In induction machine, there may be different type of faults (LG, LL, LLG, or LLL), which may occur during induction motor operation. Therefore fault analysis of a machine is essential for superior operation of the machine. The effect of line fault (LG and LLG fault) on the speed estimator’s (MRAS) performance is illustrated in this paper. This is the first time in the literature that the author has investigated the performance of the speed estimator (MRAS) during the fault conditions. No such study has been carried out as far as information to the author is available. The line to ground (LG) fault may occur in any of the phase of induction motor. Also the fault may occur during any of the operating region of the motor - transient, steady state, or loaded condition. The speed estimators are investigated when one and/or two of the incoming phases come in direct contact with the ground. Three cases are studied for a speed estimator namely when LG fault occurs during (a) Transient (starting) period (b) Steady-state no-load period (c) Steady-state loading period. A comparative study is made in terms of tracking capability and production of ripples. From the simulation results, it can be concluded that when the LG fault occurs during any of the operating region, the estimators (MRAS) speed response almost follows the actual speed response of the motor showing a good tracking capability. Large ripples are found only in case of open loop scheme and very small ripples are found in case of close loop schemes. For testing a five-phase induction motor has been taken.