 # Capacitor Bank in kVAR & µF Calculator for Power Factor Correction

How to Calculate the Capacitor Bank in kVAR & Microfarad for Power Factor Improvement? Calculator & Example

### Capacitor Bank Calculator

The following Power factor improvement calculator will calculate the required capacitor bank value in kVAR reactive power “Q” and Microfarad “µF”. The power factor correction capacitor must be connected in parallel with each phase load. In addition, both kVAR and μ-farad are terms used in capacitor banks and power factor improvement & correction to eliminate the reactive components from the load side which has multiple advantages.

To calculate the value of capacitance of a capacitor bank in kVAR and µF , just enter the values of real or active power in kW, existing power factor and targeted power factor “P.F needs to be corrected” and hit the “Calculate” button to the get the result of capacitance of a capacitor bank in μF and kVAR.

The value of voltage in volts, and frequency in Hz (50 or 60Hz) is optional in case if you only want to calculate the kVAR rating of capacitor bank. If you need to calculate the value of capacitor bank in microfarad, you must enter the known value of frequency and voltage.

 Enter Power in kilowatts kW Enter Existing P.F (θ1) e.g (0.6) Enter Required P.F (θ2) e.g (0.9) Voltage (Optional for µF) V Frequency (Optional for µF) Hz Required Capacitor in kVAr & µF for P.F Improvment Capacitor Bank Size in kVARs kVAr Capacitor Bank Size in µF µF

Related Calculators: ### Capacitor Bank in kVAR & µF Calculation Formula

#### Capacitor Bank in kVAR

The following formulas can be used to calculate the required capacitor bank in kVAR for power factor improvement.

Required Capacitor Bank in kVAR = P in kW (Tan θ– Tan θ2)

Also

• kVAR = C x f x V2 ÷ (159.155 x 106)      …     in kVAR
• kVAR = C x 2πx f x V2 x 10-9     …     in kVAR

Where:

• kVAR = Required volt-ampere-reactive in kilo.
• C = Capacitance value of capacitor in µF
• f = frequency in Hertz “Hz”
• V = Voltage in volts
• θ1 = Cos-1 = Existing power factor
• θ= Cos-1 = Target or desired power factor “which is needed to be corrected”.

#### Capacitor Bank in Microfarad “µF”

The following formulas can be used to calculate the required capacitor bank in µF for power factor correction.

Required Capacitor Bank in µF = kVAR x 109 ÷ (2π x f x V2)

Also

• C = 159.155 x 106x Q in kVAR ÷ f x V2     …     in microfarad
• C = kVAR x 109 ÷ (2πx f x V2)     …     in microfarad

Where:

• C = Capacitance value of capacitor in µF
• kVAR = Required volt-ampere-reactive in kilo.
• f = frequency in Hz
• V = Voltage in volts

Good to know:

The following are useful formulas and equation while calculating the power factor, active power, reactive power and apparent power.

Where:

• kW     = Active Power       = P = V x I x Cosθ
• kVAR = Reactive Power   = Q = V x I x Sinθ
• kVA    = Apparent Power  = S = V x I

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### How to Calculate the Capacitor Bank in kVAR & µF for P.F Correction

The following example shows how to calculate the required correction capacitor bank rating in microfarad and kVAR. You may compare the result of the solved example with the power factor calculator results.

Example 1:

A Single phase 480V, 60Hz, motor takes a supply current of 55.5A at a power factor “p.f” of 0.60. The motor power factor has to be corrected to 0.98 by connecting a capacitor in parallel with it. Calculate the required capacity of Capacitor both in kVAR and µF.

Solution:

Load in kW = P = V x I x Cosθ1

P = 480V x 55.5A x 0.60

P = 16 kW

Required Capacitor Bank in kVAR

Required Capacitor kVAR = P in kW (Tan θ1 – Tan θ2)

θ1 = Cos-1 = (0.60) = 53°.130; Tan θ= Tan (53°.130) = 1.333

θ= Cos-1 = (0.98) = 11°.478; Tan θ= Tan (11°.478) = 0.203

kVAR = 16kW x (1.333 – 0.203)

VAR = 1808 VAR

Required kVAR = 18.08 kVAR

Required Capacitor Bank in µF

C = kVAR x 109 ÷ (2πf x V2)     …     in microfarad

C = 18.08 kVAR x 109 ÷ (2π x 60Hz x 4802 V)

C = 208.2 µF

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Example 2:

A factory have a load of 300kW at 0.6 P.F. If they need to improve the power factor from 0.65 to 0.97, find the value of capacitor bank in kVAR and microfarad they need to install in parallel with the load phases.

Solution:

Given data:

• Existing Power Factor Cosθ1 = 0.65
• Target Power Factor Cosθ2 = 0.97

Required Capacitor bank in kVAR = P in kW x Tan (Cos-11) – Cos-12))

kVAR = 300kW x Tan (Cos-1(0.65) – Cos-1(0.97))

kVAR = 300kW x x Tan (49°.458 – 14°.069)

kVAR = 300kW x (1.169 – 0.250)

kVAR = 275.7 kVAR

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