Shunt capacitor sizing for inductive-load power factor correction — single-phase or balanced three-phase
Dwg No.PFC-001
ScaleNTS
MethodP·tanφ
Rev—
Reference tool only.This calculator provides a preliminary estimate of capacitor sizing for power factor correction. It is not a substitute for a qualified electrical engineer's design, site measurements, harmonic/resonance assessment, or compliance with local codes and utility requirements.
1
System & LoadPhase, connection, voltage, frequency, active power
▾
120 V
208 V
240 V
480 V
600 V
4160 V
2
Power FactorCurrent (lagging) and target power factor
▾
0.90
0.92
0.95
0.98
Industry practice typically targets 0.90–0.98. Avoid setting the target at 1.00 — this risks tipping the load into leading (over-compensated) power factor under normal load swings.
3
Harmonic / Resonance Check (optional)Nonlinear loads (VFDs, UPS, rectifiers) can create resonance with shunt capacitors
Provide the bus short-circuit capacity (from a short-circuit study or utility data) to estimate the resonant harmonic order. If unavailable, at minimum flag whether known nonlinear loads (VFDs, UPS, rectifiers, arc/induction furnaces, LED drivers) are present on this bus.
4
Cross-check (optional)Existing capacitance or measured current/kVA, for validation
These fields don't change the sizing calculation — they're shown alongside the results so you can sanity-check the estimate against what's already installed or measured on site.
5
Capacitor Bank Cable (optional)Feeder cable from switchboard to the capacitor bank — CSA C22.1