appropriate connections to the transformer windings. The diagrams illustrate the

Max Regulating Steps Max Voltage Positions

Linear

Plus/Minus

Coarse/Fine

16 17

32 33

28 29

6 Regulating Steps

Number of Loops Tap Positions (Electrical)

6 7

8 Regulating Steps

Number of Loops Tap Positions (Electrical)

8 9

10 Regulating Steps

Number of Loops Tap Positions (Electrical)

10 11

5 11

22

Linear

Plus/Minus

Coarse/Fine

12 13

6 13

6 13

14 15

7 15

7 15

16 17

8 17

8 17

10 19

9 19

12 Regulating Steps

Number of Loops Tap Positions (Electrical) 14 Regulating Steps

Number of Loops Tap Positions (Electrical) 16 Regulating Steps

Number of Loops Tap Positions (Electrical) 18 Regulating Steps

Number of Loops Tap Positions (Electrical)

23

Plus/Minus

Coarse/Fine

10 21

10 21

12 23

11 23

12 25

12 25

13 27

13 27

20 Regulating Steps

Number of Loops Tap Positions (Electrical) 22 Regulating Steps

Number of Loops Tap Positions (Electrical) 24 Regulating Steps

Number of Loops Tap Positions (Electrical) 26 Regulating Steps

Number of Loops Tap Positions (Electrical)

24

Plus/Minus

Coarse/Fine

15 29

14 29

28 Regulating Steps

Number of Loops Tap Positions (Electrical) 30 Regulating Steps

Number of Loops Tap Positions (Electrical)

15 31

32 Regulating Steps

Number of Loops Tap Positions (Electrical)

17 33

Table 4. Basic connection diagrams for the UZE and UZF series of on-load tap-changers

25

Drying Drying of the tap-changer is not normally necessary. If the tap-changer is to be subjected to a drying process, ABB Components should be consulted.

As an option, the tap-changer may also be delivered ready with a finishing coat outside. Special painting will be quoted for on request.

Painting

Weights

The tap-changer tank and the motor-drive mechanism cabinet can be supplied with various types of painting. The standard painting consists of a rust protective primer both inside and outside, and a finishing coat inside the tap-changer tank and the motor-drive mechanism cabinet.

Table 5 contains the weights of all the models in the UZ range of on-load tap-changers. The motor-drive mechanism and the oil volume is included in the overall weight.

On-load tap-changer

Approx. weight in kg

Type designation

Tap-changer without oil

} }

300, 300, 300, 300, 300,

Required oil

Total

UZELN, UZELT, UZEDN, UZEDT, UZERN, UZERT

200/150, 250/150, 380/150, 550/150, 650/150,

600 600 600 600 600

725 700 930 1100 1100

500 500 950 1250 1250

1225 1200 1880 2350 2350

UZFLN, UZFLT, UZFDN, UZFDT, UZFRN, UZFRT

200/150, 300, 600 250/150, 300, 600 380/150, 300, 600 550/150, 300, 600 650/150, 300, 600

750 720 900 1100 1100

400 400 750 1050 1050

1150 1120 1650 2150 2150

Example underlined in the table above: UZFRT 550/300

Table 5

Oil Filling Maintenance is easy to carry out since the design provides for quick and easy access and inspection. The front-cover is just removed after the oil has been drained, providing access to the entire selector switch mechanism.

For the correct oil filling procedure, consult the appropriate Installation and Commissioning Guide.

Installation For installation instructions, consult the appropriate Installation and Commissioning Guide.

An annual inspection should be carried out to read the counting device. These readings are used to determine when overhaul is due. Overhaul shall normally be carried out every seven years, and consists of checking the dielectric strength of the oil, filtering the oil, and checking contact wear according to the Maintenance Guide. The motor-drive mechanism should also be checked and lubricated, and the pressure relay checked.

Maintenance The UZ range of on-load tap-changers have been developed over many years to provide a maximum of reliability. The simple and rugged design gives a service life that equals the service life of the transformer. A minimum of maintenance is required for absolutely trouble-free operation. The only parts that require maintenance during the service life are the contacts that may need to be replaced, and the motor-drive mechanism.

The Maintenance Guide should be consulted if you need further information.

