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SECTION 7-Breaker Maintenance (Cont.)
The mechanism i s reset by disengaging the side latch
l i nk from the upper latch link or by closing the breaker if a
locklever is not provided. The side latch link, is activated
only by pushing the TRI P button or operating the shunt trip.
A slide attachment on the TRIP button shaft moves
against the side latch link when the TRIP button is pushed.
This sl ide attachment is factory adjusted to activate the
side latch before the breaker is tripped. A second arm on
the shunt trip also activates the side latch l i nk when the
shunt trip is energized.
7.1 1 .2
ADJUSTM ENTS
If a breaker is equ ipped with a bel l alarm/lockout device
original ly, all the adjustments are made at the time of
assembly.
Switch operation is controlled by means of
shims of insulating material placed between the switch
body and the bracket to which it is fastened. The adjust
ment screw is positioned so that when the locklever is in its
activated position, it holds the breaker mechanism latch in
the tripped position.
Check that TRIP button shaft and shunt trip operations,
besides tripping the breaker, displace the side latch and
prevent the bell alarm switch from operating. The other tri p
devices and interlocks m ust activate the bel l alarm when
they open the breaker.
The bracket assembled to the TRIP button shaft must be
adjusted so that it wi l l displace the side latch when or
before the shaft opens the breaker. Maintain a .030 inch
minimum gap between the bracket and the side latch when
the breaker is closed. A .187 inch depression of the TRIP
button must not trip the breaker, but a .375 inch depres
sion m ust trip the breaker and displace the side latch .
W R E LAY
X-RELAY
FIG. 36A - ELECTRICAL CONTROL COMPONENTS
7.1 1 .3
REPLACEM ENT
The bel l alarm is mounted on the right hand side of the
breaker at the rear of front frame. It is located under the
mechanism main shaft.
The bel l alarm is removed by passing it through a cutout
in the rear bend of the front frame, slipping it between the
front frame and trip shaft and out through the bottom of the
breaker as fol lows:
1 . Remove the 4 bel l alarm mounting screws from the
bottom of the front frame.
2. If the crank which is part of the main shaft has a bel l
alarm activating pin assembled t o both sides, remove these
pins.
3. Insert the flat of the mai ntenance handle between the
top of the left hand side buffer block and the end plate
assembly. This should elimi nate any interference from the
main shaft during the bel l alarm removal.
4. The trip shaft must be moved to allow the bell alarm to
fit beteen it and the front frame. Remove the retaining ring
holding the right hand trip shaft bearing to the mechanism
frame. Slide the beari ng from the frame and along the trip
shaft. There will now be enough trip shaft movement to slip
the bel l alarm past.
5. Install the replacement bel l alarm in reverse order.
6. Check the adjustments g iven in Section 7.1 1 .2
A bel l alarm with a lockout assembly or a bel l alarm i n
stalled on a 2000 amp frame (AKRT 50/SOH) breaker may not
work with the above procedure.
breaker front and back frame will have to be seperated.
7.1 2
ELECTRICAL CONTROL COM PONENTS
The operation of the electrical control components is
described in Section 5.2. The location of these components
is shown in Fig. 36A.
If this is the case, the
CHARGING
MOTOR
G SWITCH
27
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