Square D NEC1236LI Molded Case Circuit Breaker

The Square D N-frame NEC1236LI is replaced by the PowerPact P-frame series, specifically catalog number PLL36120U31A. Panel builders must verify that the enclosure and mounting space accommodate the newer P-frame footprint, as it differs physically from the obsolete N-frame design.

The LI trip function code indicates that the solid state trip unit provides adjustable Long-Time and Instantaneous protection. This allows electricians to accurately coordinate the overload and short-circuit response curves with upstream and downstream distribution equipment.

The factory mechanical lugs accept either three or four 3/0 AWG to 500 kcmil conductors per phase. These terminals are rated for use with both aluminum and copper conductors. Always ensure all connections are torqued to the specifications printed on the breaker faceplate.

No, this is a unit mount circuit breaker designed for lug-to-lug, hardwired installations. It cannot be mounted on an I-Line bus system. If an I-Line connection is required for your panelboard, an alternative N-frame or P-frame I-Line breaker must be specified.

This unit mount N-frame breaker is engineered for installation within standard Square D switchboards and motor control centers that accommodate hardwired, individually mounted devices rather than plug-on bus systems.

No. The NEC1236LI features a non-interchangeable Micrologic standard electronic trip unit. The internal components cannot be swapped with other trip units to add supplementary functions like Short-Time or Ground Fault protection.

Yes. The solid state trip mechanism utilizes true RMS sensing for highly accurate overcurrent detection. This helps prevent nuisance tripping in facilities with heavy harmonic distortion caused by variable frequency drives or large non-linear loads.