Electrical Testing Reference

IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery

Review status: Agent reviewed

First published
Not yet published
Last reviewed
Not yet reviewed
Last substantive change
2026-10-13
Revision
1
Editor of record
Editor of record not yet appointed
Reviewing engineer
Not yet engineer-reviewed

IEEE 43-2013 is the IEEE recommended practice for testing the insulation resistance of electric machinery, published under the full title IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery. [1] [2] It describes direct-voltage procedures for measuring the insulation resistance and polarization index of stator and rotor windings and explains how the results are interpreted. [3] The IEEE catalog lists the 2013 edition as an inactive-reserved standard. [4]

Scope

The publisher's catalog describes the document as covering direct-voltage procedures for insulation resistance and polarization index measurements on stator and rotor windings, together with the interpretation of the results. [3] Within the text, the scope reaches the armature and field windings of synchronous machines, induction machines, direct-current machines and synchronous condensers, and leaves out fractional-horsepower machines. [5] The stated purposes are to define the two tests, to name the factors that affect the readings, to recommend uniform test conditions and to give a basis for interpreting results. [6]

Edition history

The 2013 edition is a revision of IEEE 43-2000. [7] It was approved on December 11, 2013 and published on March 6, 2014. [8] [2] The document was sponsored by the Electric Machinery Committee of the IEEE Power and Energy Society. [9]

Status

The IEEE catalog lists IEEE 43-2013 with the status Inactive-Reserved Standard and records March 21, 2024 as its inactivation date. [4]

Structure

Clause 4 of IEEE 43-2013 deals with safety, and clause 5 sets out the insulation resistance and polarization index test procedures, including the choice of test voltage. [10] [11] Clause 6 treats the factors that influence the readings, such as surface condition, moisture, temperature and test voltage. [12] Clause 7 covers the conditions recorded at the time of test, clause 8 the winding connections, and clause 9 the measuring instruments and methods. [13] [14] Clause 10 covers the application of the test voltage, including allowance for the drop across a protective resistor. [15]

Clause 11 addresses the interpretation of results, and clause 12 gives recommended minimum values for insulation resistance and polarization index. [16] [17] [18] An informative annex, Annex A, describes variants of the polarization index based on shorter reading times. [19] [20]

Related tests

The recommended practice is the method reference for the insulation resistance test and for the polarization index of rotating machine windings. [21] [22] The dielectric absorption ratio used for rotating machinery in ANSI/NETA ATS-2025 corresponds to one of its informative variants. [23] [24]

