Leakage current
Updated 2026-10-27
Data records
- Leakage current is the small, steady current that flows through or over the surface of insulation under a sustained direct voltage after the charging and absorption currents have died away. It is the component that an insulation resistance reading ultimately represents, and a leakage current that rises from one test to the next indicates deterioration.
- An insulation tester displays a result that is the sum of the capacitive charging current, the absorption current, the surface leakage current and the leakage current through the insulation, and once the charging period has passed only the leakage and surface leakage currents remain. The surface component, present when the insulation is contaminated by dampness, grease or salts, can be diverted around the measuring circuit through the guard terminal.
Elsewhere in the family
- Insulation Resistance related entry on Circuit Breaker Reference
- Insulation Resistance related entry on Electrical Testing Reference
- Insulation Resistance related entry on Motor Testing Reference
- Insulation Resistance related entry on Protective Relay Reference
- Insulation Resistance related entry on Revenue Metering Reference
- Insulation Resistance related entry on Switchgear Testing Reference
- Insulation Resistance related entry on Transformer Testing Reference
- Dielectric Withstand related entry on Circuit Breaker Reference
- Dielectric Withstand related entry on Electrical Testing Reference
- Dielectric Withstand related entry on Motor Testing Reference
- Dielectric Withstand related entry on Revenue Metering Reference
- Dielectric Withstand related entry on Switchgear Testing Reference
- Dielectric Withstand related entry on Transformer Testing Reference
Sources
- Electrical Testing Reference editorial taxonomy, Electrical Testing Reference editorial taxonomy of test methods, 2026-10 edition, Electrical Testing Reference. Held as: Own observation.
- Megger Electrical Tester article, Insulation testing diagnostic techniques, 2008-10-16 edition, Megger. Held as: Public page. Publisher page
Changelog (4 entries)
| Date | Revision | Change |
|---|---|---|
| 2026-10-27 | created (gloss.leakage-current.definition) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (gloss.leakage-current.definition) | |
| 2026-10-27 | created (gloss.leakage-current.usage) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (gloss.leakage-current.usage) |
Cite this page
Cite the governing standard for the fact itself; cite this page as the finding aid.
"Leakage current." Test Instrument Reference. 2026-10-27. https://www.testinstrumentreference.com/glossary/leakage-current/.
Test Instrument Reference, Leakage current (Oct. 27, 2026), https://www.testinstrumentreference.com/glossary/leakage-current/.
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title = {Leakage current},
howpublished = {\url{https://www.testinstrumentreference.com/glossary/leakage-current/}},
organization = {Test Instrument Reference},
publisher = {Test Instrument Reference},
year = {2026},
note = {last substantive change 2026-10-27}
}{{cite web |title=Leakage current |website=Test Instrument Reference |publisher=Test Instrument Reference |url=https://www.testinstrumentreference.com/glossary/leakage-current/ |date=2026-10-27 |access-date=}}