26

Pressure Relay General Description

30

54

67 Two single-pole switching contacts

ABB Components

One single-pole switching contact

Cable gland ~200

~35

NO NC C NO NC C 64 66 65 61 63 62

, ,

110

Connection for test equipment

~155

15

32

11

NO NC C 61 63 62

fm_00213

Fig. 27. General Description

The pressure relay has been pre-set by the manufacturer. The pressure relay is sealed to avoid unauthorized entrance. The electrical connection shall be made to the terminal block inside the pressure relay housing. These measures are done to ensure a safe function. The pressure relay is designed for one or two switching elements.

Protection for the on-load tap-changer is provided by a pressure relay which is mounted on the tap-changer tank. In the event of an over-pressure in the tank, the relay will trip the transformers main circuit breakers. After a pressure relay trip, the tap-changer must be opened and carefully investigated according to the Repair Guide. Faults, if any are located, should be repaired before the tap-changer is energized.

Operation

Design

When the pressure acting on the face of the piston exceeds the spring load of the piston, the piston will move and activate the switching element.

The pressure relay is mounted on a three-way valve. On the other two outlets of the valve there is a connection flange on one side, and a connection for test equipment on the other, see Fig. 27.

The operation time is less than 10 ms. The operation time is the time it takes from the pressure in the tapchanger tank exceeds the function pressure, until the pressure relay gives a stable signal for operation of the transformer main circuit breakers.

The pressure relay housing is made of copper-free aluminium alloy and is externally coated with an enamel. A stainless steel model can be provided on request.

Function Pressure Voltage

Breaking capacity Resistive Inductive load load

Withstand voltage between open contacts

110 V DC

0.8 A

0.2 A

L < 40 ms R

125 V DC

0.6 A

0.15 A

220 V DC

0.4 A

0.1 A

L < 40 ms R L < 40 ms 2 kV, 50 Hz, 1 min R

125 V AC

5A

5 A cos ϕ > 0.4

250 V AC

2.5 A

2.5 A cos ϕ > 0.4

The function pressure (trip pressure) is 50 kPa (7 Psi) if the oil level is less than 4 metres above the level of the pressure relay. Pressure relay with higher function pressure can be delivered on request. Testing At commissioning of the transformer and for testing the pressure relay, the instructions in the Installation and Commissioning Guide should be consulted.

Table 6.

27

Dimensions, On-Load Tap-Changer, type UZE All dimensions are in millimetres unless otherwise stated.

It should be noted that the dimensions may change with specific models.

P

B1

A1

H

H1

P1

B2

B

A

Max 135o

R

Opening 300 x 100

Fig. 28. Dimensions, on-load tap-changer, type UZE standard tank with standard accessories.

Type UZE

BIL kV

Dimensions (mm) A A1

Three-phase

200 250 380 550, 650

130 115 100 90

75 75 90 60

TC_00179

B

B1

B2

H

H1

P

P1

R

1200 1200 1560 1850

1500 1500 1885 2140

700 700 730 695

1000 1000 1100 1300

1060 1060 1255 1430

770 770 840 810

775 775 855 885

1140 1140 1530 1750

Table 6. Dimensions, on-load tap-changer, type UZE 28

Dimensions, On-Load Tap-Changer, type UZF All dimensions are in millimetres unless otherwise stated.

It should be noted that the dimensions may change with specific models.

B1

A1

P

H H1

H2

P2 B

P1

B2

A

Max 135o

R

Opening 300 x 100

Fig. 29. Dimensions, on-load tap-changer, type UZF standard tank with standard accessories.

Type UZF

BIL kV

Dimensions (mm) A A1

Three-phase

200 130 250 120 380 140 550, 650 95

75 75 70 40

TC_00180

B

B1

B2

H

H1

H2

P

P1

P2

R

1200 1200 1600 1900

1500 1500 1905 2160

700 700 710 665

1000 1000 1100 1300

1050 1050 1145 1295

160 160 155 105

825 825 850 855

835 835 860 925

60 60 120 140

1140 1140 1530 1750

Table 7. Dimensions, on-load tap-changer, type UZF 29

On-Load Tap-Changer, type UZE with Accessories (standard and options) Valve for oil filtration

Pressure relief valve

Oil level indicator (with or without alarm)

Flange for oil conservator, or breather

Cable box for alarmed oil level indicator Dehydrating or one way breather Thermoswitch housing

Pressure relay

Valve for oil filling, draining and filtration

TC_00181

Fig. 30. On-load tap-changer, type UZE with accessories.

