The Siemens SENTRON 3VA9257-0HA20 is a motorized operating mechanism (MO) accessory designed specifically for the 3VA1 250 molded case circuit breaker frame. It provides remote electrical switching capability — opening and closing the breaker via a control signal rather than manual handle operation. Rated control supply voltage covers 110-230 V AC at 60 Hz and 110-250 V DC, with an operating apparent power of 250 VA. Typical make and break times are both 0.9 s, giving predictable switching performance for automated load shedding or emergency shutdown sequences. The mechanism fits within a 132 mm depth, 105 mm width, and 75 mm height footprint — sized to mount directly onto the 3VA1 250 breaker without additional panel rework.
Integration Notes
The motor operator mounts directly onto the 3VA1 250 breaker, sharing its DIN-rail or screw-mounting footprint. The stripped length of 7 mm on the control wiring terminals matches standard ferrule sizing for panel wiring. Control voltage selection must match the available supply — the mechanism accepts both AC and DC, but the 250 VA inrush at make should be factored into the control transformer sizing if multiple operators are ganged on the same circuit.