The Siemens 3VA1340-5EF32-0KB0 is a 3-pole IEC frame 400 molded case circuit breaker with a breaking capacity class M rated at 55 kA at 415 V AC — that's the Icu, the ultimate short-circuit breaking capacity, meaning it can safely interrupt a fault up to that level once without needing replacement. The TM240 thermal-magnetic trip unit gives you adjustable overload protection from 280 A to 400 A (Ir) and short-circuit pickup adjustable 5 to 10 times In (Ii). This is a line-protection breaker, not a motor-protection device — the TM240 curve is sized for cable and busbar protection in distribution panels.
Deployment context
Mounts on a standard DIN rail or panel-mount in an enclosure. The 55 kA SCCR at 415 V makes it suitable for main or feeder protection in industrial distribution panels where fault currents are high — think mining conveyors, crusher feed circuits, or mill motor control centers where the transformer secondary can deliver serious fault energy. The adjustable Ir (280-400 A) lets you dial in the exact cable rating without swapping trip units.