INSTRUCTIONS GEK.

-90207

POWER /VAC * VACUUM CIRCUIT BREAKER

WITH ML - 18 MECHANISM

TYPES:
V B l -4.16-250 - 1200 A -58 -0
VB 14.16 -250-2000 A -58 -0

VBl - l 3.8 -500 - 1200 A -37 -0

VB l - l 3.8 -500 -2000 A -37 -0

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Vacuum Breaker
Continuous Current
—
Nominal Voltage
—
—
Nominal MVA
Close and Latch Kiloamperes —
—
Model Designator
( No number on breaker nameplate indicates -0 Model )

GENERAL ELECTRIC

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 <<
LIST OF ILLUSTRATIONS

Page No.
Figure No .
6
I. Shippin g Block 7
2. Front View of Power / Vac* Breake r with Front Cover 7
3. Front View of Power / Vac * Circuit Breake r Withou t Front Cover 8
4. Closing Spring Gag 8
5. Manual Chargin g 10
6. Toggle Linkag e Positio nsof ML - 18 Mechan ism 13
7. Erosio n and Wipe Indicat or 14
8. Wipe Indicat or 16
8 A. Mecha nical Adjustm ents and Setting s 18
9. Schem aticof ML- 18 Mechan ism 20
10 . -
Typica l Wiring Diagra m for ML 18 Mechan ism 21
11 . Front and Left Side View of P VI Breake r 21
12 . Rear and Right Side View of PV 1 Breake r 22
13. Trip Coil Adjust ment 23
14 . Closing Coil Adjust ment 24
-
Bottom View of M L l 8 Spring Charge d Mecha nism
15 .
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2

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 CONTENTS

Page No .
Introduction 5
Safety . . . 5
General 5
Specific 5

Description 5

Receiving , Handling and Storage 6

Receiving 6
Handling 6
Storage 6

Installation 7
Safety Precautions 7
Shipping 7
Mechanical Checkingand Slow Closing 7
Electrical Checking 8

Operation 9
General 9
i
Close Spring Charging 9
Closing Operation 12
Opening Operation . . 12
Trip- Free Operation 12
Control Circuit !2
Interlocks 13

Mechanical Adjustments 14
General 14
Wipe Adjustment 14
Primary Contact Erosion Indication 25
Control Coil Plunger Travel 25
Control Switches 25

Electrical Checks 25
Control Power 25
Timing 25

Maintenance 26
General 26
Periodic Inspection 26

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 (
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CONTENTS ( Con’ t.)

Page No.
Mainten ance ( Corn . ) 26
Power / Vac* Interrup ter 26
Contact Erosion 26
Transfe r Finger Wear 26
Insulati on Tests 27
Vacuum Interrup ter Integrit yTest 27
Primary Circuit Resista nce 27
Mechan ism 27
Primary Insulati on Parts 28
Lubrica tion 28
Recomm ended Mainte nance
28
Repair and Replace ment . . . . 28
General 28
Replace ment oflnterr upter 29
Primary Discon nect Fingers 29
Mechan ism 29
Control Switch es
29
Trip or Close Coils
29
Renewa l Parts 29
Orderin g Instruc tions 30
Recomm ended Renewa l Parts

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 POWER /VAC * VACUUM CIRCUIT BREAKER
WITH ML-18 MECHANISM
TYPES VB1- 4.16- 250
r TYPES VB1- 13.8- 500
INTRODUCTION
To the extent required the products described herein meet SPECIFIC
applicable ANSI, IEEE and NEMA Standards; but no such
assurance is given with respect to local codes and ordinances 1. DO NOT WORK ON AN ENERGIZED BREAKER . A
because they vary greatly. IF WORK HAS TO BE PERFORMED ON THE
SAFETY
BREAKER , TAKE IT OUT OF SERVICE AND RE -
MOVE IT FROM THE METALCLAD.
Each user has the responsibility to instruct all personnel 2. DO NOT WORK ON ANY PARTOFTHE BREAK -
associated with his equipment on all safety precautions ER WITH THE TEST COUPLER ENGAGED .
which must be observed.
-
3. All spring charged mechanisms related to a breaker
The following are recommendations to be considered in a
user’s safety program . These recommendations are not in - must be serviced only by skilled and knowledgeable person
nel capable of releasing each spring load in a controlled
-
tended to supplant the user’s responsibility for devising a
manner. PARTICULAR CARE MUST BE EXERCISED
complete safety program and shall not be considered as
such . They are rather suggestions to cover the more import - TO KEEP PERSONNEL CLEAR OF MECHANISMS
ant aspects of personnel safety related to circuit breakers. WHICH ARE TO BE OPERATED OR RELEASED.
General Electric neither condones nor assumes any respon - Information on construction of such mechanisms is pro-
sibility for user practices which deviate from these recom- vided in this instruction book.
mendations. 4. Operational tests and checks should be made on a
breaker after maintenance, before it is returned to service , to
GENERAL insure that it is capable of operating properly. The extent of
such tests and checks should be consistent with the level of
l . All personnel associated with installation , operation maintenance performed .
and maintenance of power circuit breakers should be
--
f
I
thoroughly instructed and supervised regarding power
: *quipment in general and , also , the particular model of

uipment with which they are working. Instruction books

5. If maintenance on the Power / Vac* breaker is being
performed to an extended schedule such as on a 5 year or 10
year basis, it is recommended that the vacuum interrupter
and service advices should be closely studied and followed . integrity test be performed each time the breaker is removed
from the metalclad switchgear for reasons other then sched-
2. Maintenance programs must be well planned and car - uled breaker maintenance if it has been more than one year
ried out consistent with both customer experience and since the last vacuum interrupter integrity test.
manufacturer’s recommendations including service advices
and instruction books. Good maintenance is essential to 6. Interlocks are provided for the safety of the operator
breaker reliability and safety . and correct operation of the breaker. If an interlock does
Local environment and breaker application must be con- not function as described DO NOT MAKE ANY
sidered in such programs, including such variables as ambi - ADJUSTMENT, MODIFICATION OR DISFIGURE
THE PARTS. DO NOT FORCE THE DEVICE INTO
ent temperatures, actual continuous current , number of
operations, type of interrupting duty, and any unusual local POSITION; CONTACT THE NEAREST GENERAL
condition such as corrosive atmosphere or major insect ELECTRIC COMPANY INSTALLATION AND SERV-
problems. ICE OFFICE FOR INSTRUCTIONS.

DESCRIPTION

The Power / Vac * vacuum circuit breaker is a horizontal The Power / Vac * circuit breakers are available in con-
drawout removable and interchangeable interrupting ele - tinuous current ratings of 1200 and 2000 amperes in accord -
ment for use in metalclad switchgear to provide protect - ance with industry standards . A combination 1200 / 2000
tion and control of electrical apparatus and power systems. ampere breaker is also available . Refer to the breaker name-
plate for complete rating information of any particular
breaker .
These instructions do not purport to cover all details or variations in equipment nor to provide for every
possible contingency to be met in connection with installation, operation or maintenance. Should further in-
formation be desired or should particular problems arise which are not covered sufficiently for the
*
? purchaser' s purposes, the matter should be referred to the General Electric Company.

.
To the extent required the products described herein meet applicable A SSI IEEE and N E M A stand -
ards; but no such assurance is given with respect to local codes and ordinances because they vary greatly.

•Registered Trademark of the General Electric Company. 5

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 t
TRIP LATCH BLOCKI NG BOLT
( BLOCK ING POSITIO N)

YELLOW INSTRU CTION TAG

RATING INTERF ERENCE BLOCK

LIFTING LOCATI ON
{ V* inch diameter hole @ all four corners)

TRIP LATCH BLOCKI NG BOLT

( STORAG E LOCAT ION )

FIG. 1 SHIPPIN G BLOCK 82025

The nameplat e also describes the control power require - PROPER INSTAL LATION AND MAINTE NANCE
ments for that breaker. The applicati on of a breaker must be ARE NECESS ARY TO INSURE CONTIN UED SATIS-
such that its voltage , current and interrupt ing ratings are FACTOR Y OPERAT ION OF THE BREAKE R . The fol -
never exceeded . Since this book is written to include all lowing instructi ons will provide complete informat ion for
ratings of the breaker , as well as several design variation s, placing Power / Vac * breakers in service and for maintain ing
the instructio ns will be of a general character and all illustra - satisfact ory operation .
tions w'ill be typical unless otherwis e specified .

