400 A motor protection MCCB — what the ratings mean for fit
The Siemens SENTRON 3VA2440-5MN32-0AF0 is a 3-pole molded case circuit breaker rated 400 A continuously across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling, which simplifies panel thermal calculations for a motor control center or feeder section. Breaking capacity hits 121 kA at 415 V and 187 kA at 240 V — that's enough to interrupt high-fault conditions on a large motor circuit without cascading to upstream gear, making it a strong candidate for main or branch protection in industrial distribution. Designed specifically for motor protection, it includes phase failure detection and ships with one auxiliary switch plus one trip alarm switch HQ — the alarm switch signals a trip event directly to a PLC or annunciator, cutting troubleshooting time.
Panel fit and integration
Dimensions are 248 mm high by 138 mm wide by 110 mm deep. Maximum power loss is 63.5 W — account for that in enclosure thermal rise calculations, particularly when grouping multiple breakers in a confined MCC bucket. Operating temperature range -25 °C to 70 °C covers most indoor industrial environments; storage range extends from -40 °C to 80 °C for warehouse or seasonal shutdown conditions.