Notes

  1. IEEE 43-2013. The publisher catalog gives the full title of IEEE 43-2013 as IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery.Value: IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery. Datum std.ieee-43.title
  2. IEEE 43-2013. IEEE 43-2013 is the 2013 edition of the IEEE document titled IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery, published on 2014-03-06.Value: 2013. Datum std.ieee-43.edition.2013
  3. IEEE 43-2013. The recommended practice describes direct-voltage procedures for measuring the insulation resistance and polarization index of stator and rotor windings and explains how to interpret the results. Datum std.ieee-43.scope
  4. IEEE 43-2013. The IEEE catalog lists IEEE 43-2013 with the status Inactive-Reserved Standard, with an inactivation date of 2024-03-21.Value: Inactive-Reserved Standard. Datum std.ieee-43.status
  5. IEEE 43-2013, clause 1.1. IEEE 43-2013 covers the armature and field windings of rotating machines, among them synchronous machines, induction machines, direct-current machines and synchronous condensers, and leaves fractional-horsepower machines out of its scope. Datum tests.insulation-resistance.scope-machines
  6. IEEE 43-2013, clause 1.2. IEEE 43-2013 states that it sets out to define the insulation resistance and polarization index tests, identify the factors that change the readings, recommend uniform test conditions and give a basis for interpreting the results. Datum tests.insulation-resistance.purpose-ieee43
  7. IEEE 43-2013, clause Front matter. IEEE 43-2013 is a revision of IEEE 43-2000.Value: 2013. Datum std.ieee-43.revision-of
  8. IEEE 43-2013, clause Front matter. The 2013 edition of IEEE 43 was approved on 2013-12-11.Value: 2013. Datum std.ieee-43.approved
  9. IEEE 43-2013, clause Front matter. IEEE 43-2013 was sponsored by the Electric Machinery Committee of the IEEE Power and Energy Society. Datum std.ieee-43.sponsor
  10. IEEE 43-2013, clause 4. Clause 4 of IEEE 43-2013 deals with safety during insulation resistance testing. Datum std.ieee-43.structure.safety
  11. IEEE 43-2013, clause 5. Clause 5 of IEEE 43-2013 sets out the insulation resistance and polarization index test procedures and the choice of test voltage. Datum std.ieee-43.structure.procedure
  12. IEEE 43-2013, clause 6. Clause 6 of IEEE 43-2013 covers the factors that affect insulation resistance readings, among them surface condition, moisture, temperature and test voltage. Datum std.ieee-43.structure.factors
  13. IEEE 43-2013, clause 7, 8. Clause 7 of IEEE 43-2013 covers the conditions recorded at the time of test, and clause 8 covers the winding connections used for the test. Datum std.ieee-43.structure.conditions
  14. IEEE 43-2013, clause 9. Clause 9 of IEEE 43-2013 describes the instruments and methods for measuring insulation resistance. Datum std.ieee-43.structure.instruments
  15. IEEE 43-2013, clause 10. Clause 10 of IEEE 43-2013 covers how the test voltage is applied and held, including allowance for the drop across a protective resistor. Datum std.ieee-43.structure.voltage-application
  16. IEEE 43-2013, clause 11, 12. Clause 11 of IEEE 43-2013 covers the interpretation of test results, and clause 12 gives recommended minimum values. Datum std.ieee-43.structure.interpretation
  17. IEEE 43-2013, clause 12.2, Table 3. Clause 12.2 of IEEE 43-2013 recommends minimum polarization index values that depend on the thermal class of the insulation. Datum tests.polarization-index-and-dielectric-absorption.minimum-shape
  18. IEEE 43-2013, clause 12.3, Table 4. Clause 12.3 of IEEE 43-2013 recommends minimum one-minute insulation resistance values that depend on the type and construction of the winding and apply to the whole winding after correction to the reference temperature. Datum tests.insulation-resistance.minimum-values-shape
  19. IEEE 43-2013, clause Annex A. Annex A of IEEE 43-2013 is informative and describes variants of the polarization index. Datum std.ieee-43.structure.annex-a
  20. IEEE 43-2013, clause Annex A. Annex A of IEEE 43-2013 describes variants of the polarization index built on shorter reading times and states that no agreed pass or fail criteria exist for them. Datum tests.polarization-index-and-dielectric-absorption.annex-variants
  21. IEEE 43-2013, clause 11.2. Insulation Resistance is addressed in IEEE 43-2013. Datum tests.insulation-resistance.governed-by.ieee-43(provenance pending)
  22. IEEE 43-2013, clause 5.4. IEEE 43-2013 defines the polarization index as the insulation resistance read after ten minutes of applied voltage divided by the insulation resistance read after one minute. Datum tests.polarization-index-and-dielectric-absorption.pi-definition
  23. ANSI/NETA ATS-2025, clause 7.15.1.B.2. ANSI/NETA ATS-2025 uses a dielectric absorption ratio for rotating machinery, a measure that IEEE 43-2013 describes only as an informative variant. Datum tests.polarization-index-and-dielectric-absorption.ats-dar
  24. IEEE 43-2013, clause A.1. One variant in Annex A of IEEE 43-2013 divides the one-minute insulation resistance by a reading taken thirty seconds after the voltage is applied.Value: 30 s. Datum tests.polarization-index-and-dielectric-absorption.dar-thirty-second

