Step voltage test
Updated 2026-10-27
Data records
- A step voltage test is an insulation resistance test in which the direct test voltage is raised in successive equal steps, each held for the same period, with the resistance or the leakage current recorded at every step. A marked fall in resistance as the voltage rises points to a weakness, such as a crack or a pinhole, that a lower voltage does not reveal.
- In instrument practice the step voltage test relies on sound insulation behaving resistively, so that raising the test voltage raises the current in proportion and the computed resistance stays constant. A resistance that falls as the voltage steps up indicates ionization at pinholes or cracks in the insulating material, which is what the test is used to locate.
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
- Polarization Index and Dielectric Absorption related entry on Electrical Testing Reference
- Polarization Index and Dielectric Absorption 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.step-voltage-test.definition) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (gloss.step-voltage-test.definition) | |
| 2026-10-27 | created (gloss.step-voltage-test.usage) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (gloss.step-voltage-test.usage) |
Cite this page
Cite the governing standard for the fact itself; cite this page as the finding aid.
"Step voltage test." Test Instrument Reference. 2026-10-27. https://www.testinstrumentreference.com/glossary/step-voltage-test/.
Test Instrument Reference, Step voltage test (Oct. 27, 2026), https://www.testinstrumentreference.com/glossary/step-voltage-test/.
@misc{etr-glossary-step-voltage-test,
title = {Step voltage test},
howpublished = {\url{https://www.testinstrumentreference.com/glossary/step-voltage-test/}},
organization = {Test Instrument Reference},
publisher = {Test Instrument Reference},
year = {2026},
note = {last substantive change 2026-10-27}
}{{cite web |title=Step voltage test |website=Test Instrument Reference |publisher=Test Instrument Reference |url=https://www.testinstrumentreference.com/glossary/step-voltage-test/ |date=2026-10-27 |access-date=}}