Siemens-Allis LA-600A User manual

.-
•.
.,
SIEMENS-ALLIS
INSTRUCTIONS
~- TYPES LA-600A and LA-1600A (UNFUSED)
~
AND
TYPES LAF-600A and LAF-1600A (FUSED)
AIR CIRCUIT BREAKERS
WITH
MANUAL OR ELECTRICAL
OPERATORS
18X52 14-01
September , 1976
Courtesy of NationalSwitchgear.com

WARRANTY
Allis-Chalmers "LA" air circuit breakers are warranted to be free of defects in material and
workmanship for a
period of one year from date of initial operation but not more than eighteen
months from date of shipment by company. This warranty is limited to the furnishing of any part
which to our satisfaction has been proven defective. Allis-Chalmers will not in any case assume
responsibility for
allied equipment of any kind. (See Allis-Chalmers W arranty Form 5992-23. )
Typical Shipping Methods Used With "LA" Breakers
,I .
Courtesy of NationalSwitchgear.com

r·· -TABLE OF
CONTENTS
WARH.ANTY . . . . . . . . . . . . . . . . . . . . . . • . . . • . 1
REC1£VJNG A~ .Ll i l\SPE C'l'ION . . . . . . . . . . . . . . . 3
Introdu ct io n . . . . . . . . . . . . . . . • • • . . 3
P..eceiving and lnspt>c tion for DamagP . . . • . • . . . . 3
St.crag~ . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . ;;
INS' fALLATlON .. . . . . . . . . . . . . . . . . . . . . • . . . 3
Installation Sequen ce . . . . . . . . . . . . . . . . . . . . . 3
Cautions to be Observed in Installa.t jon
and Op< ! ration ............ , . . . . • 4
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
De sc riptio n .. ... . .......... . .. . .. . .. . . .
{A) Manually
Opera t ~d Circuit. B reak ers . . .. .•. ..
(B) Electrically Operat ed Circuit Break er s . .. . .. .
(C) Comb ina lion E.O. & M.O. Opera t ed
4
6
6
Ci rcuit Break ~ rs. . . . . . . . . . . . . . . . . . . . . 9
Ora woul Int erl ock . . . . . . . . . . • . . . . . . . . . . . . 9
Rllcklng Mechanism . . . . . . . . . . . • . . . . . . . . . . 9
Spring Discharge In te rlo ck ... .. . . . . .. . ...... JO
Li!ting Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Handling In struct i ons . . . . . . . . . . . . . . . . . . . 11
MAINTENAN CE AND ADJUSTMENT S . ...... . .. 12
Maintenan ce . . ..... . .. .... ... .... . . .. . .
L
ubrication ........ . . .... . .. . . . ...... .
Maintenan ce Closing .... . .. .. . .. . . .. . .... .
Adjustme nts . ....... . .. . . . • ..... . .... ..
Trip-Latch Engageme nt ..... • . .. .. ... .. . .
Main
Contact Make ..... .... .. . .. ......
Arcing
Co nt act Make ....... . .. . ... .....
12
13
14
16
16
17
17
Contact Repla ce m ent . . . . . . . . . . . . . • . . . . . . 18
Ms in Contact Fing er. . . . . . . . • . . . . . . . . . . . 18
Stationary Arcing Contact . . . . . . . . . . • . . . . . 111
Hinge Cont.act Fingers .... . . .. .. .... · · · · · 18
Movable Arching and Main Contact . . . . . . . . . lB
Ttlpping Actual.or . . . . . . . . . . . . . . . . . . . . . . . 18
Motor Cutoff g,.;tch . . . . . . . . . . . . . . . . . . . . . 19
Se condary Disconnect Assembly Option . . . . . . 25
Auxiliary
Switch Option . . . . . . . . . . . . . . . . . 26
Shunt Trip Option . . . . . . . . . . . . . . . . . . . . . 27
FUSE FUNCTIONS ..... . .• . .. . . .... .... ... 20
Current Limiting Fuses . . .....•.... . ....... 20
Open Fuse Trip Device . . . . . . . . . . . . . . . . . . . . 23
ACCESSORIES . . . ... . ......... . ...... . .. . 2 4.
Current Sensors - Li mi Tri p ........ . . . ... ... 24
Tripping Transformers -St.atic Trip Il. . . . . . . . . . 24
OPTIONAL DEVICES . . .. . ........ ... ...... 25
Secondary Dis conne ct Assembly Option . . ....... 25
Auxiliary Switch Option . . . . . . . . . . . . . . . . . . . 26
Undervolt.age Trip Device Option ........... . . 21
\Shunt Trip Option .. ....... . . ... ......... 27
Stati c Trip Option ....................... 27
Bell Alarm Switch Option . . . . . . . . . . . . . . . . . . 28
LUBRICATION INSTRUCTIONS ............... 28
INSTRUCTION BOOK REFERENCES . . . . . Back rover
ILLUSTRATIONS
Figure 1.
Flgur e 2.
Flgut10 3.
_,Figure
3A .
Fl&Urf 4.
Figure 5.
Flgurt> 6.
F1gure 7.
Figure 8.
Figure 9.
Figure 10.
F1gure 11.
Figure 12.
Figure 13.
Figure 14.
F1gure 15 .
Figure
16 .
F1gure
17 .
Figure
18 .
Typical
Shipping Method used with "LA" Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Fused & Unfused Breakers with Static Trip II and LimiTrip Overcurrent Trip Devices . . . . . . . . . . . . . . . . 2
LA-6
00 A, LA·800A and LA-16 00 A O perator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . 7
Typical Wiring Diagram - El eclricaliy Operated Brea. kers . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . .. . 8
Detail of Typical Rac king Me chan ism an d Drawout Interlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Typical Racking Mechanism and Dr.twout Interlock .. .... . ... . ..... . ..... . ... • . .... .. .. . . . 10
Typical LA· 1600A Br eaker Ouliine . .. . .. . .... . ..... . . . ......... .. • ............ . .. . .. 12
Typical LA·600A and LA·80 0A Breaker Out(ine ................... • .... • . • ... •.•.. ...... 13
Maintenan ce Closing ....... ..... . . .. ............. . .... . . .. ... ..... ....... . . .... 15
Typical Ope rator Assembly. . . .... .............................. . . ........... . ..... . 16
Contact ASM!m bly .... .. .... ..... .. . . .. . .. ..... . .................. . . .......... . 17
Fuse Atta ch me nt Group LAF-600A, LAF-800A Breakers ........... . ....... ...... . .. .... . .. 21
Fuse Attad1ment G rou p LAF -1 600A Breaker . ....... .. .......... . ................... . .. 22
LAF-600 A, LA F-800A and LAF·1600A Open Fiise Trip Device,Trigger Fuse Assembly ............... 23
LA·600A , LA-800A and LA - 1600A Sccon . dary Disconnect Group .. . . ......................... 25
LA-600A , LA-800A and LA- 1600A Auxiliary Switc h Group ................................. 26
Undenolla .ge Trip with or wit hout Time Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
LA·
600A , LA-800A and LA·l600A Shunt Trip Group . ..... . . .....•. .. . .. . .. . . . .. . .. . .. . .. 27
LA- 60 0A, LA· OO OA and LA ·1600A Alarm Switch Group, Bell Alann .........•.............. . .. 28
Lubricati on Cha rt .. .. .... . ..... . ......... . ....... . .................... . . . .. . .. 29
Lubrication Points on .Breaker . ......... . .. ... .... . ........ . .. ....... . ....... . ..... 30
TABLES
'Tlble 1. Ci rcuit Breaker Rating 8 at 60 Hertz . . . . . . . 5
Table 2. Fused Circuit Breaker Ratings at 60 Hertz . . . 5
'fible 3. Opera.ting Procedure -Manually
'fible 5. Main tenance Closing . . . . . . . . . . . . . . . . . 14
'fible 6. Static 'nip II Rating 'fible - Amperes . . . . . 24
'fible 7. limiTrip Rating Table - Amperes . . ....•. 24
Operat ed Breakers . . . . . . . . . . . . . . . . . 6
Table 4. Operatin g Procedurt -Electrically
Operated Breakers . . ,. . . . . .. ... .. , . . 6
\ The info rm ation cont si nod within is int ended to assist operating pe r .onnel by providing information on th e general c haracteris tics of
l
equipment of this ty pe. It does not reliev e the us er of responsibility to use sound engineering practices In the installation, epplicetion ,
operation and m eintenanc e of the particular <>quipment purch a sed.
I\ drawings or other sup p lemt>ntar y in struc tion s for specific applications ere forwarded with thi s manual or s ep o rata ly, they take preceden cej
o vor any confli cting or incom p lete Information in t his manual .
-.
' I
i
Courtesy of NationalSwitchgear.com

