MasterPact MTZ3 6300 A — what this breaker delivers
The Schneider Electric LV848357 is a MasterPact MTZ3 drawout circuit breaker rated for 6300 A continuous at 40 °C, making it the highest-current frame in the MTZ3 line. Category B selectivity (per EN/IEC 60947-2) means it holds its short-time withstand rating of 100 kA for up to 3 s, so downstream breakers clear a fault before this main trips. That 3 s withstand window is what lets you coordinate a multi-tier distribution panel without a full cascade. The drawout chassis isolates the breaker from the busbars for maintenance or swap-out without de-energizing the entire switchboard. Rear connection top and bottom keeps the cable entry plane clean. The 4-pole configuration with neutral on the right side matches the standard North American and European panel layout for full-phase plus neutral protection.
Breaking capacity and short-time ratings — the coordination numbers
The H2 performance class gives you 150 kA Ics (service breaking capacity) at 440 V AC, not just at the lower 415 V reference. At 690 V AC it still holds 100 kA Ics. Short-time withstand Icw is flat at 100 kA for 0.5, 1, or 3 s — that plateau is unusual; most breakers derate Icw as duration increases. It means this breaker can ride through a delayed downstream fault without degrading its own contacts. Maximum breaking time is 25 ms, closing response 80 ms. Those are the electromechanical limits; the actual arc-extinction time depends on the Micrologic control unit (ordered separately — this listing is the breaker chassis without a trip unit). The 12 kV impulse withstand (Uimp) and 1000 V rated insulation voltage confirm it is built for 690 V AC switchgear with safety margin.
Lifecycle and sourcing — active production, quoted to order
Standards compliance covers EN/IEC 60947-1, -2, and -2 Annex H (EMC for circuit-breakers with electronic trip units), plus IEC 61557-12 for power metering. Isolation suitability is certified per EN/IEC 60947-2, so it doubles as a visible-break disconnect when racked out.
Mounting and integration — what fits in the switchboard
Altitude derating starts above 2000 m. Power dissipation at rated current is 900 W — that heat must be vented in the enclosure design; it is not a sealed-panel breaker. IP30 protection means tools or fingers cannot contact live parts but the breaker is not washdown-rated; it belongs in a locked switchgear cubicle.