Page
xxviii
IB131021EN
Effective Mar 2018
5-3.7
TRIPPING OPERATION
Figures
3-3, 3-4, 3-5
show all components involved in a
tripping operation. An electrical trip signal can be sent to
the controller by applying an input voltage to pins 6 & 19 of
the secondary connection that is in accordance with the
control voltages listed in IEEE C37.06-2009, by depressing
the red “Push to Open” button on the front of the circuit
breaker, or by lifting the Open Floor Tripper. The VCP-WL
breaker also has an option for a Secondary Trip Signal
(Shunt Trip 2) and an Under Voltage Relay. For customers
who choose the Shunt Trip 2 option, a trip signal can be
sent to the controller by applying an input voltage to pins
12 & 13 of the secondary connection that is in accordance
with the control voltages listed in IEEE C37.06-2009. For
customers who choose a UVR option, an automatic trip
signal will be send to the controller when the control
voltage applied to pins 11 & 14 of the secondary
connection drops a certain amount below the rated control
voltage (the UVR option is described in more detail in
section 5-4.3).
Once a trip signal is sent to the controller, the controller will
discharge the stored energy from its internal “opening”
capacitor into the open coil of the electromagnetic actuator.
Once the open coil of the electromagnetic actuator is
energized, the magnetic latch between the armature and
permanent magnet inside the actuator will be broken.
Once the magnetic latch is broken, the four extended open
springs will pull the output plates and armature to the open
position. As the output plates are driven to the left when
looking at the front of the circuit breaker, they drive the
cross members and drive rod assembly toward the front of
the circuit breaker through the cam blocks. When the drive
rod assembly is driven toward the front of the circuit
breaker, the bell cranks on each pole unit are rotated
clockwise and the vacuum interrupters are driven to the
open position.
TIMING
5-4.1
The opening and closing times for the circuit breakers vary
depending upon the control voltage and the power rating.
Typical values for VCP-WL circuit breakers are shown
below:
Closing Time
(from initiation of close signal to contact
make) - 65 milliseconds MAX
Opening Time
(from initiation of trip signal to contact
break) – 3 cycle, 20-40 milliseconds – 5 cycle, 20-70
milliseconds
Re-closing Time
(from initiation of trip signal to contact
make) - 300 milliseconds MAX
SECONDARY DISCONNECTS
5-4.2
The circuit breaker control wiring is arranged to connect a
standard 25 point male plug with a corresponding
switchgear compartment mounted female plug. The circuit
breaker plug is fixed mounted on the left side under the
bottom pan of the mechanism (Figure
4-4
)
.
The female
plug is mounted in the compartment on a movable carriage
(Figure
4-2
)
.
The secondary disconnects engage automatically as the
circuit breaker is levered into the CONNECTED position,
and disengage as the circuit breaker is withdrawn from the
CONNECTED position. To engage the secondary contacts
while the circuit breaker is in the TEST position, raise the
handle and pull the carriage all the way towards the front
(Figure
4-5
)
.
This will latch the contacts. To disengage the
contacts, simple push the carriage to the rear.
5-4.3 UNDERVOLTAGE TRIP RELAY
The under voltage trip option for VCP-WL circuit breakers is
an onboard relay that automatically sends a signal to the
controller to open the circuit breaker if the rated control
voltage drops below 56.25% or the rated control voltage.
The following statements are true for the optional under
voltage relay:
If the circuit breaker is open, charged, and the
1.
UVR voltage is less than 56.25% of the rated
control voltage, the controller will not process a
close command and the circuit breaker will not be
able to be closed.
If the circuit breaker is open, charged, and the
2.
UVR voltage is greater than 56.25% of the rated
control voltage, the controller will properly process
a close command and the circuit breaker will be
able to be closed.
If the circuit breaker is closed and the UVR voltage
3.
is greater than 56.25% of the rated control voltage,
the relay will not send a signal to the controller to
open the circuit breaker.
If the circuit breaker is closed and the UVR voltage
4.
drops below 56.25% of the rated control voltage,
the relay will automatically send a signal to the
controller to open the circuit breaker and the circuit
breaker will open.
There are multiple options for the UVR nominal control
voltage. The options are 48VDC, 125VDC, 120VAC and
240VAC.