~
,. . ,·~"'
/.'· . '.'.)
·, ,J
..
Courtesy of NationalSwitchgear.com

I
INSTALLATION AND INSPECTION
Introduction .... . . .. . ... · ..
Receiving and Inspection for Damage
Installation . .
Storage
....
Maintenance.
OPERATION .
Description .
Manually-Operated Breaker
Electrically -Operated Breaker .
Racking Mechanism, Drawout Interlock, and
Lifting Bar ...... . . . .
Spring Discharge Interlock .
MAINTENANCE AND ADJUSTMENTS
Maintenance . . . . .
Lubrication . . . . .
Maintenance Closing
Adjustm ents . . . . .
Trip-Latch Engagement
Main Contact Make ..
Arcing Contact Make.
Fig. 1 Typical LA-1600A Breaker Outline.
Fig. 2 Typical LA-600A Breaker Outline .
Fig. 3
LA-600A/LA-1600A Operator . . .
Fig. 4 Typical Wiring Diagram - Electrically
Operated Breakers ...... . ..
Fig. 5 Typica l' Racking Mechanism and
Drawout Interlock . ..
Fig. 6 Maintenance Closing . .
Fig. 7
Typ ical Panel Assembly
.. .. ..
Fig. 8 Fuse Attachment Group LAF-600A Breaker
Fig. 9 Fuse Attachment Group LAF - 1600A Breaker.
Table 1 Operating Procedure - Manually-
.1
.1
.1
.1
.2
.2
.3
.3
.3
.4
.5
.6
.8
.8
.9
.9
. 10
. 10
. 10
. 11
.
18
. 18
. 19
. 20
. 21
. 22
. 23
. 24
. 25
Operated Breakers . . . . . . . . . . . . . . . . . . . . .. 4
Table 2 Operat ing Procedure - Electrically-
Operated Breakers . . . . . . . . . . . . . . . . . . . . . . . 5
Contact Replacement .. . . .
Main Contact Fingers ... .
Stationary Arcing Contact.
Hinge Contact Fingers . ..
Moving Arcing and Main Contact .
Tripping Ac t uator.
FUSE FUNCTIONS
Current Limit Fuse .
Trigger Fuse . ....
TRIPPING TRANSFORMERS
OPTIONAL DEVICES . . ...
Secondary Disconnect Assem. Option
Auxiliary Switch Option ......
Shunt Trip Option ... . . .. . .
Undervoltage Trip Device Option .
Bell
Alarm Switch Option
Static Trip Optio n . . . . .. . ..
Fig. 10 LAF-600A/1600A Anti-Single Phase Device,
Trigger Fuse Assembly
..... . .......
Fig. 11 LA-600A/1600A Secondary Disconnect Group .
Fig. 12 LA-600A/1600A Auxiliary Switch Group ... .
Fig . 13 LA-600A/1600A Shunt Trip Group .......
Fig. 14
LA-600A/1600A Under Voltage Trip Attachment .
Fig.
15 LA-600A/1600A Alarm Switch Group, Bell Alarm.
Fig. 16 Motor Cutoff Switch Action ..
Fig. 17 Lubrication Points on Breaker.
Fig. 18 Lubr i cation Chart. . . . . . . .
Table 3 Maintenance Closing .. . .. .
Table 4 Trip Rating Table - Amperes .
.
11
. 11
. 11
. 11
. 12
. 12
. 14
. 14
. 14
. 15
. 15
. 15
. 15
. 15
. 15
. 17
. 17
. 26
. 27
. 28
. 29
. 30
. 31
.
32
. 33
. 34
. 10
. 16
The information contained within is intended to assist operating personnel by providing information on the general characteristics of
equipment of this type. It does not relieve the user of responsibility to use sound engineering practices in the installation, application,
operation and maintenance of the particular equipment purchased.
If drawings or other supplementary instructions for specific applications are forwarded with this manual or separately, they ta ke precedence
over
any conflicting or incomplete information in th is manual.
Courtesy of NationalSwitchgear.com

