HROUS Define the event before requesting quotes
Before approving a filter, capacitor bank, UPS or other remedy, scope event-capable monitoring to record voltage and current behaviour at the affected load and correlate it with equipment alarms.[2][5]
Describe whether the incident is a breaker or drive trip, PLC or control-panel reset, machine lockout, momentary loss of control power or a fault that clears before maintenance arrives.[2][4][5]
For each incident, provide the best-available time, affected equipment and circuit, alarm or fault code, operating load, process stage and shift. Note machine starts and stops, compressor or welding cycles, capacitor switching, production changes and conditions in which the fault does not occur.[2][3][4][5]
Treat voltage events, abnormal current, harmonics, poor connections, neutral problems, equipment faults and external network disturbances as possibilities to test—not diagnoses inferred from the symptom.[2][3][5]
Specify an event-capable measurement package
The scope should capture phase-to-phase and phase-to-neutral voltage; phase current and relevant neutral current; frequency; real, reactive and apparent power; power factor and displacement power factor; demand trends; voltage and current harmonics; and total harmonic distortion.[2]
Require event detection for dips, swells, interruptions and transients, not only averaged trends. Each event record should retain start and end times, minimum or maximum voltage by phase, depth, duration and a waveform or high-speed record where available.[2][5] A spot-reading multimeter or non-logging panel meter may miss a short disturbance.[2][5]
- Breaker or drive trips: request RMS, peak and inrush current, including current immediately before, during and after the trip. Retain synchronised voltage and current waveforms where available.[5]
- Harmonic investigations: record voltage and current harmonics together and retain relevant individual orders, rather than reporting only total harmonic distortion. Current harmonics can indicate possible sources, while voltage harmonics show their effect at the recording point.[2]
- Event correlation: match captured events with the corresponding drive, PLC or equipment alarm.[2][5]
Depth and duration must be considered together. Prosense contrasts a dip to 85% of nominal for several cycles with a dip to 40% for half a second because equipment ride-through sensitivity differs.[2]
Choose the first recording point
Start where the symptoms are concentrated rather than automatically recording at the main switchboard:
- One machine or drive: start near that load or on its supplying circuit.
- Several machines in one area: start at the area distribution board.
- Simultaneous disturbances across multiple buildings: include the incoming supply.[2]
Add a synchronised upstream recorder when the investigation must determine where the disturbance originated. One downstream instrument may confirm a voltage event but may not distinguish a local distribution problem from an upstream or supply-side event.[2]
A dip of similar depth and duration at the incomer and affected load directs investigation towards supply records, upstream switching or large upstream or site loads. A mild upstream event but severe downstream event directs attention to local starts, cable impedance, transformer loading, conductor size and terminations.[2]
Use the same clock reference for both instruments where practical. Even a few seconds of mismatch can obstruct comparison during rapid starts and stops.[2]
Correlate measurements with plant events
Align logger timestamps with drive histories, PLC records, operator logs, production changes and downtime records.[2]
Fictional event log: a machine start is recorded, followed on the same clock by a downstream voltage dip to 85% of nominal for several cycles, a rise in the current waveform and a drive undervoltage alarm. This establishes a correlation requiring investigation—not proof that the machine start caused the dip.[2]
Sequence matters. A disturbance before a trip may have contributed to it; one recorded afterwards may be a consequence. A motor fault can produce a current surge and voltage reduction, while a supply dip can trip a drive and unload it.[2]
Other patterns can direct follow-up checks:
- A disproportionately affected phase points towards phase loading, loose connections, single-phase loads or supply unbalance.[2]
- Normal voltage with a pre-trip current spike points towards the equipment, drive settings, motor condition or mechanical load.[2]
- An event coincident with capacitor switching warrants checks of capacitor banks, detuning reactors and transient effects.[2]
Require findings, limitations and next tests
Specify a report covering the symptom investigated, recording locations, operating conditions, instrument configuration and whether a representative event was captured.
The event register should show aligned timestamps, event type, affected phases, depth and duration, voltage and current behaviour, waveform references and matching equipment alarms.[2][5] Its analysis should separate:
- Observed facts: what the instruments and plant records captured.
- Correlations: events occurring at aligned or approximately aligned times.
- Likely explanations: interpretations supported by the available evidence.
- Supported origins: conclusions backed by comparative measurements or further testing.
The report should disclose missing alarms, clock uncertainty, excluded data, uncaptured operating states, instrument constraints and any failure to reproduce the trip. A downstream record may establish what the equipment experienced without proving where the disturbance began.[2]
Recommended next steps should be prioritised by the findings. They may include checks of terminations, fuses, contactors, cable joints, neutral conductors, load current, insulation, torque or thermal condition, subject to site rules.[2]
Compare Fluke, Electrocorder and SATEC
Compare instruments against the required evidence, recording location and report outputs—not the brand name alone.
