What this MCCB carries and where it fits
The Siemens SENTRON 3VA2340-6JP32-0BH0 is a 3-pole molded case circuit breaker rated for 400 A continuous current at 40 °C, designed for line protection in distribution panels and industrial switchboards. Its interrupting capacity reaches 242 kA at 240 V and 187 kA at 415 V, dropping to 7.5 kA at 690 V — the high short-circuit ratings at common low-voltage levels mean this breaker handles fault currents from large transformers or high-capacity busbars without cascading upstream. The unit includes an undervoltage release (UVR) and a communication function, making it suitable for controlled shutdown sequences and remote monitoring in automated plants.
Breaking capacity — what the numbers mean for coordination
At 240 V the breaker clears 242 kA; at 415 V and 440 V it clears 187 kA; at 500 V it clears 121 kA; at 690 V it clears 7.5 kA. These are the maximum prospective fault currents the MCCB can safely interrupt at each voltage level. For a 400 A feed in a 480 V panel, the 121 kA rating at 500 V provides substantial headroom over typical available fault currents, allowing selective coordination with downstream breakers without requiring a current-limiting upstream device.
Thermal derating and enclosure planning
The breaker is rated 400 A continuously from 40 °C through 50 °C ambient. Above 50 °C it derates: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C. Maximum power loss is 98.5 W — a figure to account for in enclosed panel heat calculations, especially when grouping multiple breakers in a sealed switchboard. Dimensions are 248 mm high, 138 mm wide, and 110 mm deep, fitting standard MCCB mounting patterns in SENTRON distribution boards.
Built-in auxiliary and release options
Factory-fitted with 2 auxiliary switches plus 1 trip alarm switch (HQ design), and an undervoltage release (UVR). The trip indicator confirms the breaker has opened on fault. The communication function enables integration with higher-level monitoring systems — useful for remote status and energy management in SENTRON power distribution.