Capacitor Bank Calculator — Formula
## Power Factor Correction with Capacitors
Capacitor banks supply reactive power locally, reducing the reactive current drawn from the supply.
### Formula
**Q_c = P (tan(phi_1) - tan(phi_2))**
where P is real power, phi_1 = arccos(PF_old), phi_2 = arccos(PF_new). Equivalently: tan(phi) = sqrt(1/PF^2 - 1).
Capacitor banks supply reactive power locally, reducing the reactive current drawn from the supply.
### Formula
**Q_c = P (tan(phi_1) - tan(phi_2))**
where P is real power, phi_1 = arccos(PF_old), phi_2 = arccos(PF_new). Equivalently: tan(phi) = sqrt(1/PF^2 - 1).
Exemplo Resolvido
Improve power factor from 0.75 to 0.95 on a 200 kW load.
- tan(phi_1) = sqrt(1/0.75^2 - 1) = sqrt(0.778) = 0.882
- tan(phi_2) = sqrt(1/0.95^2 - 1) = sqrt(0.108) = 0.329
- Q_c = 200 x (0.882 - 0.329) = 200 x 0.553 = 110.6 kVAR
- Select 120 kVAR capacitor bank (next standard size).