Application Manual Transformer

1ZVN460100 – A

Application manual

1ZVN460100 – A 2 / 3

Table of contents 1 Rating Plate .................................................................................................................. 2 Tapchanger .................................................................................................................. 3 Bushing ........................................................................................................................ 4 Cooling Equiptment..................................................................................................... 5 Current Transformer.................................................................................................... 6 Other Acessories ......................................................................................................... 7 Drawings ...................................................................................................................... 8 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 enRev. 4, 1997-03-30

ABB Components

On-Load Tap-ChangersType UZ

Technical Guide

L37034

Manufacturer’s declarationThe manufacturer ABB Components AB

SE-771 80 LUDVIKASweden

Hereby declares that

The products On-load tap-changerstypes UZE and UZF

with motor-drive mechanismtype BUF 3

comply with the following requirements:

By design, the machine, considered as component on a mineral oil filled power transformer, complieswith 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 themanufacturer of the transformer (e.g. in compliance with our Installation Instructions) and

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

• Low Voltage Directive 73/23/EEC (modified by Directive 93/68/EEC) concerning the built-inmotor 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 beenincorporated 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 designersand engineers, access to all the technical information required to assist them in their selection ofthe appropriate on-load tap-changer and motor-drive mechanism. The guide should be used inconjunction with the Selection Guide and the Design Guides, to allow the optimum selection to bemade.

The technical information pertaining to on-load tap-changers and motor-drive mechanismsmanufactured 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 allpossible applications. Any specific application not covered should be referred directly toABB Components AB, or its authorized representative.

ABB Components AB makes no warranty or representation and assumes no liability for theaccuracy of the information in this document or for the use of such information. All information inthis document is subject to change without notice.

ABB Components also manufactures the following products:

De-energized tap-changersTransformer bushingsWall bushingsGIS bushingsTransformer cooling equipment

Table of ContentsGeneral Information ___________ 4

Design Principles _____________ 6

On-Load Tap-Changer _____________________ 6Epoxy-Resin Moulding __________________ 6Selector Switch________________________ 6Transition Resistors ____________________ 7Change-over Selector __________________ 7Geneva Gear _________________________ 7Tap-Changer Tank _____________________ 8Oil Conservator _______________________ 8Accessories for the Tap-Changer __________ 9Special Applications ____________________ 9

Motor-Drive Mechanism ____________________ 9Accessories for the Motor-Drive Mechanism _ 9Motor-Drive Mechanism Cubicle __________ 9Degree of Protection ___________________ 9

Principles of Operation _________ 10

On-Load Tap-Changer _____________________ 10Switching Sequence ____________________ 10Selector Switch________________________ 10Change-over Selector forPlus/Minus Switching ___________________ 11Change-over Selector forCoarse/Fine Switching __________________ 11Through Positions _____________________ 11

Motor-Drive Mechanism ____________________ 12Operational Description _________________ 12Local Control _________________________ 14Remote Control _______________________ 14Through Positions _____________________ 14Step-by-Step-Operation _________________ 14Protection against Running-Through _______ 14Contact Timing ________________________ 14

Characteristics andTechnical Data________________ 15

On-Load Tap-Changer _____________________ 15Type Designation ______________________ 15Rated Phase Step Voltage _______________ 15Standards and Testing __________________ 15Rating Plate __________________________ 15Mechanical Life _______________________ 16Insulation Levels_______________________ 16Sound Level __________________________ 16Contact Life __________________________ 16

Short-circuit Current Strength _____________ 17Highest Phase Service Voltage Acrossthe Regulating Winding _________________ 17Rated Through-Current _________________ 17Maximum Rated Through-Current _________ 17Occasional Overloading _________________ 17Oil Temperature _______________________ 17Motor-Drive Ambient Air Temperature ______ 18Tie-in Resistors _______________________ 18Conductors from the Windings ____________ 18Cable Lugs ___________________________ 18

Standard Version of Motor-Drive Mechanism ___ 19Control ______________________________ 19Wiring Connection _____________________ 19Protection ____________________________ 19Indication ____________________________ 19

Optional Accessories ______________________ 20Anti-Condensation Coverage _____________ 20Outlet _______________________________ 20Extra Heater __________________________ 20Hygrostat ____________________________ 20Tropical Version _______________________ 20

Extra Multi-Position Switches _______________ 20

Design, Installationand Maintenance______________ 21

On-Load Tap-Changer with Motor-DriveMechanism _____________________________ 21

Design Differences between the UZE andUZF On-Load Tap-Changers _____________ 21Schematic Diagrams ___________________ 22Drying _______________________________ 26Painting _____________________________ 26Weights _____________________________ 26Oil Filling_____________________________ 26Installation ___________________________ 26Maintenance __________________________ 26Pressure Relay ________________________ 27

General Description _________________ 27Design ____________________________ 27Operation _________________________ 27Function Pressure ___________________ 27Testing ___________________________ 27

Dimensions, On-Load Tap-ChangerType UZE ____________________________ 28Dimensions, On-Load Tap-ChangerType UZF ____________________________ 29On-Load Tap-Changers Types UZE and UZFwith Accessories _______________________ 30Oil Conservator for UZF _________________ 31

General InformationThe UZ types of on-load tap-changers operatesaccording to the selector switch principle, that is, the tapselector and diverter switch functions are combined inone.

The UZ types of on-load tap-changers are mounted onthe outside of the transformer tank. All of the equipmentnecessary to operate the tap-changer is contained in asingle compartment, with the motor-drive mechanismattached to the outside.

Because the UZ types are designed for mounting on theoutside of the transformer tank installation proceduresare simplified and the overall size of the transformer tankcan be reduced.

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

As a design option, the UZ types can be supplied withoutthe tank. This gives the transformer manufacturer theflexibility to design the tap-changer tank as an integralpart of the transformer tank.

4

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

L37037 Fig. 1b. On-load tap-changer type UZFwith standard accessories.

L37023

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

L37036 Fig. 2b. On-load tap-changer type UZFwith extra accessories.

L37024

5

Pressure relay

Change-overselector

Fixed contact

Moving contactsystem

Transition resistor

Shielding-ring

Insulating shaftSelector switchunit

Test connection

Test valve

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

Connection tooil conservator

Cover for accessto conductors Lifting eye

Motor-drivemechanism

Attachment flangeto transformer tank

Terminal

Oil valve

On-load tap-changer tank

Geneva gear

Gasket

Connectionfor oil filterunit

Front cover

Design PrinciplesOn-Load Tap-ChangerThe tap-changer is built-up by using single-phase units,each identical, mounted in the openings on the rear ofthe compartment. Each single-phase unit consists of anepoxy-resin moulding, a selector switch, transitionresistors and, in most cases, a change-over selector.

Epoxy-Resin Moulding

The one-piece moulding provides a bushing between thetransformer and the tap-changer. The conductors aremoulded into position to connect the fixed contacts to theterminals for connection to the transformer windings.Also moulded into the unit are bearings for the selectorswitch and the change-over selector.

The terminals on the moulding are numbered accordingto the schematic diagrams, see the section ”Design,Installation, and Maintenance” contained in this Guide.

6

Fig. 5. Moving contact systemFig. 4. One phase of an on-load tap-changertype UZ

L036257

Selector Switch

The selector switch consists of fixed contacts and amoving contact system.

The fixed contacts are mounted onto a bracket which isscrewed onto the terminals previously moulded into theepoxy-resin moulding. Each fixed contact has twocontact paths, one for the main moving contact and onefor the moving switching contacts.

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 commondrive-shaft. In the service position the load current iscarried by the moving main contact, which consists oftwo contact fingers, pressed onto the fixed contact bysprings. The moving switching contacts and the transitioncontacts are made as rollers, see Fig. 5, which moveover the knife-like fixed contacts. The making andbreaking takes place between the fixed and movingswitching contacts.

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

Transition Resistors

The resistors are made from spirally wound wiremounted on insulating bobbins. They are connectedbetween the moving main contact and the transitioncontacts.

Change-over Selector

The change-over selector is used for reversing theregulating winding or for changing connection in thecoarse/fine regulation.

The selector consists of a moving contact and two fixedcontacts. The moving contact is fixed to a shaft and issupported by a bearing in the moulding. The current iscarried by the four contact fingers of the moving arm, andtransferred to the fixed contacts. The change-overselector does not make or break the current duringoperation.

Fig. 7.

7

Fig. 6. Selector switch

Geneva Gear

The Geneva gear principle is used to change a rotarymotion into a stepping motion. Drive is transmitteddirectly from the motor-drive mechanism to the Genevagear. The Geneva gear operates the selector switch andthe change-over selector. The Geneva gear is also usedto lock the moving contact system when it is in position.

8

Tap-Changer Tank

A standard tank is designed for each size of UZE andUZF. The standard tanks have a number of standardflanges intended for a great variety of accessories.Flanges that are not used are mounted with greybluecovers. Adapter flanges can be bolted on if the sizes ofthe standard flanges not are suitable.

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

The tap-changer tank can be bolted (standard) or weldedto the transformer tank.

A non-standard tank can also be ordered, but to a higherprice and a longer delivery time than the standard tank.

Oil Conservator

Normally the oil compartment of the tap-changer shall beconnected to a conservator, separated from the oil of thetransformer. If the transformer oil is to be supervised bygas-in-oil analyses, the conservator for the tap-changeroil should have no connection to the conservator of thetransformer on either the oil or the air side.

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

The oil pressure difference between the transformer andthe tap-changer should not exceed 10 kPa or 1.2 metresoil column. If the pressure difference is between 10 and70 kPa a reinforced barrier should be ordered. For theversion for sealed tank transformers the pressuredifference is allowed to be up to 70 kPa (10 Psi) and forthat version the reinforced barrier is delivered.

The set point for the pressure relay connected to the UZtank is 50 kPa (7 Psi). For further information, see page27 or pamphlet 1ZSE 5492-151.

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

The tap-changer tank is separated from the transformertank by a vacuum-proof barrier, designed to withstand amaximum test pressure of 100 kPa, at a maximum of60 oC. The barrier and the gasket are oil-tight, whichmeans that they are designed and routinely tested for apermissible air leak at each leak location of 0.0001 cm3/s,at a pressure difference of 100 kPa and a temperature of20 oC. This safely guarantees the contaminated tap-changer oil to remain separated from the transformer oil.It should be noted that the barrier has not been designedto allow for a simultaneous over-pressure on one side,and vacuum on the other. All models are supplied with anoil valve, for filling and draining.

TC_00267Fig. 8b. UZF standard tankTC_00267Fig. 8a. UZE standard tank

9

Special Applications

ABB Components should be consulted for all specialapplication tap-changers, such as sealed tank trans-formers or transformers for use with arc-furnaces andconverters.

Accessories for the Tap-Changer

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

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

Motor-Drive MechanismThe motor-drive mechanism provides the drive to allowthe tap-changer to operate. As the name implies, drive isprovided from a motor through a series of gears and onto a spring energy storage device, which when fullycharged, operates the tap-changer via a drive shaft.Several features are incorporated within the mechanismto promote long service intervals and reliability.

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

Accessories for the Motor-DriveMechanism

Accessories for the motor-drive mechanism aredescribed on page 20.

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

Motor-Drive Mechanism Cubicle

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

Degree of Protection

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

Fig. 9. Motor-drive mechanism

Principles of OperationOn-Load Tap-ChangerSwitching Sequence

The switching sequence is designated the symmetricalflag cycle. This means that the main switching contact ofthe selector switch breaks before the transition resistorsare connected across the regulating step. This ensuresmaximum reliability when the switch operates withoverloads.

