Switch disconnector for load-break isolation
The Siemens SENTRON 3VA1112-1AA42-0HA0 is a 4-pole switch disconnector in MCCB design, rated for 125 A continuous current (Iu) and 800 V rated insulation voltage (Ui). It is built to provide visible-break isolation and load switching in distribution panels without overcurrent protection — no trip unit, no short-circuit protection, just a reliable disconnect for maintenance and safety isolation. Rated operational voltage reaches 690 V AC (50/60 Hz) and 600 V DC, covering common industrial supply levels. The shunt trip release (STL) operates on 12–30 V DC or 24 V AC, allowing remote trip via a control signal — useful for emergency-off or interlock circuits. Front terminals accept busbar connection, so it integrates directly into a busbar trunking system or panelboard. At 70 mm deep, 101.6 mm wide, and 130 mm tall, it fits the standard 160 A frame footprint. IP40 on the front means tools or fingers won't reach live parts, but it is not sealed against water — keep it inside the enclosure.
Integration and environment
Operating temperature spans -25 °C to 70 °C; storage range is -40 °C to 80 °C. Maximum power loss is 38 W — plan for heat dissipation in a sealed enclosure. Mechanical endurance is rated at 15,000 operations, which is standard for a switch disconnector in this class.