ABB VUBB User Manual

1ZSC000562-AAL en

Vacuum on-load tap-changers, type VUBB

User’s guide

Original instruction

The information provided in this document is general by intention and does not cover all possible applications. Any specific application not covered should be referred directly to ABB or its authorized representative.

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

This document must not be copied without our written permission, and the contents thereof must not be imparted to a third party nor be used for any unauthorized purpose. Contravention will be prosecuted.

Content

1. Safety ............................................................................................................................... 5

1.1 General ..................................................................................................................... 5

1.2 Safety warnings ........................................................................................................ 5

1.3 Safety precautions .................................................................................................... 5

1.3.1 Personal safety ................................................................................................... 5

1.3.2 Environmental safety ........................................................................................... 5

1.3.3 First aid .............................................................................................................. 5

1.3.4 In the event of fire ............................................................................................... 5

2. Introduction ...................................................................................................................... 6

2.1 General ..................................................................................................................... 6

2.2 Functional description ............................................................................................... 6

2.2.1 Switching sequence, operation with resistor side first ......................................... 7

2.2.2 Switching sequence, operation with main contact first ........................................ 9

2.3 System overview ....................................................................................................... 11

2.3.1 Types of switching .............................................................................................. 12

2.3.2 Types of connection ........................................................................................... 13

2.3.3 Housing .............................................................................................................. 14

2.3.4 Selector switch ................................................................................................... 14

2.3.5 Change-over selector ......................................................................................... 14

2.4 Contacts ................................................................................................................... 14

2.5 Vacuum interrupters .................................................................................................. 14

2.6 Transition resistors .................................................................................................... 14

2.7 Spring-loaded mechanism ........................................................................................ 14

2.8 Motor-drive mechanism ............................................................................................ 14

2.9 Accessories and protection devices .......................................................................... 14

2.10 Rating plate ............................................................................................................ 16

3. Commissioning ................................................................................................................. 17

3.1 General ..................................................................................................................... 17

3.2 Reassembly .............................................................................................................. 17

3.3 Required tools and materials ..................................................................................... 17

3.4 Tightening torques .................................................................................................... 18

3.5 Oil filling .................................................................................................................... 18

3.5.1 Oil quality ............................................................................................................ 18

3.5.2 Filling methods and restrictions ........................................................................... 18

3.5.3 Correct oil level ................................................................................................... 18

3.5.4 Filling at atmospheric pressure............................................................................ 18

3.5.5 Filling under vacuum ........................................................................................... 19

3.6 Mounting of external drive shafts ............................................................................... 20

3.6.1 Mounting of horizontal drive shaft ....................................................................... 20

3.6.2 Mounting of vertical drive shaft ........................................................................... 23

3.7 Testing ...................................................................................................................... 27

3.8 Energizing ................................................................................................................. 28

3.9 Putting into operation ................................................................................................ 28

4. Operation ......................................................................................................................... 29

4.1 Synchronization between tap-changer and motor-drive mechanism .......................... 29

5. Inspection ......................................................................................................................... 30

5.1 General ..................................................................................................................... 30

5.2 Inspection ................................................................................................................. 30

5.3 Checking oil quality ................................................................................................... 31

5.4 Maintenance ............................................................................................................. 31

5.5 Replacement of the complete switching mechanism including vacuum interrupters .. 31

6. Troubleshooting ................................................................................................................ 32

7. Repairs and adjustments .................................................................................................. 33

7.1 General ..................................................................................................................... 33

8.1.1 Serial number ..................................................................................................... 33

7.2 Oil leakage ................................................................................................................ 33

7.2.1 General .............................................................................................................. 33

7.2.2 Tools required ..................................................................................................... 33

7.2.3 Materials and spare parts required ...................................................................... 33

7.2.4 Procedure .......................................................................................................... 33

7.3 Replacement of pressure relay .................................................................................. 35

8. Electrical diagrams ........................................................................................................... 36

8.1 Standard circuit diagram BUE ................................................................................... 37

8.2 Contact timing diagram BUE ..................................................................................... 38

8.3 Standard circuit diagram BUL2 ................................................................................. 39

8.4 Contact timing diagram BUL2 ................................................................................... 40

9. Technical data .................................................................................................................. 41

9.1 Dimensions ............................................................................................................... 41

9.2 Weights .................................................................................................................... 41

9.3 Specification of materials .......................................................................................... 41

9.3.1 General .............................................................................................................. 41

9.3.2 Tap-changer housing .......................................................................................... 41

9.3.3 Selector switch ................................................................................................... 41

9.3.4 Gearing mechanism ........................................................................................... 42

9.3.5 Drive shaft system .............................................................................................. 42

1. Safety

1.1 General

This user‘s guide must be read and understood must be followed at all times.

1.2 Safety warnings

The following warnings and notes are used in the manual:

WARNING

WARNING indicates an imminently hazardous situation which if not avoided, will result in death or serious injury. This signal word is to be limited to the most extreme situations.

WARNING also indicates a potentially hazardous situation which if not avoided, could result in death or serious injury.

CAUTION

CAUTION indicates a potentially hazardous situation which if not avoided, may result in minor or moderate injury. It may also be used to alert against unsafe practices.

CAUTION may also indicate property-damage-only hazards.

INFO provides additional information to assist in carrying out the work described and to provide trouble-free operation.

1.3 Safety precautions

1.3.1 Personal safety

Unused transformer oil is somewhat harmful. Fumes from unused warm oil may irritate the respiratory organs and the eyes. After long and repeated contact with transformer oil, the skin becomes very dry. Avoid contact with the oil as much as possible and use oil-tight protective gloves when handling the oil.

Used tap-changer oil contains harmful substances. Fumes are irritating to the respiratory organs and the eyes and very easily catch fire. Used transformer oil may be carcinogenic.

1.3.2 Environmental safety

Collect used oil in oil drums.

An absorbing agent should be used when cleaning up waste oil. Treat waste oil as hazardous to the environment.

1.3.3 First aid

Skin contact

1. Wash the body part that has been exposed to the oil.

2. Rub moisturizer into the skin to counteract drying.

In the eyes

Rinse the eyes with clean water.

Swallowing

WARNING

Avoid vomiting.

1. Drink water or milk.

2. Call a doctor.

1.3.4 In the event of fire

In the event of fire, extinguish with a powder, foam or carbon acid extinguishing agent.

1ZSC000562-AAL en | User’s guide VUBB 5

2. Introduction

2.1 General

The on-load tap-changers manufactured by ABB have been developed over a period of many years to provide maximum reliability. In most applications, the simple and robust design provides a service life equal to the service life of the transformer.

