The PowerPact. J-frame circuit breakers are designed to protect electrical systems from damage caused by overloads and short circuits. J-frame circuit breakers are available with either thermal-magnetic or Micrologic. electronic trip units. The amperage ratings of the thermal trip elements are calibrated at 104.F (40.C) free air ambient temperature. Per the National Electric Code. (NEC.) and the Canadian Electrical Code, standard circuit breakers may only be applied continuously at up to 80% of their rating. This PowerPact J, circuit breaker and is 3-pole and has a breaking capacity of 18kA@480VAC and has a rated current of 250A. This ia a unit mount breaker and complies to UL listed, IEC, CCC, CE & CSA standards. With an electronictrip unit it has an LSI function and an ABC Phase Connectiion. Dimensions for this product are 7.52 in (H),4.12 in (W), 5 in (D) with an ambient temperature rating of 50 .C. This product comes with an 18 month warranty.