Door-coupling rotary operator for SENTRON 3VA moulded-case breakers
The Siemens SENTRON 3VA9277-0FK45 is a door-coupling rotary operating mechanism designed for emergency-off (E-stop) applications on 3VA6 150/250 and 3VA5 250 moulded-case circuit breakers. It provides a mechanical interface between the breaker's rotary handle and the enclosure door, allowing the operator to switch the breaker without opening the door. The mechanism includes a door interlock and a door-open position accessory, per the product description. Rated IP65 and NEMA 4/4X, this operator is suited for washdown environments, outdoor enclosures, and food-grade or chemical processing panels where a sealed, corrosion-resistant interface is required. The NEMA 4X rating specifically indicates resistance to corrosion, making it appropriate for marine or high-humidity installations.
The operator measures 105 mm in width and 82 mm in height. These dimensions define the panel cutout and mounting footprint. Verify the door thickness and handle projection against the enclosure clearance before specifying — the mechanism couples through the door, so the door must close freely without binding against the breaker's rotary handle. The door interlock prevents the door from opening when the breaker is in the ON position, a standard safety feature for emergency-off circuits per IEC 60947-1. The door-open position accessory allows the breaker to be operated even when the door is open for maintenance access.
The 3VA9277-0FK45 is a SENTRON-branded accessory specific to the 3VA6 and 3VA5 breaker families. It is not a universal handle — it couples only to the rotary drive shaft of those listed breaker frames.