Minimum maintenance is required for trouble-free operation.

Maintenance is normally not required on the parts situated in the oil of the transformer tank. The only parts requiring maintenance are the vacuum interrupters (which may require replacement), the insulating oil and the motor-drive mechanism.

WARNING

Small amounts of explosive gases are constantly discharged from the breathing devices (dehydrating breather or one-way breather). Make sure that no open fires, hot surfaces or sparks are present in the immediate surroundings of the breathing devices.

Personnel operating and inspecting the tap-changer must have good knowledge of the apparatus and be aware of the risks pointed out in this manual.

Personnel making electrical connections in the motordrive mechanism must be certified for such work.

CAUTION

After a pressure relay trip, contact ABB. The tapchanger housing must be drained and the selector switch lifted and carefully examined before the transformer is reenergized.

2.2 Functional description

The on-load tap-changer is a device for changing the tapping connection of a winding while the transformer is under load.

The main purpose is to maintain a constant voltage out from the transformer and to compensate for variations in the load situation. The tap-changer is connected to the transformer via the tap winding. The main function is tap selection, which is accomplished by changing the number of turns on the regulating winding.

Although numerous different circuit solutions are available, the selected solution has been found to offer the best combination of technical performance and potential for economic operation. By using auxiliary contacts in combination with vacuum interrupters, the contacts are used for carrying current and the vacuum interrupters are used for energized switching. With this solution, only two vacuum interrupters are required per phase.

The electrical circuit principle for the VUBB is shown in

Figs. 1-18. The purpose of the operation is to commute the load from one tap to the other in order to change the voltage.

Depending on in which direction the center shaft is rotating, two different contact sequences are obtained – either the main contacts operate first, or in the other direction, the transition contacts operate first.

The figures on the following pages show the contact sequence along with the physical position of the interrupter.

6 User’s guide VUBB | 1ZSC000562-AAL en

2.2.1 Switching sequence, operation with resistor side first

1. Position for continuous load through fixed contact 1.

2. Resistor auxiliary contact disconnects from fixed contact 1.

Fig. 1.

Fig. 2.

3. Resistor vacuum interrupter opens.

1 2

1 2

1 2

4. Resistor auxiliary contact connects to fixed contact 2.

Fig. 3.

1 2

5. Resistor vacuum interrupter closes, producing a circulating current.

Fig. 4.

Fig. 5.

1 2


6. Main vacuum interrupter opens, breaking the circulating current and commuting the load current to the resistor branch.

7. Main auxiliary contact disconnects from fixed contact 1.

Fig. 6.

1 2

1 2

8. Main auxiliary contact connects to fixed contact 2.

Fig. 7.

1 2

9. Main vacuum interrupter closes, commuting the load current to the main branch. Continuous load on fixed contact 2.

Fig. 8.

Fig. 9.

1 2


2.2.2 Switching sequence, operation with main contact first

1. Position for continuous load through fixed contact 2.

2. Main vacuum interrupter opens, breaking the load current, and in doing so commutes it to the resistor branch.

Fig. 10.

3. Main auxiliary contact disconnects from fixed contact 2.

Fig. 11.

1 2

1 2

1 2

4. Main auxiliary contact connects to fixed contact 1.

Fig. 12.

1 2

5. Main vacuum interrupter closes. The load current commutes to the main branch, producing a circulating current.

Fig. 13.

Fig. 14.

1 2


6. Resistor vacuum interrupter opens, breaking the circulating current.

7. Resistor auxiliary contact disconnects from fixed contact 2.

Fig. 15.

Fig. 16.

8. Resistor vacuum interrupter closes.

1 2

1 2

1 2

9. Resistor auxiliary contact connects to fixed contact 1.

Fig. 17.

1 2

Fig. 18.


2.3 System overview

The implementation of vacuum technology improves breaking capacity, increases contact life and reduces maintenance.

The design allows easy access to the function control for the switching sequence.

Yoke-mounting means that the tap-changer is temporarily placed on a fork located on the active part of the transformer.

See Fig. 20. The transformer cover is then lowered onto the tank, and the tap-changer is lifted and bolted to the cover.

Yoke-mounting allows the transformer manufacturer to connect the windings to the tap-changer before drying and without having the transformer cover mounted.

The VUBB tap-changer is of the in-tank design. The motordrive mechanism is attached to the transformer tank and connected to the tap-changer by means of drive shafts and a bevel gear. The motor-drive mechanism is not described in this manual.

The tap-changer is mainly comprised of a housing, a mechanical drive system, a change-over selector and a selector switch.

15 mm

The tap-changer is designed so that it is suitable for both cover mounting and yoke-mounting (pre-mounting on the transformer’s active part).

Cover-mounting means that the tap-changer is lowered through a hole in the transformer cover and then bolted straight onto the transformer cover. See Fig. 19.

Fig. 19. Cover-mounting.

Fig. 20. Yoke-mounting.

The tap-changer type VUBB can be switched using:

– Linear switching, see Fig. 21.

– Plus/minus switching, see Fig. 22.

– Coarse/fine switching, see Fig. 23.

The general arrangement of a tap-changer system can be executed using:

– Three-phase, star point connection, see Fig. 24.

– Three-phase delta, fully insulated connection, see Fig. 25.


2.3.1 Types of switching

Linear switching (type L)

With linear switching, the regulating range is equal to the voltage of the tapped winding. No change-over selector is used.

Plus/minus switching (type R)

With plus/minus switching, the change-over selector extends the regulating range to twice the voltage of the tapped winding by connecting the main winding to different ends of the regulating winding.

Fig. 21. Linear switching.

Coarse/fine switching (type D)

With coarse/fine switching, the change-over selector extends the regulating range to twice the voltage of the tapped winding by connecting or disconnecting the coarse regulating winding.

Fig. 22. Plus/minus switching.

Fig. 23. Coarse/fine switching.


2.3.2 Types of connection

Three-phase, star point (N)

Only one unit is required for all three phases. The transformer‘s neutral point is in the tap-changer.

Three-phase delta, fully insulated (T)

Only one unit is required for all three phases.

Fig. 24. Three-phase, star point connection.

Fig. 25. Three-phase delta, fully insulated connection.


2.3.3 Housing

The purpose of the housing is to seal and provide mechanical support.

2.5 Vacuum interrupters

During switching operations of vacuum tap-changers, arcing takes place in the vacuum interrupters and not in oil.

The top section forms the flange that is used for mounting to the transformer cover, and for bearing the gear box for the operating shafts. The top section includes a connection for the conservator pipe and draining connections, a grounding terminal, the supervisory device and the cover with its gasket.

