Monitoring and Investigation in One Record
When equipment trips without explanation, most facilities call for a power quality survey: an engineer connects a portable analyzer, records for a few weeks, and hopes the problem repeats with the triggers set to catch it. The survey exists because the meter in the switchgear or switchboard keeps only summaries and short windows around its triggers, so the waveform of the trip is gone. A permanent Continuous Point-on-Wave (CPOW) installation brings the two together: it stays in place like the meter, records in more detail than the survey by keeping every waveform, and so has the trip on record before anyone asks about it.
Side by Side
| Portable analyzer | Installed power quality meter | CPOW with edge analysis | |
|---|---|---|---|
| Installation | Temporary, for up to a month | Permanent | Permanent |
| Between events | Logs RMS summaries at set intervals | Logs RMS summaries at set intervals | Records every sample of every channel |
| Waveforms | Captures short windows around triggers | Captures short windows around triggers | Records all of them |
| A disturbance below the threshold | Logs a summary value, no waveform | Logs a summary value, no waveform | Records it in full |
| A question nobody asked in advance | Answers only from what it captured | Answers only from what it captured | Answers from the full record |
| Analysis | A specialist works through the data after the survey | Vendor software generates reports and alarms | Runs at the edge as data arrives; AI-guided diagnosis cites the waveform |
| When a problem appears | An engineer connects it and waits for a repeat | Raises an alarm and logs a summary | Already holds the waveform from before, during, and after |
Thirty Days of Survey, No Waveform
In a commercial building with recurring blown elevator fuses, standard power quality instruments ran for 30 days. Statistically binning their interval averages of power and current against elevator activity narrowed the cause to elevator operation. Averages, however, cannot show the inrush currents themselves or how they lined up in time, and no waveform was recorded at the moments the fuses opened, so the cause stayed an inference. A permanent continuous record would have held every elevator start, including the ones that blew fuses, with each inrush and its timing in view.
What a Permanent Record Changes
- Every trip is on record. The record covers every cycle of every week, including the week the problem happened, so nobody waits for a repeat.
- History answers new questions. Engineers query months of waveforms instead of scheduling another site visit.
- Reports come from the record, even after the fact. Summaries, alarms, and IEEE 519, SEMI F47, and ITIC metrics are computed from the same record, for any period already recorded, and each result links to the waveform behind it.
- One installation does both jobs. There is no survey equipment to rent, schedule, or move, and no gap between the meter’s alarm and an analyzer’s arrival.
Where a contract or tariff names a certified IEC 61000-4-30 Class A instrument, that instrument remains the reference for the measurement it certifies. Installed beside it, the CPOW record holds the waveforms behind what it reports.
Where to Start
Install on the circuits that cost the most when they misbehave: feeders to sensitive production equipment, the UPS and transfer path, and loads that trip without explanation.
The CPOW primer explains how continuous capture works and what to ask of any recorder; the power quality primer covers the disturbances themselves and what they cost.
Go Back to Any Moment in the Control Room
Work with a live continuous waveform record from our lab, and open any cycle it holds.