What this MCCB delivers
The Siemens SENTRON 3VA1150-5EF32-0AC0 is a 3-pole molded case circuit breaker rated for 50 A continuous current with a TM240 thermal-magnetic release. Its headline breaking capacity hits 187 kA at 240 V, 121 kA at 415 V, and 75.6 kA at 440 V — numbers that tell you it can interrupt very high fault currents without cascading upstream. That SCCR headroom matters when you're coordinating a distribution board downstream of a large transformer or feeding a motor control center with high available fault current. The TM240 release is a fixed thermal-magnetic type — no electronic adjustment, no communication module, no voltage trigger. That keeps the part simple and reliable for standard line protection where you don't need remote monitoring or ground-fault sensing. The 2 auxiliary switches (HQ version) are integrated, giving you status feedback for the panel PLC or annunciator without an add-on module.
Thermal derating and panel fit
The 50 A rating holds flat from 40 °C through 50 °C ambient. Above that, it derates linearly: 48 A at 55 °C, 47 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C. If your enclosure runs hot — say a packed panel near a furnace line — size your load at the derated figure, not the nameplate 50 A. Dimensions are 130 mm high, 76.2 mm wide, 70 mm deep. That 70 mm depth is shallow enough to clear most standard gland plates and backpanel wiring troughs. The IP40 front protection means it's dust-protected on the face but not sealed against hose-down — fine for a dry indoor panel, not for a washdown zone.