2.6 Transition resistors

The purpose of the transition resistors is to allow a makebefore-break operation by limiting the circulating current when bridging two taps.

The housing has high quality seals that guarantee vacuum and overpressure-proof performance under all service conditions. During operation, some particles from mechanical wear will be produced. These pollutants must not enter the transformer, and the housing is therefore designed to provide hermetical sealing between the vacuum selector switch and the transformer.

2.7 Spring-loaded mechanism

The spring-loaded mechanism ensures a fast and complete switching sequence even if the power supply fails.

The mechanism is normally operated by the motor-drive unit, but can also be hand-cranked by an operator.

The top and bottom sections of the housing cylinder are made of cast aluminum. They are attached to a cylinder of fiberglass-reinforced plastic. The bushings through the cylinder wall are sealed by O-ring gaskets. Each unit is tested under vacuum, and the outside is exposed to helium and checked for leaks with a helium gas detector.

The motor-drive mechanism and bevel gear are mounted on the transformer tank, and the drive shafts are mounted to complete the assembly of the motor-drive mechanism, bevel gear and tap-changer before oil filling and testing.

2.8 Motor-drive mechanism

The bevel gear, mounted on the cover, transfers the motion of the motor-drive mechanism, via the drive shafts, to the tapchanger’s spring-loaded mechanism.

2.3.4 Selector switch

The selector switch is used to execute the electrical sequence described in Sections 2.2.1 and 2.2.2.

The VUBB tap-changer contains three selector switches, one per phase.

The motor-drive mechanism provides the force for operating the tap-changer. Energy is provided from a motor through a series of gears and out through a drive shaft. Several features are incorporated within the mechanism to lengthen service intervals and improve reliability.

The function of the selector switch is to select a tap in the tap winding and to carry and commutate the load current.

The selector has multiple fixed contacts, each connected to a different tap in the regulating winding.

2.9 Accessories and protection devices

The tap-changer can be equipped with various protection devices. The standard protection device is the pressure relay.

An oil flow relay is also available.

2.3.5 Change-over selector

The tap-changer can also be equipped with a change-over selector for plus/minus or coarse/fine switching; see Figs. 22 and 23.

The selector switch has a maximum of 10 positions, but with the change-over selector, this number can be doubled.

2.4 Contacts

The contacts inside the selector switch are used for carrying the electrical load. The contacts are comprised of fixed and operating contacts. The fixed contacts are located on the housing. The operating contacts are located on the selector switch shaft.

A pressure relief device with an alarm signal is also available, as well as certain other supervisory sensors.

For more information about accessories and protection devices, see the technical description. 1ZSC000562-AAD .


Pressure relay

Top flange

Intermediate flange

(for yoke mounting)

Drive spring

Inspection cover

Position indicator window

Top cover

Bevel gear Valve

Housing

Position indicator

Spring-loaded mechanism

Change-over selector

Terminal

Main auxiliary contact

Vacuum interrupter

Terminals

Selector switch

Selector switch shaft

Shielding ring

Transition resistor

Bottom valve

Bottom flange

Fixed contact

Potential connection to bottom flange

Fig. 26. VUBB overview.


2.10 Rating plate

The rating plate is on the door of the motor-dive unit.

The unit’s serial number is on the top flange of the tapchanger.

Oil test according to IEC 60422 2005.

Fig. 27. Example of rating plate.

Fig. 28. Location of serial number plate and rating plate.


3. Commissioning

3.1 General

This section describes tasks to be carried out when the transformer is being installed and tested on site.

1. Mount the motor-drive mechanism if it is not mounted upon delivery. Mounting of the motor-drive mechanism is described in a separate instruction manual.

2. Mount the external drive shafts if they are not mounted upon delivery. See Section 3.6.

CAUTION

The motor-drive mechanism must be protected against condensation.

WARNING guide.

Make sure that the heater is energized when power is available. When power is not available, put drying agent inside the motor-drive cabinet and seal the vents.

3.2 Reassembly

The conservator and accessories that may have been removed during transport must be remounted.

The installation of accessories is described in the assortment

The motor-drive mechanism must not be installed in an explosive atmosphere. The electrical equipment creates sparks that can cause an explosion.

Do not energize the transformer before the tapchanger and motor-drive mechanism are mounted.

3. Refit the conservator.

4. Refit the accessories.

The pressure relay is usually delivered in a separate package and installed upon commissioning.

The tap-changer may be delivered filled with oil or without oil.

Depending on the transport requirements, the transformer may or may not be delivered with the motor-drive mechanism and drive shaft system attached. 3.3 Required tools and materials

The following tools are required for the installation of the tapchanger:

WARNING

Before any work is carried out on the tap-changer, make sure that the transformer is disconnected and that grounding is properly executed. Obtain a signed certificate from the engineer in charge.

CAUTION

Sealing surfaces and gaskets must be clean and undamaged.

Diametrically opposed bolts in sealing joints must be tightened alternately several times, beginning with a low tightening torque and finally with the recommended tightening torque.

– Air pump with hose, pressure gauge (0-250 kPa) and connection with internal thread R 1/8"

– Standard set of open-end wrenches (up to 18 mm)

– Standard set of sockets (up to 18 mm)

– Socket handle

– Socket extender

– Standard set of screwdrivers

– Allen keys for 5- and 6-mm sockets

– Hand crank LL 117 016-M

– Dynamometric wrenches, 5-85 Nm

– Tool for opening the oil drum

– Bucket, 10 liters

– Equipment for oil filling

– Rags (lint-free) for cleaning

Remember to place O-rings on the flanges.

The following greases (ball bearing greases) or similar are required during installation:

– GULF-718 EP

– Mobil-Grease 28

– SHELL-Aero Shell Grease 22


3.4 Tightening torques

The following tightening torques are recommended unless otherwise stated in this user's guide:

M6

M8

M10

M12

10 Nm ±10 %

24.5 Nm ±10 %

49 Nm ±10 %

84 Nm ±10 %

3.5 Oil filling

3.5.1 Oil quality

The tap-changer contains about 300 liters of oil. The oil quality should be LC set -30° according to IEC 60296:2012.

The oil should also comply with IEC 60422:2005.

3.5.2 Filling methods and restrictions

Oil filling can be carried out using one of the following methods:

– At atmospheric pressure

– Under vacuum

The tap-changer housing is designed to for a vacuum on one side and atmospheric pressure on the other.

CAUTION

The pressure difference between the inside and outside of the housing may not exceed 100 kPa.

