The Siemens SENTRON 3VA2340-5HN32-0KA0 is a 3-pole molded case circuit breaker rated 400 A continuous at 40 °C, with a maximum rated current of 4 000 A. It interrupts fault currents up to 187 kA at 240 V, 121 kA at 415 V, 121 kA at 440 V, 75.6 kA at 500 V, and 7.5 kA at 690 V — so at typical 400 V distribution voltages it clears a 121 kA bolted fault without cascading upstream breakers.
At 55 °C the continuous rating drops to 385 A, at 60 °C to 370 A, at 65 °C to 355 A, and at 70 °C to 340 A. The maximum power loss is 96 W, so adjacent breakers need spacing or forced ventilation in a sealed enclosure.