Data record `tests.insulation-power-factor-dissipation-factor.ieeec57-12-90.no-standard-values`

Verified 2026-10-24 Confidence: Medium

Notes to Table 4 of IEEE C57.12.90-2021 explain why the code sets no standard insulation power-factor value for a liquid-immersed transformer: the quantity does not track dielectric withstand, its change with temperature is large and erratic, and it depends on the liquid and the materials used; the as-measured value is therefore reported together with the liquid temperature, the code advises against applying a temperature correction, and the factory reading becomes the baseline for later periodic comparisons.

Provenance. Where this record comes from and where it is used: the cited source, the record itself and the entry that cites it.

Provenance: the chain from source to entry.
Step	Item	Detail
Source	IEEE C57.12.90-2021	Licensed standard, clause Table 4, Notes 2 and 3
Data record	tests.insulation-power-factor-dissipation-factor.ieeec57-12-90.no-standard-values	Verified 2026-10-24
Entry	Insulation Power Factor Dissipation Factor	No revisions

Subject: Insulation Power Factor Dissipation Factor (Test methods)
Kind: Method fact
Source: IEEE C57.12.90-2021, clause Table 4, Notes 2 and 3, Test Code for Liquid-Immersed Distribution, Power and Regulating Transformers, IEEE.

History

Every recorded change to this data record, oldest first.
Date	Change
2026-10-24	created
2026-10-24	revised
2026-10-24	review_status unreviewed -> software_reviewed

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

"Data record tests.insulation-power-factor-dissipation-factor.ieeec57-12-90.no-standard-values." Electrical Testing Reference. 2026-10-24. https://www.electricaltestingreference.com/data/tests.insulation-power-factor-dissipation-factor.ieeec57-12-90.no-standard-values/.

Electrical Testing Reference, Data record tests.insulation-power-factor-dissipation-factor.ieeec57-12-90.no-standard-values (Oct. 24, 2026), https://www.electricaltestingreference.com/data/tests.insulation-power-factor-dissipation-factor.ieeec57-12-90.no-standard-values/.

@misc{etr-data-tests-insulation-power-factor-dissipation-factor-ieeec57-12-90-no-standard-values,
  title = {Data record tests.insulation-power-factor-dissipation-factor.ieeec57-12-90.no-standard-values},
  howpublished = {\url{https://www.electricaltestingreference.com/data/tests.insulation-power-factor-dissipation-factor.ieeec57-12-90.no-standard-values/}},
  organization = {Electrical Testing Reference},
  publisher = {Electrical Testing Reference},
  year = {2026},
  note = {last substantive change 2026-10-24}
}

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