What this 400 A MCCB delivers
The Siemens SENTRON 3VA2340-6HN32-0AF0 is a 3-pole molded case circuit breaker rated for 400 A continuous current across the 40 °C to 50 °C ambient range, derating to 340 A at 70 °C. Breaking capacity runs from 242 kA at 240 V down to 7.5 kA at 690 V — that 242 kA figure at 240 VAC covers most North American low-voltage fault scenarios without needing a current-limiting upstream device. The line-protection design (no ground-fault monitoring, no undervoltage release) keeps it straightforward for main feeder or large branch protection where you just need a clean thermal-magnetic trip.
At 400 A continuous, this breaker holds its full rating up to 50 °C ambient — above that it steps down: 385 A at 55 °C, 370 A at 60 °C, 355 A at 65 °C, 340 A at 70 °C.
Breaking capacity by voltage level
The interrupting ratings are voltage-dependent: 242 kA at 240 V, 187 kA at both 415 V and 440 V, 121 kA at 500 V, and 7.5 kA at 690 V.
Physical fit and auxiliaries
A visible trip indicator is on the front face. No communication function or voltage-trigger release is built in — this is a straight electromechanical breaker, not a smart unit.