The ABB XT5HU340AGFF000XXX is a 400 A, 3-pole molded case circuit breaker (MCCB) from the XT5H series, fitted with an EKIP DIP LSIG 400 electronic trip unit. The LSIG designation means it provides long-time (L), short-time (S), instantaneous (I), and ground-fault (G) protection — the full suite for a main or feeder breaker in a low-voltage distribution switchboard. The FF suffix indicates fixed front terminals, so this breaker is panelboard- or switchboard-mounted, not plug-in. Rated 400 A continuous, this MCCB is sized for large motor control centers, transformer secondaries, or main incoming feeders in commercial and industrial 480 VAC / 600 VAC systems. The EKIP DIP trip unit allows field-adjustable protection curves via DIP switches, so the breaker can be coordinated with downstream devices without swapping the trip unit.
The 400 A frame and LSIG trip unit mean this breaker handles both overload and ground-fault protection in one package — critical for feeder circuits where a ground-fault relay would otherwise be a separate add-on. The EKIP DIP LSIG 400 trip unit is adjustable across L, S, I, and G parameters, so the breaker can be tuned to the specific cable and load without a software tool or handheld programmer. UL and CSA listings (from the description) confirm this variant is accepted for North American panelboard and switchboard installations without additional agency review. The 3-pole configuration suits three-phase systems; the fixed front terminals (FF) match standard bus-bar or cable-lug connections in a distribution section.