Siemens SENTRON 3VA1150-4EF42-0AA0 — 50 A 4-Pole MCCB, Line Protection
The Siemens 3VA1150-4EF42-0AA0 is a SENTRON-series molded case circuit breaker (MCCB) designed for line protection in distribution panels. It carries a 50 A continuous rating at 40 °C, with thermal derating to 45 A at 70 °C — the full thermal curve matters when the breaker shares a crowded enclosure with other heat sources. Four poles suit 3-phase + neutral applications, or three-phase with a switched neutral. The TM240 thermal-magnetic trip unit provides fixed thermal and magnetic settings; no adjustable trip or ground-fault module is fitted. Interrupting capacity is published at multiple voltages: 121 kA at 240 VAC, 75.6 kA at 415 VAC, 52.5 kA at 440 VAC, and 11.9 kA at 500 VAC and 690 VAC. At 480 V systems — common in North American industrial panels — the 440 V figure (52.5 kA) is the closest published bound; expect the actual SCCR to fall between the 440 V and 500 V values. Rated insulation voltage is 800 V, covering most low-voltage switchgear applications. Mounts on a DIN rail or panel; the front face carries IP40 protection — suitable for dry indoor enclosures, not washdown environments. Dimensions are 130 mm high, 101.6 mm wide, 70 mm deep. Maximum power loss at rated current is 14.6 W — a figure to include in thermal enclosure calculations when multiple breakers are ganged.