Square D MA36500 Molded Case Circuit Breaker

The Square D MA36500 is a legacy M-Frame breaker. The direct replacement for I-Line applications is the MGA36500 (PowerPacT M-Frame). It provides an upgraded electronic trip unit while matching the physical footprint and I-Line mounting requirements of the original breaker.

While both are 500A M-Frame breakers, the MA36500 is an I-Line plug-on breaker designed for I-Line panelboards. The MAL36500 is the unit-mount version, which features traditional mechanical lugs on both the line and load sides.

This specific breaker is designed exclusively for Square D I-Line panelboards and switchboards. It uses an I-Line plug-on jaw connection on the line side to engage the bus bars directly, while the load side uses traditional mechanical lugs.

No. The MA36500 is an M-Frame breaker with a larger physical footprint, specific bus jaw spacing, and 500A continuous current rating. It cannot be installed in panel spaces designed for smaller I-Line frames like the FA, JA, or KA series.

The standard load-side mechanical lugs on the MA36500 can accept up to three parallel conductors per phase. Each terminal is rated for aluminum or copper wire ranging from 3/0 AWG to 500 kcmil.

The LI designation means the breaker provides Long-Time (L) overload protection and Instantaneous (I) short-circuit protection. It uses a thermal-magnetic mechanism where the thermal element is fixed, but the magnetic instantaneous trip can be manually adjusted for system coordination.

Yes, in addition to standard AC voltage ratings up to 600VAC, this breaker is rated for 250VDC systems with a maximum interrupting capacity of 14kAIC.

No. Because it relies on a specific I-Line plug-on connection for the line side and mechanical lugs for the load side, this breaker is directional by design and cannot be reverse fed.