Square D LH molded case circuit breakers provide thermal magnetic protection. Their primary function is automatic opening of a circuit under overload or short circuit conditions or manual opening. Their primary function is automatic opening of a circuit under overload or short circuit conditions or manual opening. LH circuit breakers contain thermal (overload) and magnetic (short circuit) sensing elements in each pole. Push-to-Trip allows the circuit breaker to be manually tripped without exposure to live parts. This Square D LH molded case circuit breaker is a 3 pole unit mount breaker, 400A and 600VAC, with I-line connection. The thermal magnetic circuit breaker has an interrupting rating of 25kA for 600VAC and 50kA for 250VDC. LH breakers are UL 489, CSA, IEC certified. Electronic trip units provide highly accurate protection with wide setting ranges and can integrate measurement, metering and communication functions. This PowerPact circuit breaker,is a 400A, and is a 3-pole with a breaking capacity of 35kA@480VAC rated operatiuonal voltage. With a magnetic hold current of 2000A and a magnetic tripping current of 4000A. This breaker has a thermal-magnetic trip unit technology. This unit mount breaker copmplies to UL, CSA standards. Dinemsions for this product are 11 in (H)<6 in (W), 5.84 in (D), and an ambient temperature rating of40 °C.