Power Factor Correction Calculator

How It Works

1. Enter Measured Power Data

   Use measured or utility-reported kW and power factor where available. Treat estimated PF values as a source gap, especially for mixed or nonlinear loads.

2. Set a Target Prompt

   Enter the target PF used for the local screen. The actual target comes from the utility tariff, load profile, light-load behavior, and qualified review.

3. Review kVAR and Local Rows

   The app applies Q = P x (tan(arccos PF1) - tan(arccos PF2)) and compares the result to local kVAR reference rows. It does not choose a product or switching scheme.

4. Resolve Source Gaps

   Use the warnings to verify tariff basis, harmonic study needs, capacitor product data, NEC/AHJ requirements, protection, discharge, LOTO, and safe-work controls.

Built For

• Facility teams screening whether measured low PF deserves utility tariff review
• Electricians organizing kVAR prompts before product and code review
• Energy auditors documenting source gaps around demand charges and harmonics
• Plant engineers comparing fixed-bank and switched-bank review questions
• Maintenance teams identifying VFD/UPS/nonlinear-load concerns before capacitor discussions
• Project teams keeping capacitor, protection, tariff, AHJ, and safe-work assumptions visible

Features & Capabilities

Local kVAR Formula

Applies the steady-state displacement power triangle formula as a deterministic prompt only.

Local Size Rows

Shows nearby kVAR reference rows without treating them as manufacturer catalog sizes or orderable equipment.

Tariff Prompt

Shows a kVA-demand savings prompt when a rate is entered, while preserving tariff and billing-method gaps.

Harmonic Boundary

Flags unknown or nonlinear-load contexts that may require IEEE 519/PCC review and detuned or filtered equipment.

Capacitor Source Boundary

Keeps product rating, switching, fusing, discharge, protection, NEC/AHJ, utility, and safe-work gaps visible.

Report Export

Exports the local prompts, source pointers, assumptions, and residual gaps for qualified review.

Assumptions

• Power factor is treated as a positive lagging displacement PF from 0 to 1.
• Capacitor kVAR prompt uses Qcap = kW x (tan(theta1) - tan(theta2)), where theta = arccos(PF).
• Current prompts assume sinusoidal single-phase or balanced three-phase RMS values.
• Demand savings prompt assumes a simple kVA-demand basis and does not model the actual utility tariff.
• Local capacitor rows are reference prompts only and are not product, voltage, switching, or protection selections.

Limitations

• Does not perform IEEE 519 harmonic or resonance analysis.
• Does not select detuned reactors, filters, capacitor product ratings, contactors, fuses, conductors, disconnects, discharge resistors, or protection settings.
• Does not verify NEC Article 460, adopted code, local amendments, utility, AHJ, or inspection requirements.
• Does not model load cycling, minimum load, generator operation, voltage rise, switching transients, or leading-PF operation quantitatively.
• Does not replace NFPA 70E/OSHA safe-work controls, LOTO, stored-energy discharge verification, PPE, or qualified electrical review.

References

1. IEEE-1036-2020-SOURCE - shunt power capacitor application source pointer
2. IEEE-18-2025-SOURCE - shunt power capacitor equipment source pointer
3. IEEE-519-2022-SOURCE - harmonic control and PCC power-quality source pointer
4. IEEE-C37-99-2012-SOURCE - shunt capacitor bank protection source pointer
5. NEMA-CAPACITOR-PRODUCTS-2026-SOURCE - capacitor standards context
6. NFPA-70-2026 - NEC source pointer for capacitor installation context
7. NFPA-70E-2024-SOURCE and OSHA-1910-303-ELECTRICAL-SOURCE - safe-work and electrical requirements source pointers

Frequently Asked Questions