Schneider Electric JJA36250U43X Circuit Breaker

This circuit breaker features an I-Line style plug-in mounting connection. It is designed exclusively for use in Square D I-Line panelboards and I-Line switchboards.

The U43X suffix designates a MicroLogic 5.2 A electronic trip unit. It provides Long-Time, Short-Time, and Instantaneous (LSI) trip functions along with an integrated ammeter for real-time current monitoring.

This unit utilizes an I-Line bracket mounting mode. The line side uses plug-on jaws to connect directly to the bus structure of an I-Line panel, while the load side uses traditional mechanical lugs for outgoing field wiring.

The mechanical lugs on the load side of this breaker are designed to accept either aluminum or copper conductors ranging in size from 3/0 AWG to 350 kcmil.

No. This specific model has a standard continuous current rating, meaning it is designed to safely carry 80 percent of its 250A maximum nameplate rating continuously.

Yes. J-Frame Micrologic breakers equipped with the U43X trip unit are approved for single-phase applications, provided they are installed on systems operating at 240VAC or less. You may wire any two of the three poles for this configuration.

The MicroLogic LSI trip unit provides adjustable protection against overloads (Long-Time), low-level short circuits (Short-Time), and high-level faults (Instantaneous). These configurable parameters allow electricians to achieve precise selective coordination within complex power distribution systems.

The second J in the JJA36250U43X prefix indicates the specific interrupt rating tier for this PowerPacT J-Frame breaker. The J-tier provides a breaking capacity of 100kA at 240VAC, 65kA at 480VAC, and 25kA at 600VAC.