Square D JGA36250U53X Molded Case Circuit Breaker

The U53X suffix indicates the breaker is equipped with a Micrologic 5.2E (Energy) electronic trip unit. This provides adjustable Long-Time, Short-Time, and Instantaneous (LSI) trip functions, along with integrated energy metering capabilities.

A standard JGA36250 typically features a basic thermal-magnetic trip unit. The JGA36250U53X upgrades this to a solid-state Micrologic 5.2E electronic trip unit, offering precise LSI adjustability and energy management features for complex coordination studies.

This specific catalog number is standard 80% rated. For applications requiring a 100% continuous current rating, a different breaker configuration with copper-only lugs and specific enclosure requirements is necessary.

This breaker is factory-configured for standard ABC phase connections on the I-Line bus stack. If your panelboard requires a different phase arrangement, a different catalog number suffix is required.

It utilizes Square D's I-Line plug-in mounting system. The line-side jaws push directly onto the panel's bus stack, and a captive retaining screw secures the breaker to the backpan. This allows for installation or removal without disturbing adjacent breakers or bus connections.

The LSI (Long-Time, Short-Time, Instantaneous) electronic trip unit allows electricians to fine-tune the breaker's response curve. By adjusting the pickup and delay settings, you can ensure this breaker trips before the main breaker during a fault, isolating the issue and preventing wider power outages.