Power quality monitoring is useful when you need evidence: what happened, when it happened, and whether it’s coming from inside your facility or from the supply side.
Symptoms that often justify monitoring
Consider monitoring when you see patterns like:
- Nuisance trips or unexplained protection operations
- Process interruptions, PLC resets, drive faults, or UPS events
- Equipment alarms that correlate with external events (weather, switching, grid disturbances)
- Persistent overheating or abnormal behaviour where harmonics/unbalance are suspected
“We think it’s power quality” isn’t a diagnosis — monitoring is how you turn it into one.
What monitoring can (and can’t) do
Monitoring can help you:
- Capture events (dips, swells, interruptions, transients) with time correlation
- Quantify steady-state issues (harmonics, unbalance, flicker)
- Separate symptoms from causes by matching electrical events to equipment logs
Monitoring can’t:
- Fix the issue by itself
- Replace basic electrical checks (connections, loading, equipment condition)
How to frame the question (so you get a useful result)
Good investigations start with clarity:
- What equipment is affected (and what is not)?
- What does “failure” look like (trip, reset, alarm, degraded performance)?
- Is the issue random, daily, seasonal, or linked to a process cycle?
- What logs exist already (UPS, generators, drives, BMS/SCADA)?
Where monitoring is usually placed
Placement depends on the hypothesis, but common points include:
- Incoming supply / point of common coupling (to align with external disturbances)
- Critical distribution boards feeding sensitive loads
- Specific problem circuits where local issues are suspected
In data centres, this often needs to align with change control and operational constraints (see Data Centre Electrical).
Common questions
How long should we monitor?
Long enough to capture the event pattern you’re chasing. If events are rare, short monitoring windows may miss them; if events are frequent, shorter monitoring can still be very informative.
Do we need permanent monitoring?
Not always. Temporary monitoring can be enough to confirm whether a hypothesis is correct, after which you can decide whether permanent instrumentation is justified.
Can monitoring prove “it’s the utility’s fault”?
Sometimes you can correlate events with supply-side disturbances, but conclusions depend on measurement location, data quality, and what else is happening on-site. Treat it as evidence-building, not blame assignment.
Related guides
- Service overview: Power Quality Monitoring.
- If you’re defining commissioning scope: What “Commissioning” Means.
- For data centre context: Data Centre Electrical.
- Request a quote: Contact.
Disclaimer: This guide is informational only. Power quality investigation and HV work should be performed by qualified professionals under site rules and applicable standards.