The Square D PowerPact M MGP36800LV is a 3-pole unit mount breaker rated 800 A continuous with an electronic trip unit. The 18 kA interrupting rating at 600 VAC tells you it can clear faults up to that level without upstream fuses or a larger frame — sized for a main or large feeder in a 480/600 V panel where the available fault current stays under 18 kA. Unit mount means the breaker ships as a self-contained assembly with lugs off the end, ready for bus-bar or cable connection in a switchboard or panelboard. No separate mounting base or enclosure needed — it bolts directly into the gear. The electronic trip provides adjustable long-time, short-time, and instantaneous pickup — field-configurable for selective coordination downstream. That matters when you need to keep a fault on a branch from taking out the whole panel.
Category and documentation context
Catalogued under Category 01205-MG, MJ UNIT MOUNT BREAKER — this is the internal Square D classification that groups the PowerPact M unit mount family. It confirms the form factor and mounting pattern for panel layout. For a replacement sourced through independent channels, request the specific lot's declaration at quote time — coverage varies by manufacturing date.