On-Load Tap-Changer, type UZF with Accessories (standard and options) Pressure relief valve

Valve for oil filtration

Flange for oil conservator

Pressure relay

Thermoswitch housing Valve for oil filling, draining and filtration

TC_00181

Fig. 31. On-load tap-changer, type UZF with accessories. 30

Oil Conservator for UZF L

Oil level indicator (with or without alarm)

515

Cable box for alarmed oil level indicator

645

Oil conservator for UZF (only when ordered)

Dehydrating breather

Fig. 32. Dimensions, oil conservator for on-load tap-changer, type UZF

UZF Conservator

BIL kV

Dim L

200, 250 380 550, 650

625 1090 1500

Table 8. Dimensions, oil conservator for on-load tapchanger, type UZF

31

TC_00182

1ZVN460100-A

3

Bushing Ref to 1ZVN460100-C_Operation Manual

Transformer bushings, type GOB Technical guide

This Technical Guide has been produced to allow transformer manufacturers, and their designers and engineers, access to all the technical information required to assist them in their selection of the appropriate Transformer Bushing. The Guide should be used in conjunction with the Selection Guide to allow the optimum selection to be made. The technical information pertaining to bushings manufactured by ABB Components has been divided into separate documents, with one document for each type. The information provided in this document is intended to be general and does not cover all possible applications. Any specific application not covered should be referred directly to ABB Components AB, or its authorized representative. ABB Components AB makes no warranty or representation and assumes no liability for the accuracy of the information in this document or for the use of such information. All information in this document is subject to change without notice. ABB Components also manufactures the following products: Wall bushings GIS bushings On-load tap-changers Motor-drive mechanisms

2

Table of Contents Design _______________________

4 Shed form ___________________________ 4 Test tap _____________________________ 5

Testing _______________________

5 Test tap adapter ______________________ 5

Common specifications __________

5

Dimensions ___________________

6 Bushings without oil level gauge _________ 6

Electrical data _________________

7

Dimensions ___________________

8 Bushings with oil level gauge ____________ 8

Electrical data _________________

9

Connection details _____________

10 10 10 10 11 11

Inner terminal ________________________ Solid rod conductor ____________________ Outer terminal assembly _______________ Separate terminal plate with bolts ________ Arcing horns _________________________

Conductor loading ______________

11 Overloading of bushings ________________ 11 Short-time current _____________________ 11

Ordering particulars ____________

12 Bushings without oil level gauge _________ 12 Bushings with oil level gauge ____________ 14

Recommendations for positioning _

3

16

Design The bushing is built up around a centre tube on which the condenser body is wound. The upper insulator, lower insulator and mounting flange are held between the end plates by the centre tube. Sealing is accomplished by oil-resistant rubber gaskets in grooves.

Outer terminal stud Oil filling holes with sealing plug

The annular space between the condenser body and the porcelain is filled with transformer oil. A gas-filled expansion space is left at the top.

Expansion space Oil

For GOB bushings without oil level gauge the oil level can be checked by means of a dipstick in the oil filling hole.

Top washer Top housing

Porcelain insulator air side

The lower end is shielded by an epoxy resin insulated aluminium shield. Test tap

The inner terminal is attached to the centre tube by means of a through-going resilient pin which becomes locked when the outer terminal is screwed on. The design with this special resilient pin has been patented by ABB, and the pin ensures effective electrical contact between the inner and outer terminals.

Mounting flange

Flange extension

The inner terminal can be chosen for connection to leads either by brazing or crimping.

Porcelain insulator oil side Condenser body

The outer terminal is available in aluminium or copper alloy and can be supplemented by terminal plates of corresponding material.

Insulated shield

The upper insulator is made in one piece of high quality electrical porcelain. The mounting flange is manufactured of corrosion-resistant aluminium alloy. The mounting flange, the top housing and the top washer are protected by painting with a two-component primer and a grey-blue finishing coat of paint. The standard colour is Munsell 5.5B 55/1.25, environmental class C3.

Top housing Prism glass Oil filling holes with sealing plug

Fig. 1. Transformer bushing type GOB

According to IEC 815 the creepage factor C.F. is 1.1.

