A power quality audit measures how clean and stable a facility's supply is — harmonics, voltage sags and swells, flicker, unbalance and power factor — over a representative period. The results explain nuisance trips, overheating and equipment failures, and show whether filters, correction or protection changes are needed.
Key Takeaways
- Measure over a representative operating period, not a snapshot.
- Compare results with the applicable limits at the right point.
- Harmonics, sags and unbalance each have different causes and fixes.
- Findings should feed studies, not just a report.
What Is Measured
Harmonic distortion of voltage and current, voltage sags, swells and interruptions, flicker, unbalance and power factor. We measure with a Fluke 435-II analyser and report against EN 50160 and the applicable requirements.
Where to Measure
At the point of supply and at key distribution points — so internal sources can be distinguished from disturbances arriving from the network.
Reading the Results
High current harmonics usually point to non-linear loads such as drives and rectifiers; voltage sags often originate in the network or in large motor starts; unbalance indicates uneven single-phase loading.
From Audit to Action
Where problems are found, harmonic analysis and filter design, protection review or motor starting studies define the correction.
Repeat to Verify
A follow-up measurement after changes confirms the improvement.
Frequently Asked Questions
How long should measurements run?
Long enough to cover normal operating cycles — typically at least a week for a survey against EN 50160.
Will a capacitor bank fix harmonics?
Not necessarily — it can make resonance worse. Filter design should follow a harmonic study.
