Types of Single phase induction motor starter | starting

Types of single phase induction motors| starters

The different types of single phase induction motors are identified or named by their starting methods. They include:

1)Split – phase Induction Motor
2) Capacitor – Start Motor
3) Permanent – Split Capacitor Motor
4) Capacitor - Start Capacitor - Run motor

1) Split-phase induction motor

The split phase induction motor also called the inductance start motor.
The stator has two windings namely the main winding and the auxiliary winding which are displaced in space by 90 degrees.

When the motor is supplied, the rotor accelerates and when it reaches about 75% of the synchronous speed, the centrifugal switch disconnects the starting winding.

The split phase induction motor is also known as the resistance start motor when a high resistance is added in series to the starting winding.  And the operation is the same as the one above.

2. Capacitor start motor

The capacitor-start motor is similar to the split phase induction motor, the difference is that, a capacitor is connected in series with the starting winding. The capacitor used in this method helps to improve the starting performance of the motor and the start winding may have many turns as the main winding. The capacitor is usually mounted outside the motor's Yoke. This is the most common method in starting single phase induction motors.

3) Permanent -split Capacitor motor

In this method, the capacitor  is permanently connected in series with the starting winding. So, before and after starting, the capacitor is permanently connected and no centrifugal switch is required here.
This method increases the starting and running performance.

4) Capacitor-start Capacitor-Run motor

Here, two capacitors are used. During starting, the two capacitors are connected in series with the auxiliary winding. When the rotor must have accelerated to about 75 or 80% of the synchronous speed, the centrifugal switch disconnects one of the capacitor ( called the starting Capacitor) the other Capacitor is permanently connected in series with the starting winding ( called the Run capacitor).
This method greatly increases the starting and running performance of the motor.

Related:

Single phase motors

Single phase induction motors

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