At rated load the breaking takes place at the first currentzero after contact separation, which means an averagearcing time of approximately 6 milliseconds at 50 Hz.The total time for a complete sequence is approximately50 milliseconds. The tap change operation time of themotor-drive mechanism is approximately 3 seconds perstep.

Selector Switch

The switching sequence when switching from position 1to position 2 is shown in the diagrams of Figs. 10a-ebelow. The moving contact H is shown as one contactbut consists in fact of two, the main contact and the mainswitching contact. The main contact opens before andcloses after the main switching contact.

10

Fig. 10a.

Position 1. The main contact H is carrying the loadcurrent. The transition contacts M1 and M2 are open,resting in the spaces between the fixed contacts.

Fig. 10b.

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

Fig. 10c.

The transition contact M1 has made on the fixedcontact 2. The load current is divided between thetransition contacts M1 and M2. The circulating current islimited by the resistors.

Fig. 10d.

The transition contact M2 has broken at the fixedcontact 1. The transition resistor and the transitioncontact M1 carry the load current.

Fig. 10e.

Position 2. The main switching contact H has made onthe fixed contact 2. The transition contact M1 hasopened at the fixed contact 2. The main contact H iscarrying the load current.

For plus/minus and coarse/fine switching, the change-over selector is used.

Change-over Selector for Plus/MinusSwitching

The switching sequence, when the change-over selectorR changes over for plus/minus switching, is shown in thediagrams of Figs. 11a and 11b. The contact arm of theselector switch has reached the fixed contact 12 afterswitching from the fixed contact 11. The fixed contact 12is wide enough to cover the whole distance between twopositions of the selector switch. It is connected to the endof the main winding.

The contact arm of the selector switch has travelled on tothe contact 12, and the change-over selector R is in off-load condition. The load current goes directly from themain winding through the contact 12 and out through thecurrent collector at the centre of the contact arm. Theupper end of the regulating winding is still connected tothe main winding. This is the service position.

The contact arm of the selector switch has travelledfurther on the contact 12 without any breaking or makingof the current. At the same time the contact arm of thechange-over selector R, has travelled from contact B tocontact C, through which the lower end of the regulatingwinding has been connected to the main winding. This iscalled a through position, see Through Positions.

11

Fig. 11a. Service position

Fig. 11b. Through position

Through Positions

A so called ”Through Position” is a position the tap-changer has to pass without changing the ratio of thetransformer. Figs. 11a-b shows how the change-overselector is operated, while the selector moves over thedouble fixed contact. The extra position has the samenumber on the scale of the position indicator, togetherwith a letter, e.g. 12A. There might be need for morethrough positions over the operating range if the numberof taps of the winding is less than the number ofmechanical positions of the selector. The motor-drive willautomatically pass the through positions.

Change-over Selector for Coarse/FineSwitching

The mechanical switching is exactly the same as for theplus/minus switching, the electrical switching is differenthowever. The change-over selector connects ordisconnects the coarse winding.

Motor-Drive Mechanism

12

Fig. 12.

Operational Description

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

During the rotation the cam wheel drive pin tensions thesprings. When the drive pin reaches its lowest positionon the cam wheel the springs are released, and with theassistance of the flywheel, the drive is transmitted to theoutgoing drive shaft and the driving disc.

Motor

V-belt

Limit switch

Outgoing drive shaft

Driving disc

Mechanical limit stop

Cam wheel

Spur gears

Maintaining contact

Drive pin

Flywheel

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

The outgoing drive shaft, via a chain, drives the Genevagear of the indicating device. The indicating deviceconsists of the mechanical position indicator, themechanism for operating the electrical and mechanicallimit stop, and the position transmitter.

The maintaining contact is operated by the cam wheel.

Disc brake

Indicating device

Spring energy storage device

13

Fig. 13. Circuit diagram

The following is a detail list for the circuit diagram inFig. 13 and the contact timing diagram in Fig. 14.

1 Control selector switch, local/remote2 Control switch, raise/lower3 Contactor, raise4 Contactor, lower5 Starting contact6 Maintaining, interlocking and auxiliary contact7 Motor8 Limit switch:

8.1 Lower tap position8.2 Upper tap position

11 Interlocking switch, open when hand crank is fitted12 Anti-condensation heater14 Position transmitter, potentiometer15 Continuation contact19 Protective motor switch21 Contactor, step-by-step operation36 Cabinet light37 Switch, door operated43 Time relay, running-through protection51 Emergency stop push button

Lower operation

Raise operation

Protective earth

Local control

Crank

Remote control

14

Contact

Fig. 14. Contact timing diagram

Tap pos Tap pos Tap pos Tap pos

Lowerlimitpos

Upperlimitpos

Lower operationRaise operation

T1 Starting rangeT2 Spring charging startsT3 Spring releaseT4 Selector switch operatesT5 Stopping range

Note:The numbered references under the followingsections are to the circuit diagram in Fig. 13 and thecontact timing diagram in Fig. 14.

Local Control

Control selector switch (1) in position LOCAL. Raiseimpulse is given by control switch (2). Contactor (3) isthereby energized and will remain so by starting contact(5:1-2) and its own holding contact. The motor (7) startsrunning and soon the maintaining contact (6:3-4) closesand takes over control of the motor contactor (3). Thebrake is released and the starting contact (5:1-2) opens.The springs are set and will be released when fullycharged, and operate the tap-changer. Maintainingcontact (6:3-4) opens and the contactor disconnects themotor. The brake is applied, the starting contact (5:1-2)closes and the tap change operation is completed. Thelowering operation is carried out in a similar manner.

Remote Control

Control selector switch (1) in position REMOTE. Thesignal for the operation is then received from the controlcircuits for raise and lower impulses connected toterminals as shown in Fig. 13. Local operation is notpossible when switch (1) is in position REMOTE, andremote operation is not possible in position LOCAL.

Through Positions

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

Step-by-Step-Operation

Step-by-step relay (21) connected so that only one tapchange operation is obtained each time the raise/lowerswitch is operated.

Protection against Running-Through

A relay (43) stopping the motor-drive mechanism in caseof a a failure of the step-by-step control circuit whichwould cause a running-through of the motor-drivemechanism. The relay energizes the trip coil in theprotective motor switch (19).

Contact Timing

The contact timing diagram, Fig. 14, shows the contactsequences for one change of tap position for raise andlower directions.

Characteristics and Technical Data

Fig. 16.

15

Step voltage

0 100 200 300 400 500 600 ARated through-current

2000

1500

1000

500

0

Tap-changer with: max 11 positions, linearmax 23 positions, plus/minusmax 23 positions, coarse/fine

Fig. 17.

On-Load Tap-ChangerType Designation

U Z . . . XXX/YYYTypeE Insert uprightF Insert inclined

Type of switchingL LinearR Plus/MinusD Coarse/Fine

Type of connectionN Three-phase star pointT Three-phase fully insulatedE Single-phase (option)

Impulse withstand voltage200 kV, 250 kV, 380 kV, 550 kV, 650 kV

Maximum rated through-current150 A, 300 A, 600 A

Number of positionsLinear switching: max 17 positionsPlus/Minus switching: max 33 positionsCoarse/Fine switching: max 29 positions

Rated Phase Step Voltage

The maximum allowable step voltage is limited by theelectrical strength and the switching capacity of theselector switch. It is therefore a function of the ratedthrough-current as shown in Figs. 16 and 17 below.

Standards and Testing

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

The type tests include: The routine tests include:Contact temp. rise test Check of assemblySwitching tests Mechanical testShort-circuit current test Sequence testTransition impedance Auxiliary circuitstest insulation testMechanical tests Vaccum testDielectric test Final inspection

Rating Plate

Step voltage

1500

1000

500

00 100 200 300 400 500 600 A

Rated through-current

Tap-changer with: 13–17 positions, linear25–33 positions, plus/minus25–29 positions, coarse/fine

Fig. 15. Example of rating plate fm_00214

Mechanical Life

The mechanical life of the tap-changer is based on anendurance test. The test showed that the mechanicalwear was negligible, and that the tap-changer was stillmechanically sound after one million operations.

Insulation Levels

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

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

Sound Level

During tap-changing the equivalent continuous soundpressure level is about 65 dB (A) measured one metrefrom the tap-changer.

Contact Life

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

16

Fig. 21. Coarse/fine switchingFig. 20. Plus/minus switchingFig. 19. Linear switching

Fig. 18. Predicted contact life

0 100 200 300 400 500 600A

500 000

400 000

300 000

200 000

100 000

0

Rated through-current

Number ofOperations

UZE/F Insulation levels kV Permissible service voltage between phasesOn-load tap-changer type to earth between phases for fully insulated design UZE.T and UZF.T 1)

fully insulated 1) kV

200/... 200–70 250–95 38250/... 250–95 250–95 52380/... 380–150 440–165 80550/... 550–230 600–230 123650/... 650–275 650–275 145

1) Class II according to IEC 214. Clause 8.6.2

Between Between the first Between any Acrosselectrically and the last electrically non- change-over

Type of Number of adjacent contacts, contacts, a2 adjacent contacts, selector, c1switching positions a1 (Fig. 19) (Figs. 19–21) a3 (Fig. 19) (Figs. 20 and 21)

Linear 7–11 110–30 220–60 220–6013–17 110–30 220–60 200–60

Plus/minus 11–23 110–30 220–60 220–60 220–6025–33 110–30 220–60 200–60 220–60

Coarse/fine 13–23 110–30 220–60 220–60 220–6025–29 110–30 220–60 200–60 220–60

Table 1. Insulating levels

300 A-600 A150 A 50 Hz 60 Hz

17

Short-circuit Current Strength

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

Max rated Three applications ofthrough current 2 seconds durationA rms A rms

150 7000300 7000600 8000600 1) 12000

1) Reinforced performance

Table 2

Highest Phase Service Voltage Acrossthe Regulating Winding

The table below, Table 3, shows the highest permissiblephase service voltage for different types of switching anddifferent number of positions.

Highestservice

Type of Number of voltageswitching positions Insulation across kV

Linear –17 Regulating winding 22

Plus/minus –29 Regulating winding 2231–33 Regulating winding 15

Coarse/fine –29 Fine regulating winding 17.5–29 Coarse regulating winding 17.5–29 Fine and coarse regulating 35 1)

winding

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

Table 3

Rated Through-Current

The rated through-current of the tap-changer is thecurrent which the tap-changer is capable of transferringfrom one tapping to the other at the relevant rated stepvoltage, and which can be carried continuously whilstmeeting the technical data in this document.

The rated through-current determines the dimensioningof the transition resistors and the contact life.

The rated through-current is stated on the rating plate,Fig. 15.

Maximum Rated Through-Current

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

Occasional Overloading

If the rated through-current of the tap-changer is not lessthan the highest value of tapping current of the tappedwinding of the transformer, the tap-changer will notrestrict the occasional overloading of the transformer,according to IEC 354 (1991), ANSI/IEEE C57.92 andCAN/CSA-C88-M90.

To meet these requirements, the UZ models have beendesigned so that the contact temperature rise over thesurrounding oil, never exceeds 20 K at a current of 1.2times the maximum rated through-current of the tap-changer.

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

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

Oil Temperature

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

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

+80

oC

+901)

2)

3)

4)

5)

1) No operations allowed

2) Emergency overloading.The on-load tap-changer will notrestrict the occasional overloadingof the transformer according to thestandards in section OccasionalOverloading above.

3) Normal operating range

4) For operation within this range,the viscosity shall be between2-800 m2/s (=cst)

5) Operation with de-energizedtransformer only

fm_00215

0

-25

-40

Motor-Drive Ambient Air Temperature

The ambient air temperature requirements for the motor-drive mechanism are shown in Fig. 23. The normalope-rating range is between -40 and +60 oC.