/
INSTALLATION AND INSPECTION
INTRODUCTION
The
type "LA" air circuit breakers may be furnished for mounting in any one of three ways. They
may be used in metal-enclosed switchgear of the drawout type, in individual enclosures (drawout
type), or for stationary mounting in a customer's own enclosing case or switchboard. All "LA ...
breakers are completely assembled, tested, and calibrated at the factory in a vertical position
and must be so installed to operate properly. Customer's primary connections should be ad-
equately braced against the effects of short circuit currents to prevent overstressing the breaker
terminals.
RECEIVING AND INSPECTION FOR DAMAGE
Immediately upon. receipt of this equipment, carefully remove all packing traces and examine
parts, checking them against the packing list and noting any damages incurred in transit. If
such is
disclosed, a damage claim should be filed at once by the customer with the transportation
company and Al I is-Chalmers notified.
Two shipping methods are used with
11
LA
11
breakers:
l. Individually with protective covering.
2. Within a cubicle when part of a switchgear lineup. Breakers shipped.in their cubicles are
,·
'·;:. ")
- --
blocked to prevent accidental tripping during shipment. Note al I caution tags, remove 1 .. : 1.
blocking bolts, and open breaker contacts before installation. \ "11
INSTALLATION .
The
11
LA
11
air circuit breaker is completely adjusted, tested, and inspected before shipment, but
a careful check should be made to be certain that shipment or storage has not resulted in damage
or change of adjustment. Circuit breakers should be installed in a clean, dry, well-ventilated
area in which the atmosphere is free from destructive acid or alkali fumes. Stationary-type
breakers should be mounted high enough to prevent injury to personnel either from circuit in-
terruption or from moving parts during automatic opening of the breaker. Al low sufficient space
to permit access for cleaning and inspection and adequate clearance to insulating barrier above
the breaker to prevent damage from arcing during interruption. Before installing, make certain
that the breaker contacts are in the open position.
1. After the breaker is installed in position, close . it manually by the maintenance closing
method (see MAINTENANCE AND ADJUSTMENTS, page 8 ) to check proper functioning
of the mechanism and contacts.
CAUTION!!
MAKE SURE CIRCUIT IS NOT ENERGIZED.
During
the closing operation, observe that the contacts move freely without interference
or rubbing between · movable arcing contacts and parts of the arc chutes. Then refer to
OPERATION, page 3 for a detailed description of the circuit breaker operating char-
acteristics before putting the breaker in service.
Courtesy of NationalSwitchgear.com

2. Trip units and accessory devices should receive a thorough check prior to pl acing the
r ' - breaker in service to be certain that adjustments are proper and parts are not damaged.
4IJ Refer to Static Trip Device Instruction Book 18X4827.
~
w
3. Cubicle -mounted breakers of the drawout type are equipped with a drawout interlock to
prevent movement of a closed breaker into or out of the connected position. See DRAW-
OUT INTERLOCK, page 5 for a description of the interlock. Its operation should be
checked before the breaker is energized.
4. Upon completion of the installation inspection, the breaker is ready to be energized after
the control wiring, if any, is checked and the insulation tested.
STORAGE
When breakers are not to be put into immediate use, they should be wrapped or covered with a
non-absorbent material to provide protection from plaster, concrete dust, or other foreign matter.
Breakers should not be exposed to the action of corrosive gases or moisture. In areas of high
humidity or temperature fluctuations, space heaters or the equivalent should be provided.
MAINTENANCE
Occasional checking and cleaning of the breaker will promote long and trouble - free service. A
periodic inspection and servicing at least every six months should be included in the breaker
maintenance routine.
If the circuit breaker is not operated during extended periods, the breaker should not remain in
either the closed or open position any longer than six months. Maintenance opening and closing
operations should be made to ensure freedom of movement of all parts.
CAUTIONS TO BE OBSERVED IN THE INSTALLATION AND OPERATION OF
11
LA
11
CIRCUIT
BREAKERS
1. Read Instruction Book before installing or making any changes or adjustments on the
breaker.
2. As the closing springs on stored-energy breakers may be charged in either the breaker
open or closed position, extreme care should be taken to discharge the springs before
working on the breaker.
3.
4.
5.
6.
7.
When closing manually-operated breakers out of this unit, the racking mechani sm mu st be re-
turned to the test position before closing springs can be charged.
When closing manually - operated breakers, always grasp closing handle firmly until it is
returned to the normal vertical position. .
Check current ratings against single line diagram to assure that breakers are properly
located in switchgear at installation.
Check the alignment of the secondary disconnect fingers to ensure against misalignment
due to possible distortion of fingers during shipment and handling.
Once the breaker is energized, it should not be touched, except for operating, since
most of the component parts are also energized .
2
Courtesy of NationalSwitchgear.com

