The Siemens SENTRON 3VA9277-0HC35 is a motorized operating mechanism with a stored energy mechanism (SEO) — an accessory that lets you remotely open and close a molded-case circuit breaker without needing an operator at the panel door. It is designed specifically for 3VA6 frames in the 150 A and 250 A ratings and for 3VA5 frames at 250 A.
Control supply and switching performance
The mechanism accepts a wide control supply range: 110 V to 240 V AC at 60 Hz, or 110 V to 250 V DC. At full pull-in it draws 300 VA apparent power — a figure to budget for when sizing the control transformer feeding the panel. Make and break times are both a typical 0.08 s, meaning the mechanism charges its spring and fires the breaker open or closed in under one-tenth of a second.
Panel fit and environmental range
The mechanism measures 105 mm wide by 118.7 mm high by 162.8 mm deep. That depth is the key dimension for enclosure clearance — the stored-energy spring and motor assembly projects behind the breaker face, so verify the back-of-panel depth against the 162.8 mm figure before committing the layout.