Molded case switch for panel protection
The 3-pole configuration handles three-phase loads, so it fits standard 400 VAC lineups where each phase needs independent overcurrent interruption. Rated for the XT1N frame size, this breaker carries the TMF trip unit — a thermal-magnetic release that provides inverse-time overload protection and instantaneous short-circuit response. That makes it suited for general-purpose feeder and motor branch protection where coordination with downstream devices matters.
Peer variant comparison
The closest functional peer is the XT1NU3090AFF000XXX, which shares the same 3-pole XT1N frame but is rated at 90 A versus the 125 A TMF on this unit. If a panel was specified around the 90 A variant, the 125 A version will physically drop into the same mounting footprint and bus connection, but the higher amp rating changes the coordination study — verify selective coordination with upstream and downstream devices before swapping.