Tie-in Resistors

If the service voltage and the winding capacitances aresuch that the recovery voltage of the change-overselector exceeds 40 kV, it must be limited to this value orlower, by means of a tie-in resistor. The tie-in resistorscan be placed in the tap-changer tank for UZE and UZFmodels BIL 200, 250 and 380 kV. For UZE and UZFmodels BIL 550 and 650 kV the tie-in resistors areplaced in the transformer tank. There is usually a needfor tie-in resistors for UZ models, BIL 550 and 650 kV,when delta-connected and placed in the line ends of thewindings.

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

Conductors from the Windings

The temperature of the conductors connected to theterminals on the back of the on-load tap-changer mustnot exceed 30 K over the surrounding oil.

Cable Lugs

The Cat. No. and requiredquantity should be orderedseparately according to thetables below.

Hole diam. For cable Cat. No. MassØ mm area mm2 kg

11 50 LL114 003-A 0.1013 70 -B 0.1115 95 -C 0.1317 120 -D 0.1419 150 -E 0.1521 185 -F 0.16

18

Fig. 23. Motor-drive mechanism ambient air temperature

Required quantity of cable lugs per tap-changer

Linear Plus/minus Coarse/fine

Number 3-phase 3-phase 3-phase 3-phase 3-phase 3-phaseof star fully star fully star fullypositions point insulated point insulated point insulated

7 22 24 – – – –9 28 30 – – – –

11 34 36 22 24 – –13 40 42 25 27 28 3015 46 48 28 30 31 3317 52 54 31 33 34 3619 – – 37 39 37 3921 – – 37 39 40 4223 – – 43 45 43 4525 – – 43 45 46 4827 – – 46 48 49 5129 – – 52 54 52 5431 – – 52 54 – –33 – – 58 60 – –

oC

-45-50

fm_00216

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

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

3) Extra 250 W heater should be used.

4) Extra 250 W heater and anti-condensation coverage should be used.

5) ABB Components should be consulted.

1)

2)

3)

4)

5)

-40

0

+60

Standard Version of Motor-Drive MechanismControlControl selector switch, local/remoteControl switch, raise/lowerHandcrank for manual operation

Wiring ConnectionThe wiring is of grey polyvinylchloride-insulated, strandedwire. Type and data see table below. Every wire ismarked with figures corresponding to terminal numbers.All external connections are made to disconnectibleterminals of thermosetting resin.Type and data see table below.Short circuit protection (fuses) for motor, control andheater supplies, if required, should be installed in thecontrol cabinet or other separate compartment.

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

IndicationMechanical position indicatorDrag hands for max. and min. position indicationTap change in progress indicating red flagOperation counterPosition transmitter (potentiometer) for remote positionindication, 10 or 50 ohms per step.

19

Special versionSubject Standard version Alternative version at an additional price

Motor voltage 220-240/380-420 V, 208/360 V, 3-phase, 60 Hz 120 V, 240 V, 1-phase, 60 Hz3-phase, 50 Hz 220-240/380-420 V, 3-phase, 60 Hz 110 V, 220 V d.c.

440-480 V, 3-phase, 60 Hz OptionalCurrent 1.2/0.7Rated output 0.18 kWSpeed 1370 rev/min

Voltage for control circuit 220-230 V, 50 Hz 110 V, 120 V, 240 V, 50 Hz 110 V, 220 V, d.c.220-240 V, 60 Hz 110 V, 120 V, 208 V, 60 Hz Optional

Voltage for heater 220-240 V 110-127 V, 260 V Optional

Mechanical position lowest position middle position Optionalindicator marked 1 marked N (Normal position)

Terminal blocksNumber of terminalssupplied 33-Phönix URTK/S Ben

61 A, 500 V, A.C.acc. to VDECross sectional area: 0.5-6 sqmm

Max. number that can 130 - Phönix UK 4be accomodated 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 Optional90 oC

Test voltage on control circuits 2 kV (50 Hz, 1 min)

Anti-condensation heater(Functions without extraheater down to -40 oC) 50 W Additional 250 W

Operating time approx. 3 seconds

Number of turns peroperation of the handcrank 20

Degree of protection of cabinet IEC 529, IP 54

20

Optional AccessoriesAnti-Condensation Coverage

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

Outlet

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

Extra Heater

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

HygrostatFor tropical climate the heater can be controlled by ahygrostat.

Tropical VersionThe motor-drive mechanism can be equipped to meetthe requirements for humid tropical climate and desertconditions.

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 beforemake multi-position switch.Maximum 10 extra contact rows can be accomodated.If more than 4 extra contact rows are ordered a specialdrive system for the switches is required (extra price).

Extra Multi-Position Switches

Design, Installation and Maintenance

Fig. 26.

21

UZE UZF

Transformer winding

Intermediate flange

Connection cover

Transformer leads

Connection cover

On-Load Tap-Changer withMotor-Drive MechanismDesign differences between the UZEand UZF On-Load Tap-Changers

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

Fig. 24. UZFRT 650/600 seen from theconnection side

Fig. 25. The UZF-design makes the connectionof the transformer leads to the Tap-Changer easy

L037022 L034275

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

Transformer tank

Schematic Diagrams

Table 4 shows all the basic connection diagrams for theUZE and UZF series of on-load tap-changers. The basicconnection diagrams illustrate the different types ofswitching and the appropriate connections to thetransformer windings. The diagrams illustrate the

Linear Plus/Minus Coarse/Fine

Max Regulating Steps 16 32 28Max Voltage Positions 17 33 29

6 Regulating Steps

Number of Loops 6Tap Positions (Electrical) 7

8 Regulating Steps


10 Regulating Steps

Number of Loops 10 5Tap Positions (Electrical) 11 11

22

connections with the maximum number of turns in thetransformer winding connected in position 1. The tap-changer can be connected in such a way that position1gives a minimum effective number of turns in the trans-former winding with the tap-changer in position 1.

23

Linear Plus/Minus Coarse/Fine

12 Regulating Steps

Number of Loops 12 6 6Tap Positions (Electrical) 13 13 13

14 Regulating Steps


16 Regulating Steps


18 Regulating Steps


Plus/Minus Coarse/Fine

20 Regulating Steps


22 Regulating Steps


24 Regulating Steps


26 Regulating Steps


24

Plus/Minus Coarse/Fine

28 Regulating Steps


30 Regulating Steps


32 Regulating Steps


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. Ifthe tap-changer is to be subjected to a drying process,ABB Components should be consulted.

Painting

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

26

On-load tap-changer Approx. weight in kg

Tap-changer Required TotalType designation without oil oil

UZELN, 200/150, 300, 600 725 500 1225UZELT, 250/150, 300, 600 700 500 1200UZEDN, 380/150, 300, 600 930 950 1880UZEDT, 550/150, 300, 600 1100 1250 2350UZERN, 650/150, 300, 600 1100 1250 2350UZERT

UZFLN, 200/150, 300, 600 750 400 1150UZFLT, 250/150, 300, 600 720 400 1120UZFDN, 380/150, 300, 600 900 750 1650UZFDT, 550/150, 300, 600 1100 1050 2150UZFRN, 650/150, 300, 600 1100 1050 2150UZFRT

Example underlined in the table above: UZFRT 550/300

Table 5

Oil Filling

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

Installation

For installation instructions, consult the appropriateInstallation and Commissioning Guide.

Maintenance

The UZ range of on-load tap-changers have beendeveloped over many years to provide a maximum ofreliability. The simple and rugged design gives a servicelife that equals the service life of the transformer. Aminimum of maintenance is required for absolutelytrouble-free operation. The only parts that require main-tenance during the service life are the contacts that mayneed to be replaced, and the motor-drive mechanism.

Maintenance is easy to carry out since the designprovides for quick and easy access and inspection. Thefront-cover is just removed after the oil has been drained,providing access to the entire selector switchmechanism.

An annual inspection should be carried out to read thecounting device. These readings are used to determinewhen overhaul is due. Overhaul shall normally be carriedout every seven years, and consists of checking thedielectric strength of the oil, filtering the oil, and checkingcontact wear according to the Maintenance Guide. Themotor-drive mechanism should also be checked andlubricated, and the pressure relay checked.

The Maintenance Guide should be consulted if you needfurther information.

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

Weights

Table 5 contains the weights of all the models in the UZrange of on-load tap-changers. The motor-drivemechanism and the oil volume is included in the overallweight.

}}

27

Pressure Relay

General Description

Fig. 27.

General Description

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

Design

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

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

��

ABB Components

30 54 67

Cable gland~200~35

110

~155

15

32

11

One single-poleswitching contact

Two single-poleswitching contacts

NO NC C NO NC C64 66 65 61 63 62

NO NC C61 63 62

Connection fortest equipment

The pressure relay has been pre-set by themanufacturer. The pressure relay is sealed to avoidunauthorized entrance. The electrical connection shall bemade to the terminal block inside the pressure relayhousing. These measures are done to ensure a safefunction. The pressure relay is designed for one or twoswitching elements.

Operation

When the pressure acting on the face of the pistonexceeds the spring load of the piston, the piston willmove and activate the switching element.

The operation time is less than 10 ms. The operationtime is the time it takes from the pressure in the tap-changer tank exceeds the function pressure, until thepressure relay gives a stable signal for operation of thetransformer main circuit breakers.

Function Pressure

The function pressure (trip pressure) is 50 kPa (7 Psi) ifthe oil level is less than 4 metres above the level of thepressure relay. Pressure relay with higher functionpressure can be delivered on request.

Testing

At commissioning of the transformer and for testing thepressure relay, the instructions in the Installation andCommissioning Guide should be consulted.

Breaking capacity Withstand voltageVoltage Resistive Inductive between open

load load contacts

110 V DC 0.8 A 0.2 A < 40 ms

125 V DC 0.6 A 0.15 A < 40 ms

220 V DC 0.4 A 0.1 A < 40 ms

125 V AC 5 A 5 A cos ϕ > 0.4

250 V AC 2.5 A 2.5 A cos ϕ > 0.4

Table 6.

2 kV, 50 Hz, 1 min

LR

LR

LR

fm_00213

Dimensions, On-Load Tap-Changer,type UZE

All dimensions are in millimetres unless otherwise stated. It should be noted that the dimensions may change withspecific models.

28

Fig. 28. Dimensions, on-load tap-changer, type UZE standard tank with standard accessories. TC_00179

Type BIL Dimensions (mm)

UZE kV A A1 B B1 B2 H H1 P P1 R

Three-phase 200 130 75 1200 1500 700 1000 1060 770 775 1140250 115 75 1200 1500 700 1000 1060 770 775 1140380 100 90 1560 1885 730 1100 1255 840 855 1530550, 650 90 60 1850 2140 695 1300 1430 810 885 1750

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

P1

PB1

A

B2

Max 135o

B

R

A1

Opening 300 x 100

H1H

Dimensions, On-Load Tap-Changer,type UZF

All dimensions are in millimetres unless otherwise stated. It should be noted that the dimensions may change withspecific models.

