MCCB for high-fault motor circuits
The Siemens 3VA2450-0MQ32-0AA0 is a 3-pole SENTRON molded case circuit breaker rated for 500 A continuous current and a massive 440 kA breaking capacity at 415 V — enough to handle high-fault utility feeds or large transformer secondaries without cascading upstream. The motor protection designation means the ETU860M electronic trip unit includes adjustable overload curves (trip classes 10A, 10/10E, 20/20E, 30) plus phase failure detection, so it can protect a large motor directly rather than requiring a separate overload relay.
At 415 V the breaker interrupts 440 kA symmetrical; at 690 V that drops to 187 kA, still well above typical industrial service-entrance levels. Maximum power loss is 99 W, which factors into enclosure ventilation sizing.