Surge protection device with thermal protection, current limiting, and failure indication
US6477025B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 12, 1999 |
| Grant date | Nov 5, 2002 |
| Priority date | — |
| Expiry date | Oct 12, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2037/768
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The disclosure describes a surge protection device that makes use of metal oxide varistors (MOVs) to limit the magnitude of electrical surges in single phase or multi-phase power distribution networks. Since MOVs generally fail in a low impedance mode when the electrical ratings of the devices are exceeded, current limiting and thermal limiting devices are connected in series with the MOVs to limit the effect of these failures to the surge protection devices. The physical configuration of the surge protection device limits the effects of a current limiter being activated by providing a barrier between the current limiter and the associated MOV. Filler material is also used to limit the effects of debris or plasma gas from an activated current limiter. Multiple surge protection devices may be connected in parallel to provide increased current handling capability, and visual indication of a failed surge protection device may be provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.