Power factor relates real power in kW to apparent power in kVA. A local power-triangle calculation can estimate the reactive kVAR change associated with moving from one lagging displacement PF to another, but that arithmetic is only one part of a power-factor correction decision.
Before a capacitor bank is purchased or installed, the measured PF basis, utility tariff, billing interval, harmonic profile, nonlinear-load mix, minimum load, selected capacitor equipment, switching/protection, adopted NEC edition, AHJ/utility requirements, and qualified electrical review all need to be resolved.
The Local Power-Triangle Prompt
Real power (kW), reactive power (kVAR), and apparent power (kVA) form a useful steady-state triangle for sinusoidal displacement-power-factor screens. The common prompt is Qcap = kW x (tan(theta1) - tan(theta2)), where theta is arccos(PF).
This formula does not prove the selected target, bank location, equipment size, utility savings, harmonic behavior, or installation compliance. Use it as an arithmetic fixture beside measured kW/kVA/kVAR data and source warnings.
Power Factor Correction Calculator
Calculate capacitor bank sizing for power factor correction with cost savings analysis.
Utility Tariff Review
Power-factor billing can be based on kVA demand, kVAR charges, PF multipliers, meter interval data, ratchets, service class, and local riders. A flat $/kVA prompt can help frame a conversation, but it is not a bill model.
Use the actual utility tariff, recent interval data, and utility requirements before claiming savings or penalty avoidance. The same measured PF can have different financial impact depending on the metering and billing basis.
Harmonics and Load Profile
VFDs, UPS systems, LED drivers, rectifiers, welders, and other nonlinear loads can create harmonic conditions where simple fixed capacitors are inappropriate. Capacitors can resonate with system inductance, amplify distortion, or require detuned reactors or harmonic filters.
Minimum load matters as much as peak load. A fixed bank that looks reasonable at one operating point can drive leading PF during light-load periods. Switched banks add controls, stages, contactors, protection, maintenance, and commissioning requirements.
Equipment, Protection, and Code
Actual capacitor-bank work depends on voltage rating, kVAR tolerance, enclosure, environment, switching duty, short-circuit rating, fusing, conductors, disconnects, discharge resistors, controls, protection, grounding, and manufacturer instructions.
NEC Article 460, local amendments, utility requirements, AHJ review, coordination, arc-flash and shock controls, LOTO, stored-energy discharge verification, PPE, and qualified electrical engineering review remain outside the calculator.