CAUTION

Be aware of the risk of slipping due to spilled oil.

The oil dissolves gases, especially if degassed oil is used.

3.5.3 Correct oil level

If possible, the oil levels of the oil conservators for the transformer tank and tap-changer should be the same. The oil level of the oil conservator for the tap-changer may never be higher than the oil level of the transformer oil conservator.

At +20 °C, oil is filled to the level where the pointer on the oil level indicator points half-way between MIN and MAX.

For temperatures other than +20 °C, proceed as follows:

– For every 10 °C increase of temperature, adjust the oil level upwards a tenth of the scale range of the oil level indicator.

– For every 10 °C decrease of temperature, adjust the oil level downwards a tenth of the scale range of the oil level indicator.

3.5.4 Filling at atmospheric pressure

It is not necessary to perform steps 1 and 2 below. These two steps are only described to speed oil filling. Oil filling can be satisfactorily performed by only following steps 3 through 10:

1. Remove the inspection cover.

2. Pump in oil until it reaches the mechanism .

3. Open the conservator valve, if any.

4. Remove the breathing device for the tap-changer conservator.

5. Connect the pump to the oil valve on the tap-changer cover.

6. Open the valve.

7. Pump in oil to the correct level. The oil level is shown on the oil level indicator. (For correct oil level, see Section

3.5.3.)

8. Close the oil valve.

9. Disconnect the pump.

10. Refit the pipe or the breather. Make sure that the connections are airtight – use sealing tape on the threads and O-rings on the flanges.

CAUTION

Wait at least three hours before energizing the transformer after filling oil at atmospheric pressure.

This waiting period is necessary to allow air bubbles to dissipate.


3.5.5 Filling under vacuum

Oil filling under vacuum can be carried out with the conservator. After filling under vacuum, no standing time is needed. The methods below ensure that no stipulated pressure differences are exceeded.

CAUTION

To fill under vacuum, a vacuum-proof conservator must be used.

1. Make a connection between the oil conservator for the transformer and the oil conservator for the tap-changer.

Fig. 29.

2. Open the valve between the tap-changer and the conservator.

3. Close the oil valve.

4. Put the transformer under vacuum. (The tap-changer is then put under vacuum automatically as well.)

5. Let oil in through the oil valve on the tap-changer. For connection dimensions, see Fig. 30.

Ø75

Vacuum Vacuum Oil

Ø44.2

O-ring

Ø5.7

Fig. 30. Connection dimensions.

Ø20

Stud M10

Transformer

Fig. 29. Vacuum filling overview.

Tap-changer

Oil

6. When the oil level indicator has reached the correct level, close the oil inlet. For correct oil level, see Section 3.5.3.

7. When atmospheric pressure is restored in the transformer, remove the connection between the transformer and the tap-changer.

8. Connect the breathing device to the oil conservator for the tap-changer. Make sure the connection to the breathing device is properly sealed.


3.6 Mounting of external drive shafts

The external drive shafts consist of square tubes. They must be connected to the spherical shaft ends of the bevel gear and the motor-drive mechanism by means of two coupling halves.

3.6.1 Mounting of horizontal drive shaft

1. Make sure that inclination of the shaft is less than 4°.

(4° = 70 mm for every 1000 mm of shaft length.)

Protective tubes with slotted ends must be used.

The bevel gear can be turned so that the horizontal shaft for the motor-drive mechanism is in correctly positioned. See Fig.

31. The limit for turning depends on the arrangement of the accessories, but the shaft can be at any angle.

Make sure that the slots on the protective tubes are facing downwards.

Removal and inspection of the couplings must be possible when one of the tubes is pushed into the other.

2. Fit two coupling halves on one end of the shaft. See

Fig. 32.

Fig. 32. Fit two coupling halves on the square shaft.

3. Fit six screws and washers in the holes on the coupling halves. See Fig. 33.

Fig. 31. The bevel gear can be turned 360°.

CAUTION

Before mounting shafts and couplings, all parts must be cleaned and greased to ensure correct function.

Let the parts of the shaft system that should be dismantled before transporting the transformer to the site keep their identification numbers according to the packing list to simplify the remounting of the shaft system on site.

The tubes around shafts and couplings are for protection.

Fig. 33. Fit screws and washers to the coupling halves.


4. Push the shaft to the bottom of the fitting in the coupling halves.

5. Tighten the two outer screws. Tightening torque

10 Nm ±10 %. See Fig. 34.

8. Fit two hose clips. See Fig. 37.

Fig. 34. Tighten the two outer screws.

6. Tighten the remaining screws crosswise with the same tightening torque. See Fig. 35.

Fig. 37. Fit two hose clips.

9. Apply a thin layer of grease to all spherical shaft ends and unpainted surfaces of the bevel gears. Use any of the greases specified in Section 3.3.

10. Connect the shaft with the mounted coupling halves to the bevel gear shaft.

11. Fit two coupling halves on the other end of the shaft; see

Fig. 32. Be sure to offset these coupling halves 90° in relation to the couplings mounted in step 2. See Fig. 38.

Fig. 35. Tighten the remaining screws.

7. Position the two protective tubes with the slotted ends outwards. See Fig. 36.

Fig. 38. The couplings should be offset 90° in relation to each other.

Fig. 36. Position the tubes with the slotted ends outwards.


12. Fit six screws and washers in the holes on the coupling halves (see Fig. 33) and lightly tighten them.

13. Check that the axial play is no more than 2 mm. See Fig.

39. If necessary, adjust the axial play by operating the couplings on the shaft end.

Make sure that the slot on the protective tubes is facing downwards.

17. Clamp the protective tubes with the hose clips. See

Fig. 41.

Fig. 41. Clamp two hose clips.

2 mm

Fig. 39. Check that the shaft cannot be moved more than 2 mm in the axial direction.

18. Apply the self-adhesive information plates around the tubes at about the middle of the tube length. See Fig. 42.

14. Tighten the outer two screws; see Fig. 34. Tightening torque 10 Nm ±10 %.

15. Tighten the remaining screws crosswise (see Fig. 35) with the same tightening torque.

16. Push the two protective tubes horizontally until they touch the bevel gears. See Fig. 40.

Fig. 42. Self-adhesive information plates on the tubes.

Fig. 40. Push the two protective tubes horizontally.


3.6.2 Mounting of vertical drive shaft

1. Make sure that inclination of the shaft is less than 4°.

(4° = 70 mm for every 1000 mm of shaft length.)

2. Fit two coupling halves at one end of the shaft. See

Fig. 43.

