The Siemens SENTRON 3VA9978-0BD11 is a universal auxiliary release designed as an accessory for the 3VA4, 3VA5, and 3VA6 molded-case circuit breaker families. It operates on a 12 V DC control supply and draws a maximum active power of 20 W. The release occupies 3 slots in the breaker accessory bay and measures 28.8 mm deep, 25.7 mm wide, and 65.1 mm high. Stripped length for the connection wire is 10 mm (0.4 in).
Integration Notes
Mounts into the accessory slot of 3VA4, 3VA5, or 3VA6 breakers — no additional DIN-rail space required. The 12 V DC control supply must be stable within the release's tolerance; verify the power supply's ripple and sag characteristics against the 20 W maximum draw.