630 A MCCB with 187 kA interrupting capacity — what the ratings mean for your panel
The Siemens SENTRON 3VA2463-5HN32-0BL0 is a 3-pole molded case circuit breaker rated for 630 A continuous at 40 °C, designed for line protection in main distribution panels. Its interrupting capacity reaches 187 kA at 240 V AC and 121 kA at 415 V AC — numbers that govern fault-current withstand, not normal load. The 187 kA figure at 240 V means this breaker can safely clear a worst-case bolted fault up to that level without rupturing, which is the deciding factor for service-entrance or high-fault-capacity switchboards. At 690 V the rating drops to 9 kA, so verify the available fault current at your system voltage before specifying.
Thermal derating and power loss — panel integration constraints
The 630 A rating is valid at 40 °C ambient. Above that, derate linearly: 612 A at 45 °C, 593 A at 50 °C, 575 A at 55 °C, 557 A at 60 °C, 538 A at 65 °C, and 520 A at 70 °C. Maximum power loss is 164.5 W — a meaningful heat source inside a sealed enclosure. For a panel builder, this means the cubicle's thermal dissipation must account for nearly 165 W per breaker; adjacent devices, especially electronics or PLCs, should be spaced or shielded accordingly. Dimensions are 248 mm high, 138 mm wide, 110 mm deep. The breaker mounts on a DIN rail or directly to a backplate; the 138 mm width for a 3-pole unit is standard for this frame size. Storage temperature range is -40 °C to 80 °C; operating ambient is -25 °C to 70 °C.