Partial discharge
Updated 2026-10-27
Data records
- A partial discharge is a localized electrical discharge that bridges only part of the insulation between conductors, typically inside a gas-filled void, along a surface or at a sharp edge. Repeated discharges erode the insulation and precede failure, which is why their detection and measurement is a diagnostic test for high-voltage apparatus.
- In the conventional partial discharge test method of IEC 60270:2000 the measuring circuit consists of a coupling capacitor that decouples the discharge pulses, an input impedance and filter, and the measuring instrument. The magnitude and count of the discharges are overlaid on the phase angle of the applied voltage as a phase-resolved pattern, which is used to judge the type and severity of the defect.
Elsewhere in the family
- Partial Discharge Offline related entry on Electrical Testing Reference
- Partial Discharge Offline related entry on Motor 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, Q&A: Partial discharge testing, 2021-10-29 edition, Megger. Held as: Public page. Publisher page
Changelog (4 entries)
| Date | Revision | Change |
|---|---|---|
| 2026-10-27 | created (gloss.partial-discharge.definition) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (gloss.partial-discharge.definition) | |
| 2026-10-27 | created (gloss.partial-discharge.usage) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (gloss.partial-discharge.usage) |
Cite this page
Cite the governing standard for the fact itself; cite this page as the finding aid.
"Partial discharge." Test Instrument Reference. 2026-10-27. https://www.testinstrumentreference.com/glossary/partial-discharge/.
Test Instrument Reference, Partial discharge (Oct. 27, 2026), https://www.testinstrumentreference.com/glossary/partial-discharge/.
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organization = {Test Instrument Reference},
publisher = {Test Instrument Reference},
year = {2026},
note = {last substantive change 2026-10-27}
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