The LV839071 is a MasterPact MTZ2 drawout circuit breaker rated 1600 A continuous at 40 °C, 3-pole, with an breaking capacity code. What sets this frame apart is the interrupting performance: 200 kA Icu at 254 V and 508 V AC 60 Hz per ANSI C37.50, and still 130 kA at 635 V AC 60 Hz. On 50 Hz systems the numbers drop slightly — 200 kA at 254 V, 150 kA at 508 V, 100 kA at 635 V — but that is still a very high fault-interruption capability for a 1600 A frame. The 30 kA short-time withstand (Icw) for 0.5 s means it coordinates well downstream; you can hold through a delayed trip without the main taking a hit. Drawout mounting means the breaker chassis stays wired to the bus while the moving portion racks out for maintenance or replacement — no need to kill the entire switchgear section for a swap. The 4.5 in (115 mm) connection pitch matches standard ANSI bus spacing, so it fits existing drawout cradle layouts without re-drilling the backplane. Mechanical durability is rated at 12,500 cycles, electrical endurance at 2,800 cycles under ANSI C37.50. For a 1600 A frame that is solid — you are looking at years of normal switching before contact inspection, assuming typical industrial duty cycles.
Protection and coordination specifics
Integral instantaneous protection is set at 49.5 to 55.5 kA — that is the magnetic-only trip range for bolted faults. Below that threshold, the electronic trip unit handles time-current curves. Maximum breaking time is 9 ms, closing response max 70 ms. These numbers matter for arc-flash incident energy calculations: faster clearing means lower let-through energy at the arcing fault level. Rated breaking and making capacity is 55 kA — this is the value for the standard duty cycle (O-3min-CO). The higher Icu numbers are the ultimate breaking capacity, one-shot capability. In practice, for selective coordination studies, use the Icw (30 kA / 0.5 s) as the withstand rating for downstream devices.