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PART C Operating Mechanism working principle & maintenance
DRIVING LATCH
L1
CLOSING SPRING
Initial stage
CLOSING COMMAND
CLOSING LEVER
Fig C Mechanism in open condition & both the springs in
discharged condition
The spring charging motor charges the springs after
each closing operation
indication appears. Should there be no voltage during
charging, the geared motor stops, and starts recharging
the springs automatically when the voltage is on again.
It is, however, always possible to complete the charging
operation
manually.
automatically as the spring gets completely charged.
1.3.2 Manual Spring Charging
For charging the Closing-springs manually, fully insert
the charging handle into the seat and rotate it clockwise
until you see the spring-charged indication.
Ensure the handle is engaged with the seat.
The force, which can normally be applied to the charging
handle, is 130 N. In any case,
applied must not exceed 170 N. As the springs get
charged, a sound [internal latches getting engaged]
can be heard.
The arm won't rotate the charging-gear further, since
the charging-gear has no teeth on remaining periphery.
1.4 Breaker Operations:
1.4.1 Closing Operation:
Consider both the springs are in discharged condition
and breaker is open (Ref Fig. E, Page 37) In this
condition neither close nor open operation is possible
to perform on the breaker. Latch assembly (La) and
(Lb) are in released condition. The closing spring can
be charged either electrically or manually as explained
LATCHES FOR HOLDING
Power Shaft
CHARGING GEAR
SPRING CHARGING
DEVICE
ARM
until
the
spring-charged
Motor
supply
gets cut-off
the
maximum
force
in
section1.3. During the process of charging pin
(P1) comes in contact with closing lever (Ref Fig F,
Page 37). Pin (P1) will creates pressure on closing
lever as closing spring is fully charged. Position of the
closing lever in this condition is retained by half shaft.
If close command is initiated now, it will rotate half shaft
(Ref Fig. G). Rotation of half shaft will release closing
lever and hence charging gear. Due to this spring
DRIVING LATCH
L1
CLOSING SPRING
After Charging
CLOSING COMMAND
CLOSING LEVER
ARM
Fig D Closing spring is charged, ready for closing operation
energy stored in closing spring acts on power shaft,
which will cause the rotation of the cam mounted on
the power shaft. Mechanism lever (Ref. Fig.G) is resting
on the outer periphery of this cam, which is directly
connected to charging shaft. Rotation of cam will push
this mechanism lever upwards, this will results in rotation
of the charging shaft. Tripping lever is mounted on
same charging shaft. One end of this tripping lever is
connected to common shaft of the breaker via link, and
another end is connected to tripping spring. Rotation of
around
90° will close the circuit breaker as well as
charging of the tripping spring.
36
LATCHES FOR HOLDING
L1
CHARGING GEAR
SPRING CHARGING
DEVICE
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