Eaton / Cutler-Hammer KD3250 Molded Case Circuit Breaker

Yes, the KD3250 features an interchangeable thermal-magnetic trip unit. The assembly consists of a KD3400F K-Frame and a KT3250T 250A trip unit. This allows you to swap the trip unit independently if your system requirements change, without replacing the entire breaker frame.

The magnetic trip on the Eaton KD3250 is adjustable from 5 to 10 times its 250A continuous rating. You can set the instantaneous trip point anywhere between 1250A and 2500A to properly coordinate with your system's load profile.

No, standard KD-frame breakers like the KD3250 are 80 percent rated, meaning continuous loads (lasting 3 hours or more) should not exceed 200A. If your application requires a 100 percent rated breaker, you will need the Eaton CKD3250 model instead.

Yes, the KD3250 is HACR rated. This certification means the circuit breaker is rigorously tested and approved for use in heating, air conditioning, and refrigeration systems.

Out of the box, the KD3250 includes standard TA350K lugs designed for a single 250 to 500 kcmil wire per phase. To accommodate two wires, you will need to replace the standard lugs with the 3TA400K multi-wire lug kit, which accepts two #3/0 to 250 kcmil conductors.

The LI designation stands for Long-Time and Instantaneous trip functions. The long-time function provides thermal overload protection based on the fixed 250A rating, while the instantaneous function provides short-circuit protection via the adjustable magnetic trip dial.

No, the KD3250 uses a thermal-magnetic trip unit that only provides long-time (overload) and instantaneous (short-circuit) protection. It does not offer ground fault (G) or short-time (S) coordination features found in electronic trip units like the Digitrip 310+.