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Motor-drive mechanism, type BUL2 Technical guide

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Original instruction

The informat ion provided in this document is intended to be general and does not

cover all possible applications. Any specific application not covered should be

referred directly to ABB or its authorized representative.

ABB makes no warranty or representation and assumes no l iabi lity 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 writ ten permission, and the contents

thereof must not be imparted to a third party nor be used for any unauthorizedpurpose. Contravention will be prosecuted.

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Content

General information ................................................................................................. 5

Applications .... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 5

Design ............................................................................................................... 5

Cabinet .............................................................................................................. 5

Type tests .. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .. 5

Ambient air temperature. ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... . 7

Connection of motor-drive mechanism to tap-changers ........................................ 7

Rating plate ........................................................................................................ 7

Mechanical arrangements ........................................................................................ 8Drive arrangement .............................................................................................. 8

Hand crank ....................................................................................................... 8

One-turn shaft .................................................................................................... 8

Position indicator ................................................................................................ 8

Mechanical end-stops......................................................................................... 8

Electrical end-stops ............................................................................................ 8

Brake ................................................................................................................. 8

Indicator flag ...................................................................................................... 9

Operation counter .............................................................................................. 9

Holding, interlocking and auxiliary contacts .......................................................... 9

Multi-position switches ....................................................................................... 9

Position transmitter (S14), potentiometer ....................................................... 9Continuation contact (S15)............................................................................. 9

Auxi liary contacts ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... 9

Drive mechanism equipment .............................................................................. 10

Principles of operation ............................................................................................. 14

Raise operation with local control ........................................................................ 14

Lower operation with local control ....................................................................... 14

Through-posit ions ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... . 14

Remote control ................................................................................................... 14

Step-by-step-operation....................................................................................... 14

Protection against run-through ............................................................................ 14

Contact timing .................................................................................................... 14Circuit diagram ................................................................................................... 14

Contact timing diagram ....................................................................................... 16

Standard version ..................................................................................................... 17

Control ............................................................................................................... 17

Protection .......................................................................................................... 17

Indication ........................................................................................................... 17

Wiring ................................................................................................................ 17

Maintenance ...................................................................................................... 17

Design options ................................................................................................... 17

Multi-position switches ....................................................................................... 17

Technical data ..... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... .. 18Dimensions ........................................................................................................ 19

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5/201ZSC000562-ABD en | Technical guide BUL2 5

General information

Appl icat ions

The BUL2 motor-dr ive mechanism is designed for outdoor

operation of the on-load tap-changers listed below.

Tap-changer Type of connection

UBB, VUBB For all connections

UCG, VUCG Star point or single-phase

UCL, VUCL Star point or single-phase

For further information, see order data description

1ZSC000498-AAS.

Design

The motor-dr ive mechanism is mounted on the side of the

transformer tank and connected to the tap-changer by means

of drive shafts and bevel gears. The shaft system is described

in the technical guide for each type of tap-changer.

The BUL2 contains all the necessary equipment for operation

of the tap-changer. Special equipment can be supplied to

fulfill customer requests. Paralleling and voltage regulation

systems can also be supplied to supplement the motor-drive

mechanism and tap-changer.

Cabinet

The cabinet is made of welded aluminum, finished with a

complete painting system, primer and standard top coat,

suitable for outdoor use.

Upon request it can instead be finished with a primer or a

complete painting system, primer and a customer-chosen

top coat.

The door can be hinged on e ither the left or r ight side.

Provision is made for padlocking. The door is sealed and the

window is glued to the door.

The motor-dr ive mechanism is mounted to the transformer

tank on anti-vibration pads with four bolts or studs, M12. The

bottom has two flange openings for cable connection, size

FL 33; see Fig. 10.

The cabinet has two vents. Filters prevent insects and dust

from entering the cabinet. To prevent condensation inside

the cabinet, a 50-W heater is supplied which is permanentlyconnected. There is also a 100-W heater, controlled by a

thermostat.

