Switch Disconnector for Isolation Duty
The Siemens 3VA1112-1AA36-0KA0 is a SENTRON 3VA1 switch disconnector in an MCCB-style housing, rated for 125 A continuous current across the full -25 °C to 70 °C operating range — no derating needed up to the maximum ambient. It is designed for isolation and switching of circuits where overload and short-circuit protection are handled upstream or by a separate device; this unit carries no overcurrent release, only a shunt trip (STL) for remote emergency-off or controlled disconnection. The shunt trip operates on 220-250 V DC or 208-277 V AC. Rated insulation voltage is 800 V, with maximum operating voltage 690 V AC and 500 V DC. The front face carries IP40 protection — suitable for enclosed panel mounting where the front is behind a door or cover. Mechanical endurance is 15,000 operating cycles typical.
Dimensions and Panel Fit
The 3VA1112-1AA36-0KA0 measures 130 mm high, 76.2 mm wide (roughly 3 inches — three 1-inch pole spaces), and 70 mm deep. It uses front terminal connections for the main circuit, accepting lug-type conductors. An optional motor drive can be added for remote operation.