What the ratings mean for fit
The XT1HU3090AYD000XXX: The 125 A frame and TMF 90-900 trip unit mean this breaker is sized for branch circuits or feeder applications where the continuous load falls within the 90–900 A adjustable thermal-magnetic range. The 3-pole fixed configuration suits three-phase systems, common in industrial panelboards and motor control centers. UL/CSA certification confirms acceptance in North American installations per UL 489 and CSA C22.2 No. 5.
Deployment context
Mounts in standard panelboard or switchboard cubicle; the fixed fixed version has no plug-in base, so it bolts directly to the bus. Suitable for distribution panels, lighting panels, and feeder circuits in commercial and industrial buildings where UL/CSA compliance is required.