The Siemens SENTRON 3VA9978-0BL20 is a shunt trip auxiliary release for remote tripping of 3VA5 and 3VA6 molded case circuit breakers. It operates on a 380-600 VAC supply at 50/60 Hz, drawing up to 40 VA apparent power. The three-slot design occupies the accessory bay on the left side of the breaker. The 10 mm stripped length on the terminals matches standard ferrule sizing for panel wiring — no special crimp tool needed.
At 65.1 mm high, 25.7 mm wide, and 31.2 mm deep, this shunt trip nests inside the breaker's accessory compartment without increasing the overall mounting footprint. The breaker itself occupies the same DIN-rail or screw-mount position whether the shunt trip is installed or not.