Power Factor Correction Calculator
Calculate the capacitor bank size needed to improve power factor to a target value, reducing reactive power charges.
Required Capacitor Bank
55.3 kVAR
Required Capacitor Bank vs Real Power
Formule
## Power Factor Correction Low power factor means the utility must deliver more current (and apparent power) than the load actually uses. Capacitor banks supply reactive power locally. ### Formula **kVAR needed = kW x (tan(arccos(PF_current)) - tan(arccos(PF_target)))** ### Benefits - Reduced utility power factor penalties - Lower line current (smaller cables, less loss) - Freed transformer and distribution capacity Most utilities penalize power factors below 0.90. Correcting to 0.95 is a common economic target.
Exemple Résolu
100 kW load at PF 0.75, correcting to PF 0.95.
- 01Current angle: arccos(0.75) = 41.41 degrees, tan = 0.8819
- 02Target angle: arccos(0.95) = 18.19 degrees, tan = 0.3287
- 03kVAR needed: 100 x (0.8819 - 0.3287) = 55.3 kVAR
- 04kVA reduction: 100/0.75 - 100/0.95 = 133.3 - 105.3 = 28.1 kVA
Questions Fréquentes
What causes low power factor?
Inductive loads like motors, transformers, and fluorescent lighting draw reactive current that lags voltage, reducing power factor.
Can I overcorrect power factor?
Yes. A leading power factor (above 1.0 correction) can cause voltage rise and resonance. Do not exceed PF 0.98-0.99.
Where should capacitors be installed?
At the load for maximum benefit, at the main bus for simplicity, or a combination. Automatic switching banks handle varying loads.
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