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27
Installation
01.4IB.50032C
!
CAUTION
If DC high potential testing (hipot) is required,
the DC high potential test machine must
not produce instantaneous peak voltages
exceeding 50kV.
No attempt should be made to try to
compare the condition of one vacuum
interrupter with another, nor to correlate
the condition of any vacuum interrupter
with low values of DC leakage current.
There is no significant correlation.
!
CAUTION
After the high potential is removed, an
electrical charge may be retained by the
vacuum interrupters. Failure to discharge this
residual electrostatic charge could result in an
electrical shock. All six primary disconnecting
devices of the circuit breaker and the metallic
mid-band ring, if present, should be grounded
and remain grounded for at least on minute
to reduce this electrical charge before coming
into contact with the primary circuit.
3) Control Voltage Insulation Integrity
If the user wishes to check the insulation
integrity of the control circuit, it may be
done with a 500V or 1000V insulation
resistance tester or with an AC high
potential tester. The AC high potential test
should be made at 1125V, 50 or 60Hz for
one minute. The charging motor must be
disconnected prior to testing the control
circuit. The charging motor itself may be
similarly tested at a voltage not to exceed
675V, 50 or 60Hz. Be sure to remove any
test jumpers and reconnect the charging
motor when the tests are complete.
!
CAUTION
Remove all grounding conductors applied
for this test before placing the circuit breaker
back into service.
4) Mechanical Operation Check
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. Remove the
handle.
!
CAUTION
Care must be exercised to keep personnel,
tools, and other objects clear of mechanism
which are to be operated or released.
Push the manual close operator
(Figure 1, h) 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
(Figure 1, e) inward, which is located at
the top of the escutcheon and the circuit
breaker open/closed indicator will now
display
“BREAKER OPEN”
.
