Faulted current indicator with inrush restraint
US4984124A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 1989 |
| Grant date | Jan 8, 1991 |
| Priority date | — |
| Expiry date | Jun 30, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/042
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The disclosed faulted current indicator senses current in a line having a breaker or fuse, and avoids tripping in response to current inrush signals by producing a trip signal in response to an overcurrent occurring for an overcurrent duration which is inversely related to the magnitude of the overcurrent and is faster than the overcurrent operating time of the breaker or fuse. In one embodiment, this involves operating a current protection device in response to an overcurrent occurring for a second overcurrent duration inversely related to the magnitude of the overcurrent according to a first characteristic, and adjusting the first overcurrent duration to follow a second characteristic having variations substantially the same as the first characteristic but having a shorter first overcurrent duration than the second overcurrent duration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.