The Square D MGP26300 is a PowerPacT M electronic trip unit mount breaker rated 300 A, 3-pole, with an interrupting capacity of 18 kA at 600 VAC. It ships with lugs on the load end for direct cable termination — no separate lug kit needed for the line side termination.
The 18 kA interrupting rating at 600 VAC tells you this breaker can safely clear a fault up to 18,000 A on a 600 V line without self-destructing or welding its contacts. That matters when you need selective coordination downstream or want to dial in the trip curve to match a transformer inrush or motor start profile without swapping the breaker.
Deployment context
This is a unit mount breaker — it bolts directly into a switchboard or panelboard bus, not a DIN rail or draw-out cassette. The lugs-off-end termination suits line-side feed from the bus and load-side cables running out to a downstream disconnect or MCC bucket. Panel builders will want to verify the mounting hole pattern and bus spacing against their enclosure before committing the cutout.