400 A MCCB with ETU320 — selectivity and interrupting capacity
The Siemens SENTRON 3VA2340-5HL32-0AF0 is a 3-pole molded case circuit breaker rated for 400 A continuous current (Iu) at 40 °C, carrying the full 400 A through 50 °C before derating begins — at 55 °C it holds 385 A, at 60 °C 370 A, at 65 °C 355 A, and at 70 °C 340 A. Interrupting capacity reaches 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 17 kA at 690 V — figures that give the panel designer headroom for high-fault installations where SCCR coordination is critical.
Maximum power loss is 96 W; plan for ventilation if the enclosure is densely packed.