Actually the differential relay is the three number electromechanical(one for each phase) reyrolle type C21 with duobias written on it. I have searched the Siemens site but could only see the recent digital duobias-M relay and not the electromechanical type.
please I need the datasheet/installation manual for the Reyrolle type C21 (Duo-bias) Electromechanical differential relay. I need to identify the terminal M1, M2, L and the R1...R8 terminals. which is for the primary CT, secondary CT, Neutral, trip terminal and alarm?
