Timing; Secondary Disconnects; Shunt Trip Device; Under-Voltage Trip Device - Eaton VCP-W Series Instructions For Installation/Operation/Maintenance/Servicing

Instructions for installation,
operation, and maintenance of type
VCP-W vacuum circuit breakers
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 depend-
ing upon the control voltage and the power rating. Typical values for
VCP-W breaker elements are shown in
Table 22. Circuit breaker timing (made while the circuit breaker
is levered to the CONNECTED position).
Event
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)

5.4.2 Secondary disconnects

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
15). The female plug is mounted in the compartment on a movable
carriage (Figure 12 and 13).
To engage secondary contacts:
For BPI: secondary contacts engage automatically in TEST
•
position
For non-BPI: raise the handle and pull the carriage all the way
•
towards the front (Figure 16).
For automatic/manual hybrid: raise the handle, spring pres-
•
sure will force the carriage all the way towards the front. Check
contacts fully engaged.
To disengage secondary contacts:
For BPI: rack the breaker to the DISCONNECT position.
•
For non-BPI: push the carriage to the rear, contacts will
•
disengage.
For automatic/manual hybrid: push the carriage to the rear
•
against spring pressure, contacts will disengage. Allow carriage
handle to catch in latch cutout of mechanism.

5.4.3 Shunt trip device

The shunt trip device is an electro-mechanical device that operates
to open the circuit breaker. When the coil is energized by some
extenal source, it will trip the breaker open. The shunt trip device
is available with rated voltages of 24 Vdc, 48 Vdc, 125 Vdc, 250 Vdc,
120 Vac, and 240 Vac. A cap trip device must be used with the 120
Vac and 240 Vac options. If needed, continuous trip coil monitoring
is available. Also there is an option to have a second shunt trip
which can be rated at a different voltage other than the voltage
specified for the primary shunt trip.
Table 22.
Milliseconds (maximum)
45-60
30-45
140-165
Instruction Booklet IB131006EN

5.4.4 Under-voltage trip device

The under-voltage trip device for VCP-W circuit breakers is an electro-
mechanical device that operates to open the circuit breaker at 30%
or less of the voltage rating of the trip coil. The device does not
open the circuit breaker at values above 60% of the voltage rating
of its trip coil. It may operate, however, to open the circuit breaker
when the voltage across the trip coil is greater than 30%, but less
than 60% of the voltage rating of its trip coil. The circuit breaker can
be closed as long as the voltage to the trip coil is maintained at 85%
or above the rated level. The under-voltage trip device is available
only as an instantaneous type with rated voltages of
48 Vdc, 125 Vdc, 250 Vdc, 120 Vac, and 240 Vac.
For a basic understanding of the operation of the under-voltage trip
device refer to the specific items identified in
following operation description.
1. With the circuit breaker closed and sufficient voltage on the
under-voltage trip device coil, the moving clapper (1) is held
to the stationary yoke (2) by the magnetic force produced by
the coil (3) against the extension springs (4) pulling the moving
clapper apart from the yoke.
2. The moving clapper is connected to the mechanism trip "D"
shaft lever (5) by a slotted link (6).
3. When the voltage to the under-voltage trip coil goes down as
described earlier, the extension springs force overcomes the
reduced magnetic force and pulls the moving clapper up. The
slotted link in turn upsets the trip "D" shaft and the circuit
breaker trips open.
4. As the circuit breaker opens, the reset lever (8) connected to the
pole shaft lever (7) operates to reset the moving clapper. As long
as the circuit breaker remains open, the reset lever holds down
the moving clapper to the yoke.
5. When the circuit breaker closes, the reset lever moves away
from the moving clapper. If the under-voltage trip device coil has
at least 85% of the rated voltage applied, the moving clapper is
held to the yoke by the magnetic force, even though the reset
lever has moved up.
Effective March 2019
Figure 24 and the
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