The Siemens SENTRON 3VA1112-6MH32-0BC0 is a 3-pole molded case circuit breaker (MCCB) rated 125 A at 40 °C, with a breaking capacity of 220 kA at 240 V and 154 kA at 415 V — numbers that put it in the high-interrupting class for industrial distribution panels where fault currents can hit those levels.
Breaking capacity across voltages — what matters for selectivity
At 240 V this breaker clears 220 kA; at 415 V it's 154 kA; at 440 V it drops to 75.6 kA; and at 500 V and 690 V it holds at 7.5 kA. The steep drop above 440 V means you need to check the available fault current at the point of installation — if your system runs 480 V or 600 V class, the 7.5 kA rating may force a larger frame or a current-limiting fuse upstream.
Rated 125 A up to 50 °C; at 55 °C it's 122 A, at 60 °C it's 120 A, at 65 °C it's 117 A, and at 70 °C it's 114 A. The storage limit is wider because it's not under load — fine for warehousing spares. Maximum power loss is 30.6 W — that's the heat it dumps into the enclosure. If you're packing several of these in a small panel, add that to your thermal budget.
Bolts into a panel or mounts on a DIN rail adapter; the depth leaves room for rear-connected bus bars.