What the 3200 A and 50 kA ratings mean for your main switchboard
The LV846546 is a Schneider Electric MasterPact MTZ2 fixed circuit breaker, 3-pole, rated 3200 A continuous at 40 °C ambient — that is the full-load current it carries without tripping, sized for the main incoming feeder or a large bus riser in an industrial distribution board. Its ultimate breaking capacity (Icu) is 50 kA at 1150 V AC 50/60 Hz, and the service breaking capacity (Ics) matches at 50 kA — meaning after clearing a 50 kA fault the breaker remains usable, not just safe. The making capacity (Icm) of 105 kA peak at 1150 V handles the asymmetrical first peak of a fault. Short-time withstand (Icw) is 50 kA for 1 s, 0.5 s, or 3 s, which lets it ride through downstream faults while upstream breakers wait for selectivity — Category B per IEC 60947-2. That 50 kA for 1 s is the number a coordination study checks first. Rated insulation voltage (Ui) is 1250 V AC, impulse withstand (Uimp) is 12 kV — the breaker holds off surge voltages common in industrial networks fed by transformers or generators.
Physical fit and mounting — fixed rear-connection footprint
The breaker is fixed-mounted on rails or a base plate, with rear connections both top and bottom. Face dimensions are 422 mm wide by 352 mm tall, depth 300 mm — the depth is the critical dimension for enclosure depth when the rear studs project behind the mounting plane. Connection pitch is 115 mm between phase centres, which matches the standard busbar drill pattern for this frame size. IP30 enclosure protection means it is suitable for indoor switchgear but needs a door or cover to keep tools and debris out.
Lifecycle and sourcing status
Because this is a high-current main breaker (3200 A frame), lead times and allocation can vary with project load.
Standards compliance and documentation
It also meets IEC 61557-12 for power metering performance when fitted with a control unit. Electrical endurance is 500 cycles at rated voltage and current; mechanical endurance is 20000 cycles with periodic preventive maintenance. Power dissipation at rated current is 420 W — factor that into the switchgear ventilation and temperature-rise calculation.