I
OPERATION
D
ESCRI PTI ON
The LA-600A air circuit breaker has a maximum continuous current rating of 600 amperes, and an inter-
ruption rating of 25,000 amperes at 254, 508 volts 60 Hz, or 22,000 amperes at 635 volts 60 Hz. when
.
used with the short time delay trip deivce. With instantaneous trip device, the interruption rat ing is 42,000
amperes at 254 volts, 30,000 amperes at 508 volts and 22,000 amperes at 635 volts.
The
LA-1600A circuit breaker has a continuous current rating of 1600 amperes and an interruption rating
of 50,000 amperes at 254 and 508 volts, or 42,000 amperes at 635 volts when used with the short time
delay trip device. The interruption with intantaneous trip device is 65,000 amperes at 254 volts, 50,000
amperes at 508 volts and 42,000 amperes at 635 vo lt s. All currents are symmetrical amperes and voltages
are maximum.
The breakers are also available with integrally mounted current limit fuses. The basic breakers
are the same with or without the fuses. The fuses mount on a bracket arrangement that is bolted
to the side rails and upper studs on the back of the breaker. The current limit fuses increase the
interruption rating to that of the fuses. Fused breakers are identified as LAF-600A, and
LAF-1600A. Fused breakers are also equipped with an anti-single phase device to open the
breaker if one or more current limit fuses open.
The breakers can aiso be supplied for stationary mounting in which the racking components are
omitted, and brackets are provided for mounting to a stationary frame. ·
Both the LA-600A and LA-l600A circuit breakers use the same closing mechanism or operator. · '- ~ :· l..
The closing springs are larger for the 1600 ampere breaker. Three configurations of the operator W
are available for charging the closing springs.
These
are manual charging, electrical charging and combination manual-electrical charging. Al I
operators
are identical except for the means of supplying energy to the closing springs.
A
double-toggle, trip-free mechanism is used; that is, the breaker contacts are free to open at
any time, if required, regardless of the position of the mechanism.
Manua
11 y-Operated Breakers ·
The
breaker has a center-mounted frame so many of the latches and links are arranged in pairs,
for descriptive purposes they wi 11 be referred to as single items. Refer to Figure 3 and Table l.
Detail "A
11
shows the position of the trip latch and toggle linkage when the breaker is open and
the closing springs are discharged. Movement of the charging handle downward rotates closing
cam (65) against roller (28) thus pivoting closing cam (19) clockwise about pin (76) and extending
the closing springs thru link (23) and spring hanger (17). Rotation of cam (19) allows roller (41)
in
toggle linkage to be moved into position shown in Detail "B". Kickoff spring (59) moves
rollers
away from stop block (31), then the toggle linkage is moved by torsion spring until
latch (35) clears trip latch (13). Spring (15) causes trip latch (13) to reset under latch (35).
Trip flat (14) should normally stop against the front surface of latch (35).
When the closing springs are fully charged, roller (28) engages latch (7). Charging cam (65) :._ ~
engages a pawl in such a manner that the charging cam must complete the charging stroke before
it can return to its normal position.
3
Courtesy of NationalSwitchgear.com

With the ch argin g handle in its normal upright position, the breaker ca n be closed. By pressing
firmly
on ho od (8) latch (7) will disengage roller (28) and closing springs cause closing cam (19)
to
rotate against the tog gle rollers ( 41 ) moving the toggle into its upr ight pcsition, shown in
de tail "C". The closing cycle can be interrupted at any point by operation of one of the tripping
means, which cause rotatio n of trip latch (13) to a position that release latch (35) allowing
togg le I inkage to collapse to the position shown in detai I "A".
Manual opening of the breaker is accom plis hed by pressing on trip bar (48), this bar engages the
top of trip fl ap (14) which is in turn arranged to disenga ge the t rip latch.
TABLE 1 - OPERATING PROCEDURE -MANUALLY-OPERATED BREAKE RS
Oeeration
Procedure
Charging Springs Pull charging handle down all the way (approximately 120°) and return to
normal vertical position. ( En gagem ent of pawl w it h the ratchet teeth pre-
vents hand le reversal until the downward stroke is comple ted. )
Closing
Push down spring-release latch hood (8) after handle is returned to normal
ver tical position.
Tripping Push in manual
trip rod (48).
or
If shunt trip is provided, operate remote trip control switch ( CST ) (See
Figure 4).
Electrical Iy Operated Breaker
The mechanism of the electrically operated breaker is the same as the manually charged breaker except the
manual charging handle
is replaced by a motor and gea r system. Refer to Figures 3 and 4 and Table 2.
With power available
to the control circuit, closing the motor control switch (Ml) will st art the
automatic charging cycle. The motor gear box pinion rotates gear (86) counterclockwise, cam follower
(95) engages an arm of wind and close ca m (85) which rotates the cams in the same manner as for the
manually charged breaker. When the wind and close cam (85) reaches its charged position, the back of the
cam engages switch lever (91) rotating the lever away from the switch operator. Gear switch lever ( 93) will
still be holding the switch in the operate position, and the motor will continue to run until the roll pins on
the side
of gear (86) lifts lever (93) clear, releasing the motor cutoff switch (MCO). When the MCO switch
opens the
motor stops, and the closing coil circuit is set up throu gh one side of the MCO switch.
The breaker can now be closed by manually releasing hood (8) or by energizing the closing coil
(CC) through the external close control switch (CSC). When the close circuit is energized the
"Y" relay is energized and opens the "Y" contact in the motor circuit, thus preventing "p umping"
or repeated attempts to charge the closing sp rings.
If the close circuit CSC switch is opene d, the m otor will automatically recharge the closing
springs,
if pcwer is ava ilabl e for the motor circuit. The close coil ' circuit is always interrupted
by the motor cut-off switch MCO. Trip free operation of the mechanism, discharging the springs
on a closed breaker is prevented by completing the close coil circuit thru auxiliary contacts
of the breaker.
4
Courtesy of NationalSwitchgear.com