The tightness of the cabinet has been type tested for

protection class IP 66 according to IEC 60529 (protected

against dust and powerful water jets).

The lighting is automatically switched on when the door is

opened.

As standard, the inside of the cabinet has an anti-

condensation layer.

Type tests

The BUL2 motor-dr ive mechanism fu lfil ls the requi rements of

IEC 60214:2003 and IEEE C.57-131-2012.

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134

135

132

135

E3

130

S8

S9

Q1

F2 F1

104

S1

S2

133

135

133

131

131

Fig. 1. Cabinet layout. The position numbers refer to Table 1.

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Oil test according to IEC 60422 2005.

Rating plate

The rating plate shows data for both the tap-changer and

motor-drive mechanism and is placed on the upper panel of

the motor-drive mechanism.

Fig. 3. Example of rating plate.

Ambient air temperature

The ambient air temperature requirements for the motor-drive

mechanism are shown in Fig. 2. The normal operating range

is between -40 °C and +70 °C.

The motor-dr ive mechanism has been type tested at ambient

air temperatures of -40 °C and +70 °C.

Connection of motor-drive mechanism to tap-changers

The connection between the tap-changer and the motor-dr ive

mechanism is made by means of drive shafts and bevel gears.

This external shaft system is descr ibed in the technical guidefor each tap-changer.

The motor-dr ive mechanism's outgoing shaft passes through

a water-resistant bearing in the top of the cabinet. The shaft is

terminated by a multiple-hole coupling half.

Fig. 2. Motor-drive mechanism ambient air temperature.

The motor-drive mechanism must be shaded

from solar radiation by screens.

ABB should be consulted.

Normal operating range. The temperature

inside the cabinet should not exceed +75 °C.

ABB should be consulted.

°C

+70

0

-40

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Mechanical arrangements

This chapter refers to Figs. 4–7 and Table 1.

Drive arrangement

The drive mechanism motor M1 with its pul ley 121 drives,

with a ratio of 4.5:1, pulley 122 on the intermediate shaft 140

via a toothed belt 101. On the intermediate shaft is a pinion

with helical teeth 141, which with a ratio of 5:1, drives the

helical gear 142 on the outgoing shaft 103. The outgoing

shaft is then directly connected via multiple-hole coupling 143

to the shaft system of the tap-changer. The outgoing shaft

turns 5 revolutions per operation.

The mechanism is mounted on a support of cast

aluminum, 144.

Hand crank

The mechanism can be manual ly operated by means of a

hand crank 104. The hand crank is placed on the crank

shaft 105, which through the bevel pinion 123, with a ratio

of 3:1, drives the bevel gear 124 on the outgoing shaft. The

direction of operation is clockwise for a raise operation and

15 revolutions are needed per operation.

When the hand crank is placed on the crank shaft, theinterlocking switch S5 breaks the operating circuit of the

motor thus preventing electrical operation.

With manual operation, the mechanism must be put at an

exact position. If the mechanism is left between two positions

or in a through-position when under power, the mechanism

starts directly upon removal of the hand crank.

One-turn shaft

A helical p inion 106 on the outgoing shaft drives, with a ratio

of 5:1, the helical gear 102 placed on the one-turn shaft 107.

This shaf t drives two Geneva wheels 125 and 126 with a ratioof 36:1. The drive pin 108 for the upper Geneva wheel 125

shall in the normal position be in the slot of the Geneva

wheel whereas the lower Geneva wheel 126 is locked by the

circumference of the one-turn shaft.

Position indicator

The lower Geneva wheel 126 is pinned to the Geneva

shaft 145, which through a bevel gear 109, with a ratio

of 1:1, operates the position indicator shaft 146, on which

the position indicator pointer 110 is mounted. On the position

indicator shaft, drag-hands are also mounted for indication of

the maximum and minimum positions. Those drag-hands canbe manually reset. The position indicator is visible through a

window in the door.

