The Schneider LV839166 is a MasterPact MTZ2 drawout circuit breaker rated 2000 A at 104 °F (40 °C), 3-pole, with LF breaking capacity.
This part is obsolete per the manufacturer.
The 2000 A line-rated current at 40 °C sets the continuous ampacity for the drawout cassette and cradle — no derating needed at typical 40 °C ambient. The 150 kA Icu at 480 V AC UL 489 and 100 kA Icu at 600 V AC UL 489 define the interrupting capacity at those common distribution voltages; the LF breaking capacity code signals a high-interrupting variant for high-fault installations. Integral instant protection trips between 49.5 and 55.5 kA — that's the magnetic-only instantaneous pickup for short-circuit protection, not the long-time or short-time settings. The 22 kA Icw at 0.5 s UL 489 short-time withstand current tells you the breaker can hold closed under fault for 0.5 s to allow downstream coordination, then clear. Drawout mounting means the breaker slides into a cradle with disconnect position for safe maintenance without unbolting line and load connections. The 4.5 in (115 mm) connection pitch and base plate rails support define the footprint for switchboard integration.