The bushings are delivered oil-filled and ready for use. If the bushing is mounted with an inclination of more than 45° from the vertical, special measures may have to be taken to ensure sufficient filling of oil in the bushing. Further information can be obtained on request.

For special customer demands regarding creepage distance, other shed forms may be used.

Shed form The shed form for all GOB bushings is of the anti-fog type with alternating long and short sheds. For each pair of sheds the ratio between nominal creepage distance and the axial length is 3.43 and the ratio between protected and nominal creepage distance is 0.40.

Fig. 2. Shed form 4

Test tap The outer conducting layer of the condenser body is connected to an insulated test tap on the flange. During operation the test tap cover must be screwed on, in order to earth the outer layer to the flange. The max. test voltage of the tap is 2 kV, 50 Hz for 1 minute. Max. service voltage is 600 V. goh_0010

Fig. 3. Test tap

Testing During the manufacture and on its completion the bushing is subjected to a number of routine tests. A tightness test is carried out on the assembled bushing after the final drying and impregnation. The test is made with an oil overpressure of 180 kPa (1.8 bar) for 12 hours at ambient temperature. No sign of leakage is allowed.

Type tests have been carried out according to IEC 137 and IEEE. Type test reports are available on request.

Test tap adapter For testing, a special test adapter is required for permanent connection of the test tap to the measuring circuits.

Each bushing is subjected to a final electrical routine test. The test is made at room temperature with the bushing submerged in oil. Capacitance and tan d are measured in steps up to the power frequency withstand voltage, which is maintained for one minute. Capacitance and tan d are also measured at decreasing voltage at the same voltage levels as before the one minute test. Measurements for detection of internal partial discharge (PD measurements) are also made. These measurements are carried out at the same time as the power frequency withstand test. PD measurements are made in steps up to the full test voltage and down. It is always demonstrated that the PD value is max. 5 pC at test voltage equal to the rated system voltage.

goh_0011

Fig. 4. Test tap adapter, 2769 531-D.

Common specifications Application: Classification: Ambient temperature: Altitude of site: Level of rain and humidity: Pollution level: Type of immersion medium: Oil level below bushing flange: Max. pressure of medium: Markings:

Transformers Oil impregnated paper, capacitance graded, outdoor-immersed bushing +40 to -40 °C, minimum value as per temperature class 2 of IEC 137 < 1 000 m 1-2 mm rain/min horizontally and vertically, as per IEC 60-1 According to specified creepage distance and IEC 815 1 Transformer oil. Maximum daily mean oil temperature 90 °C. Maximum temporary oil temperature 115 °C Maximum 30 mm 100 kPa overpressure Conforming to IEC/ IEEE

1) IEC 815 "Guide for selection of insulators with respect to polluted conditions."

5

Dimensions Bushings without oil level gauge Draw lead length =

Fig. 5.2. Top design

Fig. 5.3 Top design

Fig. 5.4

Fig. 5.1. GOB design 1)

The bushings can be provided with a longer shield L9 + 50 mm, in which case dimensions L, L1 and L5 also increase by 50 mm.

n1 Holes D = 16

Rated Type current GOB A

Cat. No.

Space for current transformer mm

Net mass kg

Top design Dimensions in mm acc. to Fig. 5. L1) L1 1) L2

L3

L4

L5 1)

L6

L7

L8

L9 1)

