Question

3. Explain why single phase Induction motor is NOT self-starting?

Answer 1

A single-phase motor can be considered as two identical three-phase motors connected in series in the network, having a common shaft, the magnetic flows of which rotate counter. Therefore, the single-phase motor replacement circuit consists of two series-connected circuits for forward and reverse sequence. Therefore, their moments are equal and therefore a single-phase motor does not have an initial moment and cannot start working without additional movement.