5. Tighten the two outer two screws. Tightening torque

10 Nm ±10 %. See Fig. 45.

Fig. 43. Fit two coupling halves on the square shaft.

3. Push the shaft to the bottom of the fitting in the coupling halves.

4. Fit six screws and washers in the holes on the coupling halves. See Fig. 44.

Fig. 45. Tighten the two outer screws.

6. Tighten the remaining screws crosswise with the same tightening torque. See Fig. 46.

Fig. 46. Tighten the remaining screws.

Fig. 44. Fit screws and washers to the coupling halves.


7. Connect the shaft with the mounted coupling halves to the shaft of the bevel gear. See Fig. 47.

10. For BUL motor-drive mechanism, loosen the two screws on the multi-hole coupling at the top of the motor-drive mechanism. See Fig. 50.

Multi-hole coupling flanges

Fig. 47. Connect the square shaft to the bevel gear.

8. Place the two protective tubes on the vertical drive shaft.

See Fig. 48.

Fig. 50. BUL multi-hole coupling.

11. For BUE motor-drive mechanism, loosen the two screws on the multi-hole coupling inside the motor-drive mechanism. See Fig. 51.

Fig. 48. Place protective tubes on the vertical drive shaft.

9. Fit two hose clips. See Fig. 49.

Multi-hole coupling flanges

Fig. 51. BUE multi-hole coupling.

Fig. 49. Fit two hose clips.


12. Apply a thin layer of grease to all spherical shaft ends and unpainted surfaces of the bevel gears. Use any of the greases specified in Section 3.3.

13. Fit two coupling halves at the bottom end of the shaft; see Fig. 43. Be sure to offset these coupling halves 90° in relation to the couplings mounted in step 2 as shown in

Fig. 52.

16. Check that the shaft cannot be moved more than 2 mm in the axial direction (axial play). See Fig. 54. If necessary, adjust the axial play by moving the couplings on the shaft end.

2 mm

Fig. 52. Coupling halves offset by 90°.

14. Connect the bottom end of the square shaft with the mounted coupling halves to the shaft of the motor-drive mechanism. See Fig. 53.

Fig. 54. Check that the shaft cannot be moved more than 2 mm in the axial direction.

17. Tighten the two outer screws; see Fig. 45. Tightening torque 10 Nm ±10 %.

18. Tighten the remaining screws crosswise (see Fig. 46) with the same tightening torque.

19. Place the protective tube with the greater diameter upwards, facing the bevel gear. See Fig. 55.

Fig. 53. Connect the square shaft to the motor-drive mechanism.

15. Fit six screws and washers in the holes on the coupling halves (see Fig. 44) and tighten them lightly.

Fig. 55. Place the protective tube with the greater diameter upwards.

20. Secure the tube with a hose clip. See Fig. 56.

Fig. 56. Fit a hose clip.


21. Check that the motor-drive mechanism is at the EXACT position.

23. Check that the position indicators on the motor-drive mechanism (Fig. 59) and the tap-changer (Fig. 60) show the same position.

The exact position for the BUL is when the roller on the brake arm is in the notch of the cam disc. See

Fig. 57.

The exact position for the BUE is when the red indicator flag is in position and the red mark on the brake disc is aligned with the red mark on the brake pad. See Fig. 58.

WARNING

If the position indicators on the motor-drive mechanism and on the tap-changer do not show the same position, a serious transformer failure could occur.

LOWER

9 9 9 9 8 7

POSITION RAISE

13

14

Fig. 57. BUL2: Cam disc and roller on the brake arm.

Fig. 59. Position indicator on the motor-drive mechanism.

Fig. 58. BUE: Red mark on the brake disc.

9

To access the position indicator, remove the cover.

See Fig. 60.

22. If the motor-drive mechanism is out of position, manually crank the motor-drive mechanism to the exact position according to the info box above.

Fig. 60. Position indicator on the tap-changer.


3.7 Testing

When testing the transformer, the tap-changer can be operated either by the hand crank or electrically. When operating electrically, the motor-drive mechanism must be connected.

For BUL2:

7. Run the motor-drive mechanism.

8. Check that the center of the notch in the cam disc stops within ±2 mm of the center of the roller on the brake arm.

See Fig. 57.

If it does not stop within the tolerances, see the maintenance guide for the motor-drive mechanism.

9. Continue to step 14.

1. Make sure that the motor-drive mechanism and the tapchanger show exactly the same position. See Fig. 59 and

Fig. 60.

WARNING


For BUE:

10. Run the motor-drive mechanism.

11. Check that the red mark on the brake disc stops within the tolerance limits. See Fig. 59.

12. If the brake disc is outside the tolerance limits, increase or decrease pressure on the springs; see the maintenance guide for the motor-drive mechanism.

13. Continue to step 14.


See Fig. 60.

2. Operate the tap-changer with the hand crank, counting the number of turns from the exact position until the tapchanger operates.

- For BUL – the tap-changer should operate after

11.5 ± 1 turn of the hand crank.

- For BUE – the tap-changer should operate after

19 ± 1.5 turns of the hand crank.

If it does not, one of the shaft couplings of the gears is incorrectly mounted.

3. Manually crank the motor-drive mechanism to a position in the middle of the range. See Fig. 59.

4. Turn the control selector switch to the LOCAL position.

5. Send an impulse for a raise operation.

For BUE and BUL

14. Check that the position indicator on the motor-drive mechanism shows the same position as the indicator inside the cover of the tap-changer. See Figs. 59 and 60.

WARNING



See Fig. 60.

If the phase sequence is incorrect (three-phase supply), the motor-drive mechanism starts in the lower direction. The motor-drive mechanism moves back and forth around its service position until the control selector switch is turned to 0.

6. If the phase sequence is incorrect, reverse two of the motor supply cables in order to get the correct sequence.

WARNING

Dangerous voltage!

For a BUL2 motor-drive mechanism, continue at step 7.

15. Operate one step.

16. Check that the tap-changer follows the motor-drive mechanism.

17. Operate the drive mechanism electrically between the end-positions.

18. Check the end-stops. When attempting to operate it electrically beyond the end-position, the motor should not start.

19. Check the mechanical end-stop by attempting to manually crank it beyond the end-position. After a couple of turns of the hand crank, it should be mechanically stopped.

20. Manually crank back to the end-position.

21. Operate the tap-changer electrically to the other endposition.

22. Repeat the test procedure above.

For a BUE motor-drive mechanism, continue at step 10.


WARNING

The transformer must never be energized with an inoperable end-stop.

The tap-changer installation is now complete. Proceed with testing the transformer.

3.8 Energizing

The tap-changer can now be energized and commissioned.

