Shock Absorber; Auxiliary Switch - Siemens 3AH Instructions, Installation, Operation, Maintenance

Interrupter/Operator Description

Shock Absorber

Type 3AH circuit breakers are equipped with a sealed, oil-
filled, viscous damper, or shock absorber (61.8) Figure 6.
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 opera-
tion.

Auxiliary Switch

Figure 6 shows the breaker mounted auxiliary switch. This
switch provides auxiliary contacts for control of circuit
breaker closing and tripping functions. Contacts are avail-
able for use in relaying and external logic circuits. This
switch is driven by linkages connected to the jack shaft.
The auxiliary switch contains both 'b' (Normally Closed)
and 'a' (Normally Open) contacts. When the circuit breaker
is open, the 'b' switches are closed and the 'a' switches are
open.
Figure 10. Latch Details (shown charged)
Figure 11. Undervoltage Block/Operate Selection
Figure 12. Capacitor Trip Device
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