In this type of Relays, Relay Operating time is the same and the Pick up of a series of Overcurrent relaysis chosen based on the assumed fault current which varies with the position of the Fault because of the difference of the Impedance values between the source and the Fault. Major disadvantage of such type of grading is applicable only if there is large difference in magnitude of Fault current between the two Overcurrent relay locations, which is almost impossible to achieve.