Mechanical end-stops

The upper Geneva wheel 125 is supported by the Geneva

shaft and turns independently of the shaft, controlled by the

upper drive pin 108 on the one-turn shaft. On the Geneva

wheel, two screws 136 are fitted which at the end-positions

operate the mechanical end-stop 113 via arm 147. Extra

screws could be placed between the screws 136 if a

decreased tap-change range is desired.

After the end-position has been reached, the mechanical end-

stop is pressed out to obstruct knob 148 under the helical

gear 142, which prevents further movement of the outgoingshaft in that direction.

When the mechanism is returned to the end-position by

manual cranking, the mechanical end-stop will be pressed

back by springs, which also keeps it positioned in all normal

tap-change positions.

The breakpin 114 in the bevel pinion 123 on the crank shaf t

105 prevents overloading of the end-stops by hand cranking.

Electrical end-stops

On the lower end of the shaft for arm 147, cam curve 149 ismounted. When the mechanism is at an end-position, this

cam curve operates limit switches S6 and S7, which break

the operating circuit of the motor and two phases of the

motor supply. Electrical operation beyond the end-positions is

thus impossible.

In event of faulty limit switches, the motor is stopped by the

mechanical end-stop and disconnected when the thermal

overcurrent protection trips the motor protective switch Q1;

see the circuit diagram on page 15.

BrakeOn the upper end of the one-turn shaft 107 is cam disc 128,

which controls brake 117 working against brake disc 118 on

top of the intermediate shaft 140. This brake makes sure that

the motor-drive mechanism stops at the correct position after

each tap-change. The brake can be adjusted by screw 150,

which presses against the spring 151 that closes the brake.

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Drive mechanism equipment

Table 1. See Figs. 1 and 4–7.

Position Item

B1 Thermostat

E1 Anti-condensation heater, 50 W

E2 Heater

E3 Lamp

F1 Circuit breaker, heater circuit

F2 Circuit breaker, control circuit

K1 Contactor, step-by-step operation

K2 Motor contactorK3 Motor contactor

K601 T ime relay, run-through protect ion

K602 T ime relay, tap-change incomplete

M1 Motor

Q1 Protective motor switch

S1 Control selector switch

S2 Control switch

S3/S4 Cam operated contacts

33-34 Holding contact

41-42 Interlocking contact

13-14, 21-22 Auxiliary contact

S5 Inter lock ing switch, open when hand crank is f itted

S6/S7 Limit swi tch, upper/lower l imit-pos it ion

S8 Pushbutton “EMERGENCY STOP”

S9 Door-operated switch

S14 Position transmitter (potentiometer)

S15 Continuation contact

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

x Terminal board group

101 Toothed belt

102 Helical gear

103 Outgoing shaft

104 Hand crank

105 Crank shaft

106 Helical pinion

107 One-turn shaft

108 Geneva wheel drive pin

109 Bevel gear

110 Mechanical position indicator

111 Coupling

112 Multi-position switch shaft

113 Mechanical end-stop

Position Item

114 Breakpin

115 Cam disc for holding contact

116 Indicator arm

117 Brake

118 Brake disc

119 Front plate

120 Operation counter

121 Pulley122 Pulley

123 Bevel pinion

124 Bevel gear

125 Geneva wheel, upper

126 Geneva wheel, lower

127 Multi-position switches

128 Cam disc

129 Lever for holding contact

130 Rating plate

131 Hinges

132 Motor-drive mechanism cabinet

133 Door

134 Hand knob

135 Air vent

136 Screw for end-stop

140 Intermediate shaft

141 Helical pinion

142 Helical gear

143 Multiple-hole coupling half

144 Support

145 Geneva shaft

146 Position indicator shaft

147 Arm for end-stop

148 Knob for mechanical end-stop

149 Cam curve

150 Screw for adjustment of brake

151 Spring for brake

160 Printed circuit board

161 Contact arm

162 Silver rivet contact

163 Gold-plated contact surface

164 Transparent cover

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{

{

Direction of rotation for a raise operation

Fig. 4. Drive mechanism equipment.