29

Fig. 29. Dimensions, on-load tap-changer, type UZF standard tank with standard accessories. TC_00180

B B2

Type BIL Dimensions (mm)UZF kV A A1 B B1 B2 H H1 H2 P P1 P2 R

Three-phase 200 130 75 1200 1500 700 1000 1050 160 825 835 60 1140250 120 75 1200 1500 700 1000 1050 160 825 835 60 1140380 140 70 1600 1905 710 1100 1145 155 850 860 120 1530550, 650 95 40 1900 2160 665 1300 1295 105 855 925 140 1750

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

B1A1 P

H

H1

P2

H2

P1

A

Max135o

Opening 300 x 100

R

30

On-Load Tap-Changer, type UZE with Accessories (standard and options)

Fig. 30. On-load tap-changer, type UZE with accessories. TC_00181

Fig. 31. On-load tap-changer, type UZF with accessories. TC_00181

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

Oil level indicator(with or without alarm)

Cable box for alarmedoil level indicator

Valve for oil filling,draining and filtration

Pressure relay

Pressure reliefvalve Valve for oil

filtration

Pressure relief valve Valve for oil filtration

Thermoswitch housing

Valve for oil filling,draining and filtration

Flange for oil conservator,or breather

Dehydrating orone way breather

Pressure relay

Flange for oilconservator

Thermoswitch housing

Oil Conservator for UZF

TC_00182Fig. 32. Dimensions, oil conservator for on-load tap-changer, type UZF

515L

31

UZF BIL DimConservator kV L

200, 250 625380 1090550, 650 1500

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

645

Dehydratingbreather

Cable box for alarmedoil level indicator

Oil conservator for UZF(only when ordered)

Oil level indicator(with or without alarm)

1ZVN460100-A

3 Bushing


Transformer bushings, type GOBTechnical guide

2

This Technical Guide has been produced to allow transformer manufacturers, and theirdesigners and engineers, access to all the technical information required to assist them intheir selection of the appropriate Transformer Bushing. The Guide should be used inconjunction with the Selection Guide to allow the optimum selection to be made.

The technical information pertaining to bushings manufactured by ABB Components hasbeen divided into separate documents, with one document for each type.

The information provided in this document is intended to be general and does not coverall possible applications. Any specific application not covered should be referred directlyto ABB Components AB, or its authorized representative.

ABB Components AB makes no warranty or representation and assumes no liability forthe accuracy of the information in this document or for the use of such information. Allinformation in this document is subject to change without notice.

ABB Components also manufactures the following products:

Wall bushingsGIS bushingsOn-load tap-changersMotor-drive mechanisms

3

Table of ContentsDesign _______________________ 4

Shed form ___________________________ 4Test tap _____________________________ 5

Testing _______________________ 5Test tap adapter ______________________ 5

Common specifications__________ 5

Dimensions ___________________ 6Bushings without oil level gauge _________ 6

Electrical data _________________ 7

Dimensions ___________________ 8Bushings with oil level gauge ____________ 8

Electrical data _________________ 9

Connection details _____________ 10Inner terminal ________________________ 10Solid rod conductor____________________ 10Outer terminal assembly _______________ 10Separate terminal plate with bolts ________ 11Arcing horns _________________________ 11

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

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

Recommendations for positioning _ 16

4

Fig. 1. Transformer bushing type GOB

Outer terminal stud

Expansion space

DesignThe bushing is built up around a centre tube on which thecondenser body is wound.

The upper insulator, lower insulator and mounting flangeare held between the end plates by the centre tube.Sealing is accomplished by oil-resistant rubber gaskets ingrooves.

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

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

The lower end is shielded by an epoxy resin insulatedaluminium shield.

The inner terminal is attached to the centre tube by meansof a through-going resilient pin which becomes lockedwhen the outer terminal is screwed on. The design with thisspecial resilient pin has been patented by ABB, and the pinensures effective electrical contact between the inner andouter terminals.

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

The outer terminal is available in aluminium or copper alloyand can be supplemented by terminal plates ofcorresponding material.

The upper insulator is made in one piece of high qualityelectrical porcelain. The mounting flange is manufacturedof corrosion-resistant aluminium alloy.

The mounting flange, the top housing and the top washerare protected by painting with a two-component primer anda grey-blue finishing coat of paint. The standard colour isMunsell 5.5B 55/1.25, environmental class C3.

The bushings are delivered oil-filled and ready for use.

If the bushing is mounted with an inclination of more than45° from the vertical, special measures may have to betaken to ensure sufficient filling of oil in the bushing.Further information can be obtained on request.

Shed form

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

Oil

Porcelain insulatorair side

Oil filling holeswith sealing plug

Test tap

Mounting flange

Flange extension

Porcelain insulatoroil side

Condenser body

Insulated shield

Prismglass

Tophousing

Oil fillingholes with

sealing plug

Tophousing

Fig. 2. Shed form

Topwasher

According to IEC 815 the creepage factor C.F. is <3.2 andthe profile factor P.F. is >1.1.

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

5

Test tap

The outer conducting layer of the condenser body isconnected to an insulated test tap on the flange. Duringoperation the test tap cover must be screwed on, in orderto earth the outer layer to the flange. The max. test voltageof the tap is 2 kV, 50 Hz for 1 minute. Max. service voltageis 600 V.

TestingDuring the manufacture and on its completion the bushingis subjected to a number of routine tests. A tightness testis carried out on the assembled bushing after the finaldrying and impregnation. The test is made with an oiloverpressure of 180 kPa (1.8 bar) for 12 hours at ambienttemperature. No sign of leakage is allowed.

Each bushing is subjected to a final electrical routine test.The test is made at room temperature with the bushingsubmerged in oil. Capacitance and tan � are measured insteps up to the power frequency withstand voltage, whichis maintained for one minute.

Capacitance and tan � are also measured at decreasingvoltage at the same voltage levels as before the oneminute test.

Measurements for detection of internal partial discharge(PD measurements) are also made. These measurementsare carried out at the same time as the power frequencywithstand test. PD measurements are made in steps up tothe full test voltage and down. It is always demonstratedthat the PD value is max. 5 pC at test voltage equal to therated system voltage.

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

Test tap adapter

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

Fig. 3. Test tap

Common specificationsApplication: TransformersClassification: Oil impregnated paper, capacitance graded, outdoor-immersed bushingAmbient temperature: +40 to -40 °C, minimum value as per temperature class 2 of IEC 137Altitude of site: < 1 000 mLevel of rain and humidity: 1-2 mm rain/min horizontally and vertically, as per IEC 60-1Pollution level: According to specified creepage distance and IEC 815 1

Type of immersion medium: Transformer oil. Maximum daily mean oil temperature 90 °C. Maximum temporary oil temperature 115 °COil level below bushing flange: Maximum 30 mmMax. pressure of medium: 100 kPa overpressureMarkings: Conforming to IEC/ IEEE

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

goh_0010

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

goh_0011

6

DimensionsBushings withoutoil level gauge

Spaceforcurrent Top

Rated trans- Net design Dimensions in mmType current former mass acc. toGOB A Cat. No. mm kg Fig. 5. L1) L1 1) L2 L3 L4 L5 1) L6 L7 L8 L9 1)

250 800 LF 123 013– – 23 2 998 240 590 65 555 60 – 480 70 15015– 300 25 2 1258 500 590 555 260083– 500 27 3 1558 700 690 655 460

250 1250 LF 123 017– – 26 2 1063 255 605 65 580 75 – 480 70 25019– 300 29 2 1323 515 605 580 260085– 500 31 3 1623 715 705 680 460

325 800 LF 123 025– – 27 2 1198 295 735 93 700 60 – 625 70 15027– 300 31 2 1458 555 735 700 260089– 500 35 3 1758 755 835 800 460

380 800 LF 123 037– – 33 2 1303 345 790 98 755 60 – 680 70 15039– 300 37 2 1543 585 790 755 240095– 500 39 3 1843 785 890 855 440

380 1250 LF 123 041– – 37 2 1368 360 805 98 780 75 – 680 70 25043– 300 39 2 1608 600 805 780 240097– 500 43 3 1908 800 905 880 440

450 800 LF 123 049– – 42 2 1473 345 960 98 925 60 – 850 70 15051– 300 45 2 1713 585 960 925 240053– 500 48 3 2013 785 1060 1025 440

550 800 LF 123 061– 100 70 2 1823 495 1160 60 1125 90 95 1050 60 25063– 300 73 3 2108 680 1260 1225 280107– 500 77 3 2308 880 1260 1225 480

550 1250 LF 123 065– 100 105 2 1868 495 1170 68 1145 100 95 1050 60 30067– 300 109 3 2153 680 1270 1245 280109– 500 115 3 2353 880 1270 1245 480

650 1250 LF 123 073– 150 116 2 2153 580 1370 60 1345 100 120 1250 60 30075– 300 122 3 2413 740 1470 1445 280113– 500 126 3 2613 940 1470 1445 480

750 1250 LF 123 077– 200 180 2 2468 685 1580 70 1555 100 165 1460 60 30078– 300 190 3 2683 800 1680 1655 280079– 500 200 3 2883 1000 1680 1655 480

Fig. 5.2.Top design

Fig. 5.3Top design

Fig. 5.4

n1 HolesD = 16

Drawleadlength =

1) The bushings can be providedwith a longer shield L9 + 50 mm,in which case dimensions L, L1and L5 also increase by 50 mm.

Fig. 5.1. GOB design

7

Electrical dataRating Routine test Design data Nominal capacitances between

conductor and test tapRated Phase-to- Dry Wet power Dry C1 ±10 % [pF]voltage earth voltage lightning frequency 1 min. dry switching Space for current transformer

Type UR UY impulse AC 50 Hz impulseGOB kV, RMS kV, RMS kV, peak kV, RMS kV, RMS kV, peak - 100 150 200 300 500

250-800 52 52 250 105 120 230 125 205 275250-1250 52 52 250 105 120 230 165 270 375325-800 72.5 72.5 350 140 160 300 135 200 260380-800 100 72.5 380 150 162 330 145 200 245380-1250 100 72.5 380 150 162 330 185 265 320450-800 123 90 450 185 195 410 145 200 245550-800 170 123 550 230 260 470 150 170 210550-1250 170 123 550 230 260 470 175 195 240650-1250 170 145 650 275 300 580 190 235 280750-1250 170 170 750 325 365 670 205 235 275

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

Dimensions are subject to modification without notice.

Cantilever load

Max. permittedCreeepage distance loading

perpendicular 60 stotal protected to the terminal Test

D1 D2 D3 D4 D5 D6 D7 D8 D10 n1 R1 R2 T mm mm N N

86 22 86 115 88 185 225 230 46 6 8 6 16 1500±50 580 1800 2340

101 34 112 120 101 250 290 245 70 8 12 10 16 1500±50 580 3000 4000

95 22 86 115 96 185 225 230 46 6 8 6 16 1980±50 775 1500 1950

95 22 86 115 96 185 225 240 46 6 8 6 16 2210±70 870 1400 1800

112 34 112 120 112 250 290 245 70 8 12 10 16 2210±70 870 2900 3750

95 22 86 115 96 185 225 245 46 6 8 6 16 2720±80 1060 1150 1500

126 22 118 145 150 250 290 280 50 8 12 12 18 3430±100 1350 1300 1800

160 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

8

DimensionsBushings withoil level gauge

Fig. 6.2.Top design

Fig. 6.3Top design

Spaceforcurrent Top

Rated trans- Net design Dimensions in mmType current former mass acc. toGOB A Cat. No. mm kg Fig. 6. L 1) L1 1) L2 L3 L4 L5 1) L6 L7 L8 L9 1)

250 800 LF 123 171– – 24 2 1138 240 730 65 695 60 – 480 70 15173– 300 26 1398 500 260175– 500 28 1598 700 460

250 1250 LF 123 167– – 28 2 1203 255 745 65 720 75 – 480 70 25168– 300 30 1463 515 260169– 500 33 1663 715 460

325 800 LF 123 177– – 28 2 1338 295 875 93 840 60 – 625 70 15179– 300 32 1598 555 260181– 500 36 1798 755 460

380 800 LF 123 183– – 34 2 1443 345 930 98 895 60 – 680 70 15185– 300 38 1683 585 240187– 500 40 1883 785 440

380 1250 LF 123 101– – 38 2 1508 360 945 98 920 75 – 680 70 25102– 300 41 1748 600 240103– 500 44 1948 800 440

450 800 LF 123 145– – 43 2 1613 345 1100 98 1065 60 – 850 70 15147– 300 46 1853 585 240149– 500 49 2053 785 440

550 800 LF 123 189– 100 71 2 1963 495 1300 60 1265 90 95 1050 60 25190– 300 74 2148 680 280191– 500 78 2348 880 480

550 1250 LF 123 142– 100 106 2 2008 495 1310 68 1285 100 95 1050 60 30143– 300 110 2193 680 280144– 500 116 2393 880 480

650 1250 LF 123 192– 150 118 2 2293 580 1510 60 1485 100 120 1250 60 30193– 300 124 2453 740 280194– 500 128 2653 940 480

750 1250 LF 123 104– 200 187 3 2718 685 1830 70 1805 100 165 1460 60 30105– 300 197 2833 800 280106– 500 207 3033 1000 480

Fig. 6.4

1) The bushings can be providedwith a longer shield L9 + 50 mm,in which case dimensions L, L1and L5 also increase by 50 mm.

n1 HolesD = 16

Drawleadlength =

Fig. 6.1. GOB design.

