IEEE Recommended Practice for Monitoring Electric Power Quality
Updated 2026-10-27
| Standard | Edition | Kind | Current | Record |
|---|---|---|---|---|
| IEEE Recommended Practice for Monitoring Electric Power Quality | 2019 | Approval | std.ieee-1159.approved | |
| IEEE Recommended Practice for Monitoring Electric Power Quality | 2019 | Edition | std.ieee-1159.edition.2019 | |
| IEEE Recommended Practice for Monitoring Electric Power Quality | 2019 | Revision of | std.ieee-1159.revision-of |
Data records
- The 2019 edition of IEEE 1159 was approved by the IEEE-SA Standards Board on 2019-06-13. Value: 2019.
- IEEE 1159-2019 is the designation of the document titled IEEE Recommended Practice for Monitoring Electric Power Quality. Value: IEEE 1159-2019.
- IEEE 1159-2019 is a recommended practice: clause 2 states that no normative references apply to it, every cited document is bibliographic, and nothing in it is a pass or fail criterion.
- IEEE 1159-2019 is the 2019 edition of the IEEE document titled IEEE Recommended Practice for Monitoring Electric Power Quality, published on 2019-08-13. Value: 2019.
- Clause 1.2 of IEEE 1159-2019 states the purpose as a consistent set of terms for power quality phenomena, an understanding of their effects, proper and safe measuring technique, and appropriate monitor location and interpretation, written for users as well as equipment and software makers.
- IEEE 1159-2019 is a revision of IEEE 1159-2009. Value: 2019.
- IEEE 1159-2019 covers the monitoring of electric power system characteristics on single-phase and polyphase ac systems, with consistent descriptions of conducted electromagnetic phenomena, definitions of nominal conditions and of deviations arising in the supply, in load equipment or in their interaction, and discussion of measurement, application and interpretation.
- IEEE 1159-2019 was developed by the Transmission and Distribution Committee of the IEEE Power and Energy Society, with the drafting done by its Power and Energy Working Group.
- Clause 4.3 of IEEE 1159-2019 explains the terms it adds to the IEC vocabulary: sag as the North American synonym of dip, swell as the inverse of sag, a long-duration variation category tied to the ANSI C84.1 ranges, a noise category for broadband conducted phenomena, and waveform distortion as a container for harmonics, interharmonics, dc in ac networks and notching.
- Annex A of IEEE 1159-2019, which is informative, covers calibration and self-testing: calibration requirements follow the objective rather than the instrument, drift rate, temperature coefficient, where to calibrate, calibration intervals, calibration points, the limits of built-in self-test, and a practical field check that links all channels to one disturbance.
- Annex B of IEEE 1159-2019 is an informative set of waveform figures showing typical transient characteristics, among them bipolar, oscillatory, dropout, arcing and repetitive notch waveforms.
- Annex C of IEEE 1159-2019 is an informative glossary drawn from the IEEE Standards Dictionary, with terms such as dropout, electromagnetic compatibility, harmonic, nonlinear load, power quality, sag, swell, transient, total demand distortion and voltage regulation.
- Annex D of IEEE 1159-2019 is the bibliography, and because the practice has no normative references every cited standard, including IEEE 519-2014, IEC 61000-4-30:2015 and ANSI C84.1-2016, is listed there.
- Clause 7 of IEEE 1159-2019 is the application method for a typical survey: safety under the NEC, NFPA 70E and OSHA rules, monitoring location, equipment connection by circuit type, measurement thresholds and the installation time frame.
- Clause 4.3 of IEEE 1159-2019 lists the attributes that describe a phenomenon: amplitude, frequency, spectrum, modulation, source impedance, notch depth and notch area for steady-state phenomena, and rate of rise, amplitude, duration, spectrum, frequency, rate of occurrence, energy potential and source impedance for non-steady-state phenomena.
- Clause 6.5.3.3 of IEEE 1159-2019 names IEEE 1159.3-2009 as the standardized power quality data interchange format and IEC 61850-90-17 as the means of exchanging power quality data between instruments and clients, and points to external frameworks for the security of transmitted data.
- Clause 7.4 of IEEE 1159-2019 covers equipment connection: polarity and phase matching for power measurement, connection to single-phase receptacles, single-phase panels, three-phase delta and three-phase wye circuits, lead attachment practice, the voltage modes to monitor for each equipment type, ground terminals, instrument power, sensing connection quality and the common errors with clamp-on current transformers.
- Clause 6.5.3.2 of IEEE 1159-2019 describes the acquisition stage of a power quality monitor: instrument transformers or transducers at the input, phase-locked-loop sampling, rms computation over fixed or sliding windows, separate high-speed capture for transients, trigger engines that decide what is stored, periodic trended data, and time synchronization by GPS, network time protocol or IRIG.
