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A DVAC® 3 8 K V I N STA LL ATI ON , OPE R ATI ON A N D M A I NTE N A NCE M A N UA L
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Control scheme
The ADVAC® 38 kV circuit breakers are available
with one control package. The standard package
includes charge, close and open functions and 9a
and 8b auxiliary contacts for customer use. See
figure on following page for graphical sequence
of breaker operation.
1. Initial state:
a. Closing spring discharged
(33LSa open/33LSb closed).
b. Breaker open (52a open/52b closed).
2. Upon available control power:
a. With secondary engaged in test
or connected position.
b. Motor charges through 33LSb.
3. Closing spring charged:
a. 33LSa closes.
b. 33LSb opens (removing control
power to motor).
c. Breaker is ready to close.
4. Electrical control pulse sent to close circuit:
a. Current energizes close coil 52X coil through
the close blocking switch and closes breaker.
b. Closing spring discharges, 33LSa closes
and 33LSb opens.
c. 52a closes, and 52b opens.
d. Coil de-energizes with release of signal
and as 52b opens.
e. Closing spring charges, 33LSa closes
and 33LSb opens (removing control power
to motor). Breaker is ready to perform
O-C-O operation.
5. Electrical control pulse sent to open circuit:
a. Current energizes 52TC open coil.
b. Breaker opens.
c. Breaker is ready for close operation.
