1200 A power breaker with EKIP DIP LSI trip unit
The ABB XT7SU312EFFF000XXX is a 1200 A three-pole power circuit breaker from the XT7S family, fitted with an EKIP DIP LSI electronic trip unit. The LSI designation means it provides Long-time (L), Short-time (S), and Instantaneous (I) protection — the three curves you need for feeder and main breaker duty in low-voltage switchgear. The fixed front terminals (F F) simplify panel bus connections without requiring drawout cassette hardware.
The 1200 A continuous rating on a 3-pole frame sizes this for main incoming protection in a 480 V or 600 V switchboard section. The EKIP DIP LSI trip unit gives you field-adjustable long-time pickup and delay, short-time pickup and delay (for selective coordination downstream), and a fixed instantaneous pickup. That selectivity headroom is what lets you clear a branch fault without dropping the main bus — the S (short-time) band is the key parameter for coordination studies. UL listing means the breaker carries the UL 489 mark for North American panel acceptance.