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30
Installation
01.4IB.77020
PowlVac-ND
®
and PowlVac-NDA
™
Series 4
Vacuum Circuit Breakers
4) Mechanical Operation Check
Keep personnel, tools, and other objects
clear of mechanisms that are to be operated
or released. Failure to do so may result
in equipment damage and/or minor or
moderate injury.
!
CAUTION
The contacts of the vacuum interrupter
during normal operation cannot be closed
unless the secondary disconnect plug is
inserted into the secondary disconnect
receptacle. To check the circuit breaker
outside of the circuit breaker compartment,
it is necessary to simulate the connection
of secondary disconnecting device by
inserting the secondary disconnect
override device in the secondary
disconnect receptacle. This device must be
removed after testing and before the circuit
breaker is inserted into the compartment.
The mechanical operation of the circuit
breaker is checked by inserting the manual
charging handle into the manual charging
crank and pushing down until a metallic
click is heard (this indicates that the holding
pawl has dropped into place on the ratchet
wheel). Lift the handle until it is horizontal
and then depress. The procedure is
repeated until the spring charge indicator
indicates
“CLOSING SPRING CHARGED”
.
This requires about 60 operations of the
handle. Once the closing spring is charged,
remove the handle.
The MOC actuator is exposed when the circuit
breaker is outside the metal-clad switchgear
and can cause serious injury if the test
personnel or any object is in the travel path
during operation. Care should be taken to
isolate the MOC side of the circuit breaker for
these tests.
!
CAUTION
Push the manual close operator
inward and the circuit breaker
will close. The circuit breaker open/closed
indicator located above the manual close
operator will now display
“BREAKER
CLOSED”
.
Push the manual trip operator
inward, which is located at
the top of the escutcheon and the circuit
breaker open/closed indicator will now
display
“BREAKER OPEN”
.