What this MCCB does on a motor branch
The Siemens SENTRON 3VA2440-5MN32-0AG0 is a 3-pole molded case circuit breaker rated for a full 400 A across the entire 40 °C to 70 °C ambient range — no derating needed as the panel warms up. It is specifically designed for motor protection, with phase failure detection built in, so it will trip on a lost phase before the motor winding overheats.
Breaking capacity — what the voltage columns mean for your panel
This breaker delivers 187 kA at 240 V, 121 kA at 415 V and 440 V, 75.6 kA at 500 V, and 9 kA at 690 V. The steep drop above 500 V is typical for a 400 A frame — at 690 V the available fault current in most industrial panels is well under 9 kA, so it still holds. The 187 kA at 240 V means it can sit on the secondary side of a large transformer without needing a current-limiting fuse upstream.
Panel fit and mounting
Dimensions are 248 mm high, 138 mm wide, 110 mm deep. The 138 mm width is a standard 3-pole MCCB footprint for a 400 A frame — it will drop into a Siemens 3VA panel adapter or a generic MCCB mounting base without side-to-side overhang. Depth of 110 mm keeps it inside a 300 mm deep enclosure with room for the line and load lugs.