RECEIV ING , HANDLI NG AND STORAG E c

RECEIV ING breakers are left on a floor or when a lift truck is used , block
both rear wheels in both direction s to prevent any accidenta l
Each breaker is carefully inspected before shipment. Im - movemen t.
mediately upon receipt cf the circuit breaker, an examina - STORAG E
tion should be made for any damage sustained in transit. If
injury or rough handling is evident , a damage claim should It is recomme nded that the breaker be put into service
be filed immedia tely with the transport ation company and immediat ely in its permanen t location . If this is not possible,
the nearest General Electric Sales Office should be notified . the following precautio ns must be taken to assure the proper
storage of the breaker:
1 . The breaker should be carefully protected against con -
It is expected that due care w ' i be exercised during the densatio n , preferab ly by storing it in a warm dry room of
1

unpackin g and installati on of the breaker so that no damage moderate temperatu re such as 40° to 100° F . High humidity
, or from ex -
will occur from careless or rough handling may have an adverse effect on the insulatio n parts and
posure to moisture or dirt. Check all parts against the pack - should be avoided . Circuit breakers for outdoor metalclad
ing list to be sure that no parts have been overlook ed . switchge ar should be stored in the equipmen t only when
power is available and the heaters are in operation to pre -
HANDL ING vent condensa tion .
2. The breaker should be stored in a clean location , free
W' hen lifting the breaker use of the specially designed from corrosiv e gases or fumes; particula r care should be
lift truck is recomme nded . It is necessary to use the truck taken to protect the equipme nt from moisture and cement
when placing a breaker into or removing it from the metal - dust , as this combina tion has a very corrosive effect on
clad equipme nt . If it is necessary to lift the breaker with a many parts .
hoist use four Vi inch diameter hooks rated at least 500 3. Rollers , latches , etc . , of the operating mechani sm
pounds each . Lifting locations are provided in the side should be coated with 0282 A 2048 P009 grease to prevent
frame members. See Figure I . Use a spreader wider than rusting.
the breaker to prevent slings from contactin g the interrupte r
supportin g insulatin g material parts . If the breaker is stored for any length of time , it should be
inspected periodica lly to see that rusting has not started and
*
A front s \ . ivel wheel and two rear wheels are provided for
* to insure good mechanic al condition . Should the breaker be
ease of movement on flat , level floors . When unattende d stored under unfavora ble atmosphe ric conditio ns , it should
be cleaned and dried out before being placed in service .
6

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 INSTALLATION
SAFETY PRECAUTIONS
This circuit breaker uses powerful springs for energy stor -
age. DO NOT WORK. ON THE INTERRUPTERS OR
MECHANISM UNLESS BOTH THE CLOSING
SPRINGS AND OPENING SPRINGS ARE EITHER
DISCHARGED OR GAGGED AND ALL ELECTRI -
CAL POWER IS REMOVED. These precautions are
required to prevent accidental operation. Anyone working
on the circuit breaker should be familiar with the contents
of this instruction book .
SHIPPING
The circuit breaker has been shipped in the closed posi -
tion with the mechanism trip latch blocked by a bolt through
the rear frame . A yellow tag identifies this bolt ( see Figure
1 ). ( This bolt is in the storage position on breakers shipped
inside the equipment. ) Before operation or insertion into the
metalclad equipment , this bolt must be relocated to the
storage position ( 5 , Fig. 1 ) and the mechanism tripped open
with the manual trip push button . The close spring is
shipped discharged . DO NOT ATTEMPT TO TRIP THE
1. Front Cover 6. Manual Charge BREAKER BEFORE RELOCATING THE BLOCKING
2. Cover Mounting Bolts 7. Counter BOLT . ( I , Fig. 1 )
3. Manual Trip Button 8. Spring Charge Indication After removing packing material, locate and move to the
4. Manual Close Button 9. Closing Spring Gag storage position the trip latch blocking bolt indicated with a
5. Nameplate Access yellow tag on the rear plate of the mechanism . Press in on
10. Open / Close Indicator the manual trip push button ( 3, Fig . 2 ) to trip the mechan -
ism open , keeping hands away from moving parts.
FIG . 2 FRONT VIEW OF POWER / VAC * BREAKER Closing and opening springs are now in their discharged
WITH FRONT COVER positions. Check this by first pressing the manual close
button , then the manual trip push buttons. The indicator
flag on the front of the breaker should also show' “ OPEN ”
and “ DISCHARGED” .

MECHANICAL CHECKING AND SLOW CLOSING

1 . Visually inspect the circuit breaker for any signs of

damage or loose hardware.
2. Manually charge the breaker closing spring using the
charging handle provided ( I , Fig. 5 ). The closing spring is
charged by a ratcheting mechanism that advances by one
ratchet tooth at a time. When the spring is fully charged and
the spring load is held by the closing latch the spring indi -
cator ( 8 , Fig . 2 ) will change from “ DISCHARGED” to
“ CHARGED”, and a positive snap will be heard as the
spring travels over center. After the spring is completely
charged , as indicated above , further forcing the charging
handle may cause damage to the closing latch and its associ -
ated parts.
3. Insert the closing spring gag plate ( 1 , Fig . 4 ) by engag-
ing the detents on the gag plate into the slots on the closing
spring guide . Note that when the closing spring guide is ex -
posed for gaging , an interference angle is exposed on the
1 . Upper Interrupter 8. Counter left side of the breaker ( 1 , Fig . 11 ) . This angle will provide
Connection 9. Spring Charge Indicator interference preventing use of the lift truck and racking of
2. Interrupter Support 10 .Manual Charge the removable element with the closing spring in the blocked
3. Operating Rod 1 1.Manual Close Button position . No attempt should be made to alter , modify or
4. Racking Engagement Lever 12. Handle to Connect other w' ise make inoperative this safety feature .
5. Rollers for Track Secondary Disconnects in
Test Position With the gag plate in position , depress the manual close
Manual Trip Button
button . This action will partially discharge the closing
Open - Close Indicator 13. Closing Spring Gag Access
spring and also partially close the vacuum interruptei con -
tacts . Do not energize the secondary control circuit at this
FIG . 3 FRONT VIEW OF POWER / VAC * BREAKER
time.
WITHOUT COVER 7

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 4. To manually slow -close the breaker contacts, insert
the manual charging handle in the manual charge slot and
move the handle up and down about 12 times until the clos - "' ;

ing roller (5, Fig. 6) is free from the closing cam and resting
on the close prop (8 , Fig . 6).
<•-
it .
r
5. In the closed position , check and record the erosion
indicator dimensions (4 , Fig . 7 ) and the wipe indicator di -
mensions ( 5 , Fig . 8 ) . Check that the position indicator shows
“ CLOSED”. See PRIMARY CONTACT WIPE ( Page 14 )
AND EROSION INDICATOR ( Page 25 ) . Check the insul -
i •

ation resistance to ground by connecting a megohmeter be -

tween the primary circuit and ground . The minimum resis -
tance should be 10 ,000 megohms .

6. Keep clear and push the manual trip push button to

trip the breaker open . Check that the position indicator
shows “ Open ” and the operation counter advances one
count .
82014
7. Repeat ( 2 ) to charge the closing spring and then re -
move the closing spring blocking plate. 1 . Manual Charging Handle
2. Closing Spring Gag Hole
8. Discharge any stored energy in the breaker by suc- (Shown in blocked position )
cesssively depressing the manual close and manual trip
buttons. Preforming these operations leaves the breaker FIG . 5 MANUAL CHARGING
open with the closing spring discharged .

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Electrical checking consists of electrical breaker opera -
tion , secondary wiring high- potential testing ( if required ),
primary current path resistance ( if required ) , Power / Vac *
p T O P O R BOTTOM EDGE
BRE W: interrupter high - potential testing , and insulation resistance
^ to ground .

1 . To check the electrical operation attach a secondary

test coupler to the circuit breaker connector . Check the con -
\ 82015 trol voltage on the nameplate and close and open the
1 breaker several times to check electrical operation .

2. Perform a vacuum interrupter integrity test to verify

1 . Closing Spring Gag Plate the condition of the interrupters . Perform the test as de -
2 . Manual Charging Access scribed under MAINTENANC E .

MANUAL CHARGING 3. Leave the circuit breaker in an open and spring -

FIG . 4
discharged condition after checks are complete and refer ^
metalclad instruction book GEK 39672, before inserting the
circuit breaker into a metalclad unit . Reinstall the front
cover if it has been removed .

