Residual current
Updated 2026-10-27
Data records
- Residual current is the vector sum of the currents in the live conductors of a circuit, which is zero in a healthy circuit and departs from zero when current leaks to ground; a residual current device trips when this sum exceeds its rated residual operating current.
- An installation tester checks a residual current device by injecting a residual current and timing the trip, and a ramp test raises the residual current in steps from a fraction of the rated value until the device trips; the tester is set for the type of device under test, since types responding to alternating, pulsating direct or smooth direct current and time-delayed types are tested differently.
Sources
- Electrical Testing Reference editorial taxonomy, Electrical Testing Reference editorial taxonomy of test methods, 2026-10 edition, Electrical Testing Reference. Held as: Own observation.
- Fluke product page, Fluke 1664 FC Installation Multifunction Tester, web page edition, Fluke. Held as: Public page. Publisher page
Changelog (5 entries)
| Date | Revision | Change |
|---|---|---|
| 2026-10-27 | created (gloss.residual-current.definition) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (gloss.residual-current.definition) | |
| 2026-10-27 | created (gloss.residual-current.usage) | |
| 2026-10-27 | revised (gloss.residual-current.usage) | |
| 2026-10-27 | review_status unreviewed -> software_reviewed (gloss.residual-current.usage) |
Cite this page
Cite the governing standard for the fact itself; cite this page as the finding aid.
"Residual current." Test Instrument Reference. 2026-10-27. https://www.testinstrumentreference.com/glossary/residual-current/.
Test Instrument Reference, Residual current (Oct. 27, 2026), https://www.testinstrumentreference.com/glossary/residual-current/.
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title = {Residual current},
howpublished = {\url{https://www.testinstrumentreference.com/glossary/residual-current/}},
organization = {Test Instrument Reference},
publisher = {Test Instrument Reference},
year = {2026},
note = {last substantive change 2026-10-27}
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