The ABB MCCB XT5N is a 400A frame, 3P (three-pole) circuit breaker with a fixed rating of 36kA. It has an In (rated current) of 400A and I1 (adjustable thermal overload protection range) of 160-400A. The S-I2 (short-circuit breaking capacity) ranges from 240-4000A, while the I-I3 (instantaneous short-circuit protection range) is between 600-4000A. This MCCB features a touch LSI trip unit and is classified as class 1 for metering purposes. It also has front terminals for easy installation.