Square D HJA36150U33X Molded Case Circuit Breaker

The U33X suffix indicates that this circuit breaker is equipped with a Micrologic 3.2S electronic trip unit. This solid state module provides field-adjustable Long-Time, Short-Time, and Instantaneous (LSI) protection settings for precise selective coordination.

Yes. The PowerPacT H-Frame is the modern direct replacement for obsolete Square D F-Frame breakers, including the FA and FH series. The HJA36150U33X will plug directly into the same I-Line bus stack without requiring switchboard modifications.

The HJA36150U33X is designed exclusively for Square D I-Line panelboards and switchboards. It features an I-Line style plug-in connection and cannot be installed in standard unit mount enclosures or QO load centers.

The breaker features plug-on phase jaws that connect directly to the I-Line bus stack. It is mechanically secured using a mounting bracket on the back of the breaker that bolts directly to the panelboard mounting pan. No additional hardware is required to make the bus connection.

The factory-installed load lugs on this 150A breaker accept wire gauges ranging from 14 AWG to 3/0 AWG. The terminals are rated for use with either copper or aluminum conductors.

The solid state electronic trip unit provides highly accurate microprocessor-based overcurrent sensing. By allowing electricians to adjust the LSI parameters, it offers superior selective coordination to isolate faults without tripping upstream main breakers in industrial applications.