Frame rating and trip unit
The ABB XT3NU3100AFF000XXX is a 225 A, 3-pole molded-case circuit breaker in the XT3N frame series, fitted with a TMF (thermal-magnetic fixed) trip unit. The TMF trip provides fixed thermal (overload) and magnetic (short-circuit) protection curves; no field-adjustable trip dials, so the protection characteristic is locked at the factory.
Mounting and terminal configuration
Mounting is frame-style — the breaker bolts into a switchboard or panel enclosure via its mounting feet, not a DIN rail. The fixed front flat terminals accept bus bar or cable lugs on the line and load sides. This is a standard footprint for panelboard integration; verify the mounting hole pattern and terminal center-to-center spacing against your existing bus work before committing the BOM line.
UL and CSA listed per the description — the breaker carries Underwriters Laboratory and Canadian Standards Association marks, accepted for panel builds in North American installations.