Line isolation monitor
US3978465A · kind A · utility
29Cited by
6References
9Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 25, 1974 |
| Grant date | Aug 31, 1976 |
| Priority date | — |
| Expiry date | Oct 25, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/58
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A line isolation monitor which monitors ground faults on a normally ungrounded AC power line. The monitor uses a low voltage sensing current having a frequency greater than the frequency of the power line. The monitor tests each side of the power line independently. Provision can be made to indicate a double fault to ground. Further refinements include a means to monitor the connection between the monitor device and ground as well as a means for confirming continuity of annunciator lines associated with the line isolation monitor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.