- Clause 3 of IEEE 1159-2019 defines flicker, the fundamental component, imbalance, impulsive transient, the duration modifiers instantaneous, momentary and temporary, interharmonic component, long-duration and short-duration rms variation, momentary, temporary and sustained interruption, noise floor, rms variation, total interharmonic distortion, voltage change, voltage fluctuation, voltage interruption and waveform distortion.
- Clause 4.2 of IEEE 1159-2019 adopts the electromagnetic compatibility approach of the IEC, as developed by IEC Technical Committee 77, to describe power quality phenomena.
- Clause 4.4.7 of IEEE 1159-2019 describes power frequency variations as deviations of the fundamental from nominal that follow the balance between load and generation, with large excursions caused by bulk system faults or the loss of a large load or generator, and with isolated generators the most exposed case.
- Table 1 of IEEE 1159-2019 reproduces the IEC 61000-2-5 grouping of electromagnetic phenomena into conducted low-frequency, radiated low-frequency, conducted high-frequency, radiated high-frequency, electrostatic discharge and nuclear electromagnetic pulse groups, with examples under each.
- Clause 4.4.4 of IEEE 1159-2019 prefers the negative to positive sequence ratio as the definition of imbalance, acknowledges that many instruments use the ANSI C84.1 maximum deviation from the average of phase-to-phase voltages, gives equations that compute the sequence ratio from phase-to-phase rms magnitudes alone where zero sequence is absent, and cautions the reader to check which definition a monitor uses.
- Clause 6.2 of IEEE 1159-2019 lists the documents to consult for monitor design: IEEE 519-2014, IEEE 1159.3-2009 for the PQDIF data interchange format, IEEE 1453-2015, IEEE 1564-2014 for sag indices, IEC 61000-4-7:2009, IEC 61000-4-15:2010, IEC 61000-4-30:2015 and IEC 61850-90-17.
- Clause 6.1 of IEEE 1159-2019 notes that the terms power quality analyzer, power disturbance analyzer, PQ meter, PQ monitor and revenue meter with PQ have been used interchangeably without formal definition, uses power quality monitor as its own term, and points to the PQM device function of IEEE C37.2.
- Clause 6.5 of IEEE 1159-2019 distinguishes four instrument types by capability: event indicators that compare against thresholds and count or display events, oscilloscopes and waveform recorders, power quality disturbance monitors with acquisition, database, communication and visualization stages, and other devices such as multifunction meters, revenue meters, protective relays, digital fault recorders and capacitor bank controllers whose primary function is not power quality.
- Clause 6 of IEEE 1159-2019 covers measurement instruments: the four generations of power quality monitors, portable versus permanently installed units, the parameters measured, the instrument types, and the pitfalls of instrument power supplies, data quality, dc power and safety.
- Clause 8 of IEEE 1159-2019 covers interpretation: validating the configuration and the plausibility of the data, preparing a chronological summary with the Table 6 columns, extracting critical events, a reference chart in Table 7 that maps problems to analysis subclauses, signature, waveshape, sag and swell, high-frequency, harmonic, pattern and discontinuity analysis, and post-monitoring verification.
- Clause 4.4.3 of IEEE 1159-2019 covers overvoltage, undervoltage and sustained interruption as rms deviations that outlast the short-duration category, attributes overvoltage and undervoltage to load variation and switching rather than faults, deprecates the term brownout, and separates sustained interruption from the reliability term outage.
- Clause 6.5.3.2 of IEEE 1159-2019 names IEC 61000-4-30:2015 as the document that defines the measurement methods and the interpretation of results for power quality parameters, so that monitors from different vendors report the same disturbance the same way, with IEEE 519 and IEC 61000-4-7 governing harmonic parameters and IEEE 1453-2015 and IEC 61000-4-15 governing flicker.
- Clause 7.3 of IEEE 1159-2019 places a monitor as close as possible to a symptomatic load, at the secondary of the service transformer for a facility-wide survey, and at the point of common coupling for an IEEE 519 comparison, and Table 3 maps the scope of a problem, one piece of equipment, one branch or the whole facility, to the recommended monitoring location.
- Clause 5 of IEEE 1159-2019 makes the monitoring objective the first decision of any project, since it determines the instrument, the data collection method, the triggering thresholds, the analysis technique and the effort, and excludes non-conducted factors such as temperature, humidity and radio frequency interference from the practice.
- Clause 7.5.7 of IEEE 1159-2019 sizes the monitoring period to a complete power period in which the usage pattern repeats, and distinguishes baseline monitoring before equipment is installed, problem solution monitoring that lasts days to weeks, and power supply monitoring that runs for years at multiple locations.
