What it is and what it handles
The Siemens SENTRON 3VA2340-5JP32-0CC0 is a 3-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, designed for line protection in industrial power distribution panels. It carries a breaking capacity of 187 kA at 240 V and 121 kA at 415 V and 440 V, tapering to 7.5 kA at 690 V — that means it can safely interrupt massive fault currents at common distribution voltages without the arc escaping the case.
Thermal derating and operating range
The breaker holds its full 400 A rating up to 50 °C ambient. Above that it derates linearly: 375 A at 55 °C, 350 A at 60 °C, 325 A at 65 °C, and 300 A at 70 °C — the maximum operating temperature. Minimum operating temperature is -25 °C. Storage range spans -40 °C to 80 °C. If you're packing this into a hot panel next to transformers or drives, the 55 °C derating point is the one to watch.
Built-in accessories and communication
This variant ships with an undervoltage release (UVR) and two HQ auxiliary switches fitted — no separate ordering for basic status signaling. It also includes a communication function, so it can talk to a PLC or BMS for remote trip indication and load monitoring. Power loss at full rated current is 98.5 W, worth factoring into panel ventilation calcs.
Panel fit and dimensions
The case dimensions are 248 mm tall, 138 mm wide, and 110 mm deep. That 110 mm depth is the key number for enclosure depth clearance — it fits standard 200 mm deep enclosures with room for wiring gutters. Width of 138 mm means it occupies three 45 mm pole spaces on a DIN rail or mounting plate.