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54
Maintenance
01.4IB.77020
PowlVac-ND
®
and PowlVac-NDA
™
Series 4
Vacuum Circuit Breakers
13. Slowly depress the trip coil armature
using the manual charge handle.
Depress the handle until the
armature contacts the feeler gauges.
The circuit breaker should trip.
Note:
It is important to avoid “tilting”
the trip coil armature. Tilting the
armature by applying a load to the
right of the feeler gauges will produce
incorrect results.
14. If the circuit breaker did NOT TRIP
during the test performed in
step
14
, remove the feeler gauges and
trip the breaker. Decrease the gap
between the trip coil armature and
the trip lever by bending the trip
lever upwards slightly using channel
lock pliers or a small crescent
wrench. Repeat
steps 8, 9, & 13
.
Note:
Bend the trip lever in very small
increments. This process may take
several attempts.
15. Repeat
steps 8 through 14
until the
breaker does NOT trip with the
0.090” gauge inserted in the trip coil
armature gap and does trip with
0.030” gauge inserted into the trip
coil armature gap.
16. Perform the latch check switch
adjustment per the procedure found
in
Ch 5 Maintenance, B. Mechanism
Area, 4) Mechanism Adjustments,
d. Latch Check Switch Adjustment
.
17. Replace circuit breaker front cover.
d. Latch Check Switch Adjustment
Figure 21 Latch Check Switch Adjustment
b
Pivot Screw
0.045"
a
c
a. Latch Check Switch
b. Latch Check Operator
c. Secondary Trip Prop Adjusting Screw
The latch check switch adjustment
described is not required
for routine maintenance; however,
the latch check switch may need to be
adjusted after major overhaul, removal
of the mechanism, or tripping system
adjustment.
To adjust the latch check switch perform
the following steps:
1. Remove the main closing spring as
described in
B. Mechanism Area, 3) Closing Spring
2. Rotate the crank arms until the
spring charge indicator displays,
CLOSING SPRING CHARGED.
3. Loosen the two screws which secure
the latch check switch and rotate
the latch check switch about the
pivot screw downward to the lowest
position allowed. The latch check
switch contacts are now OPEN.