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 OPERATION

GENERAL

Closing and opening operations are controlled electrically

The Power / Vac* vacuum circuit breaker uses a sealed
vacuum power interrupter to establish and interrupt a pri - by the control switch on the metalclad or remote relaying.
mary circuit. Primary connections to the associated metal - Mechanical control is provided by manual close and trip
buttons on the circuit breaker. The closing spring may be
clad switchgear are made by horizontal bars and disconnect
manually charged , and a method for slow-closing the pri -
fingers, electrically and mechanically connected to the
mary contacts is available . See MECHANICAL CHECK -
vacuum interrupters. Molded supports, one per pole on a
ING AND SLOW CLOSING . The mechanism will operate
three- pole circuit breaker, provide interchangeable mount -
at the a -c or d -c voltage indicated on the circuit breaker
ings for the primary bars , interrupters , current transfer
fingers, and heat dissipation fins ( where used ). The operat - nameplate.
ing mechanism provides vertical motion at each pole loca -
tion in order to move the lower contact of the vacuum in- Mechanical and electrical interlocks are provided for safe
operation and are described in this section under INTER -
i
terrupters from an open position to a spring-loaded closed
position and then back to the open position on command . LOCKS.

-
The ML- 18 mechanism ( Fig. 9 ) is of the stored energy Figure 9 shows a front view of the ML-18 in a schematic
type and uses a gearmotor to charge a closing spring . During form . The primary contacts are open and the closing springs
charged . The closing spring charging system consists of a
a closing operation, the energy stored in the closing spring
is used to close the vacuum interrupter contacts, charge the closing spring ( 1 ) mounted on the left side of the breaker and
wipe springs which load the contacts, charge the opening the electrical charging system mounted on the right side of
springs , and overcome bearing and other friction forces. the breaker. Both components are fastened to the cam shaft
The energy then stored in the wipe and opening springs will ( 2). A manual charging system (3) is provided so that the
open the contacts during an opening operation. mechanism can be slow-closed and the closing spring can be
charged if there is a loss of electrical control power.

CLOSE SPRING CHARGING

Spring charging is accomplished electrically by a rotating complete cycles of the charging arms are needed for a full
eccentric on the output shaft of the gear motor driving charge of the closing spring. The efficient, compact gear
motor accomplishes this action in just about one ( l ) second .
pivoted charging arms (4, Fig. 9) that oscillate about the
centerline of a ratchet wheel ( 5) . A driving pawl (6) , mounted When the charging cycle is complete the ratchet wheel is
within the charging arms, oscillates with the charging arms. positioned so that a missing tooth is adjacent to the driving
-
Starting from its rear most position as the charging arms
,
pawl and any motor overspin will not drive the ratchet
rotate forward , a spring forces en ^ -igement of the driving wheel , thus preventing damage to the system.
pawl with a tooth on the ratchet wheel. The ratchet wheel is
advanced by the rotating charging arms and pawl assembly. When the spring is completely charged , the assembly is
retained in that position until it is desired to close the circuit
Advancement of one tooth spacing is provided for each breaker.
oscillation of the system. The ratchet motion is restricted to
one direction by a spring loaded holding pawl that prevents The closing coil cannot be electrically energized unless
the ratchet wheel from going backwards as the charging the closing spring is completely charged . This action is pre-
arms oscillate back to pick up the next tooth. Thirteen ( 13) vented by the 52 / CHG switch in the closing circuit.

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 FRAME
f
FRONT OF
BREAKER

( A) BREAKER OPEN — SPRING DISCHARGED

i

FRAME

1 OUTPUT CRANK
2 JACKSHAFT
3 TRIP LATCH
4 TRIP ROLLER
5 CLOSING ROLLER
6 TRIP LINK
7 a CLOSING TOGGLE
7 b CLOSING TOGGLE
8 PROP
9 CLOSING CAM
10 PROP SPRING
11 LINKAGE RETURN SPRING

Note: Shading indicates fixed pivots.

( B) BREAKER OPEN — SPRING CHARGED

FIG. 6 TOGGLE LINKAGE POSITIONS OF THE ML- 18 MECHANISM

10 ( VIEW FROM RIGHT HAND SIDE)

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1

ON
ON
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o
A
FRAME

• 1

!
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^
i i
i

-Pi
—i
( C) BREAKER CLOSED — SPRING DISCHARGED

v. l .
<t

F RAME

1
\

( D) BREAKER CLOSED - SPRING CHARGED 1!

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 The manual charging system ( 3 ) works directly on the If the closing spring has not been recharged , the trip latch
cam shaft where a one way clutch ( 7 ) driven by a manual will be held out of position . A latch checking switch ( 21 ) will '

handle provides rotation of the ratchet wheel . Manual not close unless the latch is in its normal position. The com
pumping of the handle advances the ratchet wheel and the tacts of latch checking switch are in the dosing circuit so that
holding pawl prevents counter rotation while the handle is electrically initiated closing is blocked when the trip latch is f
returning for another stroke . Six ( 6 ) to seven ( 7 ) complete not reset .
strokes of the manual handle are required for one complete
spring charging^
operation . When the spring charge indica - TRIP- FREE OPERATION ( REFER TO FIG. 9 )
tor ( 9 . Fig . 3 ) shows “ CHARGED". MANUAL CHARG -
ING MUST BE DISCONTINUED TO AVOID MECH - The linkage is mechanically tnp-free in any location on
ANISM DAMAGE . the closing stroke . This means that energizing the trip coil
while closing after the auxiliary switch contacts change posi -
CLOSING OPERATION ( REFER TO FIG . 9 ) tion will rotate the trip latch and permit the circuit breaker
to open fully . The linkage will reset as in a normal open
Bv either energizing the close solenoid or depressing the operation and the closing spring will recharge as described
manual close button the close latch ( 8 ) is rotated releasing
, under SPRING CHARGING .
the closing spring ( 1 ) . This action is transmitted to the. clos -
ing cam ( 9 ) and closing roller ( 10 ) and causes the linkage to
rise until the prop ( 11 ) can slip underand hold the linkage in CONTROL CIRCUIT
place . As the linkage moves the output crank ( 12 ) rotates the
A typical Power Vac * circuit breaker ML - IS mechanism
cross shaft ( 13 ) which in turn rotates the phase bell cranks
( 14 ) on all three poles . The rotation of the phase bell cranks
wiring diagram is shown in Fig. 10 . Check the wiring dia -
gram supplied with the actual circuit breaker for its wiring .
compresses the two opening sprtngs ( 15 ) on poles 1 and 3 .
closes the vacuum interrupters and compresses the wipe
The close spring -charging- motor circuit is established
springs ( 16 ) on each interrupter. The rotation of the cross
through the CL ' MS swatch if the close latch is reset and the
shaft ( 13 ) also changes the auxiliary switch ( 17 ) position and
the position flag on the front panel will indicate “ CLOSED’ \
SM / LS switch if the closing spring is discharged . When the
closing spring is charged , the SM LS interrupts the circuit .
After the breaker is closed , the charging motor is again
energized and the closing springs are charged as described
The close circuit is established through two normally
under “ CLOSE SPRING CHARGING". This is possible
closed Y relay contacts. 52 Y and the latch -checking switch
when the breaker is in the closed position because the link - LC , if the trip latch is reset . An auxiliary switch contact 52
age is held in position by the prop .
TABLE 1 (
NOMINAL CHARGE HQTOR CLOSE COIL TRIP COIL
CONTROL
VOLTAGE PART NO. RANGE PART NO . RANGE PART NO . RANGE

.
'd vbC 0 1 7 7C 5 0 5 0 G0 0 3 3 8-5 6 0 2 8 2 A 7 0 I 5G O O I 38 - 5 6 0 2S 2 A 701 S COO
^ 23-56

125 V0C Cl 7 7C 5 0 5 0GQ 0 I 1 0 0 - 1 AO 0 2 8 2A 7 0 I 5G 0 0 2 100- 1 A0 0 2 C 2 A 7 0 1 5G 0 0 6 -

7 0 1 A0

250 V 0C Ol 7 7 C 5 0 5 0G 0 0 2 -
200 280 0 2 3 2 A 7 0 I 5C 0 0 3 -
200 200 0 2 8 2 A 7 0 I 5G 0 0 7 -
I AQ 2 8 0

M S VAC 0 1 7 7 C S 0 5 0C O C I IOA - 1 2 7 0 2 8 2 A 7 0 I 5G0 0 A IOA - 1 2 7 N/A

2 3 0 VAC 0 1 7 7C 5 0 5 0C 0 0 2 208 - 25 A 0 2 82 A 7 0 1 5G0 0 5 203 - 25 A N/A

OPENING OPERATION ( REFER TO FIG . 9 )

is also in series with the close coil and it closes when the
By either energizing the trip solenoid ( 18 ) or depressing breaker is open and opens when the breaker is closed . Dur -
ing a close operation , cam rotation closes the SM / LS con -
the manual trip button , the trip latch ( 19 ) is rotated permit -
tact , picking up the Y relay coil thereby opening its contacts
ting the linkage to collapse and the vacuum interrupter !
to interrupt the close , coil current and sealing it in through a
contacts to open under the force of the wipe springs ( 16 ) and
normally open contact to the close signal . The sealing pre -
opening springs . At the end of the opening stroke a stop
vents reclosing on a sustained close command as the close
hits the frame and limits ovcrtravcl and rebound . Rotation
signal must be removed to drop out the Y relay , and re -
of the cross shaft from the closed to an open position oper -
ates the auxiliary switch ( 17 ) and interrupts the trip coil
establish the closing circuit , thereby providing an anti - pump
current . If the closing spring has been recharged the linkage
feature .
Circuit breaker mounted auxiliary switch contacts ml
<
will be reset so that the trip latch will fall in place on the trip
roller in preparation for another closing operation . used in the control circuit arc brought out for control ana
indication functions . The metalclad equipment may provide
a breaker operated stationary auxiliary switch for addi -
12 tional contacts .