Data records

  • The 2013 edition of IEEE 43 was approved on 2013-12-11. Value: 2013. Source: IEEE 43-2013, clause Front matter. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.approved
  • IEEE 43-2013 is the designation of the document titled IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery. Value: IEEE 43-2013. Source: IEEE 43-2013. Verified 2026-10-13. Review status: Unreviewed. Provenance pending. Record std.ieee-43.designation
  • IEEE 43-2013 is the 2013 edition of the IEEE document titled IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery, published on 2014-03-06. Value: 2013. Source: IEEE 43-2013. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.edition.2013
  • IEEE 43-2013 is a revision of IEEE 43-2000. Value: 2013. Source: IEEE 43-2013, clause Front matter. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.revision-of
  • The recommended practice describes direct-voltage procedures for measuring the insulation resistance and polarization index of stator and rotor windings and explains how to interpret the results. Source: IEEE 43-2013. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.scope
  • IEEE 43-2013 was sponsored by the Electric Machinery Committee of the IEEE Power and Energy Society. Source: IEEE 43-2013, clause Front matter. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.sponsor
  • The IEEE catalog lists IEEE 43-2013 with the status Inactive-Reserved Standard, with an inactivation date of 2024-03-21. Value: Inactive-Reserved Standard. Source: IEEE 43-2013. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.status
  • Annex A of IEEE 43-2013 is informative and describes variants of the polarization index. Source: IEEE 43-2013, clause Annex A. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.structure.annex-a
  • Clause 7 of IEEE 43-2013 covers the conditions recorded at the time of test, and clause 8 covers the winding connections used for the test. Source: IEEE 43-2013, clause 7, 8. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.structure.conditions
  • Clause 6 of IEEE 43-2013 covers the factors that affect insulation resistance readings, among them surface condition, moisture, temperature and test voltage. Source: IEEE 43-2013, clause 6. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.structure.factors
  • Clause 9 of IEEE 43-2013 describes the instruments and methods for measuring insulation resistance. Source: IEEE 43-2013, clause 9. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.structure.instruments
  • Clause 11 of IEEE 43-2013 covers the interpretation of test results, and clause 12 gives recommended minimum values. Source: IEEE 43-2013, clause 11, 12. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.structure.interpretation
  • Clause 5 of IEEE 43-2013 sets out the insulation resistance and polarization index test procedures and the choice of test voltage. Source: IEEE 43-2013, clause 5. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.structure.procedure
  • Clause 4 of IEEE 43-2013 deals with safety during insulation resistance testing. Source: IEEE 43-2013, clause 4. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.structure.safety
  • Clause 10 of IEEE 43-2013 covers how the test voltage is applied and held, including allowance for the drop across a protective resistor. Source: IEEE 43-2013, clause 10. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.structure.voltage-application
  • The publisher catalog gives the full title of IEEE 43-2013 as IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery. Value: IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery. Source: IEEE 43-2013. Verified 2026-10-13. Review status: Agent reviewed. Record std.ieee-43.title

Related entries

Sources

  • ANSI/NETA ATS-2025, Acceptance Testing Specifications for Electrical Power Equipment and Systems, 2025 edition, NETA. Cited: clause 7.15.1.B.2. Held as: Purchased single-user copy. Publisher page
  • IEEE 43-2013, IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery, 2013 edition, IEEE. Held as: Public page. Publisher page
  • IEEE 43-2013, Recommended Practice for Testing Insulation Resistance of Electric Machinery, 2013 edition, IEEE. Cited: clause 1.1; clause 1.2; clause Front matter; clause 4; clause 5; clause 6; clause 7, 8; clause 9; clause 10; clause 11, 12; clause 12.2, Table 3; clause 12.3, Table 4; clause Annex A; clause 11.2; clause 5.4; clause A.1. Held as: Purchased single-user copy. Publisher page

