What this 400 A MCCB delivers on the line
The Siemens 3VA2440-5MN32-0BH0 is a 3-pole SENTRON molded case circuit breaker rated 400 A continuously across the full 40 °C to 70 °C ambient range — no derating needed as the panel warms up, which keeps the line moving through summer peaks or tight enclosures. Interrupting capacity hits 187 kA at 240 V and 121 kA at 415 V, giving selectivity headroom for high-fault panels without cascading upstream breakers. Designed for motor protection — it includes phase failure detection and an undervoltage release (UVR) as standard, so a lost phase or sagging control voltage trips the load before the motor cooks.
Panel fit and integration
Dimensions are 248 mm high, 138 mm wide, 110 mm deep — verify the gland plate and door cutout against the existing 3VA footprint before swapping; the depth is tight in shallow enclosures. Maximum power loss is 66 W, so factor that into the enclosure thermal budget if grouping multiple breakers in a sealed cabinet. Auxiliary switch configuration is 2 auxiliary switches plus 1 trip alarm switch (HQ design), enough for remote status indication without an external interface module.