Electronic trip device comprising a test device
US5444377A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1993 |
| Grant date | Aug 22, 1995 |
| Priority date | — |
| Expiry date | Dec 15, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/335
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The terminals of a test circuit are directly connected to outputs of the transformer secondary windings and to the input of the rectifying circuit so that the test current checks operation of the trip device. A sign detection circuit supplies a processing circuit with the values of the polarities of the rectified currents. The processing circuit comprises means for determining the presence of a test current when the sign of the rectified current comprising the test current remains continuously in the same polarity. A differentiation of the continuous polarity, positive or negative, of the test current enables testing to be carried out with or without earth protection tripping.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.