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45
IB-65020A
Maintenance
21. Perform the latch check switch
adjustment per the procedure found
in
Ch 5 Maintenance
,
B. M
echAnISM
A
reA
,
4) Slow Closing of Mechanism,
d. Latch Check Switch Adjustment
.
22. Replace circuit breaker front cover.
d. Latch Check Switch Adjustment
The latch check switch adjustment
(Figure 26) 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.
Figure 26 Latch Check Switch Adjustment
b
Pivot Screw
0.045"
a
c
d
a. Latch Check Switch
b. Latch Check Operator
c. Secondary Trip Prop Adjusting Screw
d. Secondary Trip Prop Adjusting Screw Nut
To adjust the latch check switch perform
the following steps:
1. Remove the main closing spring.
Refer to
Ch 5 Maintenance,
B. M
echAnISM
A
reA
,
3) Closing Spring
Removal.
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 switch
contacts are now OPEN.
4. Insert a 0.045” gauge between
the secondary trip prop adjusting
screw (Figure 26, c) and latch check
operator. Rotate the latch check
switch upwards until the contacts
are closed. (An audible click of
the contacts will be heard). At the
position where the click is heard
hold the switch and retighten the
two screws which secure the latch
check switch. Remove the gauge.
5. To confirm that the latch check
switch is properly set, slowly depress
and release the manual trip operator
to verify that the latch check switch
OPENS and CLOSES properly. (An
audible click of the contacts will
be heard). The latch check switch
contacts will OPEN as the latch
check operator is moved by the
manual trip operator away from
the secondary trip prop adjusting
screw. Slowly withdraw the manual
trip operator and the latch check
switch contacts should close when
the latch check operator is between
0.045” to 0.015” away from the
secondary trip prop adjusting screw.
6. Depress the manual close operator
and rotate the crank arm until
resistance is felt.
7. Depress and hold the manual trip
operator inward and rotate the
crank arms until the spring charge
indicator displays, CLOSING SPRING
DISCHARGED.
8. Reinstall the circuit breaker main
closing spring.
