Power Quality Reference

Telephone influence factor (TIF)

Updated 2026-10-27

Data records

  • In IEEE 519-2022 the telephone influence factor of a voltage or current wave is the ratio of the root of the sum of the squares of the weighted rms values of all its sine wave components, fundamental and harmonics, to the unweighted rms of the whole wave, with a weighting that combines C-message weighting and a term proportional to frequency. Source: IEEE 519-2022, clause 3.1. Verified 2026-10-27. Record qty.telephone-influence-factor.ieee519.definition
  • IEEE 519-2022 defines the I-T product as the rms current multiplied by its telephone influence factor and the V-T product as the rms voltage multiplied by the factor, and Annex B gives I-T guidelines for distribution systems that are not recommended limits. Source: IEEE 519-2022, clause 3.1. Verified 2026-10-27. Record qty.telephone-influence-factor.ieee519.products
  • The telephone influence factor is a dimensionless quantity indicative of the waveform and not of its amplitude. Source: IEEE 519-2022, clause Annex B. Verified 2026-10-27. Record qty.telephone-influence-factor.ieee519.unit
  • The term is written Telephone influence factor (TIF). Value: Telephone influence factor (TIF). Source: Electrical Testing Reference editorial taxonomy, 2026-10 edition. Verified 2026-10-27. Record qty.telephone-influence-factor.title

Sources

  • Electrical Testing Reference editorial taxonomy, Electrical Testing Reference editorial taxonomy of test methods, 2026-10 edition, Electrical Testing Reference. Held as: Own observation.
  • IEEE 519-2022, Harmonic Control in Electric Power Systems, 2022 edition, IEEE. Cited: clause 3.1; clause Annex B. Held as: Purchased single-user copy. Publisher page for IEEE 519-2022Publisher information page

Obtaining the documents

Changelog (4 entries)
DateRevisionChange
2026-10-27created (qty.telephone-influence-factor.ieee519.definition)
2026-10-27created (qty.telephone-influence-factor.ieee519.products)
2026-10-27created (qty.telephone-influence-factor.ieee519.unit)
2026-10-27created (qty.telephone-influence-factor.title)

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Cite the governing standard for the fact itself; cite this page as the finding aid.

"Telephone influence factor (TIF)." Power Quality Reference. 2026-10-27. https://www.powerqualityreference.com/quantities/telephone-influence-factor/.