250

800

LF 123 013– 015– 083–

– 300 500

23 25 27

2 2 3

998 1258 1558

240 500 700

590 590 690

65

555 555 655

60

– 260 460

480

70

15

250

1250

LF 123 017– 019– 085–

– 300 500

26 29 31

2 2 3

1063 1323 1623

255 515 715

605 605 705

65

580 580 680

75

– 260 460

480

70

25

325

800

LF 123 025– 027– 089–

– 300 500

27 31 35

2 2 3

1198 1458 1758

295 555 755

735 735 835

93

700 700 800

60

– 260 460

625

70

15

380

800

LF 123 037– 039– 095–

– 300 500

33 37 39

2 2 3

1303 1543 1843

345 585 785

790 790 890

98

755 755 855

60

– 240 440

680

70

15

380

1250

LF 123 041– 043– 097–

– 300 500

37 39 43

2 2 3

1368 1608 1908

360 600 800

805 805 905

98

780 780 880

75

– 240 440

680

70

25

450

800

LF 123 049– 051– 053–

– 300 500

42 45 48

2 2 3

1473 1713 2013

345 585 785

960 960 1060

98

925 925 1025

60

– 240 440

850

70

15

550

800

LF 123 061– 063– 107–

100 300 500

70 73 77

2 3 3

1823 2108 2308

495 680 880

1160 1260 1260

60

1125 1225 1225

90

95 280 480

1050

60

25

550

1250

LF 123 065– 067– 109–

100 300 500

105 109 115

2 3 3

1868 2153 2353

495 680 880

1170 1270 1270

68

1145 1245 1245

100

95 280 480

1050

60

30

650

1250

LF 123 073– 075– 113–

150 300 500

116 122 126

2 3 3

2153 2413 2613

580 740 940

1370 1470 1470

60

1345 1445 1445

100

120 280 480

1250

60

30

750

1250

LF 123 077– 078– 079–

200 300 500

180 190 200

2 3 3

2468 2683 2883

685 800 1000

1580 1680 1680

70

1555 1655 1655

100

165 280 480

1460

60

30

6

Electrical data Rating

Routine test

Design data

Type GOB

Rated voltage UR kV, RMS

Phase-toearth voltage UY kV, RMS

Dry lightning impulse kV, peak

Wet power frequency AC kV, RMS

1 min. dry 50 Hz kV, RMS

Dry switching impulse kV, peak

250-800 250-1250 325-800 380-800 380-1250 450-800 550-800 550-1250 650-1250 750-1250

52 52 72.5 100 100 123 170 170 170 170

52 52 72.5 72.5 72.5 90 123 123 145 170

250 250 350 380 380 450 550 550 650 750

105 105 140 150 150 185 230 230 275 325

120 120 160 162 162 195 260 260 300 365

230 230 300 330 330 410 470 470 580 670

Nominal capacitances between conductor and test tap C1 ±10 % [pF] Space for current transformer -

100

150

200

300

500

205

205 270 200 200 265 200 170 195 235 235

275 375 260 245 320 245 210 240 280 275

125 165 135 145 185 145 150 175 190

Wet power frequency values apply to both IEC and ANSI requirements.

Dimensions are subject to modification without notice. Cantilever load

n1

R1

R2

T

total mm

protected mm

Max. permitted loading perpendicular 60 s to the terminal Test N N

46

6

8

6

16

1500±50

580

1800

2340

245

70

8

12

10

16

1500±50

580

3000

4000

225

230

46

6

8

6

16

1980±50

775

1500

1950

185

225

240

46

6

8

6

16

2210±70

870

1400

1800

112

250

290

245

70

8

12

10

16

2210±70

870

2900

3750

115

96

185

225

245

46

6

8

6

16

2720±80

1060

1150

1500

118

145

150

250

290

280

50

8

12

12

18

3430±100 1350

1300

1800

34

140

175

200

290

335

300

70

12

15

15

20

3430±100 1350

2400

3100

160

34

140

175

200

290

335

305

70

12

15

15

20

4080±110 1620

2600

3380

184

34

140

230

184

290

335

350

70

12

15

15

20

4800±150 1700

2600

3350

Creeepage distance D1

D2

D3

D4

86

22

86

115

101

34

112

95

22

95

D5

D6

D7

D8

D10

88

185

225

230

120

101

250

290

86

115

96

185

22

86

115

96

112

34

112

120

95

22

86

126

22

160

7

Dimensions Bushings with oil level gauge Draw lead length =

Fig. 6.2. Top design

Fig. 6.3 Top design

Fig. 6.1. GOB design.

Fig. 6.4

n1 Holes D = 16

Rated Type current GOB A

Cat. No.

Space for current transformer mm

Net mass kg

1)

The bushings can be provided with a longer shield L9 + 50 mm, in which case dimensions L, L1 and L5 also increase by 50 mm.

