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I.B. 3A74792H08
Effective
09/2014
motion of the maintenance tool will result in free
wheeling of the ratchet wheel.
5-3.3 CLOSING OPERATION
Figure
5-4
shows the position of the closing cam and
tripping linkage. Note that in Figure
5-4a
in which the
circuit breaker is open and the closing springs are
discharged, the trip “D” shaft and trip latch are in the
unlatched position.
Once charged, the closing springs can be released to
close the circuit breaker by moving the spring release
latch out of the way. This is done electrically or manually
by depressing the spring release lever, which turns the
spring release latch out of the way of the closing stop
roller. The force of the closing spring rotates the cam
shaft through the spring cranks. The closing cam, being
attached to the cam shaft, in turn rotates the pole shaft
through the main link to close the circuit breaker.
In Figure
5-4c
the linkage is shown with the circuit
breaker in the closed position before the closing springs
have been recharged. Interference of the trip “D” shaft
with the trip latch prevents the linkage from collapsing,
and the circuit breaker is held closed.
Figure
5-4d
shows the circuit breaker in the closed
position after the closing springs have been recharged.
Note that the spring charging rotates the closing cam by
one half turn. Since the cam surface in contact with the
main link roller is cylindrical in this region, the spring
charging operation does not affect the mechanism
linkage.
Since the primary contacts are completely enclosed in
the vacuum interrupter and not adjustable in any way, a
“Slow Close” capability is not provided with VCP-W
circuit breakers.
5-3.4 TRIPPING OPERATION
When the trip “D” shaft is turned either by the trip button
or trip coil, all links return to the original “open” condition
shown in Figure
5-4a.
5-4 CONTROL SCHEMES
There are two basic control schemes for 38kV VCP-W
and VCP-WR circuit breakers, one for DC control and
one for AC control voltages (Figures
5-6
and
5-7).
There
may be different control voltages or more than one trip-
ping element, but the principal mode of operation is as
follows:
As soon as the control power is applied, the spring
charging motor automatically starts charging the
closing springs. When the springs are charged, the
motor cut off LS1/bb switch turns the motor off. The
circuit breaker may be closed by making the control
switch close (CS/C) contact. Automatically upon
closing of the circuit breaker, the motor starts charging
the closing springs. The circuit breaker may be
tripped any time by making the control switch trip
(CS/T) contact.
Note the position switch (PS 1) contact in the spring
release circuit in the scheme. This contact remains
made while the circuit breaker is being levered
between the TEST and CONNECTED positions.
Consequently, it prevents the circuit breaker from
closing automatically, even though the control close
contact (CS/C) may have been made while the circuit
breaker is levered to the CONNECTED position.
The position switch (PS2) contact is in the motor
circuit. It prevents the motor from starting until the fully
CONNECTED position is reached and the secondary
contacts are firmly engaged.
When the CS/C contact is made, the SR closes the
circuit breaker. If the CS/C contact is maintained after
the circuit breaker closes, the Y relay is picked up.
The Y/a contact seals in Y until CS/C is opened. The
Y/b contact opens the SR circuit, so that even though
the circuit breaker would subsequently open, it could
not be reclosed before CS/C was released and
remade. This is the anti-pump function.
5-4.1 TIMING
The opening and closing times for the circuit breakers
vary depending upon the control voltage and the power
rating. Typical values for 38kV VCP-W and VCP-WR
circuit breakers are shown in Table
5.1.
5-4.2 SECONDARY DISCONNECTS
The VCP-W drawout circuit breaker control wiring is
arranged to connect a standard 24 point male plug with
a corresponding switchgear compartment mounted
female plug. An additional 24 point plug is optional.
Drawout circuit breakers utilize fixed mounted male
plugs located under the left bottom portion of the
circuit breaker truck. When two 24 point plugs are
supplied, they are mounted in a stacked arrangement
(Figure
5-8).
Fixed mounted circuit breaker secondary
plugs connect to corresponding movable female plugs
mounted in the bottom of the switchgear
Содержание 380 VCP-W 21
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Страница 13: ...I B 3A74792H08 Page 7 Effective 09 2014 ...
Страница 19: ...I B 3A74792H08 Page 13 Effective 09 2014 Figure 3 4 Front View VCP W 38kV Drawout Vacuum Circuit Breaker ...
Страница 21: ...I B 3A74792H08 Page 15 Effective 09 2014 Figure 3 6 Rear View VCP W 38kV Drawout Vacuum Circuit Breaker ...
Страница 22: ...Page 16 I B 3A74792H08 Effective 09 2014 Figure 3 7 Typical VCP W 38kV Escutcheon ...
Страница 23: ...I B 3A74792H08 Page 17 Effective 09 2014 Figure 3 8 Typical VCP W 38kV Escutcheon ...
Страница 33: ...I B 3A74792H08 Page 27 Effective 09 2014 compartment Figure 5 5 Charging Schematic ...
Страница 34: ...Page 28 I B 3A74792H08 Effective 09 2014 Figure 5 6 Typical VCP W DC and AC Control Schematics Drawout ...
Страница 35: ...I B 3A74792H08 Page 29 Effective 09 2014 Figure 5 7 Typical VCP WR DC and AC Control Schematics Fixed ...
Страница 38: ...Page 32 I B 3A74792H08 Effective 09 2014 Figure 5 10 Undervoltage Trip Device Configuration ...
Страница 41: ...I B 3A74792H08 Page 35 Effective 09 2014 Figure 6 1 Lubrication Points Drawout Circuit Breaker Shown ...
Страница 60: ...Page 54 I B 3A74792H08 Effective 09 2014 ...
Страница 62: ...Page 56 I B 3A74792H08 Effective 09 2014 Style 3A74792H08 Printed in USA ...
