The Square D MGP36600YP is a PowerPact M unit mount breaker rated 600 A continuous, 3-pole, with an electronic trip unit and an interrupting rating of 18 kA at 600 VAC. This is the variant with lugs off the end and a handle padlock provision — a panel-mounted main or feeder breaker sized for heavy industrial loads.
At 600 A continuous, this breaker covers the main feed for a 300–500 kVA transformer secondary or a large motor control center lineup. The electronic trip allows adjustable long-time, short-time, and instantaneous pickup — field-configurable without swapping trip units, which is the main advantage over thermal-magnetic on a frame this size. The unit mount form factor (Category 01205-MG, MJ UNIT MOUNT BREAKER) means it bolts directly into a panelboard or switchboard bus, not a DIN-rail or plug-in base. The lugs-off-end termination suits line-side or load-side cable entry in a deadfront enclosure.