145

S4

S3

129

115

126

136

125

108

128

111

148

113

136

147

S7

149

112

160

127

(S14, S15)

106

109 146

104 105 123 114 124 103

143 116 119 120

102

107

117

118

150

151

141

142

140

122

101

121

M1

110

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Fig. 5. Detailed example of printed circuit board.

Fig. 6. View of the drive mechanism from above.

162

103

144

106

150

163

142

164

136

161

120 119 110

160

125

112

117 116 107 128 109

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Fig. 7.

B1

160

E1x E2 K601 K602 K1 K2 K3 U5

S3/S4 S6/S7 105 S5 M1

104

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Principles of operation

Circuit diagram for AC supply, see Fig. 8. The feeds for the

motor, control circuits and heater are connected to their

respective terminal blocks according to the instructions on the

diagram.

Raise operation with local control

When switch S1 is set at position “Local”, the mechanism can

be operated by control switch S2. For a raise operation, the

procedure is as follows:

Motor contactor K2 is energized, the contactor closes the

motor phases, the motor starts and runs the mechanismin the raise direction. After about 0.2 seconds, the brake is

released, and after about 0.4 seconds, the holding contact

S3: 33-34 closes and takes over feed of contactor K2 when

control switch S2 is released.

Switching in the tap-changer takes place after about

3 seconds.

The drive mechanism cont inues until the cycle is completed,

which takes about 5 seconds. About 0.2 seconds before

the cycle is completed, the holding contact S3 is released,

contactor K2 falls and feed to the motor is disconnected. At the same time, the brake is engaged and the mechanism

stops at the new position.

Lower operation with local control

A similar cycle is performed, but in the lower direction, when

the control switch S2 is switched to the lower position and

contactor K3 is activated.

Through-positions

A through-position is a position the tap-changer must pass

without changing the ratio of the transformer. These positions

are passed automatically. The continuation contact S15bridges the holding contacts S3:33-34 and S4:33-34 via

auxiliary contacts on raise contactor K2 at through-positions.

In this way, the contactor K2 raise, or K3 lower, is kept

energized and the motor will automatically conduct another

operation.

The connection of S15 to auxi liary contacts on K2 means that

the drive, in the event of a control supply failure in a through-

position, always moves to a lower normal service position

when the voltage returns.

Remote control

Control selector switch S1 is placed at the “Remote” position.

The cont rol supply for the remote pushbuttons or regulating

relay is then received from a terminal in the motor-drive

mechanism cabinet. Incoming control circuits for raise and

lower impulses should be connected to other terminals as

shown in the diagram. Local operation is not possible when

switch S1 is at the “Remote” position and remote operation is

not possible at the “Local” position.

Step-by-step-operation

Step-by-step relay (K1) is connected so that only one tap-change operation is made each time the raise/lower switch is

operated.

Protection against running-through

A re lay (K601) stops the motor-dr ive mechanism in case of a

failure of the step-by-step control circuit, which would cause

a running-through of the motor-drive mechanism. The relay

energizes the trip coil in the protective motor switch (Q1).

Contact timing

The contact timing diagram, Fig. 9, shows the contact

sequences for one change of tap position for the raise andlower directions.

Circuit diagram

The diagram shows the mechanism at the middle position.

Towards motor-drive upper limit

Towards motor-drive lower limit

LOCAL control

REMOTE control

n → n+1 1 tap

n → n-1 1 tap

U Upper limit-position

L Lower limit-position

PE

Protective ground

Crank

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Fig. 9. Circuit diagram.