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 83001

1. Interrupter Support
2. Operating Rod Insulator
3. Wipe Spring
4. Erosion Indicator
5. Erosion Disk
( Shown in closed position
with no contact erosion )

FIG . 7 EROSION INDICATOR

INTERLOC KS

Each Power / Vac * vacuum circuit breaker is provided

with the following interlocks. ( 3 ) The function of the NEGATIVE T R I P INTER -
LOCK ( 5 , Fig . I I ) is to remove the trip latch from the trip
( 1 ) Rating interference plate ( 7 , Fig . 12 ) permits only a latch roller thereby preventing a closing operation . The
breaker of the matching continuous current , voltage and interlock also opens the latch checking switch in the closing
interrupting MVA rating to be inserted into a metalclad circuit thereby removing the close circuit power. The nega -
compartment . tive interlock is in operation while the breaker is moving
"
between the “ Disconnect / Test ” position and the “ Connect
The combination 1200 / 2000 ampere breaker can be used position .
in either a 1200 or a 2000 ampere compartment. The rating
interference plate must be adjusted to match the current ( 4 ) The positive interlock ( 3 , Fig. I 1 ) operates to prevent
rating of the compartment . This is done by positioning the the racking of a breaker that is closed . A linkage connected
outer interference plate so that the edge of the plate lines up to the cross shaft extends a detent bar ( 3 ) out from the side of
with the current indicated on the label attached to the the mechanism frame when it is in the closed position . If the
breaker just above the rating interference plate. breaker is in the “ Connect ” or “ Disconnect / Test ” position
in the metalclad the detent bar locks into the racking mech -
( 2 ) The function of the closing spring discharge interlock anism to prevent access to the hex section of the jack screw .
is to prevent racking into or withdrawing from the metalclad
a breaker that has the closing spring charged . This is ac - ( 5 ) The closing spring gag interlock is provided on the
complished by a roller ( 4 Fig. 12 ) on the right - hand side of breaker to prevent a breaker that has a gagged closing spring
the mechanism which contacts the racking mechanism and from entering the metalclad unit . This is accomplishe d by
discharges the closing spring unless the breaker is in the projecting an angle ( I ) out of the left side of the mechan -
Disconnect / Test ” position or the “ Connect" position in sim when the closing spring is gagged . See Fig . 1 I .
.e metalclad . This interlock also opens the CL / MS switch
in the motor charging circuit to prevent charging the closing ( 6 ) Trip Latch Block .
springs when the breaker is between the “ Disconnect / Test "
or “ Connect " position in the metalclad . 13

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 MECHANICAL ADJUSTMENTS

GENERAL
The ML-18 Mechanism has been designed for extended
intervals between maintenance. In most cases only the
wipe and gap adjustments will require re-setting throughout
c t
the life of the circuit breaker. In addition to the descriptions
of the mechanical adjustments, Table 2 contains a summary
of adjustment settings as well as additional measurements
to be checked for proper functioning of the interlocks.

WIPE ADJUSTMENT
O'
CN
Wipe is the additional compression of a preloaded spring, C
used to apply force to the vacuum interrupter contacts and *T
-
to provide opening kick off force. O

An indicator is provided on the wipe spring assembly with

graduations given in 0.050 inch on which the wipe is
indicated directly. See Figure 8 .

Improvement in the accuracy of the wipe measurement

may be obtained by using a feeler gauge between the wipe
indicator and the erosion disc . The difference in readings 2
recorded on each pole with the breaker closed and open will
be the contact wipe.

The wipe should be set as follows:

Breaker Rating Wipe ( inches)

13.8-500 0.155-0.180
Readjust when reduced to 0.075 c
4.16-250 -
0.155 0.180
Readjust when reduced to 0.075

To adjust the primary contact wipe, close the breaker and

block the trip latch with the trip latch blocking rod ( 6),
Figure 12 . This will prevent injury from accidental opening
of the breaker.
( 1 ) Loosen but do not remove the two screws (6) , Figure 8 ,
holding the interrupter clamp.
( 2 ) Check that the interrupter clamp is loose. A light pry at FIG . 8 WIPE INDICATOR
the clamp half junction may be required to loosen the
wedging action of the clamp . 1 . WIPE SPRING
2. OPERATING ROD INSULATOR
( 3) Hold the hexagon projection (9 ) , Figure 8, at the bot - 3. LOCK WASHER
tom of the operating rod insulator ( 1 inch wrench ) and
4. INTERRUPTER CLAMP
lossen the adjacent locknut (V* inch wrench ). Refer to (8 ),
Figure 8 . Adjust by rotating the operating rod insulator. The 5. WIPE INDICATOR
thread is /6 -13 and each turn will give about 0.078 inch 6. CLAMP SCREWS
'
change in primary wipe . Screw the operating rod insulator 7. EROSION DISK
toward the interrupter to increase w'ipe. 8 . LOCK NUT
9. HEXAGON PROJECTION
( 4 ) After setting the contact wipes on each phase torque
-
the operating rod locknut (8 ) , Figure 8 , to 40 50 foot pounds
while preventing the operating rod insulator ( 2 ) from
-
turning . Tighten the clamp screws ( 6 ) to 10 12 foot pounds.
Remove the trip shaft block and trip the breaker open . This After adjustment , remeasure the wipes to check the
procedure prevents accidental twisting of the operating rod adjustment . If the wipe settings are within the required
0
of the interrupter by loading the contacts with the wipe limits, there is an adequate contact closing relationship I
springs and forcing relative rotation to occur at the clamp between the poles.
interface .
14

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 0 l 44 D 1299-2

ITEM BREAKER CLOSING OPENING TRIP ADJUSTMENT DETAIL

SEE FIG . 8 A POSITION SPRING SPRING LATCH
.
1 DEPRESS PLUNGER WITH A . 19 SPACER ( EXAMPLE: . 19 DRILL ) PLACED BETWEEN
1 . TRIP COIL CLOSED DISCHARGED CHARGED UNBLOCKED PLUNGER BASE AND COIL HOUSING .
2. TURN ADJUSTING NUT UNTIL TRIP PIN MAKES CONTACT WITH TRIP ARM .
1 . ADVANCE ADJUSTING SCREW UNTIL BREAKER CLOSES
2 . CLOSE LATCH OPEN CHARGED DISCHARGED UNBLOCKED 2. BACK ADJUSTING SCREW OFF 1 / 2 TURN .
3. CHECK ELECTRICAL CLOSE / CHARGE .
1 . DEPRESS PLUNGER WITH A .19 SPACER EXAMPLE: . 19 DRILL ) PLACED BETWEEN
PLUNGER BASE AND COIL HOUSING .
3 . CLOSE COIL OPEN CHARGED DISCHARGED UNBLOCKED
2. TURN ADJUSTMENT NUT UNTILCLOSE LATCH ACTUATOR MAKES CONTACT WITH
CLOSE LATCH .
4 SPRING 1 . GAGED . 840 DIM WITH ADJUSTING SCREW BACKED OFF.
DISCHARGE OPEN CHARGED DISCHARGED UNBLOCKED 2. ADVANCE ADJUSTING SCREW TO MAKE CONTACT WITH LEVER .
INTERLOCK 3. CHECK THAT SPRING DISCHARGES AT .561 MIN . DIM .
4. CLOSE LATCH MUST RESET AS INDICATED.
5. OPENING 1 . SET ADJUSTING NUT SO THAT OPENING SPEED IS APPROX . 5.0 FT / SEC. ( MUST BE
SPRING AS REQ’D. AS REQ’D. AS REQ’ D . UNBLOCKED GREATER THAN 3.5 FT / SEC ) AND CLOSING SPEED IS APPROX . 2.75 ET / SEC ( MUST
BE LESS THAN 4 0 FT / SEC ).
1 . CLOSE BREAKER . ( LINKAGE MUST BE ON PROP LATCH ). FIG . 6 D
2. BACK OFF OPERATING ROD UNTIL CONTACTS ARE SEPARATED
CHARGED .
3. WITH BUZZER ACROSS CONTACTS ADVANCE OP ROD UNTIL CONTACTS TOUCH .
4 . ADVANCE OP. ROD 2 /5 ADDITIONAL TURNS .
6. WIPE CLOSED & GAGGED CHARGED BLOCKED
5. LOCK LOCK NUT.
‘
6. CHECK WIPE — -
MUST BE . 155 . 180 ( SET ALL 3 PHASES BEFORE MEASURING ).
7 . IF REQUIRED , ADJUST TO FINE TUNE.

