The Schneider Electric EZC400N4350N is a 4-pole molded case circuit breaker from the EasyPact EZC400N series, rated 400 A at 40 °C with a TM-D thermal-magnetic trip unit. It provides short-circuit and overload protection for distribution applications, with a breaking capacity of 36 kA Icu at 440 V AC 50/60 Hz per IEC 60947-2.
The trip unit is rated 350 A at 50 °C, so if your panel ambient runs warm — near the top of the 40 °C derate curve — the breaker still holds a 350 A continuous load. The magnetic tripping current is fixed at 5000 A, meaning instantaneous trip occurs above that threshold; coordination with downstream devices needs to account for that fixed pickup. Electrical durability is 4000 cycles at 415 V AC, mechanical durability 10000 cycles — this is a distribution breaker, not a switching device for frequent load make-break.
Fixed-mount backplate installation, front-connect terminals on both line and load sides. The 45 mm connection pitch matches standard busbar or cable lug spacing.