Top design Dimensions in mm acc. to Fig. 6. L 1) L1 1) L2

L3

L4

L5 1)

L6

L7

L8

L9 1)

250

800

LF 123 171– 173– 175–

– 300 500

24 26 28

2

1138 1398 1598

240 500 700

730

65

695

60

– 260 460

480

70

15

250

1250

LF 123 167– 168– 169–

– 300 500

28 30 33

2

1203 1463 1663

255 515 715

745

65

720

75

– 260 460

480

70

25

325

800

LF 123 177– 179– 181–

– 300 500

28 32 36

2

1338 1598 1798

295 555 755

875

93

840

60

– 260 460

625

70

15

380

800

LF 123 183– 185– 187–

– 300 500

34 38 40

2

1443 1683 1883

345 585 785

930

98

895

60

– 240 440

680

70

15

380

1250

LF 123 101– 102– 103–

– 300 500

38 41 44

2

1508 1748 1948

360 600 800

945

98

920

75

– 240 440

680

70

25

450

800

LF 123 145– 147– 149–

– 300 500

43 46 49

2

1613 1853 2053

345 585 785

1100

98

1065

60

– 240 440

850

70

15

550

800

LF 123 189– 190– 191–

100 300 500

71 74 78

2

1963 2148 2348

495 680 880

1300

60

1265

90

95 280 480

1050

60

25

550

1250

LF 123 142– 143– 144–

100 300 500

106 110 116

2

2008 2193 2393

495 680 880

1310

68

1285

100

95 280 480

1050

60

30

650

1250

LF 123 192– 193– 194–

150 300 500

118 124 128

2

2293 2453 2653

580 740 940

1510

60

1485

100

120 280 480

1250

60

30

750

1250

LF 123 104– 105– 106–

200 300 500

187 197 207

3

2718 2833 3033

685 800 1000

1830

70

1805

100

165 280 480

1460

60

30

8

Electrical data Rating

Routine test

Design data

Type GOB

Rated voltage UR kV, RMS

Phase-toearth voltage UY kV, RMS

Dry lightning impulse kV, peak

Wet power frequency AC kV, RMS

1 min. dry 50 Hz kV, RMS

Dry switching impulse kV, peak

250-800 250-1250 325-800 380-800 380-1250 450-800 550-800 550-1250 650-1250 750-1250

52 52 72.5 100 100 123 170 170 170 170

52 52 72.5 72.5 72.5 90 123 123 145 170

250 250 350 380 380 450 550 550 650 750

105 105 140 150 150 185 230 230 275 325

120 120 160 162 162 195 260 260 300 365

230 230 300 330 330 410 470 470 580 670

Nominal capacitances between conductor and test tap C1 ±10 % [pF] Space for current transformer -

100

150

200

300

500

205

205 270 200 200 265 200 170 195 235 235

275 375 260 245 320 245 210 240 280 275

125 165 135 145 185 145 150 170 205

Wet power frequency values apply to both IEC and ANSI requirements.

Dimensions are subject to modification without notice. Cantilever load

n1

R1

R2

T

total mm

protected mm

Max. permitted loading perpendicular 60 s to the terminal Test N N

46

6

8

6

16

1500±50

580

1800

2340

245

70

8

12

10

16

1500±50

580

3000

4000

225

230

46

6

8

6

16

1980±50

775

1500

1950

185

225

240

46

6

8

6

16

2210±70

870

1400

1800

112

250

290

245

70

8

12

10

16

2210±70

870

2900

3750

140

96

185

225

245

46

6

8

6

16

2720±80

1060

1150

1500

118

200

150

250

290

280

50

8

12

12

18

3430±100 1350

1300

1800

34

140

265

200

290

335

300

70

12

15

15

20

3430±100 1350

2400

3100

160

34

140

265

200

290

335

305

70

12

15

15

20

4080±110 1620

2600

3380

184

34

140

265

184

290

335

350

70

12

15

15

20

4800±150 1700

2600

3350

Creepage distance D1

D2

D3

D4

D5

D6

D7

D8

D10

86

22

86

140

88

185

225

230

101

34

112

140

101

250

290

95

22

86

140

96

185

95

22

86

140

96

112

34

112

140

95

22

86

126

22

160

9

Connection details Inner terminal Stud made of copper for connection of draw lead. The inner terminal must be provided with an outer terminal. For crimping, hexagonal or other symmetrical dies shall be used. Pressure 200 kN.

Material and Conductor design area mm² Cat. No.

Dimensions (mm) D1 D2 L

Mass kg

Copper for crimping or brazing

50 70 95

LF 170 010-M -N -L

11 13 15

14,5 35 17 35 20 35

0,3 0,3 0,3

Copper for brazing only

< 150 undrilled < 285 undrilled

LF 170 011-S -U -T -V

18 5 29 5

20 20 32 32

0,3 0,3 0,6 0,6

35 35 20 20

Fig. 7. Inner terminal.