WARNING


3.9 Putting into operation

Put the motor-drive mechanism into operation by following the instructions given in the BUE and BUL installation and commissioning guide.

Check the oil level one month after filling. It is usual for the oil level of the oil conservator to decrease due to gas absorption in the oil.


4. Operation

WARNING

Small amounts of explosive gases are constantly discharged from the breathing devices (dehydrating breather or one-way breather). Make sure that no open fires, hot surfaces or sparks are present in the immediate surroundings of the breathing devices.

CAUTION

2. Check which two holes of the upper multi-hole coupling flange coincide with two holes of the lower multi-hole coupling flange of the motor-drive mechanism. See

Figs. 58 (BUL) and 59 (BUE).

3. Fit two screws and locking nuts in the two multi-hole coupling holes that best coincide. Tighten the screws.

Tightening torque 10 Nm ±10 %.

4. Pull down the protective tube. See Fig. 62.

The hand crank must not be inserted during electrical operation.

The pressure relay is a calibrated monitoring instrument. It must be handled with care and protected against careless handling or any kind of mechanical damage.

If a power supply failure occurs during operation, the interrupted operation will be completed once the power returns.

If the tap-changer is not at its exact position and the hand crank is pulled out, the motor-drive mechanism will start and go to the exact position if the power supply is on.

Fig. 62. Pull down the protective tube.

To allow draining from the protective tubes, the amount of clearance at the bottom of the tube is important:

4.1 Synchronization between tap-changer and motor-drive mechanism

1. Loosen the multi-hole coupling. Turn the shaft first to the end-position on one side, and then to the end-position on the other side. Finally, turn halfway back. See Fig. 61.

5. Make sure that the clearance at the bottom of the tube is between 3 and 5 mm. See Fig. 63.

3 - 5 mm

1 3

2 Fig. 63. Clearance at the bottom of the tube.

6. Secure the tube with the hose clip. See Fig. 64.

Fig. 61. Turning the shaft between end-positions.

Fig. 64. Secure the hose clip.


5. Inspection

The VUBB tap-changer has been designed to provide maximum reliability. The simple and robust design provides a service life equal to the service life of the transformer.

A minimum of maintenance is required for trouble-free operation.

5.2 Inspection

It is recommended that the tap-changer be inspected at the same time as other work is carried out on the transformer.

The inspection should be carried out yearly, and can be dpne while the transformer is in service. This inspection is carried out by site personnel.

5.1 General

Maintenance of the tap-changer is organized into three major steps:

Inspection – Carried out by site personnel.

The inspection consists of a visual check of the motor-drive mechanism and the conservator. The quality of the insulating oil is also checked. During this inspection, the counter is read to determine when maintenance is due.

Maintenance –

Replacement of the complete switching mechanism including vacuum interrupters – manufacturer.

Carried out by ABB personnel.

WARNING

Carried out by the

Furthermore, the quality of the oil must be checked according to IEC 60422:2005. This is carried out by site personnel.


Table 1. Maintenance schedule.

Time or number of operations

Type of action

Check oil level at conservator

Check the breather

Visual check of motor-drive mechanism

Check the motor

Check the counter

Check the heater

Test of oil quality (IEC 60422)

Dissolved gas analysis (DGA)

(See IEC 60599 for further information.)

Inspection Oil sampling

Yearly After 6, 11, 15 years, and then every 3rd year x x x x x x x x

WARNING Before starting any work inside the motor-drive mechanism, the auxiliary power must be switched off.

Note that the motor, contactors and heating element may be energized from separate sources.

The inspection must be carried out from ground level since the transformer is energized.

CAUTION CAUTION

Before carrying out work on the tap-changer, put the LOCAL/REMOTE switch on the motor-drive mechanism to position ”0”. Shutting the door of the motor-drive mechanism and locking it with a padlock is also recommended when work is carried out on the tap-changer. The key should be kept by the technician. This is done to avoid unexpected starting of the motor-drive mechanism.

Be aware of the risk of slipping due to spilled oil.

Permission must be obtained for inspection as well as for operation of the tap-changer.

1. Check the motor on the motor-drive mechanism.

2. Check the counter on the motor-drive mechanism.

3. Check the heater on the motor-drive mechanism.

4. Register the counter’s value on the motor-drive mechanism.

Follow the instructions given in the separate guide for the motor-drive mechanism.

The registered number of operations should be noted each time inspection and maintenance are conducted.


5. Check the oil level in the conservator. The level must be as stipulated in the instructions from the transformer manufacturer.

5.4 Maintenance

For maintenance, please contact ABB or make sure that personnel performing maintenance are trained and certified by

ABB.

WARNING

The oil in the tap-changer housing may be hot.

Observe caution!

6. Check the breather according to the instructions from the transformer manufacturer. If more than half of the drying agent has changed color, it must be dried or replaced.

The drying agent normally starts to change color from the bottom of the breather. If it changes color at the top of the breather, there is a leakage in the connections to the conservator. Locate the leakage and seal it.

WARNING

Maintenance of the tap-changer should be performed regularly at intervals of 300,000 operations; see Table 2. The relevant information is stated on the rating plate. This permits confirmation of mechanical integrity and monitoring of contact wear, and the necessary preparations can be made for replacing the vacuum interrupters.

Table 2.

No. of operations

300,000

600,000

900,000

Main activity

Maintenance (sequence measurement via inspection hole on cover)

Replacement of switching mechanism (including vacuum interrupters)

Maintenance (sequence measurement via inspection hole on cover)

End of life

The breathers and the tube from the conservator contain explosive gases. No open fires, hot surfaces or sparks may be present when removing the breather.

1,200,000

5.3 Checking oil quality

Check the quality of the oil according to IEC 60422:2005.

To simplify oil sampling, the transformer should have an oil tap as shown in Fig. 65 .

5.5 Replacement of the complete switching mechanism including vacuum interrupters

The vacuum interrupters are sensitive and the settings must be exact. It is thus important that replacement is performed by an ABB-certified technician. Contact ABB or make sure that personnel performing replacement of the complete switching mechanism including vacuum interrupters are trained and certified by ABB.

An oil filter unit is normally not required on the VUBB tapchanger. But, if the tap-changer is equipped with an oil filter unit from ABB, it should be inspected once a year.

The estimated contact life of the vacuum interrupters in the selector switch at rated load is stated on the rating plate of the tap-changer. Also see Table 2.

Fig. 65 Oil sampling tap.


6. Troubleshooting

This chapter provides information used to locate faults on the tap-changer. Instructions for correcting faults, replacing parts, etc. are in Section 7.

