It is a single phase motors are widely used in electrical appliances such as washing machines, some compressors,vacuum cleaner, table drill, pump, etc.

Why it become a common use? because it has advantages :

• Good Starting Torque
• Moderate Efficiency
• Moderate Cost

it usually has a power rating from 1/20th to ¾ Hp, available to 1.5 Hp

Split phase motor has a primary winding (movement) and the additional windings (starting).

Split phase Motor Operation

• For the purpose of starting the motor, all the main and additional windings connected in parallel across the line.
• Starting winding in parallel with Running winding

• Centrifugal switch mounted in series with the additional windings to be open when the motor reaches a speed of 70% synchronous speed.
• In the stationary motor, all the windings are used to develop starting torque, but when they reach 70% of the primary speed able to accommodate the resulting torque.

• Type of Centrifugal Switch
  – Sticks Open
  – Sticks Shut