The Siemens SENTRON 3VA2340-0HN42-0AA0 is a 4-pole molded case circuit breaker (MCCB) rated for 400 A continuous current at 40 °C, with an electronic overcurrent release type ETU350.
The 400 A rating holds across 40 °C to 50 °C without derating; at 55 °C it derates to 385 A, at 60 °C to 370 A, and at 70 °C to 340 A. If your enclosure ambient runs above 50 °C, factor the thermal curve into the load schedule. The IP40 front protection is typical for enclosed distribution; no additional gasketing is needed inside a rated enclosure. The ETU350 electronic trip unit offers adjustable N-conductor protection (OFF, 50%, 100%) and a fixed I²t curve — no adjustable I-t setting. The undervoltage release and voltage trigger are not fitted on this variant; communication function is absent, so it is a standalone thermal-magnetic replacement with electronic trip logic.