630 A MCCB with communication and UVR — what the ratings mean for your panel
The Siemens 3VA2463-6KP32-0BC0 is a SENTRON series molded case circuit breaker rated for 630 A continuous current at 40 °C, with a 3-pole line-protection design that includes a built-in communication function and an undervoltage release (UVR). The 630 A rating is the continuous current at 40 °C ambient — the real-world current the breaker can carry without tripping under normal conditions. Above that temperature, the rating derates linearly: 600 A at 45 °C, 570 A at 50 °C, down to 450 A at 70 °C. If your panel ambient runs hot, size against the derated value, not the 40 °C headline. Short-circuit breaking capacity varies sharply with system voltage: 242 kA at 240 V, 187 kA at 415 V and 440 V, 121 kA at 500 V, and 9 kA at 690 V. At 415 V — common in industrial distribution — the 187 kA SCCR gives substantial headroom for high-fault panels. At 690 V the 9 kA rating is the limiting factor; verify your available fault current before specifying. The I²t selectivity range spans 945 A minimum to 5 670 A maximum, which defines the zone where the breaker coordinates with downstream devices for selective tripping. Set the instantaneous pickup within this band to avoid nuisance trips on transformer inrush or motor start.