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46
Maintenance
PowlVac
®
STD Vacuum Circuit Breaker
IB-60201
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.
Note:
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
(Figure 2, s) is adjusted by the holding
pawl adjusting eccentric (Figure 2, u).
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.
7. When the eccentric is properly set
replace the escutcheon.
Be sure that the escutcheon is
reinstalled on the proper circuit breaker,
since the escutcheon contains the
nameplate with the circuit breaker
rating and serial number information.
The serial number of the circuit breaker
is also attached to the circuit breaker
frame near the ground connection
on an engraved serial number metal
plate. The serial number found on the
nameplate must match the number
affixed to the frame.
