What the 225 A rating means in a panel
The ABB XT3SU3225AFF000XXX is a Tmax XT3 molded case circuit breaker rated at 225 A continuous, 3-pole, 480 VAC. That 225 A thermal-magnetic fixed trip means it protects a feeder or large motor circuit up to that current without needing an adjustment dial — set it and forget it, which is exactly what you want on a production line where someone shouldn't be tweaking trip settings. Panel-mount form factor bolts into a standard switchboard or MCC bucket; no DIN-rail adapter needed.
Field-service note on the fixed trip
Fixed 225 A thermal-magnetic trip means no interchangeable trip units — what's on the nameplate is what you get. That's fine for a dedicated feeder where the load won't change, but if you're kitting spares for a line with multiple ampacity points, you'll want one breaker per amp rating rather than one breaker with swap-out trip packs. Front flat terminals accept standard lugs; torque them to the values stamped on the breaker case, not the lug manufacturer's generic chart.