9

Cantilever load

Max. permittedCreepage distance loading

perpendicular 60 stotal protected to the terminal Test

D1 D2 D3 D4 D5 D6 D7 D8 D10 n1 R1 R2 T mm mm N N

86 22 86 140 88 185 225 230 46 6 8 6 16 1500±50 580 1800 2340

101 34 112 140 101 250 290 245 70 8 12 10 16 1500±50 580 3000 4000

95 22 86 140 96 185 225 230 46 6 8 6 16 1980±50 775 1500 1950

95 22 86 140 96 185 225 240 46 6 8 6 16 2210±70 870 1400 1800

112 34 112 140 112 250 290 245 70 8 12 10 16 2210±70 870 2900 3750

95 22 86 140 96 185 225 245 46 6 8 6 16 2720±80 1060 1150 1500

126 22 118 200 150 250 290 280 50 8 12 12 18 3430±100 1350 1300 1800

160 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

Dimensions are subject to modification without notice.

Electrical dataRating Routine test Design data Nominal capacitances between

conductor and test tapRated Phase-to- Dry Wet power Dry C1 ±10 % [pF]voltage earth voltage lightning frequency 1 min. dry switching Space for current transformer

Type UR UY impulse AC 50 Hz impulseGOB kV, RMS kV, RMS kV, peak kV, RMS kV, RMS kV, peak - 100 150 200 300 500

250-800 52 52 250 105 120 230 125 205 275250-1250 52 52 250 105 120 230 165 270 375325-800 72.5 72.5 350 140 160 300 135 200 260380-800 100 72.5 380 150 162 330 145 200 245380-1250 100 72.5 380 150 162 330 185 265 320450-800 123 90 450 185 195 410 145 200 245550-800 170 123 550 230 260 470 150 170 210550-1250 170 123 550 230 260 470 170 195 240650-1250 170 145 650 275 300 580 205 235 280750-1250 170 170 750 325 365 670 205 235 275

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

10

Connection detailsInner terminal

Stud made of copper forconnection of draw lead.The inner terminal must beprovided with an outerterminal.

For crimping, hexagonal orother symmetrical dies shallbe used. Pressure 200 kN.

Stud made of copper oraluminium with O-ring andlocking pin.

Other types can be providedon request.

Outer terminal assembly

Width across flats N

Fig. 7. Inner terminal.

Fig. 9. Outer terminal assembly.

Material and Conductor Dimensions (mm) Massdesign area mm² Cat. No. D1 D2 L kg

Copper 50 LF 170 010-M 11 14,5 35 0,3for crimping 70 -N 13 17 35 0,3or brazing 95 -L 15 20 35 0,3

Copper < 150 LF 170 011-S 18 20 35 0,3for brazing undrilled -U 5 20 35 0,3only < 285 -T 29 32 20 0,6

undrilled -V 5 32 20 0,6

Forbushings

Dimensions (mm) Mass with D2Material Cat. No. D L N kg mm

Aluminium LF 170 001-A 30 170 55 0.5 22-B 30 205 66 0.8 34

Copper LF 170 002-A 30 170 55 1.2 22alloy -B 30 205 66 2.3 34

Rated current 1250 ALF 170 052-

Rated current 800 ALF 170 019-

Fig. 8. Solid rod conductor.

Solid rod conductor

The rod is produced from electrolytic copper and is dividedinto two parts. For the 800 A conductor the two parts areheld together by a centre bolt with a resilient locking pin.For the 1250 A conductor the two parts are connected bycounter-sunk screws.

The lower part of the solid rod is designed to enableconnection by brazing.

The solid rod conductor can be divided either:Alt. 1: 20 mm below the bushing flange, orAlt. 2: 20 mm below the upper end of the bottom porcelain.

The solid rod conductor must be provided with an outerterminal.

11

Separate terminal plate with bolts

The separate terminal plate is used for connecting thebushing 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 thebushing.

The lower rod is fastened onto the flange with one of thefixing screws and the upper rod by means of a bracket onthe outer terminal.

The gap distances for standard arcing horns are shown inthe table. Other gap distances on request.

Overloading of bushings

If the conductor for the bushing is selected with 120 % ofthe rated current of the transformer, the bushing isconsidered to be able to withstand the overload conditionsstated in IEC 354 without further clarifications or tests,according to IEC 137.

Short-time current

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

For draw-lead of stranded copper values are given for100mm2. For other areas the short-time current is directlyproportional to the area.

Rated Short-time current (Ith) Dynamiccurrent Area 1s 2s current (Id)

Conductor A mm2 kA, RMS kA, RMS kA, peak

Solid rod 800 - 30 21 52

Solid rod 1250 - 70 50 125

Strandeddraw-lead 365 100 9.6 6.8 17

Conductor loadingThe rated currents listed in this catalogue are thestandardised values according to IEC 137 (1995) which,with the largest possible conductor, fulfil the temperaturerise test.

The GOB bushings fulfil the temperature rise testrequirements according to IEC 137 (1995) andIEEE C57.19.00-1991:

Rated current Permissible currentof bushing IEC IEEEA Conductor A A

800 Solid rod LF 170 019 800 7301250 Solid rod LF 170 052 1250 1200800, 1250 Stranded cable 50 mm2 165 150800, 1250 Stranded cable 70 mm2 225 210800, 1250 Stranded cable 95 mm2 300 285800, 1250 Stranded cable 150 mm2 475 4151250 Stranded cable 185 mm2 530 4601250 Stranded cable 285 mm2 665 570

Fig. 11. Gap distances.

Bushing K C Htype mm mm mm

GOB 250 230–440 315 112GOB 325 320–580 315 112GOB 380 400–620 315 112GOB 450 400–780 315 112GOB 550 620–960 315 114GOB 650 700–1080 380 224GOB 750 820–1290 380 224

12

Ordering particularsBushings without oil level gauge 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.

Note:The Cat. No. should have one of the following lettersadded to it, to indicate the type of insulator and oil endshield:

–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

Bushings Connection detailsInner terminal stud: Cat. No. LF 170

Space for BushingRated current tube For crimping or brazing For brazing

Type current transformer (See fig.) Conductor area Conductor area Undrilled withGOB A Cat. No. mm D2, mm 50 mm2 70 mm2 95 mm2 <150 mm2 <285 mm2 pilot hole

250 800 LF 123 013– – 22 010-M 010-N 010-L 011-S – 011-U015– 300083– 500

250 1250 LF 123 017– – 34 – – – – 011-T 011-V019– 300085– 500

325 800 LF 123 025– – 22 010-M 010-N 010-L 011-S – 011-U027– 300089– 500

380 800 LF 123 037– – 22 010-M 010-N 010-L 011-S – 011-U039– 300095– 500

380 1250 LF 123 041– – 34 – – – – 011-T 011-V043– 300097– 500

450 800 LF 123 049– – 22 010-M 010-N 010-L 011-S – 011-U051– 300053– 500

550 800 LF 123 061– 100 22 010-M 010-N 010-L 011-S – 011-U063– 300107– 500

550 1250 LF 123 065– 100 34 – – – – 011-T 011-V067– 300109– 500

650 1250 LF 123 073– 150 34 – – – – 011-T 011-V075– 300113– 500

750 1250 LF 123 077– 200 34 – – – – 011-T 011-V078– 300079– 500

Oil endshield

13

Outer terminal assembly: Cat. No. LF 170

Stud with O-ring Separate terminal Solid rod conductor Arcingand locking pin plate with bolts Cat. No. LF 170 horns

Cat. No.Aluminium Copper alloy Aluminium Copper alloy Alt. 1 Alt. 2 Mass kg LF 170

001-A 002-A 014-A 021-A 019 -A – 2.6 004 -A-D 019 -B 3.3 -A-E -C 4.2 -B

001-B 002-B 014-A 021-A 052 -A – 6.8 004 -A-D 052 -B 8.4 -A-E -C 10.6 -B

001-A 002-A 014-A 021-A 019 -F – 3.1 004 -A-K 019 -G 3.9 -A-L -H 4.7 -B

001-A 002-A 014-A 021-A 019 -M – 3.5 004 -A-R 019 -N 4.2 -A-S -P 5.0 -B

001-B 002-B 014-A 021-A 052 -V – 8.6 004 -B-Z 052 -X 10.4 -B-AA -Y 12.7 -B

001-A 002-A 014-A 021-A 019 -BL – 4.0 004 -B-BM 019 -BN 4.7 -B-BP -BR 5.5 -C

001-A 002-A 014-A 021-A 019 -T – 4.9 004 -B-X 019 -U 5.7 -C-Y -V 6.3 -C

001-B 002-B 014-A 021-A 052 -AM – 12.0 004 -B-AN 052 -AP 14.1 -C-AR -AS 15.5 -C

001-B 002-B 014-A 021-A 052 -F – 14.0 005 -A-K 052 -G 15.9 -B-L -H 17.5 -B

001-B 002-B 014-A 021-A 052 -M – 16.3 005 -B-R 052 -N 18.0 -E-S -P 19.5 -E

LF 170 052-1250 A

LF 170 019-800 A

14

Ordering particularsBushings with oil level gauge

Bushings Connection detailsInner terminal stud: Cat. No. LF 170

Space for BushingRated current tube For crimping or brazing For brazing

Type current transformer (See fig.) Conductor area Conductor area Undrilled withGOB A Cat. No. mm D2, mm 50 mm2 70 mm2 95 mm2 <150 mm2 <285 mm2 pilot hole

250 800 LF 123 171– – 22 010-M 010-N 010-L 011-S – 011-U173– 300175– 500

250 1250 LF 123 167– – 34 – – – – 011-T 011-V168– 300169– 500

325 800 LF 123 177– – 22 010-M 010-N 010-L 011-S – 011-U179– 300181– 500

380 800 LF 123 183– – 22 010-M 010-N 010-L 011-S – 011-U185– 300187– 500

380 1250 LF 123 101– – 34 – – – – 011-T 011-V102– 300103– 500

450 800 LF 123 145– – 22 010-M 010-N 010-L 011-S – 011-U147– 300149– 500

550 800 LF 123 189– 100 22 010-M 010-N 010-L 011-S – 011-U190– 300191– 500

550 1250 LF 123 142– 100 34 – – – – 011-T 011-V143– 300144– 500

650 1250 LF 123 192– 150 34 – – – – 011-T 011-V193– 300194– 500

750 1250 LF 123 104– 200 34 – – – – 011-T 011-V105– 300106– 500

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.

