Schneider Electric LJA36400U43X Molded Case Circuit Breaker

The "U43X" suffix indicates this breaker comes equipped with a MicroLogic 5.3A electronic trip unit. This advanced unit provides Long-time, Short-time, and Instantaneous (LSI) protection functions, as well as an integrated ammeter for real-time current monitoring.

Yes, the LSI functionality allows licensed electricians to precisely adjust the pickup and delay settings for both Long-time and Short-time protection, as well as the Instantaneous pickup limit. This adjustability is critical for achieving proper selective coordination within complex electrical distribution systems.

The LJA36400U43X is designed exclusively for Square D I-Line panelboards and switchboards. It features an I-Line plug-on bracket (denoted by the "A" in the catalog number) that securely mounts and connects directly to the internal bus assembly of the panel.

No, this specific model provides LSI (Long, Short, Instantaneous) protection only. If your application requires equipment ground-fault protection, you will need a PowerPacT model with an LSIG trip unit, such as one ending in the U44X suffix.

Because this is an I-Line breaker, the line side uses a jaw-type connection to snap directly onto the panel bus. The load side is equipped with factory-installed mechanical lugs that accept two 2/0 AWG to 500 kcmil aluminum or copper conductors per phase.

No. Because it is an I-Line circuit breaker with line-side plug-on jaws and load-side mechanical lugs, it is physically designed strictly to be forward-fed from the panelboard bus.

In the Schneider Electric PowerPacT nomenclature, the "J" denotes the interrupting rating tier of the breaker. For an L-frame breaker, the J-tier provides a maximum interrupting capacity of 100 kA at 240V, 65 kA at 480V, and 25 kA at 600V.

Yes, this PowerPacT L-frame breaker features an integral push-to-trip button located on the front cover. Pressing this button manually trips the breaker, allowing you to exercise the mechanical linkages and verify that the trip indicator operates properly before maintenance.