The document summarizes the technical specifications of the MC31A three phase over current and earth fault relay, which has 4 measuring elements. It can be used for feeder protection in substations and has a 4 digit LED display. The relay provides 7 selectable time characteristics and settings for over current and earth fault in steps of 0.05 times the rated current. It has separate LED indications, 4 output contacts for trip signals, and contact ratings of 250V AC/30V DC at 8A.