The Schneider Electric LV838919 is a MasterPact MTZ2 drawout circuit breaker, 3-pole, rated 1200 A at 40 °C, with LF breaking capacity. It's a UL 489 listed device for 600 VAC service, designed for main or feeder protection in switchgear where drawout extraction simplifies maintenance and downstream isolation. Its interrupting ratings are substantial: 200 kA Icu at 240 V AC, 150 kA Icu at 480 V AC, and 100 kA Icu at 600 V AC — all per UL 489.
If you're managing a lifecycle transition, the MasterPact MTZ2 series has been succeeded by the MasterPact MTZ3 family. The exact replacement order code depends on the required breaking capacity and accessory configuration; a cross-reference from the original switchgear one-line or panel schedule is the cleanest way to confirm fit.
The drawout cradle (mounting mode) means the breaker slides out for inspection or replacement without disturbing the bus connections, which is standard for main breakers in double-ended or tie-configuration gear. The LF breaking capacity code indicates the higher interrupting tier within the MTZ2 family. With a 50 kA rated breaking and making capacity and a 22 kA short-time withstand (Icw) for 0.5 s per UL 489, this breaker can handle delayed-tripping coordination schemes where downstream devices clear faster while the main holds in for a set duration. Integral instantaneous protection is set at 49.5 to 55.5 kA — that's the magnetic trip threshold for bolted faults. The maximum breaking time is 9 ms, and closing response is 70 ms, which are typical for this class of power breaker.
Mounting is drawout on base plate rails, with a connection pitch of 115 mm (4.5 in) between phases. Overall dimensions: 17.5 in wide, 17.3 in high, 16.8 in deep. That's a substantial footprint — verify the switchgear cell opening and racking mechanism compatibility before specifying, especially if retrofitting into an existing lineup.