MRD-RLJ series leakage relay is applicable to AC voltage up to 660V, frequency of 50Hz. With shunt release or no-voltage release, AC contactor and magnetic starter, they compose a set of current leakage protection equipment, to prevent current leakage and electric shock. It is optional to equip buzzer and signal indicator to compose a set of leakage warning equipment. It is of small size, easy set-up, and fixed action value with adjustable shifts, reliable action, continuous stable power supply and easy operation. It could be used for users in various regions for protecting grounding fault of wiring to prevent accidents or fire disasters of equipments and indirectly protection of human electric shock. It is applicable to low voltage power distribution system with solid grounding of neutral. The action time of the leakage relay is classified into quick type and time-delayed type, which are matched up to protect main line and branch line optionally as per grade.