Power Factor Correction Calculator
Steady-State kVAR Prompt With Tariff, Harmonic, Equipment, NEC, and Safe-Work Gaps
Use this source-aware power factor screen to organize measured kW, current PF, target PF, voltage, phase, and a local demand-rate prompt. The app applies the steady-state power triangle formula for kVAR, kVA, current, and local capacitor-size reference rows while keeping the unresolved source work visible.
The output is not a capacitor-bank design, manufacturer selection, utility tariff ruling, IEEE 519 harmonic study, NEC Article 460 installation design, protection study, permit drawing, or safe-to-energize instruction. Verify measured data, utility billing method, nonlinear-load/harmonic context, product catalog, switching/protection, adopted code, AHJ, and qualified electrical review before using any result for a purchase or installation decision.
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Power Factor Source Guide →How It Works
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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.
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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.
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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.
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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
- IEEE-1036-2020-SOURCE - shunt power capacitor application source pointer
- IEEE-18-2025-SOURCE - shunt power capacitor equipment source pointer
- IEEE-519-2022-SOURCE - harmonic control and PCC power-quality source pointer
- IEEE-C37-99-2012-SOURCE - shunt capacitor bank protection source pointer
- NEMA-CAPACITOR-PRODUCTS-2026-SOURCE - capacitor standards context
- NFPA-70-2026 - NEC source pointer for capacitor installation context
- NFPA-70E-2024-SOURCE and OSHA-1910-303-ELECTRICAL-SOURCE - safe-work and electrical requirements source pointers
Frequently Asked Questions
Learn More
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