Siemens 3AH3 Instruction Manual page 27

Since the striker pin of the undervoltage
release 3AX1103 is latched only when the
armature is energized, the undervoltage
release is provided with a screw (29.0), for
locking the striker pin (23.0) in the normal
position for adjusting purposes or for
carrying out trial operations during circuit
breaker servicing. Position A (locked)
disables the undervoltage release. Position B
(unlocked) is the normal operating position.
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 on the drawout truck or in the
stationary circuit breaker enclosure, as
space is not available inside the type 3AH
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 18).
Shock absorber
Circuit breakers are equipped with a
hydraulic shock absorber (61.8) (refer to
Figure 5). 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 6 shows the circuit breaker mounted
auxiliary switch (68.0). 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 (68.1) connected to the
jack shaft (63.0). 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 (88.0)
Spring-charging motors (50.4) (refer to
Figure 5) are available for either ac or dc
operation. If operated with ac voltage, a
rectifier is installed in the circuit breaker.
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