Schneider Electric JDA36250U43X Circuit Breaker

This breaker is designed exclusively for Square D and Schneider Electric I-Line panelboards and switchboards. It features a plug-in bracket on the line side that connects directly to the I-Line bus.

The U43X designation indicates that the breaker is equipped with a Micrologic 5.2 A (Ammeter) electronic trip unit. This solid-state unit provides adjustable LSI (Long-time, Short-time, and Instantaneous) trip functions and includes an integrated screen for current monitoring.

No. Because this is an I-Line style breaker, it is designed strictly for plug-in line connections on the busbar and mechanical lug connections on the load side. It cannot be reverse fed.

The LSI (Long-time, Short-time, Instantaneous) settings on the Micrologic trip unit allow electricians to precisely adjust the time-current curve. This enables accurate selective coordination with downstream breakers, ensuring that a fault clears at the breaker closest to the issue without tripping the main power.

No, this is a standard 80 percent rated circuit breaker. Per National Electrical Code (NEC) guidelines, continuous loads lasting three hours or more should not exceed 80 percent of its 250A rating, which equals a maximum continuous load of 200A.

This 3-pole breaker is configured for ABC phase connections. It will draw power from all three phases of the I-Line busbar simultaneously.

No separate mounting hardware is required for the line side. The breaker features built-in I-Line jaws that plug directly into the panelboard bus, securing it in place. The load side requires standard wire bending space for the mechanical lugs.

Yes, this PowerPacT J-frame breaker can often be used to upgrade or replace legacy Square D KA-frame or older J-frame I-Line breakers of the same amperage. Always verify that the D-interrupting rating meets your current fault current requirements before installing.