The ABB XT6HQ3600EFF000XXX is a Tmax XT6H molded case circuit breaker rated 600 A continuous on a 3-pole, 600 VAC system, housed in an 800 A frame with an E.DIP LS/I electronic trip unit. The 800 A frame means the breaker's mechanical and thermal capacity exceeds the 600 A trip rating — you get headroom for short-duration overloads without nuisance tripping, and the same frame can be re-rated upward if the load grows, as long as the trip unit is swapped. The E.DIP LS/I trip unit provides long-time (L), short-time (S), and instantaneous (I) protection curves, configurable for selective coordination downstream — typical for a main or feeder breaker in a distribution panel where you need time-delayed short-circuit response to let branch breakers clear first.
The 600 VAC rating covers 480Y/277 V and 600 V delta systems common in North American industrial distribution, as well as 400 V IEC networks. At 600 A continuous, expect cable or busbar sizing in the 2× 500 kcmil per phase range (copper, 75 °C termination).