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45
Maintenance
01.4IB.60306
4) Slow Closing of Mechanism
The slow closing of mechanism described
is not required for routine maintenance;
however, it may be a useful procedure
for troubleshooting circuit breaker
misoperation.
a. With the main closing spring assembly
removed, rotate the camshaft so that
the crank arms are pointing downward.
The fundamental linkage will now move
into the reset position.
b. Push the manual close operator inward
and hold it in while operating the
charging handle to rotate the camshaft.
c. When the close release latch arm has
passed the close shaft latch plate, the
manual close operator may be released.
As the main closing cam engages
the main cam roller, the jackshaft will
commence to rotate.
d. Continue to operate the charging
handle until the crank arms point
upward. The circuit breaker will now be
closed and there will be a gap between
the operating pushrod lock nuts and
the pivot blocks.
e. Return the circuit breaker to the open
position by depressing the manual trip
operator.
f. To install the main closing spring
assembly reverse the preceding removal
procedure.
5) Mechanism Adjustments
Several factory adjustments in the stored
energy mechanism are described in this
section. NO ADJUSTMENT OF THESE
SETTINGS IS REQUIRED FOR ROUTINE
MAINTENANCE, but they may need to be
adjusted after a major overhaul or removal
of the mechanism.
CAUTION
Do NOT adjust these settings unnecessarily as
damage to the circuit breaker may occur.
a. Adjustment of Ratchet Wheel Holding
Pawl
The holding pawl support arm
) is adjusted by the holding
pawl adjusting eccentric (
If the pawl is not properly adjusted,
there will be a “knocking” noise when
the ratchet mechanism is operating or
the stored energy mechanism will not
ratchet at all.
To adjust the pawl perform the
following steps:
1. Remove the escutcheon to gain
access to the head of the bolt
holding the adjusting eccentric.
2. Loosen the bolt slightly.
3. Grip the eccentric with a pair of
slip-joint pliers or a similar tool and
rotate the stop slightly.
4. Tighten the holding bolt with the
eccentric in the new position.
5. While charging the main closing
springs, using the charging motor
to drive the mechanism, observe
the ratcheting operation for
improvement.
6. If the ratcheting operation has not
improved, repeat the preceding
sequence until the ratcheting
operation is smooth. This may
require several charging cycles.