Square D MEC436LI Molded Case Circuit Breaker

The Square D MEC436LI Molded Case Circuit Breaker is a heavy-duty MCCB designed for three-phase distribution, rated for 400 A at up to 600 V AC and built to mount in standard industrial panels. With a 50/60 Hz operating range, the LI designation indicates Long-Time and Instantaneous trip functionality to interrupt fault currents promptly while protecting conductors and equipment. This unit includes an auxiliary switch for local status indication or control, aligning with Square D's practice of integrating control features with protection devices. Common applications include feeder protection and circuit protection in large commercial and industrial installations where a 400 A, 600 V MCCB with LI protection and an auxiliary contact is appropriate.