Enter two known values—Reactive Power, Line Voltage, or Capacitor Value—into the calculator to determine the missing parameter.
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3 Phase Motor Capacitor Formula
The following equation is used to calculate the capacitor value when Reactive Power and Line Voltage are provided.
C = (Q * 10^9) / (2*pi*f*V^2)
- Where C is the capacitor value (µF)
- Q is the reactive power (kVAR)
- f is the frequency (Hz), typically 60 Hz
- V is the line voltage (V)
To calculate a missing value, leave the field corresponding to that parameter empty and click Calculate.
What is a 3 Phase Motor Capacitor?
Definition:
A 3 phase motor capacitor is used in electrical systems to improve power factor and enhance motor efficiency by compensating for reactive power. It helps reduce energy losses and balance loads in three-phase networks.
How to Calculate 3 Phase Motor Capacitor Parameters?
Example Problem:
The following example outlines the steps and information needed to calculate the missing capacitor parameter.
First, determine the known parameters. In this example, the reactive power is 50 kVAR and the line voltage is 400 V.
Next, calculate the squared value of the line voltage: 400² equals 160,000.
Finally, determine the capacitor value using the formula above:
C = (Q * 10^9) / (2*pi*f*V^2)
C = (50 * 10^9) / (2*pi*60*160000)
C ≈ 829.5 µF
FAQ
What parameters can be calculated using this calculator?
You can calculate the missing parameter—Reactive Power, Line Voltage, or Capacitor Value—by leaving its corresponding field empty.
Why is the frequency set to 60 Hz?
Most three-phase systems in many regions operate at 60 Hz; however, if your system uses a different frequency, you may need to adjust the calculation accordingly.
How do I ensure an accurate calculation?
Enter exactly two known values and leave the field for the unknown parameter blank so that the calculator can compute the correct value using the formula.