It uses standard parts and is designed and manufactured with a compact structure. It can install load three-tire light weight withdrawal type Air Circuit Breaker (ACB). It has an embedded ACB with high reliability and interception to increase the reliability of power provision. It also satisfies customer demand in quality and cost by adopting a wide range of parts. Securing a sufficient working space makes installment and repair easy. The surveillance and controlling is also easy as various controlling devices and gauges are installed in the front. The circuit breaker with same capacity adopts standard planning to be excellent in its compatibility.