- Clause 6.6 of IEEE 1159-2019 warns that the power supply of an instrument can distort the measurement, lists missing, latched, out-of-range and extreme values as data quality errors, and sets considerations for dc powered instruments and for safety.
- Clause 4.4.2 of IEEE 1159-2019 covers interruptions, sags and swells, designates each as instantaneous, momentary or temporary by duration, attributes most of them to faults, large load energization and loose connections, and states the remaining voltage convention under which an unspecified sag magnitude means the voltage that remains.
- Table 2 of IEEE 1159-2019 is the categories table of power system electromagnetic phenomena: each row is a category or subcategory and the three data columns give the typical spectral content, the typical duration and the typical voltage magnitude, with a note that the terms are measurement terms distinct from the reliability terms of IEEE 1366-2012.
- The seven top-level categories of Table 2 of IEEE 1159-2019 are transients, short-duration rms variations, long-duration rms variations, imbalance, waveform distortion, voltage fluctuations and power frequency variations.
- Within Table 2 of IEEE 1159-2019, transients split into impulsive and oscillatory kinds, short-duration rms variations into instantaneous, momentary and temporary bands that each contain sag, swell and, beyond the shortest band, interruption and voltage imbalance, long-duration variations into sustained interruption, undervoltage, overvoltage and current overload, imbalance into voltage and current, and waveform distortion into dc offset, harmonics, interharmonics, notching and noise.
- Clause 7.5 of IEEE 1159-2019 explains that measurement thresholds decide what a monitor records, ties threshold selection to the survey objective and to equipment susceptibility curves such as ITIC and SEMI F47, offers Table 5 as suggested starting thresholds for one voltage class of load, and gives a stepwise procedure for settling the thresholds.
- Table 4 of IEEE 1159-2019 recommends voltage and current transducer types for each monitoring location, substation, overhead feeder, underground feeder, service entrance and inside the facility, with metering transformers preferred over relaying transformers to avoid system interaction.
- Clause 6.4 of IEEE 1159-2019 treats voltage and current as the primary measurements, explains why average-sensing and peak-sensing meters misread distorted waveforms, compares current transformer probes, Hall effect probes and shunts, lists accuracy, phase shift, overcurrent range and crest factor capability as the points for selecting a current transformer, and shows how a potential transformer with its cabling and the monitor input impedance forms a frequency response with resonances.
- Clause 4.4.1.3 of IEEE 1159-2019 adds the characteristics that help trace the source of a transient: its direction relative to the sine wave, and whether it is unipolar, bipolar, oscillatory, arcing, multiple zero crossing, periodic notching or a capacitor switching transient, together with a note on the difficulty of computing transient energy.
- Clause 4.4.1 of IEEE 1159-2019 classifies transients as impulsive or oscillatory by waveshape, deprecates the term surge for this purpose, subclassifies oscillatory transients by spectral content into low, medium and high frequency ranges chosen to match common causes such as capacitor bank energization, cable switching and local switching events, and distinguishes common-mode from normal-mode transients.
- Clause 4.4.6 of IEEE 1159-2019 separates voltage fluctuation, the electromagnetic phenomenon, from flicker, its effect on lighting, discourages the phrase voltage flicker, refers to IEC 61000-3-3 and IEEE 1453-2015 for the fluctuation types and their measurement, and names arc furnaces as the most common cause.
- Clause 4.4.5 of IEEE 1159-2019 describes five types of waveform distortion, dc offset, harmonics, interharmonics, notching and noise, adds voltage notching ringing as a resonant variant of notching, and refers to IEEE 519 for harmonic limits and for the total demand distortion measure.
- The licensed copy gives the full title of IEEE 1159-2019 as IEEE Recommended Practice for Monitoring Electric Power Quality. Value: IEEE Recommended Practice for Monitoring Electric Power Quality.
