The Siemens SENTRON 3VA2440-5HN32-0AA0 is a 3-pole molded case circuit breaker rated for 400 A continuous current at 40 °C through 70 °C, meaning it holds full ampacity across a wide ambient range without derating — a real advantage in a crowded enclosure where heat builds. Interrupting capacity runs 187 kA at 240 V, 121 kA at 415/440 V, 75.6 kA at 500 V, and 9 kA at 690 V — that covers most industrial service-entrance and feeder applications where fault current is high.
The maximum power loss of 63.5 W factors into your enclosure's thermal calculation — it's not negligible in a sealed cabinet, so account for it in the ventilation or cooling plan.