Power-quality measurement log calculator
Summarise entered voltage, current or harmonic measurement rows for Australian power-quality records.
minimumValue = min(rows); maximumValue = max(rows); averageValue = sum(rows) / rowCount; rowsAboveThreshold = rows where value > reviewThreshold- Rows are user-entered measurement values.
- Min, max and average are meaningful only when the row values are comparable.
- The threshold is entered by the user from project, report, equipment or engineering criteria.
| Variable | Meaning | Unit | Use |
|---|---|---|---|
| rows | Measurement rows | varies | User-entered measurement rows with timestamp, label, value and unit. |
| minimumValue | Minimum value | row unit | Smallest entered row value. |
| maximumValue | Maximum value | row unit | Largest entered row value. |
| averageValue | Average value | row unit | Arithmetic average of entered row values. |
| reviewThreshold | Review threshold | row unit | User-entered comparison value. |
| rowsAboveThreshold | Rows above threshold | count | Number of rows with value greater than the entered review threshold. |
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Power-quality measurement log calculator technical guide
Summarise entered voltage, current or harmonic measurement rows for Australian power-quality records.
Use this calculator when a short power-quality log needs a transparent summary before the record is reviewed. It turns entered rows into minimum, maximum, average and count above an entered threshold while keeping row labels and units visible.
This is not a replacement for a power-quality study. It is a record worksheet that can point to the next calculator or table when a row needs deeper treatment.
Measurement Log Inputs
| Field | Why it matters | Review note |
|---|---|---|
| Log reference | Names the site, analyser, feeder or record. | Keeps the summary tied to a source record. |
| Measurement rows | Carries timestamp, label, value and unit. | Use comparable rows before interpreting averages. |
| Review threshold | Provides the comparison value. | Must be entered by the user. |
| Threshold basis | Explains the comparison source. | Prevents a hidden-limit impression. |
The calculator does not infer instrument settings, event class, voltage quality category or network response. Those remain part of the source record and review process.
Result Interpretation
| Output | Meaning | Practical reading |
|---|---|---|
| Maximum value | Largest entered row value. | Main result for quick record review. |
| Minimum value | Smallest entered row value. | Shows the low point in the row set. |
| Average value | Arithmetic average of entered values. | Useful only when rows are comparable. |
| Rows above threshold | Count of rows over the entered threshold. | Points to rows needing closer review. |
If rows have mixed quantities or units, use the min, max and average cautiously. The row labels remain visible so the summary does not imply a single physical quantity when the log is mixed.
Boundary With Related Calculators
| Question | Correct owner | Input basis |
|---|---|---|
| What summary statistics follow from entered PQ rows? | Measurement log calculator | Timestamped rows with values and units. |
| What voltage sag percentage follows from an event row? | Voltage sag calculator | Pre-event and event voltage. |
| What TDD follows from current harmonics and demand current? | Harmonic current TDD calculator | Harmonic current RMS rows and demand current. |
| What fields belong in a power-quality record? | Power-quality measurement record table | Instrument, location and measurement context. |
Worked Records
| Situation | Inputs | Result pattern | Interpretation |
|---|---|---|---|
| Mixed PQ snapshot | Voltage, current and THD rows | Maximum 233.2, average 139.97 | Mixed units need careful interpretation. |
| Voltage-only below threshold | Three voltage rows | Maximum 231.1 | Below the entered 240 review value. |
| Current row review | Three feeder-current rows | Maximum 126 | One row above the entered 120 review value. |
Stop Points
- Rows with different units are being treated as one engineering quantity.
- The threshold has no stated project, equipment, report or engineering basis.
- The source instrument, measurement window or row labels are missing.
- A row needs a dedicated formula calculator rather than a basic summary.
- The summary is being used as event classification without wider power-quality review.
Mixed PQ snapshot
A short log carries voltage, current and THD rows from one analyser note.
- Reference
- PQ-LOG-01
- Rows
- 3
- Review threshold
- 200
- Threshold basis
- Project review threshold
- Minimum4.2
- Maximum233.2
- Average139.97
Largest entered row value in the measurement log.
The maximum row is above the entered threshold, so the mixed units and threshold source should be checked before interpreting the summary.
- Rows are user-entered values.
- The threshold is a record value.
- Mixed units require careful interpretation.
Voltage-only below threshold
Three voltage readings are summarised against a high review value.
- Reference
- PQ-VOLTAGE-LOG
- Rows
- 3
- Review threshold
- 240
- Threshold basis
- Project voltage review value
- Minimum229.8
- Maximum231.1
- Average230.43
Largest entered row value in the measurement log.
The maximum value stays below the entered threshold while still remaining a measurement-log summary.
- Rows use matching units.
- The review value is user-entered.
- Instrument context remains external.
Current row review
A compact current log highlights the largest row in a switchboard review note.
- Reference
- PQ-CURRENT-LOG
- Rows
- 3
- Review threshold
- 120
- Threshold basis
- Engineering review value
- Minimum112
- Maximum126
- Average119
Largest entered row value in the measurement log.
One current row is above the entered threshold and should be carried forward with the measurement context.
- Rows belong to one feeder record.
- Current values are RMS values.
- The summary does not replace load analysis.