Solid rod conductor The rod is produced from electrolytic copper and is divided into two parts. For the 800 A conductor the two parts are held together by a centre bolt with a resilient locking pin. For the 1250 A conductor the two parts are connected by counter-sunk screws. The lower part of the solid rod is designed to enable connection by brazing. The solid rod conductor can be divided either: Alt. 1: 20 mm below the bushing flange, or Alt. 2: 20 mm below the upper end of the bottom porcelain. The solid rod conductor must be provided with an outer terminal.

Rated current 800 A LF 170 019-

Rated current 1250 A LF 170 052-

Fig. 8. Solid rod conductor.

Outer terminal assembly Stud made of copper or aluminium with O-ring and locking pin. Other types can be provided on request.

Dimensions (mm) D L N

Mass kg

For bushings with D2 mm

Aluminium LF 170 001-A -B

30 30

170 205

55 66

0.5 0.8

22 34

Copper alloy

30 30

170 205

55 66

1.2 2.3

22 34

Material

Cat. No.

LF 170 002-A -B

Fig. 9. Outer terminal assembly.

10

Width across flats N

Separate terminal plate with bolts The separate terminal plate is used for connecting the bushing to the line conductor.

Material

Cat. No.

Aluminium

LF 170 014-A

Copper alloy

LF 170 021-A

Fig. 10. Separate terminal plate with bolts.

Arcing horns Arcing horns of galvanised steel can be mounted on the bushing. The lower rod is fastened onto the flange with one of the fixing screws and the upper rod by means of a bracket on the outer terminal. The gap distances for standard arcing horns are shown in the table. Other gap distances on request.

Bushing type

K mm

C mm

H mm

GOB GOB GOB GOB GOB GOB GOB

230–440 320–580 400–620 400–780 620–960 700–1080 820–1290

315 315 315 315 315 380 380

112 112 112 112 114 224 224

250 325 380 450 550 650 750

Fig. 11. Gap distances.

Conductor loading The rated currents listed in this catalogue are the standardised values according to IEC 137 (1995) which, with the largest possible conductor, fulfil the temperature rise test.

Overloading of bushings If the conductor for the bushing is selected with 120 % of the rated current of the transformer, the bushing is considered to be able to withstand the overload conditions stated in IEC 354 without further clarifications or tests, according to IEC 137.

The GOB bushings fulfil the temperature rise test requirements according to IEC 137 (1995) and IEEE C57.19.00-1991: Rated current of bushing A Conductor

Permissible current IEC IEEE A A

800 1250 800, 1250 800, 1250 800, 1250 800, 1250 1250 1250

800 1250 165 225 300 475 530 665

Solid rod LF 170 019 Solid rod LF 170 052 Stranded cable 50 mm2 Stranded cable 70 mm2 Stranded cable 95 mm2 Stranded cable 150 mm2 Stranded cable 185 mm2 Stranded cable 285 mm2

Short-time current The rated thermal short-time current (Ith) is calculated according to IEC 137 (1995).

730 1200 150 210 285 415 460 570

For draw-lead of stranded copper values are given for 100mm2. For other areas the short-time current is directly proportional to the area.

11

Conductor

Rated current A

Area mm2

Short-time current (Ith) 1s 2s kA, RMS kA, RMS

Dynamic current (Id) kA, peak

Solid rod

800

-

30

21

52

Solid rod

1250

-

70

50

125

Stranded draw-lead

365

100

9.6

6.8

17

Ordering particulars When ordering, please state: • Type and Catalogue number for bushings. • Catalogue number for inner and outer terminal assembly. • Additional accessories or modifications. • Test required, in addition to the normal routine tests. • Test tap adapter, if required.

Bushings without oil level gauge

Note: The Cat. No. should have one of the following letters added to it, to indicate the type of insulator and oil end shield: –K Normal oil end shield, brown porcelain –L Normal oil end shield, light grey porcelain –M Longer oil end shield, brown porcelain –N Longer oil end shield, light grey porcelain Oil end shield

Bushings

Connection details Inner terminal stud: Cat. No. LF 170 Space for current transformer mm

Bushing tube (See fig.) D2, mm

For crimping or brazing For brazing Conductor area Conductor area Undrilled with 2 2 2 50 mm 70 mm 95 mm