Elsewhere in the family
- Power quality analyzer related entry on Test Instrument Reference
- Electromagnetic compatibility (EMC) - Part 4-30: Testing and measurement techniques - Power quality measurement methods related entry on Test Instrument Reference
Sources
- IEEE 1159-2019, Recommended Practice for Monitoring Electric Power Quality, 2019 edition, IEEE. Cited: clause Front matter; clause 2; clause 1.2; clause 1.1; clause 4.3; clause Annex A; clause Annex B; clause Annex C; clause Annex D; clause 7; clause 6.5.3.3; clause 7.4; clause 6.5.3.2; clause 3; clause 4.2; clause 4.4.7; clause 4.4.4; clause 6.2; clause 6.1; clause 6.5; clause 6; clause 8; clause 4.4.3; clause 7.3; clause 5; clause 7.5.7; clause 6.6; clause 4.4.2; clause 4.4; clause 7.5; clause 7.3.6; clause 6.4; clause 4.4.1.3; clause 4.4.1; clause 4.4.6; clause 4.4.5. Held as: Purchased single-user copy. Publisher page for IEEE 1159-2019Publisher information page
Obtaining the documents
- IEEE 1159-2019: available from the publisher
Changelog (46 entries)
| Date | Revision | Change |
|---|---|---|
| 2026-10-27 | created (std.ieee-1159.approved) | |
| 2026-10-27 | created (std.ieee-1159.designation) | |
| 2026-10-27 | created (std.ieee-1159.document-type) | |
| 2026-10-27 | created (std.ieee-1159.edition.2019) | |
| 2026-10-27 | created (std.ieee-1159.purpose) | |
| 2026-10-27 | created (std.ieee-1159.revision-of) | |
| 2026-10-27 | created (std.ieee-1159.scope) | |
| 2026-10-27 | created (std.ieee-1159.sponsor) | |
| 2026-10-27 | created (std.ieee-1159.structure.added-terms) | |
| 2026-10-27 | created (std.ieee-1159.structure.annex-a) | |
| 2026-10-27 | created (std.ieee-1159.structure.annex-b) | |
| 2026-10-27 | created (std.ieee-1159.structure.annex-c) | |
| 2026-10-27 | created (std.ieee-1159.structure.annex-d) | |
| 2026-10-27 | created (std.ieee-1159.structure.application) | |
| 2026-10-27 | created (std.ieee-1159.structure.attributes) | |
| 2026-10-27 | created (std.ieee-1159.structure.communication) | |
| 2026-10-27 | created (std.ieee-1159.structure.connections) | |
| 2026-10-27 | created (std.ieee-1159.structure.data-acquisition) | |
| 2026-10-27 | created (std.ieee-1159.structure.definitions) | |
| 2026-10-27 | created (std.ieee-1159.structure.emc-approach) | |
| 2026-10-27 | created (std.ieee-1159.structure.frequency-variations) | |
| 2026-10-27 | created (std.ieee-1159.structure.iec-classification) | |
| 2026-10-27 | created (std.ieee-1159.structure.imbalance) | |
| 2026-10-27 | created (std.ieee-1159.structure.instrument-standards) | |
| 2026-10-27 | created (std.ieee-1159.structure.instrument-terms) | |
| 2026-10-27 | created (std.ieee-1159.structure.instrument-types) | |
| 2026-10-27 | created (std.ieee-1159.structure.instruments) | |
| 2026-10-27 | created (std.ieee-1159.structure.interpretation) | |
| 2026-10-27 | created (std.ieee-1159.structure.long-duration) | |
| 2026-10-27 | created (std.ieee-1159.structure.measurement-methods) | |
| 2026-10-27 | created (std.ieee-1159.structure.monitoring-location) | |
| 2026-10-27 | created (std.ieee-1159.structure.monitoring-objectives) | |
| 2026-10-27 | created (std.ieee-1159.structure.monitoring-period) | |
| 2026-10-27 | created (std.ieee-1159.structure.pitfalls) | |
| 2026-10-27 | created (std.ieee-1159.structure.short-duration) | |
| 2026-10-27 | created (std.ieee-1159.structure.table-2) | |
| 2026-10-27 | created (std.ieee-1159.structure.table-2-categories) | |
| 2026-10-27 | created (std.ieee-1159.structure.table-2-subcategories) | |
| 2026-10-27 | created (std.ieee-1159.structure.thresholds) | |
| 2026-10-27 | created (std.ieee-1159.structure.transducer-recommendations) | |
| 2026-10-27 | created (std.ieee-1159.structure.transducers) | |
| 2026-10-27 | created (std.ieee-1159.structure.transient-characteristics) | |
| 2026-10-27 | created (std.ieee-1159.structure.transients) | |
| 2026-10-27 | created (std.ieee-1159.structure.voltage-fluctuations) | |
| 2026-10-27 | created (std.ieee-1159.structure.waveform-distortion) | |
| 2026-10-27 | created (std.ieee-1159.title) |
Cite this page
Cite the governing standard for the fact itself; cite this page as the finding aid.
"IEEE Recommended Practice for Monitoring Electric Power Quality." Power Quality Reference. 2026-10-27. https://www.powerqualityreference.com/standards/ieee-1159/.
Power Quality Reference, IEEE Recommended Practice for Monitoring Electric Power Quality (Oct. 27, 2026), https://www.powerqualityreference.com/standards/ieee-1159/.
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title = {IEEE Recommended Practice for Monitoring Electric Power Quality},
howpublished = {\url{https://www.powerqualityreference.com/standards/ieee-1159/}},
organization = {Power Quality Reference},
publisher = {Power Quality Reference},
year = {2026},
note = {last substantive change 2026-10-27}
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