What the 55 kA @ 415 V Means for Your Panel
The Siemens 3VA2463-5HN42-0AB0 is a 4-pole IEC molded-case circuit breaker in the 3VA2 frame, rated 630 A continuous with an interrupting capacity of 55 kA at 415 V AC — that's the Icu (ultimate breaking capacity) for the 'M' (medium) breaking capacity class. The ETU350 trip unit gives you LSI protection: long-time (overload) adjustable from 250 A to 630 A, short-time (short-circuit with delay) from 1.5x to 9x Ir, and instantaneous fixed at 9x In.
Integration Notes for the Panel Builder
The 4-pole configuration covers three-phase plus neutral, with the neutral conductor protection adjustable to OFF, 50%, or 100% of the phase rating. Two auxiliary switch changeover contacts (form C) are built in, giving you status feedback for the open/closed position without needing an external accessory.
Coordination and Selectivity
The ETU350 electronic trip unit supports adjustable short-time delay (Isd), which is the key to achieving selective coordination downstream. By setting Isd with a deliberate time delay, you can let a downstream breaker clear a fault first, keeping this main breaker closed and the rest of the panel live. The instantaneous pickup (Ii) at 9x In (5,670 A) acts as a backup for high-impedance faults. For a site electrical engineer mapping SCCR headroom, the 55 kA Icu at 415 V gives a solid ceiling for most industrial distribution panels.