TAB LE 2 - OPERATING PROCEDURE -ELECTRICALLY-OPERATED BREAKERS
Operation Procedure
Charging Springs Energize con tro l circuit. Mo
ve motor con tro l switch (M l} on front of
breaker to "ON" position.
Closing
After springs are charged, actuate remote close control switch ( CSC).
or
Push down spring-release l atch hood (8A).
Tripping
Actuate remote trip control switch (CST).
or
Push in manual trip rod (48).
Combination Operated Breaker
The
combination manually charged and electrically charged breaker i ncludes both the motor-gear
charging system as welI as the manual charge handle. NOTE: Manual Handle must be in vertical
position during electrical charging.
Racking Mechanism, Drawout Interlock and Lifting Bar
Cubicle mounted breakers of the drawout type include as integral parts the mechanism to rack 1· · .
the breaker in and out of the cubicle compartment, interlocking to prevent racking a closed ~
breaker into or out of the connected position, and interlocking to prevent withdrawing a breaker
from the cubicle while the closing springs are charged.
Refer to Figure 5, with the breaker resting on the cubicle rail, the fol lowing sequence should be
used to rack the breaker into the cubicle.
CAUTION!!
ON ELECTRICALLY OPERATED BREAKERS, BE SURE MOTOR CONTROL SWITCH ON THE
FRONT OF THE BREAKER IS OFF.
1. Push trip bar in and lower interlock slide (110), note, slide interlock cannot be opened
unless manual trip bar is pressed in . While the trip bar is pressed in, the breaker
is in the TRIP-FREE position and cannot be closed.
2. With the switchgear operating crank, rotate the racking screw (89) untiI the racking
shaft is in the disconnected position, the clevis can now engage the racking pins in the
cubicle. The breaker should now be pushed along the rail into the disconnected position,
double check that the racking clevis does engage the pins in the cubicle.
3. Counterclockwise rotation of the racking screw will rack the breaker into the TEST
position. At the TEST position, the floor mounted interlock cam does not engage the ·
roller i nterlock (67) and the cover slide interlock can be closed, allowing the trip bar to \:.: .· £1 ·)
extend and the breaker can be operated • ~ .• -..;
5
Courtesy of NationalSwitchgear.com

Betwe~ (6he TEST position and
engag@che floor cam and the
even
i· ie cover slide is close
In the am)NNECTED position,
cubicl:D
~This prevents moving
4. To wit' saaw the breaker from 1
the ra< · 1g screw rotation is c
5. Before' ch-empting to operate ti
with nleC;ence to the marking
stop
mse (are provided on the r
adjust'3urby setting the
angle c
tightepn g the nuts against the
agains
-:ich other.
CAUT I '\J !!
TO A\HE!D DAMAGE TO THE
ING 01'\NK IN THE COUNT
POSIT
N.
Spring Discha1 Interlock
When racking:.Jtoe breaker out to t
he c
discharge,
at ;prlbefore reachi ng the c
interlock
(s ee rel,ures 3 and 4), this ir
closing spring:
CAUTION!!
ON MANUA!HE
1
CHARGED BREAKEF
CHARGE CAf.)C<AND MUST BE CLEA
POSITION.
NOTE:
Manual
charg1isr:>0ndle must be in vert
returned to themest position before cli
cubicle.
Note also thah cie spring discharge in
stored energy1e rthe springs is dissipat
trol switch
off rar the TEST position, c
the normaI me er.
CAUTION!!
W
ITH COVER BR;MOVED AND Cl RCL
WI LL CLOSE I CAEN THE STORED EN
SINCE THE SI ;EI NTERLOCK IS N<
~ CONNECTED positm t, the roller interlod th17} does
~aker will be tripped~ trough the interlock m•breanism,
t F th x:I •
.e roller interlock wil CGain clear the floor c th; of the
:losed breaker into ore.
it of the CONNECTEa <)Osition.
CONNECTED positihdr.
the procedure is th~heme only
:kwise. :kir loc
b
reaker, the position at ·the device should be1e iecked
the
cubicle, to be c~feiin that it is fully conrin ted. Two
dng screw to set the Jts lnected position, the: acbre
he racking clevis, a~d bwn in detail "A" FiM te 5, and
JP washer
(84) the tw1in1uts (95) should be th' stdocked
t e:
I Ot
\CK ING MECHANIS/O DO NOT ROTAT E T: RJ RACK-
CLOCKWISE DIRECT:RtN, WH EN IN THE 0ER4NECTED
10
;onnected position, thhdosing springs wi II aHscmatically
.onne
ct position. Theor rrel nut engages the Hsdng
:
rn connects to the m< figal close hood which ~ ti.eases the
s.
THE CLOSE HOOD _L )l NTERLOCKED TO ns, MANUAL
~EFORE RACKING HA, BREAKER TO THE Dl~R p)NNECT
11 position during racle hg and racking mechaficc.n must be
:-ig springs can be chae t:d, while breaker is rosipved from
lock produces a TRI Pt tKEE operation in whic1terl I of the
in the mechanism. lof> preferable to turn tl--ednotor
con-
:e the breaker normal= ilin that position, then:lo~k out in
inn =
BREAKER CONTACT RDPEN, THE CIRCUITJITEAKER
GY SPR! NGS ARE DIWf.HARGED AUTOMATIER\LL Y
IN PLACE. LID )T
6
Courtesy of NationalSwitchgear.com

Lift Bar
See Figure 5. The Iifting bar connects as shown in Figure 5 for the standard b rea k er and the
fused breaker. The additional lifting lugs ore provided as part of the breaker because the
additional overhang of the fuses shifts the center of gravity, and lifting from the usual position
causes tipping of the device.
7
:
Courtesy of NationalSwitchgear.com

