630 A MCCB with 187 kA interrupting capacity — line protection for high-fault panels
The Siemens SENTRON 3VA2463-5JQ32-0DA0 is a 3-pole molded case circuit breaker rated for 630 A at 40 °C, designed for line protection in distribution panels. Its 187 kA breaking capacity at 240 V AC means it can safely clear a fault up to that level without upstream fuses needing to operate — critical for high-fault installations like transformer secondaries or large motor control centers. The breaker carries an undervoltage release (UVR), so if control voltage drops, the breaker trips automatically; this is standard for safety circuits where loss of control power must isolate the load.
Thermal derating and power loss — sizing for enclosure heat rise
The 630 A rating holds at 40 °C ambient; above that, the breaker derates linearly to 450 A at 70 °C. If your panel ambient runs 50 °C, plan for 570 A continuous — not the full 630 A. Maximum power loss is 164.5 W, so enclosure ventilation or forced cooling may be needed when ganging multiple breakers in a sealed cabinet.
Breaking capacity across voltage levels — coordination headroom
At 415 V and 440 V, the breaker still interrupts 121 kA; at 500 V it drops to 75.6 kA, and at 690 V to 9 kA. For a 480 V panel (common in North America), the 75.6 kA figure at 500 V is the relevant SCCR — enough for most industrial services. The adjustable thermal-magnetic trip range spans 126 A to 630 A (full-scale), giving selectivity with downstream feeders.