The LV839031 is a Schneider Electric MasterPact MTZ3 ANSI power circuit breaker, rated 5000 A at 40 °C, 3-pole, drawout-mounted, with H3 breaking capacity code. It is built for main or feeder protection in 635 VAC switchgear, delivering 100 kA Icu at 508 VAC and 85 kA Icu at 635 VAC per ANSI C37.50. This variant ships without a Micrologic trip unit — you select and install the protection relay separately, matching the trip curve to your coordination study.
Breaking performance and selectivity headroom
The H3 breaking capacity code on this MTZ3 50 H3 means 100 kA Icu at 254 VAC and 508 VAC, and 85 kA Icu at 635 VAC — all per ANSI C37.50. That puts it in the high-interrupting tier for industrial switchgear where fault currents exceed 65 kA. The rated short-time withstand (Icw) is 85 kA for 0.5 s, which supports delayed-tripping coordination downstream without the breaker sacrificing itself during a through-fault. Integral instantaneous protection triggers between 171 and 209 kA, a narrow band that avoids nuisance trips on motor-start inrush while still clearing a bolted fault fast.
Physical footprint and drawout integration
At 31.07 in wide, 18.8 in tall, and 16.8 in deep, this drawout breaker occupies a full cubicle compartment in standard ANSI switchgear. The drawout mechanism (racked in/out without unbolting power conductors) lets you isolate the breaker for maintenance or replacement while the bus remains live — critical for continuous-process plants where a full bus outage is unacceptable. Mounting support is base plate rails; connection pitch is 9.06 in (230 mm) between phases. Plan for a dedicated compartment with rear-accessible primary disconnects and a separate control wiring trough for the trip unit interface.
Electrical durability is 2800 cycles under ANSI C37.50, and mechanical durability is 12500 cycles; that is a maintenance-cycle breaker, not a daily-switching device. The 25 to 30 ms maximum breaking time means it clears a fault within 3 cycles at 60 Hz, fast enough to limit let-through energy on downstream equipment. Maximum closing response is 70 ms, which matters when synchronizing with auto-transfer schemes.