Note:The Cat. No. should have one of the following lettersadded to it, to indicate the type of insulator and oil endshield:

–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 endshield

15

Outer terminal assembly: Cat. No. LF 170

Stud with O-ring Separate terminal Solid rod conductor Arcingand locking pin plate with bolts Cat. No. LF 170 horns

Cat. No.Aluminium Copper alloy Aluminium Copper alloy Alt. 1 Alt. 2 Mass kg LF 170

001-A 002-A 014-A 021-A 019 -AM – 3.0 004-B-AS 019 -AT 3.7 -B-BB -BC 4.3 -B

001-B 002-B 014-A 021-A 052 -BC – 7.7 004-B-BF 052 -BD 9.3 -B-BG -BE 10.8 -B

001-A 002-A 014-A 021-A 019 -AN – 3.5 004-B-AU 019 -AV 4.3 -B-BD -BE 4.8 -B

001-A 002-A 014-A 021-A 019 -AP – 3.9 004-B-AX 019 -AY 4.6 -B-BF -BG 5.1 -B

001-B 002-B 014-A 021-A 052 -BK – 9.6 004-B-BN 052 -BL 11.4 -B-BP -BM 12.6 -B

001-A 002-A 014-A 021-A 019 -BS – 4.4 004-C-BT 019 -BU 5.1 -C-BV -BX 5.6 -C

001-A 002-A 014-A 021-A 019 -AR – 5.3 004-C-AZ 019 -BA 5.8 -C-BH -BK 6.4 -C

001-B 002-B 014-A 021-A 052 -AT – 13.0 004-C-AU 052 -AX 14.4 -C-AV -AY 15.8 -C

001-B 002-B 014-A 021-A 052 -AD – 14.9 005-B-AE 052 -AF 16.1 -B-AG -AH 17.7 -B

001-B 002-B 014-A 021-A 052 -AZ – 18.0 005-F-BA 052 -BB 19.0 -F-AK -AL 20.5 -F

LF 170 052-1250 A

LF 170 019-800 A

16

The maximum stresses in the oil at the surface of the shieldinsulation must be limited to those values normal forinsulated conductors and similar components in the sametransformer.

The adjacent recommendations are intended as guidelines when complete calculations are not carried out.

Recommendations for positioning

Earthedlayer

Distance touninsulated detail Distance to flat

surface e.g. tank orcore clamp

––––––––––––––––––––––––––––––––––––––––––––––Type Internal RGOB insulation level (mm)

of transformer(kV)

––––––––––––––––––––––––––––––––––––––––––––––250/800 170-70 65

250-95 75

250/1250 170-70 75250-95 85

325/800 250-95 75325-140 100

380/800 325-140 100380-150 105

380/1250 325-140 105380-150 110

450/800 380-150 105450-185 125

550/800 450-185 130550-230 155

550/1250 450-185 140550-230 160

650/1250 550-230 160650-275 185

750/1250 650-275 185750-325 210

––––––––––––––––––––––––––––––––––––––––––––––

Nameplate withmarking example.

No. 257 007Ur/Uy 52/52 kV Ir 800 A 50/60 HzLI / AC 250/120 kVM 23 kg L 240 mm 0-90 °

C1 128 pF Tan � 0.33 %C2 80 pF Tan � 0.45 %

ABB Components Ludvika, SwedenLF 123 013-KGOB 250

1ZVN460100-A

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ABB TRANSFORMERS LTD. Km 9, National High Way 1A, Thanh tri, Hanoi, Vietnam

Telephone : + 84 - 4 - 8611010

Fax : + 84 - 4 - 8611009

Page 1 of 5


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1ZVN460100-A

5 Current Transformer

1ZVN460100-A

6 Other Accessories 6.1 Pressure Relay

6.2 Pressure relief valve

6.3 Winding temperature indicator

6.4 Oil temperature indicator

6.5 Oil level indicator

6.6 Bucholz Relay

6.7 Dehydrating breather

6.8 Rapid Pressure Rise Relay

Pressure relay for on-load tap-changers

Technical information

Table 2. Function pressureTable 1. Technical data - Micro-switch

General descriptionProtection for the on-load tap-changer is provided by a pressurerelay which is mounted on the tap-changer oil compartment. Inthe event of an overpressure in the tap-changer oil compartment,the pressure relay will trip the transformer main circuit breakers.

DesignThe pressure relay is mounted on a three-way valve. On the othertwo outlets of the valve there is a connection flange on one side,and a connection for test equipment on the other, see fig.

The relay is made of copper-free aluminium alloy and is externallycoated with an enamel. A stainless steel model can be providedon request. Degree of protection IP66.

The function pressure (set point) has been set by the manufacturerin accordance to the requirements for each application.

The electrical connection shall be made to the terminal blockmounted onto the pressure relay.

The pressure relay is designed for one or two switching elements(micro-switches). The micro-switch is hermetically sealed andfilled with nitrogen with over-pressure, and separated from theconnection space with a sealed cap.

Piston

NO NC C NO NC C64 66 65 61 63 62

NO NC C61 63 62

Switching contact - micro switch

Connection fortest equipment

~200

One single-poleswitching contact

Two single-poleswitching contacts

~155

Adjusting nut

Spring

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OperationWhen the pressure acting on the face of the piston exceeds thespring load of the piston, the piston will move and activate theswitching element. See fig.

The function time is less than 15 ms in the temperature range of-40 °C to +80 °C, with a pressure increase of 20-40 MPa/sec. Thefunction time is the time from the pressure in the on-load tap-changer oil compartment exceeds the adjusted set point of thepressure relay until the pressure relay gives a stable signal foroperating the main circuit breakers.

Function pressureThe value of the adjusted function pressure (set point) dependson the distance (H) between the pressure relay and the oil levelin the oil conservator.

Further information in the Technical, Installation & Commissioning,Maintenance and Repair Guides for each type of on-load tap-changer.

Mounting detailsThe following parts are supplied together with the pressurerelay: studs M10x40 (4x), nuts M10 (4x), washers 10x22x2 (4x)and O-ring 44.2x55.6 (1x).

675430

~35

110

32

15Pr 22.5

11

Distance H Type of OLTC Function pressurein metres (set point)

H < 4 UZ 50 kPa (7 psi)

4 ≤ H < 7 UZ 100 kPa (14 psi)

H < 7 UB, UC 100 kPa (14 psi)

7 ≤ H < 10 UZ, UB, UC 150 kPa (21 psi)

10 ≤ H < 14 UB, UC 200 kPa (28 psi)

Breaking capacity Withstand voltageVoltage Resistive Inductive between open

load load contacts

110 V DC 0.8 A 0.2 A < 40 ms

125 V DC 0.6 A 0.15 A < 40 ms

220 V DC 0.4 A 0.1 A < 40 ms

125 V AC 5 A 5 A cos ϕ ≈ 0.4

250 V AC 2.5 A 2.5 A cos ϕ ≈ 0.4

2 kV, 50 Hz, 1 min

LR

LR

LR

1ZS

E 5

492-

151

en,

Rev

. 3, 2

000-

11-1

5

Printed in Sweden by Globe, Ludvika, 2000

ABB Components ABSE-771 80 Ludvika, SWEDENTel.+46 240 78 20 00, Fax +46 240 121 57E-mail: [email protected]/transmission

Manufacturer:BETA B.V., Rijswijk, The Netherlands

ABB LTD. Km 9, National High Way 1A, Hoang Mai, Hanoi, Vietnam

Telephone : + 84 - 4 - 8611010

Fax : + 84 - 4 - 8611009

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PRESSURE RELIEF DEVICE

Dimension Drawings


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OIL AND WINDING TEMPERATURE INDICATOR SERIES 34 & 35

1. METHOD FOR MEASURING


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2. MATCHING RESISTANCE


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3. INSTRUCTION


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4. ELECTRICAL CIRCUIT 4.1. ELECTRICAL CIRCUIT FOR OIL TEMPERATURE INDICATOR


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4.2. ELECTRICAL CIRCUIT FOR WINDING TEMPERATURE INDICATOR


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4.3 ELECTRICAL CIRCUIT – LAST VERSION OVERVIEW


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5. MEASURING RANGES AND BULB TYPES


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6. DIMENSION DRAWINGS AND CONTACT RATING 6.1. DIMENSION DRAWINGS


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6.2. TECHNICAL DATA FOR SWITCHES


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OIL LEVEL INDICATOR

Dimension Drawings


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BUCHHOLZ GAS-ACTUATED RELAY

DIMENSION DRAWINGS


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DEHYDRATING AIR BREATHER

Dimension Drawings


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FIG. 1


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FIG. 2

1ZVN460100-A

7 Drawings 7.1 Mechanical Drawings

7.2 Control Drawings

1ZVN460100-A

8 Final Test Report

1ZVN460100-A

9 Assemblies and Oil Filling at Site See in 1ZVN460100-B_Installation Manual

10 Site test and Commissioning


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1ZVN 460100-B, Based on BA TPT Standard 1ZBA 4601-216 Page 1 of 19

Acceptance test and Energization

1. TESTING AFTER ASSEMBLY OF A TRANSFORMER ON SITE After a transformer has been assembled on site, it has to be tested as below in order to check that it has not been damaged in a way that may risk its future operation. All tests should be carried out with instruments with proven valid calibration. The results of the tests are to be recorded on a Test Record. Product Information 1ZBA 4601-217 The first sheet of this Test Record is a list of all possible tests in question. When the person in charge of the order or the assembly supervision has marked all applicable tests with a cross, this sheet forms an order-bound directive for the tests to be carried out. After the assembly is completed, a Notice of Delivery is issued (see Encl. 1). The Notice of Delivery should be signed both by the assembly supervisor in charge and by the customer's representative. The Test Record and the Notice of Delivery are to be sent to the local ABB representative for further distribution and filling. When the documentation is complete and the transformer/reactor has been completed as far as ABB is concerned, the ABB Installation and/or Service department issues a Service Certificate (see Enclosure 2).

1.1 Ratio test 1.1.1 General A ratio test is carried out in order to check that the tap-changer has been correctly connected, that the transformer is set for the correct ratio and finally to check that no damage has occurred during shipping and assembly. 1.1.2 Equipment A ratio measuring bridge with measuring cables As an alternative the following equipment can be used: Voltmeter and ammeter Measuring cables Auxiliary power of approx. 380 V Pocket calculator 1.1.3 Procedure Testing is carried out in such a way that the test voltage is connected to the winding that has the highest voltage. The voltage on the other windings are to be measured at all tap positions, and the results should be recorded in the field test report, 1ZBA 4601-217. The results should be within ±0.5% of the calculated values. While taking measurements when the tap-changer is at rated and both end positions, the current in the incoming conductor to each phase is checked. Make sure that the voltage variation at every setting of the tap-changer’s position is the same in every phase and that each step will be of correct size. A deviation of ±10% of calculated the value is considered acceptable due to the relatively low measurement accuracy providing that the 3 phases are equal. Measuring current in the feeding phase conductor is performed in order to detect any possible short-circuit turns in the windings. A maximum current value is not available, but as a guideline the current must not exceed 50 mA (the common value is 1-20 mA). Notice that the side phases magnetic circuit are different from the middle phase. This often causes the current in the side phases to be 40-50% greater than in the middle phase.

1.2 Winding resistance test (this test is optional) Measure the resistance of each winding at the rated and extreme tap positions and compare the results to the original value in the test report. Do not attempt to measure resistances using a contact resistance micro-ohmmeter. A safety hazard for operating personnel occurs when the inductive charge created by the windings arcs across to the leads as they are withdrawn away from the windings.


