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Page 14
4-8.2 OPERATION CHECK PERFORMANCE
Move the circuit breaker to the TEST position and
engage the secondary contacts following the procedure
described in Paragraph 4-8.1. As soon as control power
becomes available, the motor will charge the closing
springs with this condition indicated by a Spring
Charged/Discharged Indicator on the front of the circuit
breaker (Figure 3-7). In addition, the status of the main
contacts, open or closed, is indicated on the front of the
circuit breaker.
Using the close and trip buttons on the front of the cir-
cuit breaker, close and trip the circuit breaker several
times to verify the closing and tripping operations.
Conclude the check by closing the circuit breaker.
4-9 BREAKER/STRUCTURE INTERFACING
Type VCP-W Vacuum Circuit Breakers are supplied with
a series of interlocks to insure safe and proper interfac-
ing between the circuit breaker and a compatible struc-
ture compartment. The specific interlocks are described
in the next paragraph to provide the proper familiariza-
tion. Once the interlocks are reviewed, an interfacing
check can be performed as described in Paragraph
4-9.2.
4-9.1 INTERFACE INTERLOCKS
Each circuit breaker is supplied with the following inter-
locks to insure safe and proper operation (Figure 4-2):
Code Plates
Code plates are mounted at the bottom of the circuit
breaker to prevent the insertion of a circuit breaker into
a structure of higher power rating. A set of two code
plates on the circuit breaker and two in the compartment
form this interlock.
NOTICE
Code plates do not block out control voltage or
scheme incompatibility.
Close and Trip Floor Trippers
Mounted on the bottom of the circuit breaker, these
interlocks interface with compatible structure interlocks
to render the circuit breaker mechanism mechanically
and electrically trip free during the levering process.
Anti-Close Interlock
This interlock prevents releasing the closing springs
electrically or manually if the circuit breaker is already
closed (Figure 5-5). On a closed circuit breaker, the
interlock lever moves toward the rear. In this position,
the movement of the spring release clapper does not lift
the lever and thus the spring release latch cannot be
moved.
4-9.2 INTERFACING CHECK
Keep in mind that an interfacing check will be made with
a compatible structure. As such, the instructions provid-
ed with the assembly will suggest other interfacing con-
ditions that should be observed and/or checked, such as
primary shutter operation, MOC/TOC operation and lev-
ering handle insertion. A complete, coordinated inter-
face check, therefore, will be a blend of the circuit
breaker instructions and those provided with the struc-
tural assembly. Together all required standards are met
and the ultimate in safety is achieved.
Insert the circuit breaker into the structure and lever it
into and out of each different position by following the
procedures described in Paragraph 4-8.1.
When the secondary contacts are manually engaged in
the TEST position, the motor will charge the closing
springs. Close the circuit breaker. Attempt to engage the
levering crank to begin moving the circuit breaker to the
CONNECTED position. It will first be noticed that the
levering crank cannot be engaged with the breaker
closed. In addition, charged springs will be discharged
as the circuit breaker starts to move.
Once in the CONNECTED position, remove the levering
handle, close the circuit breaker and the motor will begin
charging the closing springs if control power is available.
Once again engage the levering handle which can only
be accomplished with the circuit breaker open.
Lever the circuit breaker toward the TEST position. The
circuit breaker will be in a trip-free condition. Continue to
lever the circuit breaker all the way to the TEST position
and the secondary contacts will be disengaged, now
making it the DISCONNECT position
Manually engage the secondary contacts and the motor
will charge the closing springs. Close the circuit breaker
and begin to remove the circuit breaker to the WITH-
DRAWN position by lifting and pulling on the Lift/Pull
handle. The circuit breaker will trip, close and trip as it
moves from the TEST position.
I.B. 3A74792H04
Effective 7/97
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