The Schneider Electric LV846443 is a fixed-mount MasterPact MTZ1 circuit breaker, 4 poles, rated 630 A at 40 °C. Category B selectivity (per IEC 60947-2) confirms full discrimination with downstream devices, so a fault on a branch feeder clears without tripping this main breaker.
Breaking capacity and coordination headroom
Rated short-time withstand (Icw) is 30 kA for 3 seconds — that is the thermal and mechanical stress the breaker can handle during a delayed trip coordination scheme. Short-circuit making capacity (Icm) is 145 kA at 415 V AC, which covers the peak asymmetrical current on a faulted 400 V transformer secondary. The 12 kV impulse withstand (Uimp) and 1000 V rated insulation voltage (Ui) give headroom for 690 V operational voltage (Ue) applications, common in industrial motor control centers.
Mounting and integration in the switchboard
Fixed mounting on rails or a base plate. The 346 mm width, 301 mm height, and 209 mm depth fit standard MasterPact MTZ1 cutouts. Connection pitch is 70 mm; both front and rear connections are available on the upside and downside. Neutral is on the left. IP30 protection covers the front face against tools and wires.
Environmental and operational limits
Altitude derating applies above 2000 m — no derating needed up to 2000 m. Power dissipation at rated current is 30 W, which should be factored into enclosure thermal calculations. Electrical durability is 6000 cycles at 440 V AC under AC-23A and AC-3 duty; mechanical durability is 10,000 cycles with periodic preventive maintenance. Maximum breaking time is 25 ms; closing response is 50 ms.