Siemens 3VA9978-0AA12 Auxiliary Switch Changeover Type HQ 7 mm

The Siemens 3VA9978-0AA12 is an auxiliary switch with changeover contacts for SENTRON 3VA molded case circuit breakers. It signals the position of the breaker main contacts to a control or monitoring circuit.

The switch is of Type HQ with a 7 mm width, and fits into the accessory compartment of the breaker so no extra rail space is needed. The changeover contact form allows both a make and a break signal to be taken from a single device.

It is an accessory for the 3VA4, 3VA5 and 3VA6 families. Supplied with a net weight of 0.028 kg in a 100 x 175 x 8 mm pack, it is used wherever breaker status has to be reported to a PLC, control panel or building management system.