SENTRON 3VM1150-3ED32-0AA0 — 50 A MCCB for Line Protection
The Siemens SENTRON 3VM1150-3ED32-0AA0 is a 3-pole molded case circuit breaker (MCCB) rated for line protection, carrying a TM210 thermal-magnetic trip unit. It is rated 50 A continuously at 40 °C ambient, with a thermal derating curve that holds flat to 50 °C (still 50 A) and then steps down: 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. That means if this breaker lives in a warm cabinet — say a panel near a furnace line or a sun-loaded enclosure — you lose only 5 A from the 40 °C rating by the time you hit 70 °C. The breaking capacity is substantial: 76 kA at 240 V AC, 53 kA at 415 V, 32 kA at 440 V, and 12 kA at 500 V. For a 50 A frame, that is serious fault-current headroom; it will clear a high-energy fault on a 240 V secondary without upstream coordination worries.
Panel Fit and Mounting
The 3VM1150-3ED32-0AA0 measures 130 mm high, 76.2 mm wide, and 70 mm deep. At 3 inches wide, it occupies a standard three-module footprint on a DIN rail or panel-mount base. The front face carries an IP40 protection class — splash protection is not present, so keep it behind a panel door in washdown areas. Maximum power dissipation is 15 W at rated load; that is modest enough that forced ventilation is not required in a typical 600 mm wide enclosure, but worth checking if the panel is densely packed with other heat sources.
Trip Unit and Protection Design
The TM210 designation indicates a thermal-magnetic trip with a fixed time-current characteristic — thermal for overloads, magnetic for short-circuits. This is a line-protection design, meaning it is optimized for feeder and distribution circuits rather than motor-starting duty. There is no undervoltage release, no ground-fault monitoring, and no communication function on this variant. The rated insulation voltage is 800 V, which covers 480/277 V and 600 V systems with margin. If you need ground-fault or communication, you would step up to a 3VA-series breaker with electronic trip.