Westinghouse RC, Инструкция по эксплуатации

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TYP E RC AUTOMATIC R E CLOSI N G RELAY
O P E R A T I O N
Operation of the relay and associated equipment
will be described, using the external schematic in
figure 7, in conjunction with figures 4 and 5, which
show contact positions as a function of the drum posi­
tion. Fi gure 5 is based on the factory cam adjust­
ment - im mediate , 15 and 45 second reclosures , with
one drum revolution in 60 seconds. It is further as­
sumed in figure 5 that the instantaneous trip is locked
out after the first reclosure , and the fault is not
cleared prior to lockout.
Motor Control
Motor energization is controlled by cams 1 and 2.
In the start position the motor is energized through
111 and 52b contacts when the breaker opens. As the
drum moves away from the start position, 112 contact
closes to energize the motor through the 52a contact
during the time that the breaker is closed.
If the
breaker is closed at the lockout position the drum
will continue to rotate until the 112 contact opens at
the start position.
If
the breaker is open, the drum
will stop in the lockout position, since the 11 1 , 52a
and Y7 contacts are all open at this point.
Contact Y7 keeps the motor energized when the
breaker remains clo sed after an immediate rec lo sure
until the #2 contact can close. For this condition,
52b opens before the drum can rotate s ufficiently to
close the #2 contact. Contact Y7 has no significance
during subsequent reclosing operations.
C l o s i n g S e q ue n c i n g
The number of reclosures and the time at which
they oc cur is determined by the location of the #3 cam
screws, which clo se the #3 contact.
I n s ta n ta neo u s T r i p L o ck o u t
A s s hown in figures 5 and 7, the trip circuit of
the instantaneous trip units is opened by Y13 and
14 contacts from the time of the first reclosure until
the drum returns to the start position. During the
initial reclosing, contact Y13 is opened and remains
open until the Y unit is completely reset at 6 seconds.
The purpose of contact Y13 is to keep the trip cir­
cuit open until cam contact, 14, can be opened by the
drum rotation. Contact Y13 has no significance during
subsequent reclosing operations.
X -Y C i rc u i t
Referring to figure 7 , when the breaker clo se cir­
c uit is energized throu gh 52bb, Y5 and #3 contacts,
the 7 9X coil is also energized . Then, XB and X9
contacts seal around the Y5 contact and energize
4
79Y coil, respectively. Contact Y5 opens and re­
mains open until the Y unit is completely reset at 6
seconds. As the breaker closes, 52bb contact opens,
de-energizing the
X and Y coils. Should the breaker
immediately trip again, contacts Y5 and X8 will be
open to prevent premature energization of the breaker
close circuit.
C o m p l e te O pe ra t i ng S e q u e n c e
Fault-Trip - Immediate Reclosure
Refer to figure 7. With the timing drum in the
"Start" position, a #3 cam spring will be holding
contact #3 closed. The breaker switch contacts 52b
and 52bb close, energizin g the motor 7 9M through
contact #l, and the drum begins to rotate. At the
same time the coil of the contactor unit, 79X, is en­
ergized through drum contact #3 , contact Y5, and
integrating lockout contact 9A, when used . When
the breaker latch checking switch, 52LC, closes , the
breaker control relay 52X is immediately energized
through the p reclosed contacts Y5 and 3 . This in
tum energizes the closing coil of the breaker, 52C.
Simultaneously, contactor unit, 7 9X, seals in through
its c ontact X8 , while its o ther contact, X9, energizes
the coil of solenoid unit 79Y to open contacts Y5 and
Y13 and close contacts Y6
f
nd Y7. As the circuit
breaker closes , the breaker auxiliary s witc hes 52b
and 52bb open, and 52a closes . Opening 52bb de�
energizes 79X and 79Y. The latter then resets against
its latch to open contact Y6 and remains in this posi­
tion, thus leaving contacts Y5 and Y13 open and
contact Y7 closed until the latch is released. Before
the latch is released , the drum-operated contact, 14.
will be opened and will remain open until the drum
returns to the "Start " position.
Preparing for Second Reclosure
The drum continues to rotate, since the motor i s
energized through Y7. When the breaker trips the
second time, no immediate operation occurs. At about
one second , 112 cam contact closes to set up the motor
circuit when the breaker is s ubsequently reclosed. At
about the three second drum position contact 113 opens.
At about 6 seconds, the Y unit latch is released by
the 115 cam, resetting the Y unit. The relay is now
ready for another reclosure as soon as contact 113 is
closed by the 113 cam spring. The drum w ill continue
to rotate, since the motor is energized through 5 2b
and 111 contacts.
Second and Third Reclosures
At 15 and 45 seconds the #3 contact closes to
reclose the breaker. After each reclose, the Y unit
is unlatched by the action of cam
#5 .
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