The ABB XT4LU3025AFF00NXXX is a molded case circuit breaker (MCCB) from the XT4L series, built on a 250 A frame and fitted with a TMF (thermal-magnetic fixed) trip unit adjustable from 25 A to 400 A. The 3-pole configuration with fixed trip and front terminals (F F) makes it a straight drop-in for UL/CSA panels needing branch circuit protection on motor loads, feeders, or distribution buswork.
The 3-pole fixed-trip configuration is standard for three-phase power circuits — no neutral pole, so it fits a 3-wire delta or ungrounded wye system as delivered. UL/CSA listing means the breaker has been tested and certified to North American standards for branch circuit protection (UL 489 / CSA C22.2 No. 5). This is a jurisdictional requirement for most industrial panels in the US and Canada — a breaker without these marks cannot be used in a UL 508A panel.
Front terminals accept copper or aluminum conductors; torque values and strip lengths follow the nameplate. The breaker occupies a standard 3-pole MCCB footprint — verify depth clearance against the enclosure door before committing the gland plate layout.