The ABB XT7SU310ESFF000XXX is an XT7S-frame electronic trip unit rated 1200 A, configured for LSIG protection (long-time, short-time, instantaneous, ground fault) with an RP1000 rating plug and 3-pole UL listing. This is the brains of the breaker — it measures current, decides when to trip, and communicates the event. The LSIG profile means it covers overload, short-circuit, and ground-fault protection in one package, common on main or feeder breakers in switchboards where selectivity with downstream devices matters.
1200 A continuous current at the frame rating — this is the maximum the trip unit is calibrated for. In a UL 489 molded-case breaker, that rating governs the bus and lug capacity. The LSIG electronic trip gives adjustable pickup and time-delay settings for each protection function, letting you coordinate with downstream breakers without swapping trip units. Ground-fault (G) protection is built in, so no external GF relay needed for that function.