Mill Utilities
Correction removes no kilowatts. It removes the kVA the tariff bills you for.
— kVAr
From the tangent difference at the stated active load
The calculation assumes a single representative operating point. Real plant load varies through the shift and across the week, so a bank sized from a peak reading over-corrects at light load - use automatic switched stages and size each from a load profile rather than a single measurement. Harmonic distortion is not modelled and is the main practical risk in a mill with many variable frequency drives: a plain bank can amplify harmonics or resonate with the supply, and a detuned bank costs more per kVAr than the figure entered here. The loss reduction applies only to the distribution between the metering point and the load, not to losses inside the motors. Tariff structures vary widely; confirm whether the charge is on peak kVA, on kVArh, or as an energy surcharge before trusting the saving.
Power Factor Correction kVAr Sizing, Demand Saving & Payback — free, with the formula and a worked example, at Textile School.