Starting torque of capacitor start motor:

Capacitor start motor is a type of single-phase induction motor, which is used for high starting torque applications. The starting torque of capacitor start motor is very high, which makes it suitable for heavy-duty applications. The starting torque of capacitor start motor is explained in detail below.

Working principle of capacitor start motor:

Capacitor start motor works on the principle of split-phase induction motor. The stator of the motor has two windings, namely main winding and auxiliary winding. The main winding is connected directly to the AC source, whereas the auxiliary winding is connected through a capacitor. The capacitor is used to create a phase shift between the main winding and auxiliary winding, which results in a high starting torque.

Starting torque equation:

The starting torque of capacitor start motor can be calculated using the following equation:

Starting torque = (2πn/60) * ((Ks * Im * Is) / (Ks^2 * Im^2 + Is^2))

Where,
n = speed of the motor in RPM
Ks = ratio of the number of turns in the auxiliary winding to the number of turns in the main winding
Im = current in the main winding
Is = current in the auxiliary winding

Factors affecting starting torque:

The starting torque of capacitor start motor depends on various factors, such as:

- Capacitance of the capacitor
- Ratio of the number of turns in the auxiliary winding to the number of turns in the main winding
- Current in the main winding and auxiliary winding
- Resistance of the windings
- Power factor of the motor

Advantages of capacitor start motor:

- High starting torque
- Suitable for heavy-duty applications
- Easy to start and operate
- Low cost and maintenance

Disadvantages of capacitor start motor:

- Low power factor
- Low efficiency at full load
- Limited speed control range
- Noise and vibration