MAINTENANCE AND ADJUSTMENTS
W Maintenance
Occasional checking and cleaning of the breaker wil I promote long and trouble-free service. A
periodic inspection and servicing at intervals of six months or one year should be included in the
maintenance routine. Circuit breakers located in areas subject to acid fumes, cement dust, or
other abnormal conditions, require more frequent servicing. After a severe overload interruption,
the breaker should be inspected.
If the circuit breaker is not operated during extended periods, it should not remain in either the
closed or open position any longer than six months. Maintenance opening and closing operations
should be made to ensure freedom of movement of all parts.
A suggested procedure to follow during maintenance inspections is given below.
1. De-energize the primary and control circuits.
2. Rack cubicle-mounted breakers of the drawout type to the disconnected position.
3. Remove breaker from cubicle~
4. Remove arc chutes (7 5, Figure 1 and 2) and examine for burned, cracked or broken parts.
To remove arc chutes, proceed as follows:
a. Move breaker to disconnect position.
b. Turn racking screw until crank is in yertical position, giving maximum clearance
between screw and holding bar.
c. Remove wing nuts from holding bar.
d. Ti It top of holding bar toward back of breaker and move bar down.
5. Wipe the contacts with a clean cloth saturated with a non-toxic cleaning fluid.
6. Replace badly burned or pitted contacts. (See Contact Replacement, page 11)
7. Wipe al I insulated parts with a cJean cloth saturated with a non-toxic cleaning fluid.
8. Bearing pins and other sliding or rotating surfaces should be cleaned and then coa ted with
a Ii ght fi Im of grease ( see Lubrication, next paragraph).
9. Crank racking mechanism so that the racking clevis (90, Figure 1) is in the test position or the
vertical position of step 4b to permit charging of the closing springs.
8
Courtesy of NationalSwitchgear.com

I
'
10. Operate the breaker manually in maintenance closing position (see Maintenance Closing, below)
to check latch and linkage movement.
11. Check breaker adjustments (see Adjustments, page 10).
NOTE:
After inspection and before inserting breaker in the cubicle or moving the breaker to test posi-
tion, turn racking screw (89) until racking clevis (90) reaches its normal disengaged position.
Lubrication
Lubrication should
be a part of the servicing procedure. Needle bearings are packed with grease
anp should require no further attention. Old grease should be removed from bearing pins and
other non-current ·carrying rotating or sliding surfaces, and they should be wiped with a thin
film of petroleum-oil-base precision-equipment grease such as BEACON P-290. Greasing
should be done with care because excess grease tends to collect foreign matter which in time
may make operation sluggish an9 may affect the dielectric strength of insulating members.
Faces
of main and arcing contacts should not be lubricated. The rubbing surfaces of the main
contact fingers and hinge contact fingers are lubricated with a coating of A-C contact lubricant
15-171-370-002. If dust has accumulated disassembly is necessary to relubricate these points.
(See Contact Replacement, page 11 .)
Maintenance Closing
During
inspection prior to installotion and for routine maintenance inspections, the breaker con- · -w
tacts may be closed slowly to check clearances, contact adjustments, and movement of links and
latches. The manual closing handle is used for maintenance closing the breaker.
Electrically-operated breakers do not have a manual closing handle, but a manual closing
handle-cam assembly is available as a maintenance item. Figure 6 shows the maintenance
closing handle being inserted in an electrically-operated breaker after removal of the front
cover from the breaker. When the hole in the maintenance closing handle assembly is aligned
with the holes in the operating mechanism frame, the pin which is attached to the chain is in-
serted. This pin holds the assembly in place and acts as a pivot point for the cam.
After insertion of the maintenance closing handle assembly on the electrically-operated breaker,
the actual maintenance closing operation is the same for both the electrically-operated breaker
and the manually-operated breaker. Refer to Table 3 and Figure 6.
CAUTION!!
THE PROCEDURE IN TABLE 3 SHOULD BE USED FOR MAINTENANCE CLOSING ONLY.
MAINTAIN A FIRM GRIP ON THE MANUAL CHARGING HANDLE DURING THE CLOSING
STROKE - THE BREAKER MAY SUDDENLY LATCH FULLY CLOSED AND APPLY UNEXPECTED
FORCE
TO THE CLOSING HANDLE,
9
Courtesy of NationalSwitchgear.com

TABLE 3. MAINTENANCE CLOSING
Operation Procedure
Closing Contacts
1. Pull charging handle DO WN ALL THE WAY (approximately 120° ).
2. Place blade of screwdriver between hood and spring release latch and
hold
it in this position.
3. Slowly return handle to vertical position.
Observe contact touch,
mechanical operation, etc.
4. Remove screwdriver and pull charging handle to the fully charged
position.
Allow spring release latch to hold closing springs. Move
charging
handle to the vertical position.
5 . Close breaker norma lly by pressing close hood.
Opening Contacts
Push in manual trip rod.
NOTE:
Holding
the spring release latch down prevents the stored-energy springs from propping in the
charged position. Thus, when the handle is slowly returned to the normal vertic al position, the
energy in the springs is slowly released against the closing handle assembly cam face.
Adjustments
During
maintenance inspections, the following items should be checked to ensure that the original
settings are maintained:
Trip·Latch Engagement
(R efer to Figure 3.) Toggle latch (35) should engage the full width of trip latch (13) when the
breaker is closed in the normal manner. To adjust, the tension on spring (15) can be increased
by bending spring
tab on trip flap towards the front of the breaker. Too much tension will interfer
with the capability of the tripping actuator to move the trip flap, so over bending should be
avoided.
Main Contact Make J!Jl- -
IYg
(Refer to Figure 7.) Compression of contact fingers (9) should be between .093" an .125". This
is
the difference in the measurement from the breaker base to the tip of the finger contact surface
when
the breaker is open and the measurement in the same place when the breaker is closed. This
is
checked with a normal closing operation - not maintenance closing. Adjustment is provided by
positioning screws (35) after loosening nuts (36). Counterclockwise rotation of screws (35) in-
creases compression. Care should be taken to retighten nuts ( 36 ) after adjustment. If it is desired
to check contact pressure, a push-type spring scale can be used to compress contact fingers (9),
with breaker open. Contact pressure should be between 20-30 lbs.
10
Courtesy of NationalSwitchgear.com

