What this MCCB is and what it does
The Siemens 3VM1050-2ED42-0AA0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. Four poles, 50 A continuous at 40 °C, with a 500 A frame that sets the maximum short-time withstand and the physical envelope. The TM210 thermal-magnetic release handles overloads thermally and short circuits magnetically — no electronic trip unit, no communication function, no voltage or undervoltage release on this variant.
Thermal derating and panel fit
Rated 50 A straight across from 40 °C to 50 °C, then it begins to taper: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. If the panel ambient runs hot — say next to a transformer or in a non-climate-controlled enclosure — the continuous load must be trimmed to the derated figure. The 15 W maximum power loss is modest for a 4-pole 50 A MCCB; ventilation in the enclosure is still advisable. Physical footprint: 130 mm high, 101.6 mm wide, 70 mm deep. That 70 mm depth (2.76 in) is the dimension that matters for gland-plate clearance and whether the breaker fits a shallow backpanel enclosure. IP40 on the front means tools and fingers are kept out, but the sides and back are not sealed — mount it inside a rated enclosure, not exposed.
Lifecycle and sourcing posture
The lifecycle stage is marked current — meaning Siemens still actively manufactures and supports this order code. No end-of-life notice or last-time-buy window has been published for the 3VM1050-2ED42-0AA0. For a BOM freeze or a line-down replacement, this part is a standard catalog item, not a phase-out risk.