630 A MCCB with communication — panel fit and derating
The Siemens SENTRON 3VA2463-6KP32-0AB0 is a 3-pole molded case circuit breaker rated 630 A continuous at 40 °C, with a maximum breaking capacity of 242 kA at 240 V. This is a line-protection design carrying a communication function and two auxiliary switches HP. The 630 A frame is sized for large feeders or main incomers in industrial distribution panels — think the main breaker feeding a 400 V switchboard or a high-current motor control center. The 110 mm depth, 138 mm width, and 248 mm height determine the mounting footprint; verify the panel cutout against these dimensions before committing the BOM.
Derating curve and thermal management
Above that, the continuous current must be derated: 600 A at 45 °C, 570 A at 50 °C, 540 A at 55 °C, 510 A at 60 °C, 480 A at 65 °C, and 450 A at 70 °C (–). Maximum power loss is 162 W, which drives ventilation requirements inside the enclosure — a sealed box at 70 °C ambient will need forced air or a larger cabinet to stay within the derated current.
Breaking capacity varies significantly with system voltage: 242 kA at 240 V, 187 kA at both 415 V and 440 V, 121 kA at 500 V, and 9 kA at 690 V. For standard 400 V distribution, the 187 kA rating covers most high-fault scenarios.