A low cost prototype for testing stator winding shorted turns in 3-phase induction motors

This paper presents a prototype of stator winding shorted turns detector for three-phase induction motors. The focus condition is turn-to-turn short circuit, because this condition is the initial problem. The diagnosis technique is detectable from the voltage sum of the three instantaneous line to star-point voltage. In the testing, the supply is sinusoidal waveform and the motor must be star connected with floating neutral. Before diagnosis, this instrument will also determine the level of supply voltage imbalance, if it is over the limit, the test instrument will not diagnose shorted turns. From experimental results, 3-hp and 5-hp induction motors were used for testing this equipment which is capable of accurately identifying percentage of stator winding shorted turns.