Sag
Updated 2026-10-27
Data records
- IEEE 1159-2019 attributes voltage sags mainly to system faults, and also to the switching of heavy loads and the starting of large motors, whose starting current drops the voltage across the system impedance.
- In IEEE 1159-2019 a sag is a decrease of the rms voltage or current below the nominal range that lasts within the short-duration band of clause 3; its magnitude is stated as the remaining voltage, and the term is the North American synonym of the IEC term dip.
Sources
- IEEE 1159-2019, Recommended Practice for Monitoring Electric Power Quality, 2019 edition, IEEE. Cited: clause 4.4.2.2. 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 (2 entries)
| Date | Revision | Change |
|---|---|---|
| 2026-10-27 | created (gloss.sag.ieee1159.causes) | |
| 2026-10-27 | created (gloss.sag.ieee1159.definition) |
Cite this page
Cite the governing standard for the fact itself; cite this page as the finding aid.
"Sag." Power Quality Reference. 2026-10-27. https://www.powerqualityreference.com/glossary/sag/.
Power Quality Reference, Sag (Oct. 27, 2026), https://www.powerqualityreference.com/glossary/sag/.
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title = {Sag},
howpublished = {\url{https://www.powerqualityreference.com/glossary/sag/}},
organization = {Power Quality Reference},
publisher = {Power Quality Reference},
year = {2026},
note = {last substantive change 2026-10-27}
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