CHARGED OR
-
1 . SET ADJUSTING NUT SO THAT GAP IS . 545 600 .
7 GAP OPEN DISCHARGED UNBLOCKED 2. CHECK THAT TRIP LATCH WILL RESET .
DISCHARGED
3. ADJUST GAP IF TRIP LATCH WILL NOT RESET.
8 . N O. 1. ADJUST SWITCH FOR RECESS SHOWN WHEN PLUNGER IS DEPRESSED ( CONTACTS
AS REQ’ D.
SWITCHES CLOSED )

TABLE 2 SUMMARY OF ADJUSTMENTS AND CRITICAL DIMENSIONS

 TRIP ARM

CLOSE! LATCH
ACTUATOR
c
TRIP PIN ADJUSTING NUT
&C "
I '
'

I CLIP

ADJUSTING NUT

M COIL HOUSING
COIL HOUSING
SiJ
DEPRESS PLUNGER
rDEPRESS PLUNGER
I FOR .19 GAP
FOR .19 GAP 1
T : V.n . - PLUNGER BASE
PLUNGER
BASE

TRIP COIL CLOSE COIL

SEE TABLE 2 — ITEM 1 SEE TABLE 2 — ITEM 3 C

ADJUSTING SCREW 0
r
—
.840 MIN. POSITION
TO PERMIT CLOSE
ADJUSTING SCREW 0
T
/ 1, -
LATCH RESET
rc .

II
;n
I
' ( i/ f —.
1 561 MIN. POSITION TO
DISCHARGE SPRING

f.l .
<L >

CLOSE LATCH
SEE TABLE 2 — ITEM 2 i
SPRING DISCHARGE INTERLOCK
SEE TABLE 2 — ITEM 4

16

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*
0144D1299 -2

je

- CP •

I
OPERATING ROO
1
•

LOCK NUT
OPENING SPRING I

ADJUSTING NUT DISK

EROSION
i
INDICATOR

Hi
rr ft? ;
FLU
I t
:
u
11

f
i r • i
i
i
i
i

i
WIPE SEE TABLE 2 - ITEM 6
EROSION INDICATOR
i
i

£.27 i
•
i
i

REF
i
t
i i »
* i

J SI

{ GAP ADJUSTING
3.43 NUT
REF 065 .010
.
*
[ SWITCH BOOT
n PLUNGER
i i
;

©
u
OPEN POSITION
CLOSED POSITION N.O. SWITCHES
SEE TABLE 2 — ITEM 8
OPENING SPRING SEE TABLE 3 - ITEM 5

GAP SEE TABLE 2 — ITEM 7

FIG. 8 A

MECHANICAL
ADJUSTMENTS
AND
SETTINGS
17

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 VIEW 0 VIEW A view
0144 D1299-4 e
A

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VIEW 0 0 VIEW
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FIG . 9 SCHEMATIC OF ML- I 8 MECHANISM

f
1. CLOSE SPRING 12. OUTPUT CRANK

2. CAM SHAFT 13. CROSS SHAFT

3. MANUAL CHARGE 14. BELL CRANKS

4. CHARGING ARMS 15. OPENING SPRINGS

5. RATCHET WHEEL 16. WIPE SPRINGS

6. DRIVING PAWL 17 . AUX . SWITCH

7. ONE- WAY CLUTCH 18. TRIP SOLENOID

8 . CLOSE LATCH 19 . TRIP LATCH

9 . CLOSE CAM 20 . OVER -TRAVEL STOP

10. CLOSE ROLLER 21 . LATCH CHECK SWITCH

II . PROP 22. GEAR MOTOR

/

18

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o.
>

r^i
a *
/

PARTIAL VIEW — A
7

DIRECTION ^
OF ROTATION
15

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PARTIAL VIEW — D

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PARTIAL VIEW —C i

V y
=: /

19

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fO
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I

CONNCCUON 0 JAGKAM INSERT

i 2 3 5 6 7 8 m 11 12 13 U l3 16 17 18 19 20 2 \ 22 23 2 ‘
* *
|\ J J | j\ Jv | Jv j |v j
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/ / ' v
/ \ / \ / / / \ / \ / / \
INSERT
k / /
CLOSING CIRCUIT
5
Q o o r o > - »- O i%(
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ii a . ^ a r s Q. <A A. » & m ©
7 2

1 MOTOR
CIRCUlT
TRIP
CIRCUlT 'o 2
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52 3 9 5 6 7 8
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4 32 13 16 15
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NOT USED 2i 2T L C S >
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--
1 L 2I -
3 L11
--
6
7 1 LC32 3C -L 1 2 1 L3 DISCONNECT PIN

i K l x lfx f *i
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1C X 2
-
2C L 9
-
6 L 13
6 C -L 1 6 SM / TS 2 S1
-
3 L5
CONTACT
N/0
TYPE
N/ C
LOCUTIONS
or
-. WIRE
^
1C
. C 3 -11 3 7 -L l 9 - SIDE BKR

. s5 /r$
cr;
3 L2 32
f f T P ia
2 3 C - L 2I
3 C -L l 6
-
7C L 22
8 -L I 7
6-Y1
3 -L l i
2 32X
CHG
CL /MS
x COUPLER
3-x 1
1» I k *•C - T C 2 0 C -L 1 0
6-Y6
32
x
6 -L 0
32

MM ®
METAL JUMPER X
CHG

- S2
2-
1
L6
3 2/ 0 6 0
32
SM/L S
X

-- .

-
AUX
L 10
--
l
1 1 1 D3 CLOSING RESIST
2 P C CONTACTS
* 2 PIC
P CIRCUIT 1 1
PROMT OF BREAKER 2
*
BOT TOM VIEW 19

7C
7
23

SPARE
t 1- ©
001
002
VOLTAGE
6 0 v DC

1 2 3 V 0C
OHMS

NOTES BREAKER SHOWN " OPEN " AND WITH

CLOSING SPRING DISCHARGED" - 22
003
0 0 **
003
2 3 0 VOC
\ l3vAC
2 3 0 VAC
3300
0
0
CLOSING LATCH MONITORING SWITCH I S CLOSED SPRING RELEASE COIL OPERATES LATCH
32 x
32 WHEN L A T C H i s C A P A B L E OF B L O C K I N G FULLY WHICH RELEASES CLOSING SPRING TO
C L / M S C H A R G E D C L O S I N G S P R I N G, H E L O O P E N CLOSE 52 .
BETWEEN OISC .
t CONNECT POSITIONS . GROUND P I N U S E D F O R I N S P E C T I O N B O X
L I M I T SWITCH FOR SPRING CHARGING MOTOR -
©
ONL T .
32
SM/LS
ARE FULLY
- -
CONTACTS < 1 2 1 1 3 6 ) OPEN WHEN SPRINGS
C M O R G E O. 52 TRIP LATCH CHECKING SWITCH
LCS CLOSCO WHEN LATCH I S RESET .
32 CONTACTS CLOSEO WHEN CLOSING SPRINGS
CMG ARE FULLY CHARGEO . SEE TABLE FOR RES. VALUE

FIG . 10 TYPICAL WIRING DIAGRAM ML I 8 MECHANISM -

0209 B8199 - 1
 9

!. GAG INTERLOCK ANGLE

2. TRACK ROLLERS

3. POSITIVE I N T E R L O C K B A R

4. CLOSING S P R I N G
DISCHARGE ROLLER P VI BREAKER — F R O N T A N D L E F T S I D E VIE W
5. NEGATIVE INTERLOCK ROLLER

