Split phase starting of 3 phase motors

When 3 phase induction motors are to be operated from single phase lines, split phase starting is frequently used. The optimum values of external resistance and reactance for split phase starting may be determined by the method of symmetrical components. In the present paper, equations for determining these values for each of the 2 commonly used split phase starting schemes are derived. The result of calculations based upon this method are shown to compare favorably with experimental data.