Error condition

High oil level alarm

Troubleshooting procedure

A rising oil level in the tap-changer conservator may indicate leakage between the tap-changer and the transformer main tank.

1. Make sure that the alarm is not due to overfilling upon commissioning or maintenance. This can be checked by adjusting the oil level according to Section 3.5.3.

2. Recheck the oil level later.

Low oil level alarm

Pressure relay has tripped

A low oil level in the tap-changer may indicate leakage.

1. If there is no visible leakage, adjust the oil level according to

Section 3.5.3.

2. Check the oil level later.

For troubleshooting instructions regarding the pressure relay, see the assortment guide.

The control system or the motor-drive mechanism is malfunctioning

Note the number of operations and then lift the tap-changer insert. Inspect the tap-changer according to the maintenance guide.

Follow the instructions given in the separate guide for the motor-drive mechanism.

Drying agent has changed color from the bottom of the breather

Dry or replace the drying agent.

Drying agent has changed color from the top of the breather

There is a leakage in the connections to the conservator.

Locate the leakage and seal it.

CAUTION

Do perform service on the transformer after a pressure relay trip; contact the manufacturer.


7. Repairs and adjustments

7.1 General

Repairs on the VUBB tap-changer fall into two categories:

Repairs – Replacing worn or end-of-service-life parts

Modifications – Improving the already very high standard of reliability and taking actions to prolong the service life of the equipment. Modifications may only be as issued by ABB.

The modifications fall into two areas:

Immediate – The modification is to be made at the earliest possible opportunity.

Routine – The modification is to be made during routine service.

7.2.2 Tools required

Standard set of metric combination wrenches.

7.2.3 Materials and spare parts required

– O-rings

– Grease for ball bearings (Section 3.3).

7.2.4 Procedure

WARNING


CAUTION

Be aware of the risks of slipping due to oil leakage.

Protect the tap-changer from water.

WARNING

When oil that has been used in a selector switch housing is pumped out, all tubes and hoses that can conduct electricity must be grounded to avoid the risk of explosion due to the gases produced by arcs during service.

8.1.1 Serial number

Before consulting ABB for technical advice, for assistance with repairs, to order consumables or to complete repairs, the tap-changer serial number must be available. The serial number can be found on the rating plate on the motor-drive mechanism and on the flange of the selector switch housing

(see Section 2.19).

1. Check if oil is leaking anywhere else than from the tapchanger.

The following procedure applies to all connections other than the connection between the bevel gear and the top cover.

2. Retighten the nuts at the top of the cover. Tightening torque 84 ±10 %. See Fig. 66.

The serial number must be stated in all correspondence with the manufacturer. Failure to use the serial number may cause delays.

7.2 Oil leakage

7.2.1 General

This instruction is a guide in dealing with oil leakage from the tap-changer. Leakage might be caused by one of the following:

– Damaged O-ring at the top cover of the tap-changer.

– Leakage between the bevel gear flange and the transformer cover.

Fig. 66. Bolts on top cover.


If oil leakage remains, the O-ring must be replaced:

3. Lower the oil level in the tap-changer by 100-150 mm.

4. Remove the bolts and washers from the top cover. See

Fig. 66.

CAUTION

Be careful not to drop any screws or other items into the tap-changer.

Place all removed items in a box to prevent them from falling into the tap-changer.

5. Carefully lift the cover at least 10 cm straight up before moving it horizontally. See Fig. 67.

Be sure not to damage the bevel gear and the pipe when lifting.

7. Carefully refit the cover. Be sure to lower the cover straight down the last 10 centimeters above the upper flange. See

Fig. 69.

Fig. 69. Procedure for lowering the cover.

10 cm

10 cm

8. Refit the M12 bolts and washers to the top cover. See Fig.

66.

9. Tighten the bolts. Tightening torque 84 ±10 %.

10. Refill the oil; see Section 3.5.

If there is still oil leakage, check if the leakage is between the bevel gear flange and the tap-changer. Follow the this procedure:

Fig. 67. Procedure for lifting the cover.

6. Replace the O-ring with a new one. See Fig. 68.

If the leakage is in the gear box (from the tapchanger into the gear box), contact ABB for further instructions.

11. Be sure that the oil level in the tap-changer is lowered by

100-150 mm.

12. Loosen the hose clip on the protective tube at the bevel gear. See Fig. 70.

Fig. 68. Replace the O-ring.


Fig. 70. Hose clips on the protective tube.

13. Push the protective tube aside.

14. Remove the bevel gear. See Fig. 71.

Be sure not to twist the horizontal drive shaft.

Clamps

Bevel gear flange

Tap-changer cover

O-ring

Fig. 71. Bevel gear.

15. Refit the bevel gear on the tap-changer cover.

Once the bevel gear is back in place, it is important to check that the vertical drive shaft has not been disturbed.

Synchronize the shaft as described in section 4.1.

Fig. 72. Refit the bevel gear box cover.

16. Check that the position indicator in the motor-drive mechanism (Fig. 59) shows the same position as the indicator inside the top-cover of the tap-changer (Fig. 60).

WARNING



17. Refit the protective tube with the greater diameter upwards, facing the bevel gear. See Fig. 55.

18. Secure the hose clip on the protective tube facing the bevel gear. See Fig. 56.

7.3 Replacement of pressure relay

If the pressure relay fails to pass the insulation test and/or the function test, it must be replaced. This is described in the assortment guide.

CAUTION

It is not permitted to only replace the microswitch inside the pressure relay.


8. Electrical diagrams

On the following pages, the standard circuit diagrams and the contact timing diagrams for BUE and BUL2 are shown.

Be sure to use the circuit diagram and the contact timing diagram delivered with your tap-changer.


8.1 Standard circuit diagram BUE

SUPPLY FOR MOTOR SUPPLY FOR HEATER SUPPLY FOR CONTROL CIRCUIT

HOLDING CIRCUIT INITIATION

LOWER RAISE REMOTE

TRIPPING

1) CONTINUATION CONTACT INCLUDED ONLY WHEN THE TAP-CHANGER HAS THROUGH-POSITIONS.

CLOSED WHEN THE TAP-CHANGER IS AT THROUGH-POSITIONS.

TAP-

CHANGE

IN

POSITION

TAP-

CHANGE

IN

PROGRESS

TAP-

CHANGE

IN

PROGRESS

OPEN AT

LOWER

LIMIT

OPEN AT

UPPER

LIMIT

CLOSED

AT

UPPER

LIMIT

CLOSED

AT

LOWER

LIMIT

ITEM Q1 OFF/

RUN-THROUGH

ALARM

STEP-BY-

STEP DE-

ENERGIZED

REMOTE 0 LOCAL


8.2 Contact timing diagram BUE

TURNS ON HAND

CRANK FOR

MOTOR-DRIVE

MECHANISM

CONTACT

POS.

