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4.7.
The positive interlock roller should be
centered in the upper "VEE" and the
interlock roller should have 1/16" clear-
ance to the stationary plate directly un-
der it.
Figure 6 and 53.
4.8.
To lower the breaker, proceed the same
as for raising, except, place the selec-
tor switch to "LOWER".
4.9.
To raise or lower the breaker, the clutch
must be held in the engaged position,
otherwise a spring will return it to its
disengaged position and open the elec-
trical circuit to the motor.
4.10. The breaker may be raised or lowered
by an emergency hand crank which can
be inserted after removing the motor.
The motor is removed by unlatching the
motor assembly from its support and dis-
connecting the motor lead plug.
After removing the motor, insert the
manual crank and pull the clutch for-
ward. Rotate the crank until the coupling
engages the clutch. The clutch handle
will be held in the down position by a
latch on the crank assembly. The breaker
must be open before the crank can be
inserted and held in the clutch coupling.
4.11. After the breaker is lowered and with-
drawn from the unit, inspect the con-
tact surfaces of both the breaker studs
and the stationary disconnecting de-
vices.
a. Each segment of the stationary discon-
necting device should make a heavy im-
pression in the contact lubricant on the
breaker studs. Contact wipe should start
not less than .125" from the top of the
contact ball, although each contact need
not start at the same location. Figure 9.
b. The penetration of the breaker stud in-
side the stationary disconnecting device,
as indicated by the contact lubricant,
should be .75" to .875". This indicates
that the breaker studs contacted at the
full pressure center of the silver band on
the stationary disconnecting device. Fig-
ure 9.
c. Should the inspection of the contacts
show that the breaker is not being raised
Courtesy of NationalSwitchgear.com
Chapter 14. Stationary Cubicle Subassembly
d. If proper contacting cannot be attained
CAUTION: DO NOT MAKE THESE ADJUST-
MENTS. CONTACT YOUR LOCAL GE REPRE-
SENTATIVE FOR ADDITIONAL INFORMATION.
5. Positive Interlock
The cell-side positive interlock cam causes a
closed and charged breaker to open and all
springs to discharge. While engaged the posi-
tive interlock cam prevents closing the primary
contacts when the breaker is being raised or
lowered by holding the breaker mechanism in
a trip condition. The breaker mechanism holds
the positive interlock switch open during rack-
ing and prevents the charging motor from oper-
ating. Figure 6 and 53.
1. Lower the elevating mechanism lifting
brackets until the lifting brackets are in the
fully lowered position. The breaker should
then enter the housing freely. After first
assuring that the breaker is in the open po-
sition, insert the breaker into the unit until
it rests against the rear of the front lifting
saddle of the elevating mechanism. Refer-
ence Figure 6 and 53.
2. When inserting a breaker into a unit for el-
evating, engaging the elevator clutch will
trip a closed breaker and discharge the
opening and closing springs if they are en-
ergized.
WARNING: AGAIN, IT IS EMPHASIZED THAT
BEFORE PROCEEDING WITH THIS CHECK,
IT IS NECESSARY THAT THE PRIMARY CIR-
CUITS BE DE-ENERGIZED.
3. Open the breaker. Elevate the breaker to
the raised position. The positive interlock
roller should engage into the upper Vee.
Breaker can be electrically closed.
4. Snap the selector switch to the "LOWER"
position. Pull the clutch handle forward.
The breaker should be open and the clos-
ing spring will discharge, when engaging
the clutch and lowering the breaker.
55
PowerVac
5kV Vertical Lift
®
to the proper position, readjust the up-
per stop bolts and limit switches to raise
or lower the breaker to the proper loca-
tion. Lock the stop bolts in the new posi-
tion. Figure 6.
by the above methods, additional adjust-
ments may be necessary.
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