**Capacitor Bank Calculation For APFC Panel**

Welcome to this introductory part onÂ capacitor bank calculation for an APFCÂ panel.Â When I first started working on the calculationÂ of capacitor bankÂ I have struggled for many hours to figure out what was going on in this Capacitor bank calculation. Therefore, I have decided to write this tutorial for the ones who are new to these topic.

In this tutorial, we will discuss the calculation for capacitor bank in a simple way.

There are two methods for calculation of capacitor bank –

**Simple Table Method for Capacitor bank calculation****Classical Capacitor bank Calculation Method**

Let us take a exampleÂ of 3Phase induction motor

**1.Simple Table Method for capacitor bank calculation â€“Â **

Motor Input = 5kW

From Table, Multiplier to improve Power factor from 0.7 to 0.96 is 0.692

Required Capacitor kVAR to improve P.F from 0.7 to 0.96

Required Capacitor kVAR = kW x TableÂ Multiplier of 0.7 andÂ 0.96

= 5kW x 0.692

= 3.46**Â kVAR**

And Rating of Capacitors connected in each Phase

3.46/3 = 1.15**Â kVAR**

**2. Classical capacitor bank Calculation Method**

Motor input = P = 5 kW, Voltage- 400V

Original Power factor= CosÎ¸_{1}Â = 0.7

Final Power factor = CosÎ¸_{2}Â = 0.96

Î¸_{1}Â = Cos^{-1}Â (0.7) = 0.7953; TanÂ Î¸_{1Â }= Tan (0.7953) = 1.0200

Î¸_{2Â }= Cos^{-1}Â (0.96) = 0.2837; Tan Î¸_{2Â }= Tan (0.2837) = 0.2915

Required Capacitor kVAR to improve Power factor from 0.7 to 0.96

Required Capacitor kVAR = P (TanÂ Î¸_{1Â }â€“ TanÂ Î¸_{2})

= 5kW (1.0200 â€“ 0.2915)

= 3.46**Â kVAR**

And Rating of Capacitors connected in each Phase

3.46/3 = 1.15**Â kVAR**

**Â **

These are the main Formulas to Convert CapacitorÂ **kVARÂ **intoÂ **FaradsÂ **and Vice Versa

**C = kVAR / (2 Ï€ f V ^{2}) in microfarad**

**C = 3.46/ (2 Ï€* 50*400 ^{2}) in microfarad**

**C= 6.88* 10^-8 microfarad**

## Leave A Comment