DZ20 Series MCCB apply to the exchange of 50Hz, rated voltage of 380V power distribution lines, as a power distribution line protection and to prevent the supply of electricity and equipment overload, short circuit and under voltage. Under normal circumstances, as the lines often do not use conversion, as motors can also be carried out to protect and often do not start. DZ20L series leakage circuit breakers in addition to the above purposes, it also has a personal electric shock protection may also be used to prevent equipment damage to the insulation, resulting in earth fault current caused by the fire.