What this 4000 A drawout breaker is for
The Schneider Electric LV839303 is a MasterPact MTZ3 3-pole drawout circuit breaker rated 4000 A at 40 °C, with L breaking capacity. It carries UL 489 listing for 200 kA Icu at 240 V AC, 150 kA Icu at 480 V AC, and 100 kA Icu at 600 V AC — so it handles high-fault service-entrance and main-tie applications where SCCR headroom matters. The drawout cradle lets you rack the breaker out for maintenance without disturbing line and load connections, standard for switchgear lineups.
Breaking performance and coordination
Rated short-time withstand current (Icw) is 100 kA for 0.5 s per UL 489, which supports selective coordination downstream — the breaker rides through a fault long enough for a branch device to clear. Maximum breaking time is 9 ms, and the integral instant protection range is 153 to 187 kA. The L breaking capacity code means this frame is optimized for high interrupting duty in the 600 V class.
Drawout mounting on base plate rails, with a connection pitch of 9.06 in (230 mm). Overall dimensions: width 31.07 in (789.1 mm), depth 16.8 in (426.8 mm), height 18.8 in (478.1 mm). These are the envelope dimensions for the drawout cradle — verify switchgear cell cutout against the Schneider MTZ3 mounting template before specifying.
This order code ships without a Micrologic trip unit — the LV839303 is the bare frame with ArcBlok arc-extinction technology. The trip unit (Micrologic 2.0, 5.0, 6.0, or 7.0 series) must be ordered separately and field-installed. This lets you match the protection curve (LSI, LSIG, or advanced metering) to the load without buying a fixed-configuration breaker.