Measuring loop resistance
US12019107B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 2022 |
| Grant date | Jun 25, 2024 |
| Priority date | — |
| Expiry date | Oct 17, 2042 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R27/08
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Loop resistance is measured in a live-earth conductor loop comprising a residual current device powered by an alternating current mains supply. A measurement circuit having a low-pass filter characteristic arranged to substantially remove signal components at the frequency of the alternating current mains supply is used to measure, in a first period, a voltage across live and earth conductors of the live-earth conductor loop to determine a first voltage. A current application circuit is used to apply a unipolar test current having a magnitude below a trip current value of the residual current device for a second period and the measurement circuit is used to measure a second voltage between the live and earth conductors. Based on a difference in test current between the first and second periods and a difference in voltage between the first voltage and the second voltage, the resistance of the live-earth conductor loop is calculated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.