The LV839143 is a Schneider Electric MasterPact MTZ2 drawout circuit breaker, UL 489 listed, rated 2500 A continuous at 104 °F (40 °C) on a 600 VAC network, 50/60 Hz. Three-pole, H breaking capacity code — meaning 100 kA Icu at 240 VAC, 100 kA Icu at 480 VAC, and 85 kA Icu at 600 VAC per UL 489. This is the frame without a Micrologic trip unit; the ArcBlok arc-extinction system is integral. Drawout mounting on base plate rails (connection pitch 115 mm) means the breaker slides into a fixed cradle — the cassette stays wired while the breaker is racked out for isolation or swap. Panel builders spec this for main or tie positions where service continuity matters: rack the breaker to test/disconnect position without pulling the bus.
Breaking performance and coordination
Rated breaking and making capacity is 90 kA. Short-time withstand (Icw) is 65 kA for 0.5 s per UL 489 — that is the current the breaker can carry closed during a delayed trip, critical for selective coordination downstream. Integral instantaneous protection triggers between 135 and 165 kA; maximum breaking time is 25 to 30 ms, closing response within 70 ms. Mechanical durability is 12,500 cycles, electrical durability 2,800 cycles per ANSI C37.50. For a main breaker at 2500 A, that electrical endurance covers years of normal switching; the mechanical figure matters for racking and test operations.
Product status is Active per Schneider's current lifecycle record. This is not a phase-out or last-time-buy line — the MasterPact MTZ2 series is the current-generation UL 489 platform for high-current distribution.
Physical integration into the switchboard
Dimensions: width 17.5 in (444.3 mm), height 17.3 in (438.8 mm), depth 16.8 in (426.8 mm). The drawout cradle adds depth behind the mounting plate; verify the enclosure depth against the racked-in dimension plus clearance for the arc-chamber exhaust. Base plate rails support the assembly — no DIN-rail mounting on this class of breaker.