RAISE OPERATION POS. POS.

LOWER OPERATION POS.

TAP-CHANGE OPERATION

UPPER

LIMIT POS.

LOWER

LIMIT POS.

E1 Anti-condensation heater

E3 Cabinet light

K1 Contactor, step-by-step operation

K2 Contactor, raise

K3 Contactor, lower

K6 Time relay, run-through protection

M1 Motor

Q1 Motor protective switch

S1 Control selector switch

S2 Control switch

S5 Interlocking switch, open when hand crank is fitted

S6 Cam switch (limit switch)

S8 Pushbutton, EMERGENCY STOP

S9 Switch, door operated

S11 Cam switch

1-2 Starting contact, 3-4 Auxiliary contact

S12 Cam switch

1-2, 3-4 Holding contact

5-6, 7-8 Interlocking contact

9-10, 11-12 Auxiliary contact


S14 Position transmitter (potentiometer)

S15 Continuation contact

X Terminal board group

Raise operation

Lower operation

Upper limit pos.

Lower limit pos.

Remote control

Local control

Protective earth

Crank


8.3 Standard circuit diagram BUL2

SUPPLY FOR MOTOR SUPPLY FOR HEATER SUPPLY FOR CONTROL CONTACT

HOLDING CIRCUIT INITIATION

PREPARED FOR

PROTECTION RELAY

REMOTE

TRIPPING

CIRCUIT BREAKER

OFF

1) CONTINUATION CONTACT INCLUDED ONLY WHEN OLTC

HAS THROUGH-POSITIONS. CLOSED WHEN OLTC IS AT

THROUGH-POSITIONS.

2) REMOVE CONNECTION X4:1-2 TO DISABLE STEP-

BY-STEP FUNCTION AND X3:11-12 TO DISABLE THE

RELAY K601 (RUN-THROUGH PROTECTION).

UPPER LIMIT LOWER LIMIT CLOSED AT

UPPER LIMIT

CONTACTS OPEN TOWARDS

CLOSED AT

LOWER LIMIT

ITEM Q1 OFF/RUN-

THROUGH ALARM

STEP-BY-STEP

IN OPERATION

STEP-BY-STEP

DE-ENERGIZED

REMOTE 0 LOCAL

ITEM F2 OFF TAP-CHANGE IN

PROGRESS

ITEM Q1 ON ITEM Q1 OFF TAP-CHANGE

INCOMPLETE

REMOTE 0 LOCAL


8.4 Contact timing diagram BUL2

TURNS ON THE

HAND-CRANK OF

MOTOR-DRIVE

MECHANISM

CONTACT

POS.

POS.

POS.

(MBB) (S14)

(BBM)

(S15)

TAP-CHANGE OPERATION

UPPER

LIMIT

POS.

POS.

LOWER

LIMIT

POS.

B1 Thermostat

E1 Anti-condensation heater

E2 Heater

E3 Lamp

F1

F2

Circuit breaker, heater circuit

Circuit breaker, control circuit

K1

K2

Contactor, step-by-step operation

Motor contactor

K3 Motor contactor

K601 Time relay, running-through protection

K602 Time relay, tap change incomplete

M1 Motor

Q1 Protective motor switch

S1

S2

Control selector switch

Control switch

S3/S4 Cam operated contacts

33-34 Maintaining contact

41-42 Interlocking contact

S5


Interlocking switch, open when hand crank is fitted

S6/S7 Limit switch, upper/lower limit position

S8

S9

Pushbutton, EMERGENCY STOP

Switch, door operated

S14 Position transmitter (potentiometer)

S15 Continuation contact

U5 Power supply unit, 100-240 V AC /24 V DC

X Terminal board group

X3x Internal terminal board group n → n+1 1 tap n → n-1 1 tap

U Upper limit-position

L Lower limit-position

LOCAL control

REMOTE control

PE

Protective ground

Crank


9. Technical data

9.1 Dimensions 9.3 Specification of materials

140 mm

CAUTION

Materials listed in the tables below, without any specification of amount, are included because they may cause pollution problems during decommissioning, even in the small quantities used.

1854 mm

9.3.1 General

Upon disposal of this product, compliance with the local environmental regulations of each country is recommended.

The materials used are specified for environmental reasons.

470 mm

9.3.2 Tap-changer housing

Material

Aluminum

Fiberglass

Copper

Epoxy resin

Steel

Nitrile rubber

Stainless steel

Glass

Brass

Silver

Fig. 73. VUBB dimensions.

9.2 Weights

The approximate weight of the VUBB tap-changer is specified below. The specified weights do not include the weights of the motor-drive mechanism and the drive shaft system.

Tap-changer without oil ............. 280 kg

Weight of required oil ................ 270 kg

Total weight .............................. 550 kg

9.3.3 Selector switch

Material

Aluminum

Copper

Fiberglass

Steel

Epoxy resin

Ceramics

Brass

Stainless steel

Polyester resin

Polyphthalamide

Chrome

Nitrile rubber

Glass

Polyamide

Bakelite

Silver

PTFE

6

0.5

0.3

0.16

0.02

0.01

Approximate amount (kg)

95

46.8

36

13.2

3

3

13.2

6.15

2.5

2.5

1

0.5

0.2

0.06

0.04

0.03

0.02


108

52

49.6

36


9.3.4 Gearing mechanism

Material

Steel

Brass

Stainless steel

Aluminum

9.3.5 Drive shaft system

Material

Steel


21

1.3

1

0.1


10.1


Contact us

ABB AB

Components

SE-771 80 Ludvika, Sweden

Phone: +46 240 78 20 00

Fax: +46 240 121 57

E-Mail: [email protected]

www.abb.com/electricalcomponents

ABB VUBB User Manual

Vacuum on-load tap-changers, type VUBB

User’s guide

Content

1. Safety

2. Introduction

3. Commissioning

4. Operation

5. Inspection

6. Troubleshooting

7. Repairs and adjustments

8. Electrical diagrams

9. Technical data

Contact us

Related manuals

Table of contents

ABB VUBB User Manual

Vacuum on-load tap-changers, type VUBB

User’s guide

Content

1. Safety

2. Introduction

3. Commissioning

4. Operation

5. Inspection

6. Troubleshooting

7. Repairs and adjustments

8. Electrical diagrams

9. Technical data

Contact us

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Table of contents