The Siemens SENTRON 3VA2340-5HL32-0BK0 is a 3-pole molded case circuit breaker rated for 400 A continuous current at 40 °C, with a maximum breaking capacity of 187 kA at 240 V AC — enough to handle high-fault utility feeds or large transformer secondaries without cascading upstream.
Continuous current holds at 400 A from 40 °C up to 50 °C, then derates to 385 A at 55 °C and 340 A at 70 °C — so in a warm enclosure you still get full rating up to 50 °C ambient. Breaking capacity steps down with system voltage: 187 kA at 240 V, 121 kA at 415/440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V — verify your available fault current at the point of installation.
Maximum power loss is 98.5 W, so plan for ventilation or derating if the breaker is enclosed in a small, sealed sub-panel.