The Siemens SENTRON 3VA1050-2ED42-0DA0 is a 4-pole molded case circuit breaker (MCCB) rated for 50 A continuous current, sized for line-protection duty in distribution panels. Its TM210 thermal-magnetic release handles overloads and short-circuits without needing an external trip unit, which keeps the wiring straightforward — no auxiliary supply to the release itself. Breaking capacity runs 52.5 kA at 240 V, 32 kA at 415 V, 13.6 kA at 440 V, and 7.5 kA at 690 V — so the same breaker can serve 240 V branch panels and 400 V motor control centers as long as the available fault current stays under those numbers. The 800 V rated insulation voltage (Ui) gives headroom for 690 V line-to-line systems. This version includes an undervoltage release (UVR) that trips the breaker when supply drops below the dropout threshold — common for emergency-stop circuits that need to drop a load on loss of control power. No auxiliary contacts, no communication module, no phase-failure detection; it's a plain line-protection MCCB with a UVR coil.
Thermal derating and panel fit
The breaker carries 50 A continuously from 40 °C through 50 °C ambient, then derates to 48 A at 55 °C, 47 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. If the panel ambient runs hot — say, a sealed enclosure next to a furnace line — you lose about 1 A per 5 °C above 50 °C. The operating range spans -25 °C to 70 °C, storage from -40 °C to 80 °C. Dimensions are 130 mm tall, 101.6 mm wide, 70 mm deep. It mounts on a DIN rail or panel via the standard SENTRON footprint. The front face carries IP40 protection — fine for a dry indoor panel, but not for washdown areas. Mechanical endurance is rated at 15,000 operations — that's a maintenance breaker, not a daily-switched disconnect. For frequent switching, look at the 3VA contactor-based motor-protector variants instead.