Single Phase Motor Capacitor Calculator

This is the single phase motor capacitor calculator.

With the help of this calculator you can be able to find –

• Capacitor value in microfarad for starting winding of the single phase motor.
• Capacitor value in microfarad for running winding of the single phase motor.

Single Phase Motor Capacitor Calculator

How to use the calculator?

For calculating starting capacitor value for single phase motor-

• Select the suitable option of your choice.
• Enter Motor power in watts. If the motor power available is in horsepower, convert it into kW by multiplying it by 746 watts.
• Enter input voltage.
• Enter power factor (cos-phi) value. If you do not know, enter 0.8.
• The calculator would display the result.

For calculating Running capacitor value for single phase motor-

• Select the suitable option of your choice.
• Enter Motor power in watts. If the motor power available is in horsepower, convert it into kW by multiplying it by 746 watts.
• Enter input voltage.
• Enter rated frequency.
• Enter the efficiency of the single phase motor. If you do not know the value, just enter 80 percentage.
• The calculator would display the result.

How to size capacitor for starting winding of single phase motor?

To size the capacitor for starting winding of the single phase motor, we have the following formula –

Where,

I = Current of the motor in amperes

F = rated frequency of the motor

V = rated voltage of the motor

Example

Assume that we have a single phase 1 HP pump having a rated voltage of 230 Volts and a rated frequency of 50 Hertz. The power factor is 0.8 and the efficiency is 80%. The starting capacitor required would be 56.14 Microfarad.

How to size capacitor for running winding of single phase motor?

To size the capacitor for running winding of the single phase motor, we have the following formula –

Where,

η = Efficiency of the motor

F = rated frequency of the motor

V = Rated voltage of the motor

Example

Let us take an example of a ceiling fan. Assume that we have a ceiling fan of 70 Watts having a rated voltage of 230 Volts and a rated frequency is 50 Hertz. The efficiency of the fan is 80 percent. The running capacitor required would be 2.12 Microfarad.