Siemens 3AH35-SE Series, Instruction Manual

21

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 in the 
outdoor circuit breaker enclosure, as space is 
not available inside the type 3AH35-SE 
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 15: 
Capacitor-trip device on page 20).

Shock absorber

Circuit breakers are equipped with a hydraulic 
shock absorber (61.8) (refer to Figure 6: 
Stored-energy operating mechanism (circuit 
breaker shown in OPEN position) on page 
12). 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: Stored-energy operating mechanism 
(circuit breaker shown in OPEN position) on 
page 12) 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)

Spring-charging motors (50.4) (refer to Figure 
6: Stored-energy operating mechanism 
(circuit breaker shown in OPEN position) on 
page 12) are available for either ac or dc 
operation. If operated with ac voltage, a 
rectifier is installed in the circuit breaker.