Power Factor and cosφ

What is power factor

cosφ = active power / total power. For motors and transformers it is 0.7-0.9; for LED with good drivers — 0.9+.

Why it matters

A low cosφ loads the network with reactive power: losses in lines, voltage drops, transformer overload — and the supplier charges for reactive power.

How to fix

Capacitor banks (PFC) with automatic controllers raise cosφ to 0.95+. For small objects — a single compensation at the input.

Where cosφ is measured

At the input metering node; the supplier's invoice includes reactive energy if the cosφ is below the contract value.

Practical numbers

cosφ 0.8 → 0.95 reduces the current by about 16% for the same useful power — the line and the transformer free up.

GorkyCAD

Counts the total cosφ of the project and shows where compensation is needed.