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The resistance is dependent on the temperature of the winding, so its temperature must be known. The mean temperature of the oil is representative of the winding temperature, and can be determined by taking the average temperature of samples taken at the top and at the bottom of the tank. The formula giving the relation between the resistance and the temperature is:

R R K TK TT T2 1

21

= ×++

⎛⎝⎜

⎞⎠⎟

where RT2 = Resistance of the winding at temperature T2 RT1 = Resistance of the winding at temperature T1 K = 234.5 for winding made of copper 225.5 for winding made of aluminum

1.3 Check of vector group 1.3.1 General The purpose of this series of tests are to check the polarity and the phase relationship of the multiple windings of in a transformer. The test is carried out simultaneously with the transformer turns ratio test when using a turns ratio test set. So in order to define the connection of a three-phase transformer and to facilitate the parallel connection with other transformers, the international standards prescribe specific vector groups. Every country has its own designation for the vector groups. IEC and IEEE (in USA) have recommended a method which will result to standardized and fully defined designations. 1.3.2 Equipment without turns ratio test set The test is carried out simultaneously with the transformer turns ratio test when using a turns ratio test set. When such a test set is not available a three-phase alternating current of suitable voltage and 2 voltmeters can be used. 1.3.3 Procedure for vector group as per IEC Connect the bushings according to this instruction on fig. 1, and the 3-phase auxiliary power (220 or 380 V) to the HV-side of the phase bushings. Measure the voltages that are stated on fig. 1. Compare the measured voltages and find the relation that agrees with a value in the right column on fig. 1. In this way we can determine which group (0-5-6-10-11) the transformer is connected to. Compare the results with the stated vector group as shown on the nameplate. If it states, e.g. vector group Dy11, and you find the vector according to group 11, i.e. voltages Bc = Bb Bc < Ab Cc < Cb then the transformer is correctly connected.


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1.3.4 Procedure for vector group as per IEEE Connect the bushings according to this instruction on fig.2 and the 3-phase auxiliary power (208 or 460 V) to the HV-side of the phase bushings. Measure the voltages that are stated on fig2. Compare the measured voltages and find the relation that agrees with a value in the right column on fig 2 In this way we can determine which group the transformer is connected to. Compare the results with the stated vector group as shown on the nameplate. If it shows e.g., vector group Y-Delta - angular displacement 30 degrees, and you find the vector according to same group description, i.e. voltages H3-X2 = H3-X3 H3-X2 < H1-H3 H2-X2 < H2-X3 H2-X2 < H1-H3 then the transformer is correctly connected.

1.4 Insulation test To determine the state of active part of an installation, the resistance between the windings and between the windings and earth, must be measured. For this purpose a megger is used. It is essential that it is of a type which is approved for measurement on transformers and transformer core insulation. The positive pole of the DC-voltage must be connected to earth and the negative pole to the winding when testing between winding and earth. Testing time is 1 minute. 1.4.1 Transformer main windings When conducting an insulation test on transformer windings, a 2.5 or a 5 kV megger is used. Test every winding to the earth and between every winding. Make sure the bushing porcelains are cleaned since dirt deteriorates the insulation resistance. The transformer tank must be earthed during the test. If the insulation resistance is > 1 Mohm/kV system voltage for the winding, it is acceptable. When observing lower values, this should be reported to your ABB representative. 1.4.2 Current transformers When insulation-testing a current transformer, a 500 or 1000 megger is used. Test every connection to the earth. The acceptable value is 10 Mohm. 1.4.3 Control- circuit cabling and auxiliary power cabling When insulation-testing control circuit cables and supply cables, a 500 or 1000 V megger is used. The acceptable value is10 Mohm.Test every connection to the earth. 1.4.4 Core to tank/core clamp When insulation-testing a transformer core a 1000 V megger is used. The testing time is 1 minute. Warning! Testing must not be carried out with alternating current because the insulation between the

individual core plates can be damaged. The transformer tank must be earthed during the test. The cover of the terminal box (on one side at the bottom) for the earthing device is removed. The terminal box contains a terminal block with three terminals: - the terminal marked CL is connected to the core laminations. - the terminal marked CC is connected to the core clamps.


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- the terminal marked G is connected to ground (the tank). Disconnect the closing link that connects the two terminals CL-G and apply 1000 DC voltage between CL and G. The insulation value must be at least 100 Mohm. There is no general requirement on the insulation level CC-G.

1.5. Check of bushings By means of a buzzer check the potential connection between the tank and turret(s), and between bushing flanges and tank.

1.6 Polarity check of current transformers 1.6.1 General In order to make sure that the current transformer is in its correct position in relation to the bushing (conductor), a polarity check must be carried out. By checking the polarity in this rnanner we are also certain that the current transformer generates a secondary current. The ratio test and the magnetizing curve is not performed on site in conjunction with the transformer assembly. 1.6.2 Equipment 1 mA-meter and 1 flashlight battery, e.g. 4.5 volts. Connect the milliammeter as shown in figure 1. Connect the battery's negative terminal to the (earthed) neutral point. Keep an eye on the milliammeter and send an impulse to the top of the bushing by briefly touching it. At the moment of making contact the milliammeter will show a positive reading and at the moment of breaking contact a negative reading. The milliammeter should be connected to the current transformer terminals in the control cabinet in order to check also to continuity of the leads. On most transformers it may be necessary to short-circuit the other side of the transformer in order to obtain a large enough current impulse through the current transformer. If the current transformer is not fitted to the transformer then a flexible cord can be used as the primary conductor. Pass the cord through the current transformer and connect the battery. Then touch it and read the meter.

1.7 Check of thermometers and thermostats Oil and temperature gauges must be tested with their associate control, alarm and trip circuitry. Register the test records and compare them with the set points on the circuit diagram. Open the both of the connections of the current transformer feeding the heating resistor of the winding temperature indicator, and measure the total heating resistance. Record the value in the test record and compare the result with the resistance in the test report of the transformer. 1.7.1 Equipment Resistance bridge or ohmmeter which can read resistances below 1 ohm.

1.8 Oil tests 1.8.1 Check of the oil level Check the oil level in:

- the transformer - the tap-changer/diverter switch - the other separate compartments

Check that all devices containing oil have been de-aired


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1.8.2 Check of dielectric strength values

1.8.2.1 General The transformer's performance and longevity greatly depends on the quality of the oil that is used. Therefore the oil's dielectric strength is checked before the transformer is handed over. A sample is taken from the conservator and the transformer/reactor's bottom valve and in some cases even from separate cooling batteries, etc. Since the value of the dielectric strength greatly depends on which type of electrodes that are used, it is essential to record the information in the test report. The acceptable dielectric strength value is: Standard Electrode Electrodes Strength spacing type value IEC 156 2.5 mm hemispherical ≥60 kV1) ASTM D1816 0.08 in. hemispherical ≥56 kV ASTM D 877 0.1 in. cylindrical ≥30 kV2) 1) : For oil of type 1 and 2 2) : This method is accepted only for transformers with nominal voltage below 230 kV

1.8.2.2 Equipment Oil test set, hose connections and a bucket. Occasionally a number of test vessels for gas analysis samples will be required.

1.8.2.3 Procedure Make sure that the sample receptacle is clean. Rinse it thoroughly with oil and be careful not to touch the inside of the receptacle with your bare hand. Fill the receptacle and let the oil stand for approximately 30 minutes. In accordance with IEC standards, 6 measurements (5 according to ASTM D1816) are to be taken with an interval of 3 minutes between them. An average is calculated from the last 5 measurements. Repeat this procedure on the remaining samples. The results are recorded in the test report. 1.8.3 Power factor/Dissipation factor at 90°C or 100°C (Optional) The power factor or dissipation factor is a measure of the dielectric losses in the oil when used in an alternating electric field and of the energy dissipated as heat. A low power factor or dissipation factor indicates low a-c dielectric losses. It can be useful as a means to see changes in quality resulting from contamination and deterioration in service or as a result of handling. The test should be made as per IEC 247 or ASTM D 924. For new oil that has never been in contact with the transformer , the power factor or dissipation factor at 90°C or 100°C and 50 or 60 Hz shall not exceed 0.005. 1.8.4 Interfacial tension (Optional) This test has shown by practice to give a reliable indication of the presence of hydrophilic compounds. The test should be made as per ISO 6295 or ASTM D 971. For new oil that has never been in contact with the transformer the interfacial tension against water shall be ≥ 40 Nm/m at 25 °C. 1.8.5 Sampling of oil for dissolved gas analysis by customer's request Certain customers require that an oil test for a gas analysis is taken. There are special instructions regarding this test within the ABB group. If the analysis is conducted at another laboratory, other vessels and methods might be prescribed.

1.9 Operational test of supervisory equipment


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Transformers and reactors are provided with special equipment for supervision of operation, overloading, cooling and many other purposes. After installation has been completed and before the transformer or reactor is put in service, all the accessory equipment is tested preferably in conjunction with the equipment with which it will be used in service. The supervisory devices which will cause the breaker to trip are tested with the breaker triggered so that the breaker will actually trip. Devices which send alarm signals are tested all the way to the control room. If this is not feasible then individual testing is conducted using a buzzer that is connected to the appropriate terminals in the control cabinet. Prior to energizing, the customer is obliged to perform complete commissioning tests, which include the functions of the entire system, to which the transformer is integrated.

1.10 Operational test of other equipment 1.10.1 Cooling equipment Before the transformer is taken into service, the rotation direction of the pumps and fans of the cooling equipment are checked. Furthermore, the tripping of the motor-protection devices are checked as well as the signal that is activated for each tripped motor-protection device. The rotation direction of the pump is checked according to the following: When the pump is filled with oil and has the correct rotation direction, only a slight purring sound is heard. If the pump wheel rotates in the wrong direction, a rattling sound will occur that is several times louder. If uncertainty prevails, shift the two phases on the motor so that it will run in the opposite direction. It will then be easy to determine which rotation direction is correct. Note that if the pump housing is only partially filled with oil, a rattling sound will also occur. The rotation direction of the fans is checked visually. The thermal over-current protection relays of the fan motors are set according to the rated current that is stamped on the rating plate. The relays for the pump motors are set according to what is stated on the list of apparatus. The thermal over-current protection relays of the motors are tripped by a 2-phase connection of each motor. The signal of the tripped motor-protection device is checked by means of a buzzer to the appropriate terminals in the control cabinet. Verify that shipping plugs, if applicable, have been removed from the motors. 1.10.2 De-energized tap-changer with driving mechanism At the end of the assembly and before being put into service, the de-energized tap-changer and the drive mechanism are checked. Operate the tap-changer to its end positions. Check by ration measuring that the drive mechanism and the tap-changer are in their proper positions. Then check the drive mechanism’s locking device. Check that the contacts on the drive mechanism and its interlocking device connect and disconnect before the lock in the locking device is completely released. 1.10.3 On-load tap-changer with motor-drive mechanism If the transformer is fitted with an on-load tap-changer, then the tap-changer and the motor-drive mechanism are tested before the transformer is put into service. The following checks should be done: − All the external shafts have been lubricated − The local/remote control is functioning correctly − The heater in the drive mechanism is working − The pressure relay operates adequately to the pressure setting − The motor-protection is adjusted to the amount of amps which is stated on the motor’s rating plate. − The drive mechanism indicates the same position as the tap-changer.


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− The drive mechanism has been operated through all positions manually (with the hand crank) and electrically in ascending and descending positions.

− The mechanical stops at extreme positions are working properly − The interlocking switch for the mounted hand crank is working properly For the details on how to perform the above tests, refer to the appropriate tap-changer product information in the instruction manual.

1.11 Final bleeding After all the tests have been carried out, the transformer and every separate compartment, including radiator banks, etc., is bled through the appropriate bleeding valves.

