Overload relay having adaptive differential mechanism
US4806897A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1987 |
| Grant date | Feb 21, 1989 |
| Priority date | — |
| Expiry date | Dec 17, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2071/109
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a plural phase overload relay, a pivot lever (12) is mounted to the ambient compensator deflector (9), and a second pivot lever (34) is mounted to both driver and follower slide bars (36 and 38) and driven thereby to engage and pivot the first lever on the ambient compensator deflector to trip a cut-out switch. The ambient compensator deflector adjusts both the three phase current trip threshold and the loss of phase current trip threshold, and also affords ambient compensator of each. A constant ratio relationship between these two thresholds is provided throughout the entire range of current trip threshold settings. The driver bar moves a first distance for three phase trip and a second shorter distance for loss of phase trip. The ratio of these distances is constant notwithstanding adjustment by the ambient compensator deflector changing the length of such distances.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.