Arcing Contact Make
(Refer to Figure 7
.) With movable arcing contact (27) in any one phase touching the mating
stationary contact when the breaker is closed by the maintenance closing method (see Table 3),
the phase to phase variation should not exceed .062
11
• Adjustment may be made by positioning
screws
(3 5) as in the previous paragraph, but it is essential that the main contact compression be
maintained within the tolerance Iisted in the previous paragraph. Arcing contact pressure should
be between 30 and 40 pounds when checked with a pull-type spring scale at the base of the arc-
ing contact tip insert with the breaker contacts closed.
Contact Replacement
(Refer to Figure 7
.) The contact structure consists of main current carrying contacts and arcing
contacts arranged so that initial contact make and final contact break is by means of the arcing
contacts. The actual contact surfaces are clad with an alloy facing which greatly reduces
mechanical wear and arc erosion.
When inspection of the alloy facing indicates that the contacts should be replaced, it should be
noted that hinge contact fingers (20, 21) main contact fingers (9) and arcing : contacts (27) ore
spring loaded. Therefore, care must be exercised in removal and installation of any of the con-
tacts.
Main Contact Fingers
_<),
· ~
.. t
With the breaker contacts open and the stored-energy springs discharged, main contact fingers \J
(9) may be removed by loosening screws (18) enough to relieve the compression on springs (10).
There ore two springs behind each finger and it is important that they be positioned properly upon
reinstal
lotion. If difficulty is experienced in correctly positioning these springs, the upper and
lower primary disconnects (123, Figure
1) may be removed from each phase and the breaker in-
verted to rest on the ends of connectors (4) and (11). After the contact fingers are replaced,
connector (4) should be positioned in the center of the slot in the molded base to assure correct
alignment of the primary disconnect fingers.
Stationary Arcing Contact
The stationary arcing contact is a part of connector (4) and may be replaced by proceeding as
above. In this case, screws (18) must be removed • However, to provi de clearance for removaI
of connector (4) first insert a 3/16" diameter rod at least 2
11
long through the opening in support
(13). It ~ay be necessary to compress contact (21) opposite arcing contact (27) in order to insert
the rod. This will -- hofd hinge contact fingers (21) in position to permit removal of pin (38) . After
removaI of pin (38), main contact (28) and arcing contact (27) can be positioned so that con-
nector (5) can be removed.
Hinge Contact Fingers
Hinge
contact fingers (20,21) may be removed as follows: Remove top screw (17) from support
(13)
and replace it with a 1/4-20 screw at least 1-1/2" long. Remove lower screws and then
gradually back off the 1-1/2" screw to relieve the loading from springs (16). The hinge contact
fingers can now be removed. To provide easier access to the hinge contact fingers, pin (38)
may
be removed after the loading is relieved from springs (16).
11
Courtesy of NationalSwitchgear.com

Moving Arcing and Main Contact
~ Either moving arcing contact (27) or main contact (28) or both may be removed and replaced as
follows: Follow the steps outlined in the above paragraph including removal of pin (38) or if
hinge contact fingers are not to be replaced, omit these steps and begin by placing a 3/16
11
diameter rod at least 2
11
long through the opening in support (13). Remove pin (38) if not removed
previously.
The complete movable
contact assembly may now be brought to a bench. It is suggested that a
1/ 2
11
thick piece of wood or phenolic be placed upright in a vise and the open slot in clevis (26)
placed against it as a rest. The location of spacers should be noted.
CAUTION!!
EXTREME CARE SHOULD BE TAKEN TO HOLD THE ASSEMBLY FIRMLY TO RETAIN SPRING
GUDE (32) AND SPRING (33,34) UPON REMOVAL OF THE SCREWS.
The moving arcing contact or the main contact may now be easily replaced. The reverse proce-
dure is fol lowed for re-instal lotion. Core should be taken to replace spacers correctly. Check
alignment and adjustment of contacts upon reassembly.
Tripping Actuator
When
the static trip device senses a circuit condition that requires the circuit breaker to open, it
produces an output that is fed to the tripping actuator. This device then causes the circuit
breaker contacts to open and isolate the circuit .
Mounted on the circuit breaker, the tripping actuator is held in a charged position by a perma-
nent magnet. It contains a coil that is energized by the output of the static trip device. When
energized, the coil causes the magnetic flux to shift to a new path, releasing the stored energy
of a spring located inside the tripping actuator. The spring provides the energy to trip the
breaker moving the trip flap clear of the toggle latch.
If the spring loaded armature does not reset during trip operation as explained above, spacer
washers may be added to obtain positive reset of the armature.
If adding spacers does not al low the armature to be reset, the tripping actuator should be re-
placed (if br~ker mechanism is not at fault ) .
NOTE:
Do not attempt to disassemble the tripping actuator as this may d'estroy the magnetic field set-up
by the permanent magnet and wi 11 render the actuator latch inoperative untiI remagneti zed.
When replacing a tripping actuator, the coiI leads must be connected to the terminal block of
the static trip in the correct polarity relationship.
The black lead of coil must be connected to terminal 7 (negative) and the red lead of coil
connected to terminaI 8 (positive) of the static trip device.
12
Courtesy of NationalSwitchgear.com