TRIP LATCH BLOCKING ROD 26981 - 2

7. RATING INTERFERENCE PLATE

8. FRONT COVER

9. R A C K I N G E N G A G E M E N T LEVER

10 . SECONDARY COUPLER

F I G . 12 PVI BREAKER — REAR AND RIGHT SIDE VIEW

21

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 82007

F I G . 13 T R I P COIL ADJUSTMENT

1 . T R I P COIL

2. CLOSING SPRING
3. T R I P COIL ADJUSTING

SCREW A N D NUT

>
’•

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f

82018

F I G . 14 CLOSING COIL ADJUSTMENT

CLOSING COIL ADJUSTING NUT

2. CLOSING COIL ADJUSTING SCREW

3. LINK TO CLOSING LATCH

23

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 83004

B O T T O M V I E W O F M L- 18 S P R I N G C H A R G E D M E C H A N I S M

I. CLOSING SPRING 9. 52Y RELAY

2. OPENING SPRING 10 . PIVOT BOLT

3. AUXILIARY SWITCH 11. INTERLOCK BRACKET

4. SPRING CHARGING MOTOR 1 2. SM/ LS MOTOR CONTROL SWITCH

5. TRIP COIL 1 3. L/ C LATCH CHECKING SWITCH

6. C L O S I N G C O I L 1 4. CL/ MS CLOSING LATCH

MONITORING SWITCH
7. RATCHET WHEEL
15 . STATIONARY AUXILIARY SWITCH
8. CLOSING CAM OPERATOR

24 1 5. CLOSE LATCH ADJUSTING SCREW

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 ELECTRI CAL CHECKS

INDICAT ION CONTRO L POWER

PRIMARY CONTACT EROSION
* ( 5), Figure 7, After the breaker has been operated several times with the
in the closed position , the indicator disk manual charging lever and the mechanism adjustment s are
ow the operating rod insulator is aligned with a reference
) on new interrupter s. With the breaker in the closed checked as described , the closed circuit operating voltages
( 4
irm
disk ( 5), Figure 7, will move upward should be checked at the close coil, trip coil, and motor
position , the indicator
alignment with the reference point due to contact terminals. Control power for electrical operation of the
: rom breaker may be from either an alternating or direct current
:rosion. Contact erosion will decrease the wipe
which may
brought back to normal by performing wipe adjustment . source . The operating ranges for the closing and tripping
voltages as given on the breaker nameplate, are as follows:
ie A
When erosion reaches 1 / 8 inch, the Power / Vac* inter -
upters should be replaced . Do not readjust the alignment of Trip
Rated Close or
he erosion indicator except when installing a new vacuum Circuit
Nominal Motor Circuit
nterrupter. Min. Max .
Voltage Min. Max .
CONTRO L COIL PLUNGER TRAVEL
48 DC 38 56 28 56
TRIP COIL 125 DC 100 140 70 140
250 DC 200 280 140 280
With the breaker in the open position and the closing
spring in the charged position , make certain that the trip
linkage and trip shaft move freely over the full plunger 120 AC 104 127 Not available in
.ravel. 240 AC 208 254 ML-18

CLOSE COIL
If the closed circuit voltage at the terminals of the coil or
With the closing spring discharged operate the plunger in motor does not fall in the specified range , check the voltage
the same manner as described above for the trip coil. Make at the source of power and line drop between the power
:ertain that the plunger moves freely over its full stroke in source and breaker.
; he coil .
When two or more breakers operating from the same
CONTRO L SWITCHE S control power source are required to close simultaneo usly ,
the closed circuit voltage'at the closing coil or motor of each
There are three switch locations on the ML 18 - breaker must fall within the specified limits.
mechanism. The CL / MS closing latch monitoring switch
( 14 ), Figure 15, is to the rear of the ratchet wheel and is TIMING
operated from the closing latch linkage. The SM / LS spring
motor limit switches ( 12), Figure 15, control the spring Timing may be checked by monitoring control circuit
-
charging motor and the anti pump relay. The 52 charge voltage and using no more than six volts DC and one
switch , which is in the same location, can be used for remote ampere through the vacuum interrupter contact to indicate
indication of the charged condition of the spring. L / C latch closed or open condition. Typical time ranges vary with coil
checking switch 13, Figure 15 , monitors the position of the voltage but nominal values are:
trip latch .
Initiation of trip signal to contact parting
The switches are adjusted as described in Table 2 Item 8. -
35 45 Millisecon ds

Initiation of close signal to contact closing

60-90 Millisecon ds

Trip-free operation may be checked by applying a simul -

reclose
taneous close and trip signal and a minimum
operation may be checked by tripping a charged breaker
open while maintainin g a close signal .

Instantane ous reclose time* 100-150 Millisecon ds

Time from applicatio n of trip signal and close signal

until breaker opens and recloses.

25

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 MAINTENA NCE interruption remain in the chamber and are deposited on
metal shields thus insuring a high dielectric value of the i
GENERAL vacuum and the walls of the glass container.
Power / Vac* circuit breakers have been designed to be as
maintenance free as practicable. They include features such
as sealed vacuum interrupters and long life synthetic greases
which contribute to many years of trouble free performance
CONTACT EROSION

Check in the breaker-closed position per PRIMARY

f
with a minimum amount of maintenance attention . CONTACT EROSION INDICATION . When erosion
reaches 1 / 8 inch , the interrupter should be replaced .
SERVICE CONDITION S
TRANSFER FINGER WEAR
The frequency of required maintenance depends on the
severity of the service conditions of the switchgear applica -
Examine the moving contact rod projecting below the
tion . If the service conditions are mild the interval between
transfer fingers with the breaker open , wiping off the
maintenance operations may be extended to 10 years or
lubricant in order to see the metal surface condition . The
10 ,000 no load or normal load switching operations.
finger locations should present a burnished silver contact
Mild service conditions are defined as an environment in without copper appearance at more than one location . If
• copper is visible at more than one location per pole or the
which the switchgear is protected from the deleterious ef -
fects of conditions such as: silver plating is torn , the interrupter assembly should be
replaced .
Salt spray
Changes in temperature that produce condensation INSULATION TESTS
Conductive and / or abrasive dust
Damaging chemicals and fumes
Vibration or mechanical shock
High relative humidity ( 90%) Since definite limits cannot be given for satisfactory
-
Temperature extremes ( 30° C, 40° C) insulation values , a record should be kept of the megoh -
meter readings as well as temperature and humidity read -
BEFORE ANY MAINTENAN CE WORK IS PER - ings. This record should be used to detect any weakening of
FORMED, MAKE CERTAIN THAT ALL CONTROL the insulation from one check period to the next.
CIRCUITS ARE DE - ENERGIZED AND THAT THE
BREAKER IS REMOVED FROM THE METAL-CLAD The primary circuit insulation on the breaker may be
UNIT . DO NOT WORK ON THE BREAKER OR
MECHANISM WHILE IN THE CLOSED POSITION
WITHOUT TAKING PRECAUTION S TO PREVENT
ACCIDENTA L TRIPPING. THIS CAN BE DONE BY
checked phase to phase and phase to ground using a 2500 V
megohmeter.

To measure the breaker secondary circuit insulation re

( ^-
REPLACING THE TRIP LATCH BLOCKING BOLT sistance, remove the motor leads, and thread a wire con-
USED FOR SHIPPING TO BLOCK THE TRIP SHAFT necting all secondary disconnect pins together except pin
AND SECURE THE INTERRUPT ER CONTACTS IN # 24 (ground pin). The measurement may be made by con -
THE CLOSED POSITION. DO NOT WORK ON THE necting a 500 V megohmeter from the wire to ground .
BREAKER WHILE THE CLOSING SPRING IS
CHARGED UNLESS IT IS SECURED IN THAT HIGH-POTENTIAL TEST
POSITION BY THE CLOSE -SPRING GAG.
If high potential tests to check the integrity of the
FAULT INTERRUPT IONS insulation are required , the AC high potential test described
The erosion rate of the primary contacts in the vacuum is strongly recommended . DC high potential testing is not
interrupters is very low for no load and normal load switch
ing operations. However, fault current interruptions at or
- recommended except for the VACUUM INTERRUPT ER
INTEGRITY TEST, The following procedure must be
near the breaker rating may result in appreciable contact adhered to.
erosion. With frequent fault interruptions it is necessary to
perform maintenance based on the number of interruptions. CAUTION: IF DC HIGH POTENTIAL TESTING IS RE -
After each 15 fault interruptions the following should be QUIRED, THE DC HIGH POTENTIAL MACHINE
performed . MUST NOT PRODUCE PEAK VOLTAGES EXCEED-
ING 50 KV.
1 . Contact erosion per page 27
2. Wipe and gap per Table 3 Item 6 & 7 ( 1 ) Primary Circuit —The breaker should be hipotted in
the closed breaker mode. An AC hipot machine
3. Vacuum interrupter integrity test per page 27 capable of producing the test voltages shown below
may be used to hipot the breaker phase to phase and
POWER / VAC* INTERRUPT ER phase to ground .
The Power / Vac * interrupter used in this breaker is
a reliable , clean interrupting clement . Since the contacts are
BREAKER VOLTAGE
Rating
TEST VOLTAGE
60 HZ ( RMS )
*
contained in a vacuum chamber , they remain clean and
require no maintenance at any time . The metallic vapors 4.16 KV 14 KV
eroded from the contact surfaces during high current 13.8 KV 27 KV
26

