The EZC400H44350 is a 4-pole molded case circuit breaker from Schneider Electric's EasyPact EZC400H series, rated 400 A at 40 °C. The TM-D thermal-magnetic trip unit provides overload and short-circuit protection for distribution applications. At 220–240 V AC that rises to 70 kA. For a 400 A MCCB in a 400 V distribution board, 50 kA is solid headroom for most industrial service entrances and sub-distribution panels. The 350 A trip rating at 50 °C matters when the breaker is in a warm enclosure — that's the de-rated continuous current, not the 40 °C nameplate. It's Category A, meaning it's not intended for selectivity under short-circuit conditions with downstream breakers that have a lower Icu; for selective coordination you'd step to a Category B breaker. Mechanical durability is 10,000 cycles, electrical durability 4,000 cycles at 415 V AC — that's typical for a distribution MCCB; don't use it for frequent switching duty like a contactor.
Deployment context
This breaker mounts fixed to a backplate with front-front connections — no DIN rail, so plan for bolt-down mounting in a panel or enclosure. The 140 mm width and 140 mm depth mean it fits a standard 4-pole MCCB cutout; the 44 mm pole pitch is the standard for 400 A frame sizes. IP20 finger-safe terminals are fine for enclosed panels; IK07 impact rating means it handles incidental tool drops during commissioning. Pollution degree 3 — the breaker expects a conductive-pollution environment typical of control rooms and light industrial, not clean-room or outdoor.
Designed to IEC 60947-2, JIS C8201-2-2, and GB/T 14048.2. The toggle control gives visual on/off status. No earth-leakage protection built in; if you need ground-fault, add an external relay or choose a Vigi version.