13
Magnetic-actuator operating mechanism
The energy needed for closing and tripping is
stored in two or three capacitor boards
(106.1) (depending on circuit breaker rating)
charged to approximately 160 V. The self-
discharging function is activated by removing
the connector (105.2) of the controller board
(105.0). Do not unplug connector (106.3)
from the capacitor boards, or damage to the
capacitor board or the controller board may
occur. The capacitors are charged
automatically when control power is applied.
From fully discharged condition, the
capacitors are fully charged in approximately
30-35 seconds.
If the capacitors have been fully discharged
for a very long time, charging time may be
significantly longer than indicated. If
capacitor charging time is much longer than
expected on initial energization, refer to
“Capacitor charging after very long de-
energization” on page 40 of the
“Maintenance” section of this instruction
manual.
The capacitor charge is monitored constantly
by the controller board (105.0). If the control
power source fails, the capacitors can initiate
one open operation initiated by the operator-
mounted pushbutton (54.0). This last
operation must be initiated within 300 s after
loss of control power supply.
Within 300 s after loss of operator control
power, the circuit breaker can perform one
open operation initiated by a remote
command if the remote command is from a
wet (powered) contact.
The green LED, when illuminated indicates
that energy is sufficient for an OPEN-CLOSE-
OPEN operation.
Vacuum interrupter/operator module
The vacuum interrupter/operator module
consists of the three poles, each with its
vacuum interrupter and primary insulators,
mounted above the common magnetic-
actuator operating mechanism housing
(60.0). This module is shown in Figure 6:
Vacuum circuit breaker magnetic-actuator
operator module on page 12.
Construction
Each of the circuit breaker poles is fixed to the
pole support channel (16.0) by two cast-resin
insulators. The insulators also connect to the
fixed- and moving-end pole heads (20.0 and
40.0) that in turn support the ends of the
vacuum interrupter. The pole supports are
aluminum castings or sheet steel (for 15.5 kV
and 27.6 kV up to 25 kA). Refer to Figure 3:
Operator panel controls on page 10 and
Figure 4: Vacuum circuit breaker magnetic-
actuator operator module on page 11, Figure
7: Pole assembly on page 14 and Figure 8:
Magnetic-actuator operating mechanism on
page 15.
The magnetic-actuator mechanism and all the
control and actuating devices are installed in
the operator housing.
The CLOSE-OPEN indicator, Open pushbutton,
Close pushbutton, the LEDs on the controller
board and the operation counter are located
on the front of the mechanism housing.
The control connector for the control and
signalling cables is a multi-contact plug. The
mating control plug wiring connects to the
terminal blocks in the relay and control
compartment.
Circuit breaker pole (refer to Figure 7:
Pole assembly on page 14)
The vacuum interrupter is bolted to the fixed-
end pole head (20.0), which is rigidly
connected to the pole support channel (16.0)
by the post insulator (16.1). The moving
contact end of the vacuum interrupter is
stabilized against lateral forces by a centering
ring (28.1) on the moving-end pole head
(40.0). The external forces due to switching
operations and the contact pressure are
absorbed by the struts (28.0).
Current-path assembly (refer to Figure 7:
Pole assembly on page 14)
The current-path assembly consists of the
fixed-end pole head (20.0), the stationary
contact and the moving contact, plus a
flexible shunt (29.1) between the moving
contact terminal clamp (29.2) and the
moving-end connection pad (29.0).
Vacuum interrupter (refer to Figure 7:
Pole assembly on page 14)
The moving-contact motion is aligned and
stabilized by a guide bushing. The metal
bellows follows the travel of the contact and
seals the vacuum interrupter against the
surrounding atmosphere.
