Electronic trip units powered by current transformers and circuit breakers comprising the same
US9842709B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2015 |
| Grant date | Dec 12, 2017 |
| Priority date | — |
| Expiry date | Nov 20, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H1/046
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit breaker includes a set of separable contacts moveable between a closed position and an open position, an operating mechanism configured to open the set of contacts, a conductor coupled to the set of contacts, a current transformer coupled to the conductor, and a trip circuit coupled to the operating mechanism and to the current transformer and configured to cause the operating mechanism to open the set of contacts when a current through the conductor exceeds a current threshold that is greater than a saturation threshold of the current transformer. The trip circuit is further configured to vary the current threshold during an interval following a closure of the set of the contacts and to provide a fixed current threshold thereafter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.