MCCB with real headroom for motor circuits
The Siemens SENTRON 3VA2440-0MN32-0AA0 is a 3-pole molded case circuit breaker rated for 400 A continuous current, with a breaking capacity of 440 kA at 415 V — that's the kind of short-circuit rating that lets you place this breaker close to the transformer without worrying about cascading failures upstream. It's designed specifically for motor protection, so the ETU350M electronic release gives you adjustable trip classes of 10A, 10E, and 20E, meaning you can dial in the overload curve to match the starting characteristics of your motor load — pump, conveyor, or compressor — without nuisance tripping on inrush.
Sizing and thermal performance
That's flat derating across the typical panel temperature range — you don't have to oversize the frame just because the enclosure runs hot. That storage range matters if you're staging spares in an unheated warehouse — it won't degrade sitting through a cold winter.
That's a standard MCCB form factor for the 400 A frame class — it'll drop into a typical DIN-rail or panel-mount arrangement without surprises. The width is the critical dimension for multi-breaker lineups; 138 mm per pole set means you can calculate your backpanel real estate in advance.