What this 3VA1150-6EF32-0BC0 is and what the ratings mean for fit
The Siemens 3VA1150-6EF32-0BC0 is a SENTRON 3-pole molded case circuit breaker (MCCB) rated for line protection — meaning it sits on the incoming feeder or main distribution bus, not on a motor branch. Its rated continuous current Iu is 50 A, and it holds that 50 A rating from 40 °C up through 50 °C ambient without derating; at 55 °C it still carries 48 A, at 60 °C it carries 47 A, and at 70 °C it carries 45 A. That thermal curve matters for a panel that runs warm — you don't lose headroom until you cross 50 °C. The breaking capacity figures are the headline: 220 kA at 240 V, 154 kA at 415 V, 121 kA at 440 V, and 17 kA at 690 V. At 415 V — common in European industrial distribution — 154 kA is well above what most upstream transformers can deliver, so this breaker gives you full selectivity headroom without cascading upstream. The TM240 overcurrent release is thermal-magnetic, fixed-trip, no electronic adjustment; the part includes an undervoltage release (UVR) as standard and carries 2 HQ auxiliary switches (form C, high-qualified contacts).
Panel integration and mounting
The 3VA1150-6EF32-0BC0 mounts on a DIN rail or can be screw-fixed to a backplate. Its width is 76.2 mm (roughly 3 inches, 4 module spaces on a 18 mm DIN pitch), depth is 70 mm, height is 130 mm. Front IP40 protection means it's fine inside a closed panel but not for washdown areas. The undervoltage release coil and the 2 HQ auxiliary switches are factory-integrated; the auxiliary trip accessory order code is 3VA9608-0BB11 if you need to add a shunt trip later.