50 A fixed, 4-pole — what the ratings mean for fit
The Siemens SENTRON 3VA1150-4GE46-0AA0 is a 50 A fixed-rated molded case circuit breaker (MCCB) with a TM220 thermal-magnetic release. The 4-pole configuration switches all three phases plus neutral. Rated insulation voltage is 800 V. Breaking capacity is the headline: 121 kA at 240 V, 75.6 kA at 415 V, 52.5 kA at 440 V, and 11.9 kA at both 500 V and 690 V. That 121 kA figure at 240 V tells you this breaker is built for high-fault locations — think transformer secondaries or large motor control centers where available fault current runs high. At 690 V the 11.9 kA rating is still respectable for most industrial loads, but you'd verify it against the transformer nameplate if the panel is near a large step-down. Thermal derating is straightforward: full 50 A from 40 °C through 50 °C, then a gradual drop — 49 A at 55 °C, 48 A at 60 °C, 46 A at 65 °C, 45 A at 70 °C. If your panel ambient runs hot, you lose about 10% at the top end. Power loss at rated load is 14.6 W — negligible for a single breaker but worth summing if you're packing a dozen into a sealed enclosure.
Panel fit and mounting
Dimensions: 130 mm height, 101.6 mm width, 70 mm depth. IP40 on the front. Operating temperature range -25 °C to 70 °C; storage -40 °C to 80 °C.