To properly sizing the amount of capacitor (kVAR) required to correct the lagging power factor,we must have three (3) important of information below:

• kW (kilowatts)

• Existing Power Factor ( % )

• Desired Power Factor ( % )

From this information,now we can calculate the capacitor size for power factor correction.The formula to calculate the required kVAR is:

Calculation Example :

1 unit air-compressor ( 3 phase 415 VAC ) used an average of 90 kW with an existing power factor of 80%.The desired power factor is 95%. The factor value for this case is 0.421 to raise the power factor from 80% to 95% using table 1.

0.421 x 90 kW = 38 kVAR