No-Load Test: At no-load the machine runs at very small slip sufficient to provide power for windage and friction loss, core loss and also a certain amount of stator copper loss, which has to be, accounted for because of the large no load current. With low slip, the following approximation will hold good. R2?(1/s-1) is very high R2?/s>>X2? With these approximations the necessary formulae for finding out Xm will be given while conducting the no-load test.
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