2. ENERGIZATION Prior to the energization, the transformer should be visually inspected and the following items checked:

2.1 Preparation for energization Prior to energizing verify the following: a) The oil level in the oil conservator b) The drying agent and the oil level in the dehydrating breather c) Check that all valves are set at the right position d) Check that the transformer, the control cabinet and all accessories are cleaned and touch up-painted if

needed e) Check that the heating element in the control cabinet is connected and in operation f) Check that the gas-operated relay is de-aired g) Check possible leakage. If the transformer has been stored more than two months after the assembly, all

sealing joints must be retightened h) Check that connections to lines, bus-bars and earth are effectively made i) Check that the distances between phases and phase to earth are sufficient j) Check that the covers are installed on the test taps and/or potential taps (if no potential device is

connected) of the bushings to assure proper grounding of the taps. k) All temporary protective grounds have been removed from conductors. l) All protective and alarm circuits are operational and placed into service before the transformer is

energized. m) Get confirmation that all installation procedures have been completed successfully. n) Get confirmation that there is no current transformer secondary open circuits. o) Set the cooling controls for automatic operation. p) The control selector-switch for the on-load tap changer in the control cabinet is set on REMOTE position. The transformer is ready for service upon the successful conclusion of the tests and completion of the set time.

2.2 Energization If possible the transformer should be energized in such a way that the voltage is increased step by step up to the rated voltage. This may be done by connecting the transformer to a generator by which the voltage is slowly increased. The higher the rated voltage, the more important to energize the transformer as described. If it is not possible to use a generator, the transformer may be connected directly to a live transmission line at no load. After energizing, the transformer has to be kept under careful observation for the first 12 hours. Check and record the oil temperature, the winding temperature, its instrumentation, the tank pressure and ambient temperature. Watch particularly for any sudden changes. When the transformer successively is loaded, observe carefully the transformer for a few hours, especially the temperature gauges and the gas relay. The observation should continue on a daily schedule for seven days and then weekly for the first month of operation.


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An oil sample should be taken after the first and twelfth month of operation for Gas-ln-Oil Analysis. The results of these two analysis should be sent to the ABB representative as soon as they are known. This analysis should then be repeated annually. When the transformer has been in service at normal working temperatures for some weeks, all sealing joints have to be retightened.

2.3 Shut down and reenergisation of transformers with Inertaire or COPS oil Preservation System. 2.3.1 Transformers equipped with Inertaire or Sealedair Oil Preservation System. When you deenergize the transformer and plan to have it out of service for any reason , no special start-up/shut-down provisions are needed unless the transformer is provided with oil pumps. For FOA transformers follow this procedure: Deenergize the transformer. Run one half of the pumps until the unit reaches temperature equilibrium with the ambient. Do not run any of the cooling fans during this cool-down cycle. This procedure moves the oil past the interface with the gas blanket to speed up the release of nitrogen from the oil. Running just one half of the pumps will reduce the static charge build up and not running the fans prevents too rapid cooling. Starting up after Shut Down Run one half of the pumps for 15 minutes to one hour and then deenergize these pumps and run the other half of the pumps for 15 minutes to one hour. This will dislodge any pockets of nitrogen in the oil and move the gas past the oil to gas blanket interface. Do not run both sets of pumps at one time because this may cause static charge buildup. Within twelve hours after running the second set of pumps, energize the transformer and set the cooling controls for automatic operation. This will allow the cooling to be initiated as required by the increasing winding temperature. 2.3.2 Transformers with COPS Oil Preservation System Transformers equipped with COPS oil preservation systems do not require the special shut down and start up procedures because there is no gas blanket on the transformer.


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FIELD TEST RECORD Order No

Transformer type

Serial No

Tap-changer type

Serial No Motor-drive mechanism type

Serial No

CONTENT Page Yes No 1. Ratio test...................................................................................10 1.1 Windings .................................................................................10 2. Check of vector group...............................................................11 3. Insulation test............................................................................12 3.1 Windings .................................................................................12 3.2 Current Transformers..............................................................12 3.3 Control-circuit cabling and auxiliary power cabling .................12 3.4 Core ........................................................................................12 4. Check of potential connection between tank and turret ..............5 5. Polarity check of Current Transformers ....................................13 6. Check of winding temperature circuits ......................................13 7. Oil test.......................................................................................13 8. Operational test of supervisory equipment ...............................14 9. Operational Test of other equipment ........................................17 9.1 Coolers....................................................................................17 9.2 De-energized tap changer with driving mechanism ................17 9.3 On-load tap-changer with motor drive mechanism .................17 NOTE: The X-marks state whether the respective test is to be carried out our not.


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1. Ratio test 1.1. Windings

Tap changer position

Magnetizing on ___-kV

side

No load current

U-measured on ___kV side

Calculated voltage


Calculated voltage

Volt Volt a-b

Volt a-c

Volt b-c

Volt a- b-c

Volt a-b

Volt a-c

Volt b-c

Volt a-b-c

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

Tap- changer

Volt Ampere Volt Volt Volt Volt Volt Volt Volt Volt


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Tap changer position

Magnetizing on ___-kV

side

No load current


Calculated voltage


Calculated voltage

Volt Volt a-b

Volt a-c

Volt b-c

Volt a- b-c

Volt a-b

Volt a-c

Volt b-c

Volt a-b-c

position

U between phase-0 checked ? Yes No

2. Check of vector group Connect A with a Magnetized on kV side _____________

Measured voltage U between

Bb Cc AB Bc Cb Connection

Connect A with a Magnetized on kV side ______________

Measured voltage U between

Bb Cc AB Bc Cb Connection

The vector group corresponds with connection diagram No Remarks


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3. Insulation test 3.1. Windings

Megger kV Note Maximum 5kV megger Terminal to earth M ohm Terminal to earth M ohm Terminal to earth M ohm Terminal to earth M ohm Terminal to terminal M ohm Terminal to terminal M ohm Terminal to terminal M ohm Terminal to terminal M ohm Terminal to terminal M ohm Terminal to terminal M ohm Weather conditions:

3.2. Current Transformers Megger V Note Maximum 1kV megger Location: Terminal: to earth Mohm Location: Terminal: to earth Mohm Location: Terminal: to earth Mohm Location: Terminal: to earth Mohm Location: Terminal: to earth Mohm Location: Terminal: to earth Mohm Location: Terminal: to earth Mohm Location: Terminal: to earth Mohm Location: Terminal: to earth Mohm Weather conditions:

3.3. Control-circuit cabling and auxiliary power cabling Megger___________ V Note Maximum 1kV megger Cables to earth (min value) ________________ M ohm

3.4. Core Megger___________ V Note Maximum 1kV megger The Megger must be of an of ABB Transformer approved type


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Core - earth ________________M ohm Yoke beams -earth ________________Mohm Weather conditions:___________________________________________________________ REMARKS:___________________________________________________________________ _____________________________________________________________________________

4. Check of potential connection between tank and turret The potential connection between tank and turret has been checked with buzzer __________________

5. Polarity check of Current Transformers Check of Current Transformers according to diagram No ___________________________________ Location/terminal Location/terminal Location/terminal Location/terminal Location/terminal Location/terminal

6. Check of winding temperature circuits Current transformer for Location Location Location Measured resistance for: Current transformer ohm ohm ohm

Instrument ohm ohm ohm

7. Oil test The oil level checked in Date

1) Transformer reactor 2) Tap-changer/diverter switch 3) Other separate compartments

The oil system has been de aired Oil samples are taken from

Oil conservator Breakdown voltage kV Transformer/reactor tank Breakdown voltage kV Cooling group No Breakdown voltage kV Cooling group No Breakdown voltage kV Cooling group No Breakdown voltage kV Cooling group No Breakdown voltage kV

Oil test equipment type with electrodes


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Electrode distance mm Oil samples for dissolved gas analysis have been taken REMARKS

8. Operational test of supervisory equipment Alarm circuit tested to Trip circuit tested to Control circuit

Cabinet Control room Control circuit

Cabinet Breaker

No/OK No/OK No/OK No/OK Gas detector relay transformer Gas detector relay tap changer Oil level indicator tap changer High Low Oil level indicator transformer High Low Pressure relief valve for transformer Pressure relay for transformer Pressure relay for tap changer Flow indicators for coolers Cooler group 1 min oil flow max. oil flow min water flow max. water flow Cooler group 2 min oil flow max. oil flow min water flow max. water flow Cooler group 3 min oil flow max. oil flow min water flow max. water flow Manometers for coolers Cooler group 1 min oil pressure max. oil pressure min water pressure max. water pressure Cooler group 2 min oil pressure max. oil pressure min water pressure max. water pressure Cooler group 3 min oil pressure max. oil pressure


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min water pressure max. water pressure


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Alarm circuit

tested to Trip circuit

tested to

Control circuit Cabinet

Control room Control circuit Cabinet

Breaker

No/OK No/OK No/OK No/OK Thermometer for top oil Set for alarm Deg Set for trip Deg Set for start of Cooler group 1 Deg Cooler group 2 Deg Cooler group 3 Deg Cooler group 4 Deg Cooler group 5 Deg Cooler group 6 Deg Thermometer for kV winding Set for alarm Deg Set for trip Deg Set for start of Cooler group 1 Deg Cooler group 2 Deg Cooler group 3 Deg Cooler group 4 Deg Cooler group 5 Deg Cooler group 6 Deg Thermometer for kV winding Set for alarm Deg Set for trip Deg Set for start of Cooler group 1 Deg Cooler group 2 Deg Cooler group 3 Deg Cooler group 4 Deg Cooler group 5 Deg Cooler group 6 Deg


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Alarm circuit

tested to Trip circuit

tested to

Control circuit Cabinet

Control room Control circuit Cabinet

Breaker

No/OK No/OK No/OK No/OK Thermometer for kV winding Set for alarm Deg Set for trip Deg Set for start of Cooler group 1 Deg Cooler group 2 Deg Cooler group 3 Deg Cooler group 4 Deg Cooler group 5 Deg Cooler group 6 Deg Thermometer for kV winding Set for alarm Deg Set for trip Deg Set for start of Cooler group 1 Deg Cooler group 2 Deg Cooler group 3 Deg Cooler group 4 Deg Cooler group 5 Deg Cooler group 6 Deg


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9. Operational Test of other equipment 9.1. Coolers

1) Pump rotation direction checked 2) Fans rotation direction checked 3) Over current protection tipped

at 2-phase connection: Fan No After

(sec.) Current setting

(A) Pump No After

(sec) Current setting

(A) 1 2 3 4 5 7 8 9

10 11 12

Alarm obtained for tipped current protection at terminals in the control cabinet.

9.2 De-energized tap changer with driving mechanism Contact movement The Tap changer was operated from end to end positions The interlocking device of the driving mechanism checked. Alarm obtained when the driving mechanism was operated terminal No in the control cabinet

9.3. On-load tap-changer with motor drive mechanism The position indicators in motor drive mechanism and tap changer indicate the same position

Shaft coupling lubricated with grease Gear box filled with lubricant to correct level Motor drive mechanism checked and test runned

lubricated end position contacts local/remote control interlocking switch manually and with the crank assembled setting of motor protection tripping time for blocked motor pressure relay tested heating element connected and In operation

1ZVN460100-A

11 Maintenance See in 1ZVN460100-D_Maintenace Manual

Document Title

Application Manual

©Copyright 2007 ABB, All rights reserved

Document No.

1ZVN460100-A Date & Rev. Ind.

1 No. of Pages

174 Page

174

Application Manual Transformer

Documents

mechanical

thermoswitch

contact timing

transition

transition

transition

nominal creepage

abb components