What it is and what it does
The Siemens 3VA1150-4EF32-0JC0 is a SENTRON molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a continuous current rating of 50 A at 40 °C and holds that rating up through 50 °C, then derates to 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, and 45 A at 70 °C — so in a warm enclosure you still get nearly full ampacity. Rated insulation voltage is 800 V, and the interrupting capacity varies by line voltage: 121 kA at 240 VAC, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. That gives you solid SCCR headroom for most industrial service-entrance or feeder applications. The 3-pole unit ships with a factory-installed shunt trip (STL) auxiliary release and two HQ auxiliary switches. No undervoltage release, no ground-fault monitoring, no communication module — it's a straightforward thermal-magnetic MCCB with a remote trip coil for emergency-off or safety circuits.
Panel fit and integration
The breaker measures 130 mm high, 76.2 mm wide, and 70 mm deep — a standard SENTRON 3VA footprint. The 70 mm depth (2.76 in) leaves clearance behind a typical enclosure door. Maximum power dissipation is 14.6 W at rated load, so in a multi-breaker lineup you need to account for the cumulative heat. The operating temperature range is -25 °C to 70 °C; storage range is -40 °C to 80 °C.