When the tripping actuator has been replaced the circuit breaker should be given a FUNCTION
TEST to ensure proper operation of all components. Refer to Allis-Chalmers Instruction Book <J
18X4827 for the procedures of the FUNCTION TEST.
Motor Cutoff Switches
The
function and adjustment of the motor cutoff switches on electrically operated breakers is described
in Figure 16.
13
Courtesy of NationalSwitchgear.com

I
FUSE FUNCTIONS
Current Limiting Fuse
(See Figure 8-9.) The C.L. Fuses are special purpose fuses having NE MA Class "J" or Class "L" character-
ist
ics and have an interrupting r·ating of 200,0 00 Amps RMS Symmetrical.
When replacement
is required due to the C. L. fuse interrupting, replace only with a fuse of the same manu-
facturer and rating
as supplied with the circuit breaker. Fuses of different manufacture will not mount on
the breaker terminals.
Open Fuse
Tripping Device
(See Figure 10.) The open fuse trip mechanism has three functions. The first function is to trip the circuit
breaker mechanically when a C. L. fuse has interrupted.
The second function is to indicate which phase C. L. fuse has interrupted. The plunger on top of
the trigger fuse (12) indicates visu ally whi ch phase C. L. fuse has interrupted.
The third function is to retain the breaker in the trip-free position until the trigger fuse is
replaced.
Each trigger fuse is wired in parallel with one of the C. L. fuses. When the C. L. fuse interrupts,
its associated trigger fuse also opens and releases a plunger which releases a precompressed
spring
contained in the trigger fuse hous~ng.
The plunger operates arm (2) which moves the toggle, releasing the spring loaded lever (19)
which engages circuit breaker interlock thru link (20). This trips the circuit breaker and holds
the circuit breaker in the mechanical trip free position.
The circuit breaker will remain trip free (cannot be closed) until the trigger fuse has been re-
placed and the associated trip mechanism reset tever (17) has been manually reset (pulled down).
To remove the trigger fuse remove strap (14), remove plastic cover (13), then the trigger fuse.
To insert the trigger fuse, reverse the above procedure.
CAUTION!!
THE TRIGGER FUSE (12) MUST BE INSERTED WITH THE PLUNGER FACING ARM (2) . THE GAP
DIMENSION OF 0 - .03
11
MAX. MUST BE MAINTAINED FOR EACH FUSE . BE SURE TO RE-
PLACE BOTH THE TRIGGER FUSE AND IT'S CORRESPONDING C.L. FUSE BEFORE THE
BREAK ER IS RES ET.
NOTE:
•· • \
Do not remove Trigger Fuse cover when breaker is in connected osition. Line voltage ma be
.J avai a le inside t e Trigger Fuse assem ly.
14
Courtesy of NationalSwitchgear.com

ACCESSORIES
Tripping Transformers
There o
re a number of tripping transformer ratings ovoi loble, each with seven ca librated pickup
settings ( Table 4).
T
he tripping transformers on the upper connectors of the circuit breakers a re mounted with the
polarity ma rks facing the breaker panel.
The tripping transform er on the lower co nn ector is mounted with the pola r ity mark facing away
from the breaker panel . OPTIONAL DEVICES
Secondary Disconnect
Assem . Option
The
electri ca l atta chments are wired to the terminals of a secondary disconnect assembly (see
Figure 11)
which is mounted on the left side of the breaker. Two blocks of ten terminals each
can be mounted on the breaker. The secondary disconnect assembly is accessible from the front
of the breake r and aligns with a stationary unit in the cu bic le. The stationary contact strips
should
be lubricated with a light film of contact grease which is furnished with the switchgear.
Auxiliary Switch Option
The
au xi liary sw it ch (s ee Figu re 12) is of the rotary type and functions by direct connect to the
br
ea ker mechanism. T he contacts are factory set for "a " ( open when b reaker is open ) and
11
b11
( closed when breaker is open ) position, b ut each rot or ( 250 ) may be adjusted individually in
steps of 30 deg ree s. This adj us tment is made by remo ving cover (257) and lifting the entire rotor
assembly
out of case (245) after di sconnecting ann ( 252 ) from the Iinka ge. Cotter pin ( 256 ) and
bearing (251) are removed to permit remov al of rotors (250) from shaft (249) . To change rotors
(250) from
11
a
11
to
11
b
11
position, the rotor should be rota ted 60° in the clockwise direction after
removal and re p laced on the shaft in this new position.
Shunt Trip Option
Each
electrically -o perated breaker is equipped with a shunt trip attachment for tripping from a
remote location. {See Figure 13.) Since the shunt trip coil is designed for a momentary duty
cycle, an
11
a
11
auxiliary contact switch is used to interrupt its circuit immediately after the
breaker is tri p ped. Energization of the coil causes the armature to pick up and rotate the trip
latch to trip the breaker. A co mpression spring (148) r eturns the armature to its normal position.
Undervoltage Trip Device Option
The
undervoltage tri p device (Figure. 14. ) automaticall y trips the breaker on loss of v oltage.
Either instantaneous or time- delay operation can be supplied. Adjusting screw ( 19 ) should be
set to pro vide an air gap of .25
11
between the sole noid pole h ead and ar mature with the device
d e-energi zed as shown in the front vi e w. A . 06
11
gap should be m ain tain ed between flap ex-
tension and pulI li nk ( 22 ) when the device is energized w it h the b rea k er closed. Pick -u p and
drop- out adjusting nut (13) should be set so that the device picks up at a voltage of 85 % or less
of ra ted V? I ue and drops out be twe en 30% and 60 % of t he ra ted va I ue.
NOTE:
Pick-up an d d rop-out are not individually adjustable.
On devices equipped with time delay airpot (2), the airpot adjusting screw can be set to provide
a ra nge of time delay between 0.5 and 4.5 seconds. Tightening the screw increases time delay.
15
'-)
i
Courtesy of NationalSwitchgear.com