Square D LA 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. 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 2 pole unit I-Line breaker, 400A and 600VAC, with I-Line connection on line side and lugs on load side. The thermal magnetic circuit breaker has an interrupting rating of 25kA for 600VAC and 50kA for 250VDC with an AC phase connection. LH breakers are UL 489, CSA, IEC certified.