ABB XT4LU3040AFF000XXX XT4L 250 TMF, current lifecycle

The XT4LU3040AFF000XXX: The 250 A TMF designation tells you this breaker uses a fixed thermal-magnetic trip — no interchangeable trip units. That locks the continuous current rating at 250 A, so the load must be sized to that value. The XT4L frame itself is a compact molded-case design typical for panelboard and switchboard mounting; it bolts onto a bus or mounts via the rear terminals. No IP rating is stated, so it's intended for indoor, dry-location installation inside an enclosure.