Fluke
Recorded scope: Fluke describes the VR1710 as recording RMS average, transients, flicker and harmonics. The 1760 supports correlation of multiple events and Class-A verification.[1]
Investigation use: Fluke groups recorders as detailed-event tools, energy loggers as three-phase energy and load-study tools, and analysers as power-quality troubleshooting, logging and reporting tools. Analysis software is included with the listed power-quality and energy-analysis tools.[1]
Selection limit: The exact current-channel configuration, neutral-current capability, accuracy, calibration status, triggers, memory and export formats remain to be confirmed for the selected model.[1]
Electrocorder
Recorded scope: The EC-7VAR-RS measures three-phase voltage, current, power factor and energy. The EC-3V and compact SL-3V record three-phase voltage, while the EC-2V records single-phase voltage.[4]
Investigation use: Electrocorder positions the EC-7VAR-RS for combined supply-voltage and machine-load investigations. Its voltage-only models suit narrower scopes where current and load behaviour are not required.[4]
Selection limit: Waveform capture, trigger settings, sampling, memory, calibration, Australian support and report outputs remain to be confirmed.[4]
SATEC
Recorded scope: SATEC says its analysers and Expertpower software support event logging, waveform and harmonic analysis, trends and visualisation. Listed parameters include THD, TDD, K-Factor and crest factor.[3]
Investigation use: The combination is positioned for event records, trends and visualisation. SATEC’s NMI-approved meters with NITP-14 test-verification certification address billing-grade measurement; SATEC does not state this is necessary for an ordinary trip investigation.[3]
Selection limit: The selected hardware, portable or fixed deployment, accuracy, triggers, memory, calibration and exported deliverables remain to be confirmed.[3]
These capabilities are vendor-reported. The cited pages provide no independent evidence that any named product will resolve a particular facility disturbance.[1][3][4]
Apply an evidence gate before approving a remedy
Monitoring and remediation are separate decisions: recording identifies the conditions, while corrective equipment should address the measured mechanism.[2]
Use three approval questions:
- What measured mechanism does the proposal identify, and which events, waveforms or trends support it?
- How does the proposed equipment address that mechanism?
- What post-installation measurement will verify its performance?
A harmonic filter addresses distortion, while reactive-power equipment addresses changing kvar demand. A UPS or ride-through system targets continuity for sensitive loads. These functions are not interchangeable.[2]
Scrutinise capacitor-based power-factor correction proposals. Measured harmonic content and resonance risk should be reviewed because standard capacitors in a distorted system may be associated with overheating, blown fuses or repeated switching faults.[2]
Compare hardware with supported operational or maintenance responses, including changing start sequences or acceleration ramps, relocating a sensitive control supply, repairing poor terminations or balancing phases.[2]
Issue a quote-ready investigation scope
Ask the electrical specialist to price:
- Monitoring of the stated symptoms and affected assets, including phase voltages, relevant current channels, power, harmonics and triggered event records.[2][5]
- The first recording point and, where source attribution matters, an optional synchronised upstream point.[2]
- A monitoring window covering representative loads, starts, shifts and switching conditions, with clock alignment to equipment alarms, PLC histories and operator records.[2]
- Event files, raw data and a report separating observations, correlations, likely explanations, limitations and recommended follow-up work.
- The instrument, channel configuration, installation method, calibration status, exclusions and total quoted price.
What to confirm with each provider
The cited pages publish technical details, including three-phase voltage, current, power factor and energy and around 10 days’ recording at two-minute averaging, but do not publish the commercial and service details needed to compare Australian proposals.[1][3][4]
- Australian availability, service area and personnel qualifications;
- price, GST treatment, installation charges and report fees;
- minimum monitoring period and availability;
- accuracy, calibration traceability, sampling, trigger settings and memory;
- channel configuration, neutral-current capability and waveform capture;
- raw-data format, report exports, data ownership and excluded periods; and
- contract duration, payment schedule, cancellation, rescheduling, warranty and service terms.
Prosense advises that qualified personnel install monitoring under site isolation and safety procedures, using fixed meters and current transformers suited to the installation.[2] The practitioner should also confirm the Australian standards and site rules applicable to the work.
References
- Power Quality Analysis and Measurement: Analysers, Meters, Recorders, Loggers | Fluke (fluke.com)
- Industrial Power Quality Monitoring for Troubleshooting Voltage Events and Harmonics (prosense.com.au)
- How To Diagnose Nuisance Tripping In Electrical Systems – SATEC (Australia) Pty Ltd (satec-global.com.au)
- Machines Tripping or Resetting – Electrocorder (electrocorder.com)
- How to Use a Power Quality Analyzer to Troubleshoot Equipment Trips – Lakeland Engineering (lakelandengineering.com, 2026)
