35
Instruction manual
| Types SDV-R and SDV-R-AR distribution circuit breakers
Figure 22: Capacitor-trip device
120 or 240 Vac
supply
01
T
24
23
52a
19
33
34
52a
A1
A2
52T
1
2
9
3
10
XO C2
Capacitor trip device
XO D2
25
Capacitor trip device
The capacitor trip device is an auxiliary
tripping option providing a short-term
means of
storing adequate electrical energy
to ensure circuit breaker tripping. If
provided, a capacitor trip device must be
located in the outdoor circuit breaker
enclosure, as space is not available inside
the operator housing. This device is applied
in circuit breaker installations lacking
independent auxiliary control power or
station battery. In such installations, control
power is usually derived from the primary
source. In the event of a primary ac source
fault or disturbance the capacitor trip device
will provide short-term tripping energy for
circuit breaker opening due to protective
relay operation or operation of a circuit
breaker control switch.
The capacitor trip converts 120 or 240 Vac
control voltage to a dc full-wave voltage
that is used to charge a large capacitor to
the peak of the converted wave (refer to
Figure 22: Capacitor-trip device).
Shock absorber
Circuit breakers are equipped with a
hydraulic shock absorber (78.0) (refer to
Figure 17: Stored-energy operating
mechanism shown in OPEN position on
page 30). The purpose of this shock
absorber is to limit overtravel and rebound
of the vacuum interrupter movable contacts
during the conclusion of an opening
operation. The shock absorber action affects
only the end of an opening operation.
Auxiliary switch (52a/b)
Figure 17: Stored-energy operating
mechanism shown in OPEN position shows
the circuit breaker mounted auxiliary switch
(61.0). This switch provides auxiliary
contacts for control of circuit breaker closing
and opening functions. Contacts are
available for use in relaying and external
logic circuits. This switch is driven by linkage
(62.0) connected to the main shaft (68.1).
The auxiliary switch contains both “b”
(normally closed) and “a” (normally open)
contacts. When the circuit breaker is open,
the “b” contacts are closed and the “a”
contacts are open.
Spring-charging motor (88)
Spring-charging motors (74.0) (refer to
Figure 17: Stored-energy operating
mechanism shown in OPEN position) are
available for either ac or dc operation. If
operated with ac voltage, a rectifier is
installed in the circuit breaker.