UPPER LIMIT

ITEM F2 OFF

LOWER LIMIT CLOSED ATUPPER LIMIT

SUPPLY FOR MOTOR SUPPLY FOR HEATER SUPPLY FOR CONTROL CONTACT

HOLDING CIRCUIT INITIATION

PREPARED FOR

PROTECTION RELAY

REMOTE

TRIPPING

P R E P A R E D F O

R O U T L E T . S E E S E P A R A T E

D I A G R A M W H E

N O U T L E T I S O R D E R E D .

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).

CONTACTS OPEN TOWARDS

TAP-CHANGE IN

PROGRESS

CLOSED ATLOWER LIMIT

ITEM Q1 ON

ITEM Q1 OFF / RUN- THROUGH ALARM

ITEM Q1 OFF

STEP-BY-STEPIN OPERATION

TAP-CHANGE

INCOMPLETE

STEP-BY-STEPDE-ENERGIZED

REMOTE

REMOTE

0

0

LOCAL

LOCAL

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(S14)

(S15)

Contact timing diagram

Fig. 9. Example of contact timing diagram.

TURNS ON

HAND CRANK OF

MOTOR-DRIVE

MECHANISM

CONTACT

(MBB)

(BBM)

UPPER

LIMIT-

POS.

POS. POS. POS. POS.

LOWER

LIMIT-

POS.

TAP-CHANGE OPERATION

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Standard version

Control

– Control selector switch, Local-0-Remote.

– Control switch, Raise-0-Lower.

– Hand crank for manual operation.

Protection

– Circuit breaker in heater + control circuit

– Protective switch for the motor with thermal overload

release and magnetic overcurrent release.

– Limit switches – in both control and motor circuits.

– Mechanical end-stops.

– Interlocking contact in the control circuit to preventelectrical operation during manual operation.

– Interlocking contacts in raise and lower control circuits to

prevent operation in incorrect direction of rotation (with

incorrect phase sequence).

– Motor contactors are electrically interlocked.

– Protection against run-through in case of a failure of the

step-by-step control circuit.

– Emergency stop pushbutton.

Indication

– Mechanical position indicator

– Drag-hands for max. and min. position indication. – Red flag for indication of tap-changer in progress.

– Operation counter.

(The four items above are visible through the window in the

cabinet door.)

– Position transmitter, potentiometer, for remote position

indication.

Wiring

The wiring is executed with grey polyvinylch loride-

insulated, stranded wire. Each wire is marked with numbers

corresponding to terminal numbers. All external connections

are made with thermosetting resin. For type and data, see

Technical data.

No fuses are required for the motor, as the motor protective

switch has magnetic overcurrent release.

Maintenance

All bear ings in the motor-dr ive mechanism type BUL2 haverubber seals and are permanently lubricated. Certain gears

and moving parts are made of self-lubricating material. No

lubrication is necessary during the lifetime of the motor-drive

mechanism under normal operating conditions.

The motor-dr ive mechanism should be inspected once year ly.

For correct inspection and maintenance procedures, consult

the appropriate maintenance guide.

Design options

For previously prepared design options, please see theordering data form. If other options are required, please

consult ABB.

Multi-position switches

Maximum of 8 contact rows can be accommodated, including

one continuation contact when there are through-positions.

Position transmitter Auxiliary contact

Break-before-make

Auxi liary contact

Make-before-break

Step switches for parallel control

Type 1 Type 2

Number of contact rows

1 1 1 1 2

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Weight: 95 kg

Dimensions

408

49

1274 1197

45

79

384

146

8034

45

36.591.5

292475

6 x Ø 12.5

6

2 x FL 33

Ground

connection M12

1212

37

21560

626

475

33

75

202

213

352.5

550

293

36

30

Ø 75

M12

A

A

A - A

A A

Anti-vibration pad

Max 120°

Fig. 10. Dimensions.

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Contact us

© C o p y r i g h t 2 0 1 2 A B B ,

A l l r i g h t s r e s e r v e d .

1 Z S C 0 0 0 5 6 2 - A B D e n ,

2 0 1 2 - 1 1 - 1 5 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

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