The Schneider Electric EZC400H4350 is a 4-pole molded case circuit breaker from the EasyPact EZC400H range, rated 400 A at 40 °C with a thermal-magnetic TM-D trip unit. Its 50 kA Icu at 400 V AC (50/60 Hz) per IEC 60947-2 gives you solid headroom for distribution panels where fault currents are in that range — the H breaking capacity code tells you it's the high-interrupting variant. The 690 V insulation voltage (Ui) and pollution degree 3 rating mean it's built for industrial environments, not clean-room light commercial.
The 185 mm width and 255 mm height fit standard MCC bucket cutouts; the 44 mm pole pitch matches busbar tap-off spacing common in 400 A switchboards. IP20 finger-safe terminals are fine for enclosed panels; IK07 impact resistance handles routine handling during assembly.
Durability and trip unit
Thermal-magnetic TM-D trip unit provides overload and short-circuit protection with a fixed thermal pickup at 350 A at 50 °C (derated from the 400 A at 40 °C rating). Electrical endurance is 4000 cycles at 415 V AC under Category A (no intentional short-time delay), mechanical endurance 10000 cycles — figures typical for a distribution breaker, not a motor-circuit protector. The toggle control gives positive contact indication, so you can visually confirm open/closed state.