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20
PowlVac® CDR 27kV & 38kV Vacuum Circuit Breaker
IB-65020A
Equipment Description
e. Control Circuit
The typical AC & DC electrical control
schemes are shown in Figure 11.
The control scheme of any particular
circuit breaker may differ depending
on the user’s requirements, operating
solenoids, and the control devices
furnished with that circuit breaker.
The sequence of operation for all
control schemes is shown in
Figure 10. Circuit breaker mounted
auxiliary contacts not used in the
control circuit are brought out for
control and indication functions. The
metal-clad switchgear equipment
may provide a circuit breaker MOC
(Mechanism Operated Cell Switch) for
additional contacts.
c. r
AckInG
M
echAnISM
The racking mechanism is the mechanical
assembly that facilitates moving the circuit
breaker between the breaker
test/disconnected and connected positions
in the circuit breaker compartment. The
main racking mechanism is located in the
switchgear. Refer to
IB-65000, PV System 38
®
Metal-Clad Switchgear
for racking information.
d. c
IrcuIt
B
reAker
c
oMpArtMent
I
nterfAceS
1) Primary Disconnecting Devices
There are six primary disconnecting
devices on the circuit breaker. They are
arranged, two per phase, with the upper
device connected to the stationary end
of the vacuum interrupter, and the lower
device connected to the moving end of the
vacuum interrupter assembly.
Each primary disconnecting device
(Figure 2, a & d) has multiple contact fingers
which will mate with the stationary primary
disconnecting devices in the circuit breaker
compartment.
Do NOT handle or move the circuit breaker by
the primary disconnecting devices, as damage
may occur.
CAUTION
CAUTION
!
2) Secondary Disconnecting Devices
Control power is transferred from the
metal-clad switchgear to the circuit
breaker by means of the secondary
disconnecting devices. The secondary
disconnect receptacle (Figure 1, f) is
located on the top left side of the circuit
breaker. The secondary disconnect plug is
attached to the switchgear and is located
on the left side wall of the circuit breaker
compartment. This arrangement allows the
secondary connection to be visible in all
positions of the circuit breaker.