Obtaining the documents

Changelog (47 entries)
DateRevisionChangeReasonBy
2026-10-131created hand-written exemplar for the article generator (Task 10)agent
2026-10-13created (std.ieee-43.approved)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (std.ieee-43.approved)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (std.ieee-43.edition.2013)extracted from public pageagent
2026-10-13reviewed (std.ieee-43.edition.2013)fresh-context agent review, research-review.mdagent
2026-10-13created (std.ieee-43.revision-of)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (std.ieee-43.revision-of)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (std.ieee-43.scope)extracted from public pageagent
2026-10-13reviewed (std.ieee-43.scope)fresh-context agent review, research-review.mdagent
2026-10-13created (std.ieee-43.sponsor)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (std.ieee-43.sponsor)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (std.ieee-43.status)extracted from public pageagent
2026-10-13reviewed (std.ieee-43.status)fresh-context agent review, research-review.mdagent
2026-10-13created (std.ieee-43.structure.annex-a)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (std.ieee-43.structure.annex-a)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (std.ieee-43.structure.conditions)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (std.ieee-43.structure.conditions)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (std.ieee-43.structure.factors)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (std.ieee-43.structure.factors)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (std.ieee-43.structure.instruments)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (std.ieee-43.structure.instruments)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (std.ieee-43.structure.interpretation)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (std.ieee-43.structure.interpretation)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (std.ieee-43.structure.procedure)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (std.ieee-43.structure.procedure)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (std.ieee-43.structure.safety)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (std.ieee-43.structure.safety)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (std.ieee-43.structure.voltage-application)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (std.ieee-43.structure.voltage-application)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (std.ieee-43.title)extracted from public pageagent
2026-10-13reviewed (std.ieee-43.title)fresh-context agent review, research-review.mdagent
2026-10-13created (tests.insulation-resistance.governed-by.ieee-43)seeded from the test taxonomyagent
2026-10-13created (tests.insulation-resistance.minimum-values-shape)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (tests.insulation-resistance.minimum-values-shape)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (tests.insulation-resistance.purpose-ieee43)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (tests.insulation-resistance.purpose-ieee43)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (tests.insulation-resistance.scope-machines)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (tests.insulation-resistance.scope-machines)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (tests.polarization-index-and-dielectric-absorption.annex-variants)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (tests.polarization-index-and-dielectric-absorption.annex-variants)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (tests.polarization-index-and-dielectric-absorption.ats-dar)method fact from the IEEE 43-2013 digest mapping section, which compares the ATS-2025 rotating-machinery clauses with IEEE 43-2013 (Task 10 exemplars)agent
2026-10-13created (tests.polarization-index-and-dielectric-absorption.dar-thirty-second)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (tests.polarization-index-and-dielectric-absorption.dar-thirty-second)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (tests.polarization-index-and-dielectric-absorption.minimum-shape)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (tests.polarization-index-and-dielectric-absorption.minimum-shape)fresh-context review task-10-exemplars-review.md + fix round 1agent
2026-10-13created (tests.polarization-index-and-dielectric-absorption.pi-definition)method fact restated from the licensed-copy digest (Task 10 exemplars)agent
2026-10-13reviewed (tests.polarization-index-and-dielectric-absorption.pi-definition)fresh-context review task-10-exemplars-review.md + fix round 1agent

Cite this page

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

Permanent revision URL: https://www.electricaltestingreference.com/standards/ieee-43/rev/1/. Current version: https://www.electricaltestingreference.com/standards/ieee-43/.

Plain

"IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery." Electrical Testing Reference. Revision 1, 2026-10-13. https://www.electricaltestingreference.com/standards/ieee-43/rev/1/.

Legal (Bluebook, internet source)

Electrical Testing Reference, IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery (rev. 1, Oct. 13, 2026), https://www.electricaltestingreference.com/standards/ieee-43/rev/1/.

BibTeX

@misc{etr-standards-ieee-43-rev1,
  title = {IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery},
  howpublished = {\url{https://www.electricaltestingreference.com/standards/ieee-43/rev/1/}},
  organization = {Electrical Testing Reference},
  publisher = {Electrical Testing Reference},
  year = {2026},
  note = {Revision 1; last substantive change 2026-10-13}
}

Wikipedia

{{cite web |title=IEEE Recommended Practice for Testing Insulation Resistance of Electric Machinery |website=Electrical Testing Reference |publisher=Electrical Testing Reference |url=https://www.electricaltestingreference.com/standards/ieee-43/rev/1/ |date=2026-10-13 |access-date= |version=1}}