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 with its output CAUTIO N: MANY DC HIGH POTENT IAL MA-
The machine should be connected CHINES ARE HALFW AVE RECTIF IERS. THIS TYPE
the voltage increased to the test voltage
,* potentia l at zero and OF HI- POT TESTER MUST NOT BE USED TO TEST
ind that voltage maintain ed for 60 seconds . The voltage
zero and the hipol machine VACUU M INTER V iu* PTCRS. THE CAPAC ITANCE OF
ii
(

should then be returned to

- moved from the circuit . NOTE — Do not exceed the test THE POWER / VAC* BOTTLE S IS VERY LOW AND
THE LEAKAG E IN THE RECTIF IER AND ITS DC
:age indicate d for the applicab le breaker voltage rating
.
;
VOLTA GE MEASU RING EQUIPM ENT IS SUCH
— Prior to hipotting the breaker THAT THE PULSE FROM THE HALFW AVE RECTI -
( 2 ) Secondar y Circuit
secondary circuit , remove the motor leads, thread FIER MAY BE IN THE NEIGHB ORHOO D OF 120 KV
a wire connectin g all secondar y disconne ct pins to - WHEN THE METER IS ACTUAL LY READIN G 40 KV .
gether except pin # 24 ( ground pin ) . Connect the IN THIS CASE , SOME PERFEC TLY GOOD BOTTLE S
hipot machine from this wire to ground . Increase the CAN SHOW A RELATI VELY HIGH LEAKA GE CUR -
voltage to 1 125 volts ( rms ) 60 Hz and maintain for RENT SINCE IT IS THE PEAK VOLTA GE OF I 20 KV
60 seconds. Reduce the voltage to zero and remove THAT IS PRODUC ING ERRONE OUS BOTTLE LEAK -
the hipot machine from the circuit . Remove the AGE CURREN T. IN ADDITI ON , ABNORM AL X -
wire connectin g the secondary disconne ct pins and RADIAT ION MAY BE PRODUC ED.
reinstall the motor leads.
• An acceptabl e high potential machine is available
from
VACUU M INTERR UPTER INTEGR ITY TEST the Medium Voltage Switchge ar Business Section , Burling-
ton , Iowa , Catalog Number 282 A 2610 P001 . The followin g
CAUTIO N: X - RADIAT ION MAY BE PRODUC ED IF machine s are also acceptabl e.
\ N ABNOR MALLY HIGH VOLTAG E IS APPLIED
ACROS S A PAIR OF ELECTR ODES IN A VACUUM. Hipotron ics Model 860 PL
X - RADIAT ION MAY INCREA SE IN VOLTAG E AND /
OR A DECREA SE IN CONTA CT SEPARA TION . Hipotron ics Model 880 PL

DURING A HIGH POTENT IAL OR A VACUU M IN - Hipotron ics Model 7 BT 60 A

TEGRIT Y TEST ANY X-RADIAT ION WHICH MAY Catalog 222060
BE PRODU CED WILL NOT BE HAZAR DOUS AT A James G. Biddle
DISTAN CE SAFE FOR HIGH POTENT IAL TESTIN G ,
:F THE TEST IS CONDU CTED AT THE RECOM - PRIMAR Y CIRCUI T RESISTA NCE
MENDE D VOLTAG E AND WITH THE NORMA L
°EN CIRCUI T BREAKE R CONTAC T SEPARA-
ON . A resistanc e check of the primary circuit may be made
with the breaker closed . Use a low resistanc e measurin g
instrume nt which measure s microhm s. The 100 ampere
DO NOT APPLY VOLTA GE THAT IS HIGHER THAN reading should not exceed 50 microhm s when connected
THE RECOM MENDE D VALUE. DO NOT USE CON- across the primary bars on the breaker side of the disconne ct
TACT SEPARA TION THAT IS LESS THAN THE fingers.
NORMA L OPEN POSITIO N SEPARA TION OF THE
BREAKE R CONTA CTS. MECHA NISM

Check all items on Table 2, Summary of Adjustm ents and

Critical Dimensi ons, readjusti ng or tightenin g as required.
This test of the vacuum interrupte r will determin e its in - Lubricat e as recomme nded under LUBRIC ATION .
ternal dielectric conditio n and vacuum integrity. With the
breaker open individua lly check each interrupte r by con-
necting the hipot machine “ hot ” lead to the upper stud and PRIMAR Y INSULA TION PARTS
:he ground lead to the lower stud . If the machine has a center
point ground , the connecti ons may be made either way. Ap -
Using dry non linting cloth or industria l-type wipers,
-
ply 36 kV ( rms ) 60 Hz or 50 K V DC (except for P / V 42 A in- -
clean accessibl e insulatio n surfaces on the interrupt er sup
terrupters apply 19 kV ( rms ) 60 Hz or 27 KV DC) and hold a
ports and operating rod insulator s. In service locations
minimum of five ( 5) seconds. If no breakdow n occurs the where contamin ation is heavy or external flashove rs have
interrupt er is in acceptab le conditio n . If a breakdow n oc - occurred during interrupt er high -potential testing, remove
curs, the interrupt er should be replaced . the interrupt er assembly per the procedur e in REPAIR
AND REPLAC EMENT and clean the inside surface of the
No attempt should be made to try to compare the interrupte r supports and the outer insulatio n surface of the
condition of one vacuum interrupte r with another nor to Power / Vac* interrupt ers. Be sure to discharge the inter -
correlate the condition of any interrupte r to low values of rupter midband ring before removing the interrupt ers.
DC leakage current . There is no significan t correlatio n . Removal and reassemb ly of interrupt ers will normally not
require readjustm ent due to the design of the interrupt er
After the high potential voltage is removed , discharge any operating rod insulator connecti on. They should be re -
electrica l charge that may be retained . turned to the same location from which they were removed.

27

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 LUBRICATION RECOMMENDED MAINTENANCE
Proper lubrication is important for maintaining reliable The following operations should be performed at each
-
circuit breaker performance. The ML !8 mechanism uses maintenance.
bearings which have a synthetic lining in some locations.
These bearings do not require lubrication to maintain low
friction, but lubrication does not harm them and oiling
lightly is recommended . Sleeve bearings are used in some
1. Perform a visual inspection of the breaker. Check for
loose or damaged parts.
f
linkage locations and needle or roller bearings are used for 2 . Perform the slow closing operation described on page
low friction on trip shaft and close shaft. 1 2.
Bearings are lubricated during factory assembly with 3. Check the erosion indicator and the wipe and gap as
grease and oil but , all lubricants have a tendency to described on pages 14 and 25 .
deteriorate by oxidation or contamination with age .
Providing a fresh lubricant supply at periodic intervals is 4. Perform the vacuum interrupter integrity test as de -
essential to proper breaker operation , especially where scribed on page 27.
frequent operation may have forced lubricant out of the
bearing surfaces. Apply a few drops of light synthetic ma - 5 . Lubricate the breaker operating mechanism as de -
chine oil such as Mobile l at each bearing . Apply a coat of scribed on this page.
0282 A2048 P009 on the four corners of the closing spring
guide where it enters inside the spring. 6. Check the electrical operation using the test cabinet
Electrical primary contact surfaces also require periodic ( if available ) or the test position in the metalclad switchgear.
lubrication to inhibit oxidation and minimize friction. At -
each inspection and maintenance interval, do the following:
1. Examine the movable contact rod of the vacuum in
terrupter. With the breaker open, wipe the lubricant off the
( 1 ) Metal contact surfaces such as the movable contact rod and examine the silver surface . The rod should have a
rod of the interrupter should be lubricated with burnished appearance without copper appearing through
.
0282 A2048 P009 This grease is available packaged in the silver. If copper is visible at more than one location per
a pint can to provide cleanliness and prevent oxida- pole, or if the silver plating is torn , the interrupter assembly
tion. should be replaced . Relubricate movable contact rod with
( 2 ) Silvered primary contact surfaces. Wipe clean and 0282 A2048 P009 grease .
-
apply a light coat of 0282 A2048 P009 on primary dis
connect fingers. 8. If desired , perform the additional electrical tests
( 3 ) Pins of the secondary disconnect coupler should be
lightly coated with 0282 A2048 P009.
( Megger , primary and secondary high potential, and pri
mary circuit resistance ) . See page 26.
REPAIR AND REPLACEMENT
-
f
GENERAL

The following information covers in detail the proper 1. Close the breaker and remove the coupling clamp, ( 2 )
method of removing various parts of the breaker in order to Fig. A2. Open the breaker and remove the four bolts hold -
make any necessary repairs. This section includes only those ing the pole assembly to the mechanism and remove the old
repairs that can be made at the installation on parts of the pole assembly.
breaker that are most subject to damage or wear.
2. Set the new pole assembly in place and install the four
IMPORTANT: UPON COMPLETION OF ANY KIND mounting bolts. Set the pole assembly so that the distance
OF REPAIR WORK , ALL INTERRUPTER AND between the primary studs and the studs on the adjacent pole
MECHANISM ADJUSTMENTS MUST BE CHECKED. assembly are 10" apart.

