The LV839007 is a Masterpact MTZ3 60 HA non-automatic switch disconnector — a 4-pole, fixed-mount unit rated 6000 A at 104 °F (40 °C) for distribution duty. It's the kind of part that lives in a main switchboard, not a branch panel: you use it to isolate a transformer, a generator tie, or a large bus riser where you need a visible break and full-load disconnect capability.
Breaking capacity and short-time withstand — what they mean on site
The 65 kA Icu at 254 V, 508 V, and 635 V AC (ANSI C37.50) is the interrupting rating with an external relay — meaning this switch can clear a fault up to 65 kA without welding its contacts, provided the upstream protection coordinates. The 85 kA Icw for 0.5 s is the short-time withstand: it tells you the switch can hold closed under a let-through fault current for half a second while the downstream breaker clears. That's the number you need for selective coordination studies — if your upstream device trips faster than 0.5 s, this switch stays closed and the fault stays isolated to the branch.
Fixed-mount, so it bolts into a cutout or onto a mounting plate — no draw-out cradle. The footprint is 39.2 in wide by 13.9 in tall, with a depth of 11.7 in. Connection pitch is 9.06 in between phases, which matches the standard Masterpact MTZ3 bus-bar spacing. Push-button control on the front for open/close; no motor operator unless added externally.