The ABB XT4HU3225AYJ000XXX is a molded case circuit breaker (MCCB) from the XT4H 250 series, configured as a 3-pole unit with a TMF (thermal-magnetic fixed) trip block rated 225-2250 A. The "F F" designation indicates fixed thermal and fixed magnetic trip settings — no field-adjustable dials, so the trip curve is locked at the factory to the 225-2250 A band. UL/CSA listing on the label means it carries the North American safety certifications for panelboard and switchboard installation.
The TMF trip unit covers a continuous-current range of 225 A to 2250 A, which is the band the breaker is calibrated to carry without tripping. For a panel builder or site engineer, that 10:1 span means the same frame can serve a 225 A feeder or a 2250 A main — the trip unit is selected at order, not adjusted in the field. The fixed thermal and magnetic settings suit applications where the load profile is well-characterized and does not require coordination tuning after installation. UL 489 listing certifies the breaker for branch-circuit protection in North American panels; CSA C22.2 No. 5 covers the Canadian equivalent.
Deployment context
The XT4H 250 frame is a draw-out or fixed-mount MCCB sized for switchboard and panelboard integration — not a DIN-rail miniature breaker. It connects to busbars or cable lugs in a distribution panel, typically as a main or large-feeder breaker in commercial or industrial power systems up to 250 A frame rating. The UL/CSA mark means it is accepted for service entrance equipment in North American jurisdictions.