Siemens 3VA9978-0BL30N Soft Starter for Motors

Siemens 3VA9978-0BL30 shunt-trip voltage release accessory for Siemens 3VA4/5/6 molded-case circuit breakers. It energizes from 24 V AC (50/60 Hz) or 24–30 V DC to remotely trip the associated breaker, enabling emergency-stop and protective interlock functions in industrial control schemes. The unit is a left-hand mounting accessory designed specifically for 3VA4/5/6 series, ensuring compatible integration within Siemens switchgear. The part is cataloged under the 3VA9978-0BL30 family and is intended to be used in conjunction with the corresponding 3VA4/5/6 breaker rather than as a standalone motor controller or soft starter. Typical applications include remote safety interlocks, fault-initiated trips, and safety circuits requiring a remote trip signal in industrial automation environments.