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Instructions for VR-Series
Replacement Breakers for
Westinghouse Type B20B/B22B
I.B. 94A1994R01
Page 19
Effective: April 2005
IB01301018E
Table 5.1 - Time Per Event
75
45
190
Event
Milliseconds/Maximum
Closing Time
(From Initiation of Close
Signal to Contact Make)
Opening Time
(Initiation of Trip Signal
to Contact Break)
Reclosing Time
(Initiation of Trip
Signal to Contact Make)
breaker from closing automatically, even though the control close
contact may have been made while the breaker is levered to the
CONNECTED position.
When the CS/C contact is made, the SR closes the breaker. If the
CS/C contact is maintained after the 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 breaker
would subsequently open, it could not be reclosed before CS/C
was released and remade. This is the anti-pump function.
5.6 SECONDARY CONNECTION BLOCK
The breaker control circuit is connected to the switchgear control
through secondary connection block, located at the lower left rear
of the breaker. The contacts engage automatically when the
breaker is racked into the “test” and “connect” positions. The
socket half of the connection is located in the cubicle and a jumper
of multiconductor cable can complete the control connections (for
testing) when the breaker is withdrawn from the cell.
5.7 INTERLOCKS
There are several interlocks built into the VR-Series vacuum
replacement breakers. Each of these interlocks, though different in
form, duplicate or exceed in function that of the original breaker.
These interlocks exist to safeguard personnel and equipment. The
basic premise behind the interlocking arrangement on the vacuum
replacement breaker is that the breaker must not be inserted into or
removed from a live circuit while the main contacts are closed. Also
considered in the interlocking is that the breaker should pose no
greater risk than necessary to the operator in or out of the cell. In
addition to the original interlocks, VR-Series breakers provide an
anti-close interlock.
INTERLOCKS ARE PROTECTIVE DEVICES FOR PERSONNEL AND
EQUIPMENT. DO NOT BYPASS, MODIFY, OR MAKE INOPERA-
TIVE ANY INTERLOCKS. DOING SO COULD CAUSE DEATH,
SERIOUS PERSONAL INJURY, AND/OR PROPERTY DAMAGE.
5.7.1 ANTI-CLOSE INTERLOCK
The anti-close interlock prevents discharging of the closing springs
if the breaker is already closed (Figure 5-5, Item 2). When the
breaker is closed, the interlock component moves away from the
spring release clapper so that it cannot lift the spring release latch
(3).
5.7.2 SHUTTER INTERLOCK
Each breaker cell is equipped with a shutter to shield the high
voltage stabs in the cubicle when the breaker is not in the cubicle.
The shutter is regulated by an operator located on the breaker that
opens the shutter as the breaker is racked into the cell and closes
the shutter as the breaker is racked out of the cell.
5.7.3 RACKING SYSTEM CAM INTERLOCK
The racking system tripping and spring release cam interlocks
perform the following:
a. Set the breaker mechanically trip-free between connect and
disconnect positions.
b. Close the position switch (PS1) to prevent energizing of the
spring release coil whenever the breaker is between the, connect
or disconnect position.
c. Set the breaker in a safe condition (breaker open, springs
discharged) when moved from the disconnect to the withdrawn
position.
5.8 MOC (Mechanically Operated Contacts) OPERATOR
The MOC operator located on the breaker is linked to the MOC
operator inside the VCP-WR element. When the breaker closes,
regardless of whether it is in the cubicle, the MOC linkage of the
breaker will cause the exterior MOC operator to rapidly rise. Care
should be exercised to avoid contact with this mechanism. Inside
the cubicle, there is a lever system connected to a MOC switch. If
the breaker is in the “test” or “connected” position the MOC operator
will operate the MOC switch when the breaker closes. The MOC
switch contains contacts which are used to interlock the circuit
breaker with other external devices and can provide breaker status
indication.
EXTREME CARE SHOULD BE TAKEN TO AVOID PERSONNEL OR
EQUIPMENT CONTACT WITH THE MOC SYSTEM WHEN OPERAT-
ING THE BREAKER DUE TO THE ASSOCIATED MECHANICAL
FORCE. CONTACT WITH THE MOC OPERATOR DURING
OPERATION COULD RESULT IN INJURY OR EQUIPMENT DAM-
AGE.
WARNING
WARNING