Device for detecting and for indicating fault current through a lightning arrestor or an insulator
US5373242A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1993 |
| Grant date | Dec 13, 1994 |
| Priority date | — |
| Expiry date | Mar 29, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T1/12
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A device for detecting and indicating a fault current flowing through a lightning arrestor or an insulator, the current being DC or at AC mains frequency, the device being housed inside a box that is provided with a frangible window and that has a piece of metal electrically connected to an end fitting of the lightning arrestor or of the insulator passing therethrough. The device has: a transformer for transforming the current, the primary of the transformer being constituted by the piece of metal, and the secondary of the transformer being connected to a peak-limiting circuit to make pulses of current due to surges corresponding, in particular, to lightning strikes inoperative; a heating resistance fed by said transformer and constituting an igniter for a pyrotechnic composition in which it is embedded, the composition being designed to break the frangible window; and preferably indicator means suitable for being released by rupture of the frangible window.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.