It is a self powered inverse time over current and earth fault relay, used for selective phase and earth fault protection in time graded systems for A.C. machines, transformers, feeders etc. A non-directional heavily damped induction disc relay, which has an adjustable inverse time/current characteristic with a definite minimum time. The relay has a high torque movement combined with low burden and low overshoot. The relay disc is so shaped that as it rotates the driving torque increases and offsets the changing restraining torque of the control spring.