The Schneider Electric EZCV250H44125 is a 4-pole molded case circuit breaker from the EasyPact EZCV250H series, rated 125 A at 40 °C with a TM-D thermal-magnetic trip unit and integral earth-leakage protection. The H breaking capacity code tells you this is the high-end interrupt rating for the frame — not the standard or economy variant — so it handles high-fault scenarios without cascading upstream.
At 440 V AC the Icu drops to 25 kA, so if your line side is a 440 V distribution transformer, that's your coordination ceiling. Earth-leakage protection is built in, so you don't need a separate RCCB downstream — one device covers overload, short-circuit, and ground fault.
Where it goes in the panel
Fixed mounting on a backplate, with front-facing connections top and bottom — no DIN-rail clip, so you bolt it to a mounting plate in the enclosure. The 35 mm connection pitch matches standard busbar systems and lug kits. IP20 finger-safe on the front, but the terminals need enclosure protection. IK07 impact rating handles tool drops during panel work.