The LV839319 is a Masterpact MTZ3 40 HC switch disconnector rated 4000 A at 104 °F (40 °C) — that is the continuous current it carries without derating in a typical 40 °C switchroom. The 200.0 kA Icu at 254 V AC (with external relay, per ANSI C37.50) tells you it can safely interrupt a fault up to that level without blowing apart; the same unit also carries 200.0 kA Icu at 508 V AC and 130.0 kA Icu at 635 V AC. The 100.0 kA short-time withstand (Icw) for 1.5 s per ANSI C37.50 means it holds its closed position under fault current long enough for downstream breakers to clear — selectivity coordination. The drawout chassis lets you rack the unit out for maintenance without unbolting line and load conductors, which is standard for large air breakers in metal-clad switchgear.
Deployment context
This is a 3-pole drawout-mounted chassis unit for distribution applications. It goes into a switchgear lineup — ANSI metal-clad or metal-enclosed — not a standalone enclosure. The 31.07 in width, 18.8 in height, and 16.8 in depth are the cell dimensions you need for the cubicle cutout and racking mechanism. Connection pitch is 9.06 in for the primary stabs.