In case of split phase motor, the phase shift between currents in

SOLUTION

Split Phase Induction Motor:

• The Split Phase Motor is also known as a Resistance Start Motor.
• It has a single cage rotor, and its stator has two windings known as main winding and starting winding.
• Both the windings are displaced 90 degrees in space.
• The main winding has very low resistance and a high inductive reactance whereas the starting winding has high resistance and low inductive reactance. 

• A resistor is connected in series with the auxiliary winding.
• The current in the two windings is not equal as a result the rotating field is not uniform.
• Hence, the starting torque is small, of the order of 1.5 to 2 times of the start, running torque.
• At the starting of the motor both the windings are connected in parallel.

The phasor diagram of the Split Phase Induction Motor is shown below.

• The current in the main winding (I_M) lag behind the supply voltage V almost by the 90^∘  
• The current in the auxiliary winding IA is approximately in phase with the line voltage.
• Thus, there exists a time difference between the currents of the two windings.
• The time phase difference ϕ is not 90 degrees, but of the order of 30 degrees.
• This phase difference is enough to produce a rotating magnetic field.