This work presents a protection algorithmto diagnose the fault and its type, using alienation coefficients of current signals, on a parallel transmission system. Alienation Coefficients are computed by comparing samples of post-fault current signals for successive cycles, obtained for a quarter cycle period. This Alienation Coefficient is compared with the threshold to detect the faulty phase and consequent classification of type of fault. Thus.the fault detection time for this algorithm is only a quarter cycle period. The performance of the proposed scheme has been established by various case studies in which fault locations, incipient angles and fault impedances are varied. © 2018 IEEE.