Siemens SENTRON 3VL System Manual page 323

Figure 14-7
Table 14- 5
S0
S01
K1
PE
Note
Automatic charging/close
A separate alarm switch contact (7-8) can be connected for automatic charging after tripping.
Automatic switching on of a circuit breaker must be prevented, otherwise a short-circuit could
automatically occur after a tripping event.
The contact of auxiliary contactor K1 or K3 prevents no-load operation of the circuit breaker
when the undervoltage release "<U" is without power. No load operations represent a high
level of stress for the circuit breaker. If the undervoltage release is without power, auxiliary
contactor K1 or K3 has not picked up. The contact in the ON circuit (control circuit) of the
motorized operating mechanism is thus not closed, that is, the circuit breaker cannot be
switched.
This auxiliary contactor is not necessary in principle when the undervoltage release is
supplied uninterrupted (e.g. pushbutton S01) from the same source as the motorized
operating mechanism itself (e.g. contact 4).
3VL molded-case circuit breakers
System Manual, 03/2009, 110 0110 - 02 DS 01
Stored-energy motorized operating mechanism
Stored-energy operator for VL160X, VL160, VL250, VL400, VL630 and VL800 with
undervoltage release
OFF (to be provided by customer) S1
Remote command (to be provided
by customer)
Auxiliary contactor (to be provided
by customer)
Protective grounding
ON (to be provided by customer)
-F1, -F2 Control circuit fuse
U< Undervoltage release
Circuit diagrams
323