MasterPact MTZ2 40 H10 — 4000 A fixed breaker
The LV846557 is a fixed-mount MasterPact MTZ2 circuit breaker, 4 poles, rated 4000 A at 40 °C. It belongs to the H10 performance class, delivering 50 kA service breaking capacity (Ics) at 1150 V AC — the voltage level common in large industrial distribution and data-center power paths. Category B selectivity means it coordinates downstream with full discrimination up to its Icu, so a fault on a branch feeder clears without dropping the main bus.
The sensor rating range (2000 A / 2500 A / 3200 A / 4000 A) lets you match the electronic trip unit to the actual load, not the breaker frame. Ics of 50 kA at 1150 V AC is the service rating: the breaker clears that fault and is expected to be usable afterward, not just survive once. Icw of 50 kA for 3 seconds supports selective coordination with downstream feeders — the breaker holds closed long enough for the branch device to clear. Rear connections both top and bottom suit switchboard or drawout-cassette installations where cable access is from the back. Dimensions 537 mm wide × 352 mm high × 300 mm deep; the 115 mm connection pitch matches standard busbar and cable-lug spacing for this frame size.
Designed to EN/IEC 60947-1 and 60947-2, plus Annex H for power circuit-breaker coordination and IEC 61557-12 for measuring equipment. Isolation capability is confirmed per EN/IEC 60947-2 — the breaker can serve as a visible disconnect when open.