The Siemens SENTRON 3VA9978-0BA24 is a shunt trip auxiliary release designed for remote tripping of 3VA4 and 3VA51 through 3VA64 molded case circuit breakers. It operates on a 380-500 V AC supply at 50/60 Hz, drawing up to 650 VA apparent power during the trip pulse.
The 650 VA apparent power consumption is the peak demand during the shunt trip coil energization — this is a momentary pulse, not a continuous load, but the control transformer feeding it must be sized to handle that inrush without voltage sag. The 4 kV surge voltage resistance (Overvoltage Category III) means the internal insulation withstands transient overvoltages typical of industrial distribution panels, so it's rated for direct connection to the breaker's line side without additional suppression.
Physically it's compact at 65.1 mm high, 21.7 mm wide, and 31.2 mm deep — designed to snap into the accessory slots on the left side of the 3VA4/3VA5 breaker frame. The three accessory slots accept up to three auxiliary releases or auxiliary switches; this shunt trip occupies one slot. Stripped length for the screw terminals is 10 mm (0.4 in).