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Operation
01.4IB.51000C
Figure 29 Standard Circuit Breaker in Test
Position
2) Inserting the Circuit Breaker to the Connected
Position
a. Press and hold the manual trip operator
and simultaneously open the racking
drive shaft shutter (Figure 30). Place the
racking handle socket onto the racking
drive shaft. The racking handle socket
may be used to push down the shutter
to gain access to the racking drive shaft.
b. Release the manual trip operator. It will
remain actuated as long as the shutter is
held open by the racking handle socket.
Figure 30 Pushing Manual Trip Operator &
Accessing Racking Drive Shaft
c. Turning the racking handle clockwise
will begin to rack the circuit breaker
into the compartment (Figure 31).
When the circuit breaker is racked into
the compartment, the force needed
to rotate the racking handle will be
low at the beginning of motion as the
movement of the racking crank arms
is only opening the shutters. Once the
shutters are open, the circuit breaker
begins to move toward the stationary
primary disconnecting devices. When
the movable primary disconnecting
devices of the circuit breaker engage
the stationary primary disconnecting
devices of the compartment, the
force required to rotate the racking
handle will increase appreciably. This
force will decrease as the primary
disconnecting devices spread and
engage fully. Continuing rotation
of the racking handle will cause the
circuit breaker to travel further into
the compartment ensuring wipe or
overlap of the primary disconnecting
devices. Continue racking until the
breaker position indicator displays
“
BREAKER CONNECTED
”. This will
be approximately 22 rotations from
the starting point. When the circuit
breaker reaches the end of the
racking travel, the user will notice
an increased amount of force. If the
operator continues to apply force, a
torque limiter on the racking handle
will produce a sharp clicking sound
indicating the torque limit is reached at
35 -ft-lb. Should the operator continue
to apply force, the torque limiter will
continue to operate with no further
buildup of torque on the circuit breaker
mechanism.