630 A MCCB with 330 kA interrupting capacity — selectivity and SCCR headroom
The Siemens SENTRON 3VA2463-7HN32-0AE0 is a 3-pole molded case circuit breaker rated 630 A continuous at 40 °C, with a 330 kA interrupting capacity at 240 V. That interrupting rating drops to 242 kA at 415 V and 440 V, 187 kA at 500 V, and 52.5 kA at 690 V — so for a 480 V panel the available fault current must stay under 187 kA to maintain full coordination.
Thermal derating — the real ampacity in a warm panel
At 45 °C it derates to 612 A, at 50 °C to 593 A, at 55 °C to 575 A, at 60 °C to 557 A, at 65 °C to 538 A, and at 70 °C to 520 A.