Refer to the sections on MECHANICAL AND ELEC- 3. Close the breaker using the Slow Closing Operation .
TRICAL ADJUSTMENTS. Perform theclosing operation slowly while guiding the tip of
the operating rod into the base of the movable contact rod ,
REPLACEMENT OF INTERRUPTER ASSEMBLIES ( 2 ) Fig . 8 , on the vacuum interrupter. After the breaker is
fully closed install the coupling clamp.
Interrupters are supplied as complete pole units which
include the vacuum interrupter mounted in the interrupter 4. Check and adjust the erosion indicator ( 5 ) Fig . 7 ( if
support . The primary studs with disconnect fingers are part new interrupter assembly is installed ) , and the Wipe and
of the interrupter assemblies. Gap as described in Table 3 Item 6.

CAUTION 5. Perform the Vacuum Interrupter Integrity test .

DO NOT ATTEMPT TO REMOVE OR REINSERT 6. Check primary stud wipe. ( Refer to GEK 39672 , I n - j
THE VACUUM INTERRUPTER I N T H E INTERRUPT - structions and Recommended Parts For Maintenance . See
ER SUPPORT ASSEMBLY . SPECIALTOOLS AVAIL - section on Breaker Installation and Removal )
ABLE ONLY AT THE FACTORY ARE REQUIRED.
28

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 CAUTION 5. Remove the closing spring.

6. Loosen the interlock bracket ( 11 ).

THE PRIMARY STUD WIPE CAN ONLY BE
CHECKED WHEN THE SWITCHGEAR IS DEENER-
:ED. 7. Remove the nuts from the coil bracket leaving the two
bolts in place.
PRIMARY DISCONNECT FINGERS
8. The trip coil can now be removed by cutting the coil
The primary disconnect Finger assemblies can be removed leads .
removing roll pins which hold them in place on the pri -
mary studs. Finger contact surfaces should be coated with To install the new coil connect leads with insulated butt
1282 A -2048 P009 lubricant . connectors and reverse the above procedure . See Table 3
M LCHANISM Item I for setting the stroke of the armature . Apply Loctite
to the threads of the pivot bolt when it is replaced . Charge
Pin Retaining Rings
ML 18 mechanism to retain
—
These rings are widely used in the
pins. They can be installed and
the breaker and electrically close and trip it to make certain
it has been reassembled correctly.
emoved with a pair of standard pliers. Reuse is not
. To remove , slowly squeeze the
recommended after removal CLOSING COIL REPLACEMENT
'emoval ears while pulling . To install , position on the pin
groove and squeeze the installation ears closed to no more Remove the closing coil housing (6 ) , Figure 15.
:han 1 / 16 inch gap between ears . Disassemble the closing armature and closing coil
adjustment screw ( 2 ). Figure 14. Cut the leads to the closing
-
coil and remove the coil . Butt splice the new coil into the
wiring harness and reassemble the coil and housing.
_
»«STAU ATlON REMOVAL
Readjust the closing coil armature travel in accordance with
«$ EARS instructions in Table 3 Item 2.

RENEWAL PARTS

It is recommended that sufficient renewal parts be carried

in stock to enable the prompt replacement of any worn ,
broken , or damaged parts. A stock of such parts minimizes
service interruptions caused by breakdowns , and saves time
CONTROL SWITCHES
and expense. When continuous operation is a primary
consideration , more renewal parts should be carried , the
Control switches may be removed from their mounting amount depending upon the severity of the service and the
brackets by disconnecting the wires and removing the two time required to secure replacements.
mounting screws . Use a small screwdriver to remove and
replace the switch on the bracket checking that the correct Renewal parts which are furnished may not be identical to
type , normally open or normally closed , is used . Reinstall
the original parts , since improvements are made from time
wire and adjust per MECHANICAL ADJUSTMENTS
CONTROL SWITCHES.
— to time. The parts which are furnished , however , will be
interchangeable .
TRIP COIL REPLACEMENT The renewal parts list covers all breakers on the cover .
TOOLS REQUIRED

— 5 / 16 Allen wrench
" ORDERING INSTRUCTIONS
— Needle nose pliers
— 77 / 1616 socket wrench
" 1. Always specify the complete nameplate data of both
— / box / combination wrench
" the breaker and the mechanism .
— 1 / 4 square drive ratchet
"

— 1 / 4 square 3 extension
" " 2. Specify the quantity , catalog number ( if listed ) , refer -
— Loctite # 271 or equivalent ence number ( if listed ) , and description of each part
ordered , and this bulletin number .
Perform the operation in the foilwing sequence:
3. Standard hardware , such as screws, bolts , nuts , wash -
1 . Charge closing spring and install gag plate . ers , etc. is not listed in this bulletin . Such items should
be purchased locally .
2. Depress the close and then the trip buttons .
4 . For prices or information on parts not listed in the
3. Pump the manual close handle 3 -4 times . Renewal Parts List , refer to the nearest office of the
General Electric Company .
4 . With the 5 / 16" Allen wrench remove the pivot bolt
( 10 ) , Figure 15 , on the closing spring ( 1 ) . 29

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 -
RECOMMENDED SPARE PARTS FOR POUER/ VAC BREAKERS WITH ML 18 MECHANISM

NO. REQ' O CATALOG

NO.
f
PER BRKR. MODEL DESCRIPTION
Charging Motor
1 0 48 V - DC 0177C5050G003
-
125 V - OC and 120 V AC
250V -DC and 240V - AC
0177C5050G001
01 77C5050G002

Relay (Non -Nuclear)

1 0 48V -DC 0282A2008P001

0282A 2008P002
-
125 V 0C
250V -DC 0232A 2008G001
120V -60 Hz 0282A2008P003
0282A2008P004
-
240V 60
120V -50
Hz
Hz 0282A 2008P005
240V -50 Hz 0282A2008P006

Potential Trip Coil

(5 Cycle)
1 0 48V - DC
125 V -DC
0282 A 7015G004
0282A 7015G006 f
250V -DC 0282A 7015G007

Closing Coil (Standard)

1 0 48V -DC 0282A7015G001

---
125 V DC 0282A 7015G002
250V DC 0282A 7015G003
120V AC 0282A 7015G004
240V - AC 0282A7015G005

Control Switch ,
2 0 Normally Open 0282A 7094P001

Control Switch ,
2 0 Normally Closed 0282A 7094P002

1 0 Auxiliary Switch 0209B8064P001

0
1

30

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 -
RECOMMENDED SPARE PARTS FOR POWER / VAC BREAKERS WITH ML 18 MECHANISM
INTERRUPTER ASSEMBLY
( POLE UNIT COMPLETE )

I BREAKER CONTINUOUS c u TYPE CATALOG

TYPE MODEL CURRENT CURRENT APPLICATION Q7Y . NUMBER
AMPERES RATING , KA

VBl 0 1200 58 STANDARD 3 0282A 2751G077

4.16 - 250 0 2000 58 & 3 0282A 2751G079
0 1200 / 2000 58 SEISMIC 3 G282 A 2751G081

VBt 0 1200 37 STAWAKO 3 0282 A2751G052

13.8 - 500 0 2000 37 & 3 0282A 2751G054
0 1200 / 2000 37 SEISMIC 3 0282A 2751G068

.!
J

VBl 0 1200 58 STANDARD 3 0282A2751G089

13.8- 500 0 2000 58 & 3 0282A 2751G090
1200 / 2000 58 SEISMIC 3 0282A 2751G091

-
RECOMMENDED SPARE PARTS FOR POWER / VAC BREAKERS WITH ML 18 MECHANISM

QUANTITY PER BREAKER

1200 /
] 200 2000 2000
DESCRIPTION MODEL 37 58 37 58 37 58 CATALOG NO .

PRIMARY 0 6 0282 A 2725 G002

DISCONNECT 0 6 0282 A 2701 GQ02
CONTACT 0 6 6 9282 A 2700G004
ASSEMBLY 0 6 6 0282 A 2334 G002
f

OPERATING
ROD 0 3 3 3 3 3 3 0177 C 50146001

3!

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