What the cabinet meter tells you about the drivers.
Learning Track · Module 4: Energy and carbon · Step 28 of 101
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Example: 1.9 kW ÷ 2.0 kVA = 0.95
- PF drops when lights dim. Normal for most drivers.
- PF drops slowly over months. Failing drivers or other loads.
- PF is leading. An old capacitor bank for discharge lamps overcompensates. Disconnect it.
Harmonic limits: Europe, Middle East: IEC 61000-3-2. South Asia: IEC 61000-3-2 (IS 14700-3-2). Some utilities charge for low power factor, so check it on the bill. USA: IEEE 519 at the service point, and driver THD limits in the specification (often 20% or less). Many poor drivers can push neutral current above phase current on three-phase circuits.
Sources
- IEC 61000-3-2 Limits for harmonic current emissions
- IEEE 519 Harmonic control in electric power systems
Changes: 30 October 2026: First publication: guides for Europe, the Middle East, South Asia, and the USA; failure library; tender clause library; comparisons; tools; downloads. See the changelog. Found a mistake? Report it.