The ABB XT5SU330ABFF000XXX is a 3-pole molded case circuit breaker from the XT5S family, built around a 400 A frame and fitted with a TMA thermal-magnetic-adjustable trip unit covering the 300–3000 A range. The 'FF UL' suffix confirms UL-listed construction for North American panel applications. Rated for a 400 A frame, this MCCB handles feeder and main breaker duty in switchboards and panelboards. The TMA trip gives you adjustable thermal (long-time) and magnetic (short-time and instantaneous) settings, so coordination studies can be dialed in without swapping trip units.
Integration into a panel
The 400 A frame mounts into a standard switchboard or panelboard cubicle with bus-bar connections. The TMA trip unit's adjustment dials are accessible from the front, allowing coordination settings to be set during commissioning without removing the cover. Line and load terminals accept bus bars or cable lugs sized for the 400 A continuous rating. The 3-pole configuration covers three-phase feeders; the solid-state trip provides selective coordination downstream.