400 A MCCB with ETU550 — full-temperature rated, communication-ready
The Siemens SENTRON 3VA2440-7JP42-0AA0 is a 4-pole molded case circuit breaker rated 400 A continuous — and it holds that 400 A across the entire operating range from -25 °C to 70 °C, no derating curve to chase. That's unusual for a frame this size; most breakers start pulling back above 40 °C. The ETU550 electronic trip unit gives you adjustable overload and short-circuit protection curves, plus a communication function onboard for integration into a monitoring network. Interrupting capacity hits 330 kA at 240 V and still delivers 242 kA at 415 V and 440 V, so it handles high-fault utility feeds without cascading upstream.
Interrupting capacity and coordination
At 240 V the 3VA2440-7JP42-0AA0 interrupts 330 kA — that's the highest short-circuit rating in the 3VA2 frame class. At 500 V it still clears 187 kA. Only at 690 V does it drop to 9 kA, so if your system runs 690 V you need to check the available fault current against that limit. The 5 kA rating limited to 1 second is a short-time withstand figure for selectivity with downstream breakers.
Panel fit and mounting
Dimensions are 248 mm high by 184 mm wide by 110 mm deep. The 110 mm depth is a key check for shallow enclosures — measure your can depth before committing. IP40 on the front means it's protected against tools and wires >1 mm, but the terminals and body need to be inside a panel enclosure; it's not a standalone outdoor unit. Power loss runs 63.5 W maximum at rated load, so factor that into your enclosure thermal budget.