What this MCCB delivers
The Siemens 3VA2340-7HL32-0AB0 is a 3-pole SENTRON molded case circuit breaker rated for 400 A continuous current (Iu) and an insulation voltage of 800 V. Its ETU320 electronic trip unit provides adjustable overload and short-circuit protection for line protection duty. The breaking capacity hits 330 kA at 240 V AC, tapering to 242 kA at 415/440 V, 187 kA at 500 V, and 52.5 kA at 690 V — numbers that matter when you're coordinating selectivity downstream of a large transformer or feeding a high-fault bus.
Thermal derating and endurance
The breaker holds its full 400 A rating up to 50 °C ambient; above that it derates linearly to 340 A at 70 °C. Mechanical endurance is listed at 15 000 operations — typical for a 400 A frame in distribution duty. The auxiliary contact version ships with two HP auxiliary switches, and there's no undervoltage release or ground-fault module on this variant.