What this MCCB carries and what it means for your panel
The Siemens SENTRON 3VA2440-6HN32-0DA0 is a 3-pole molded case circuit breaker rated for a continuous current of 400 A across the full ambient range from 40 °C to 70 °C — no derating needed up to that ceiling, which simplifies panel thermal budgeting. Its interrupting capacity hits 242 kA at 240 V AC and still holds 187 kA at 415 V and 440 V AC, so it can sit ahead of high-fault transformers or busways without needing an upstream current-limiting fuse. The breaker includes an undervoltage release as the auxiliary release type — if control power drops, the UVR trips the breaker, which is the standard arrangement for emergency-stop or mains-loss disconnects in machine-tool panels.
Physical fit and integration
The case measures 248 mm high by 138 mm wide by 110 mm deep — a standard SENTRON 3VA footprint that drops into existing panel cutouts and busbar systems for the 400 A frame class. Maximum power dissipation is 66 W at rated load; account for that heat in the enclosure ventilation calculation, especially when grouping multiple breakers in a compact switchboard.
What the ratings mean for selectivity and coordination
The 242 kA SCCR at 240 V gives the 3VA2440-6HN32-0DA0 enough headroom for most 480Y/277 V secondary-side main breakers, while the 187 kA at 415 V suits European 400 V industrial grids. At 690 V the rating drops to 9 kA — this breaker is not intended for 690 V main service, but it can serve as a branch device behind a higher-rated upstream breaker.