The Eaton Cutler-Hammer KD3250T56W Digitrip OPTIM 550 Electronic Circuit Breaker is a high-performance Electronic Circuit breaker with interchangeable plug rating, used for overload protection in applications where a high level of system coordination is required. This circuit breaker is designed with a programmable electronic trip unit which provides a microprocessor-based RMS current sensing and is equipped with up to 10-time current setting options that are programmed electronically via a programming device. The KD3250T56W has a continuous current rating of 250 Amps, with a standard interrupting capacity of 35 KAIC and is suitable with a 600 Volt AC voltage distribution system. This circuit breaker is capable of providing both overloads and short-circuits trip action using current transformers and solid-state circuitry, which initiates tripping in the event of an overload or short circuit and it has trip element installed on all 3 poles. The KD3250T56W has a fixed rated plug for line protection, and it is designed with a built-in over temperature trip, which protects the trip unit and the entire breaker when the operating temperature exceeds the designated value.

This device has a long delay pickup adjustable from 0.4 to 1.0 plug rating, with a delay time ranging from 2 to 24 seconds, and it has a short delay pick value between 150 to 800% of long delay pickup setting and a delay time of 100 to 500 milliseconds. The KD3250T56W also has an adjustable instantaneous pickup setting, as well as a discriminator circuit which protects users from unsafe conditions, and it also has ground fault protection feature, with 20 to 100% of sensor rating fault pick up value and 100 to 500 milliseconds fault delay time. It has a powered thermal memory which remembers trip timing sequence from past overcurrent events and imposes shorter delay timing in the event of subsequent overcurrent. The KD3250T56W has full system diagnosing capabilities with a cause of trip LED module, which provide trip information via light indicators. It has an operating temperature range of -20 to +85 degrees Celsius and can function within a 0 to 95% non-condensing and non-corrosive relative humidity range. The KD3250T56W has a net weight of 11.5 pounds, with a dimension of 5.5 x 10. X 4.1 inches, and it AS, UL, BS, and IEC certified.