Method of detecting and correcting relay tack weld failures
US7522400B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 2004 |
| Grant date | Apr 21, 2009 |
| Priority date | — |
| Expiry date | Dec 27, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2047/003
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of detecting and attempting to correct a relay tack weld failure of its contacts is presented. This method senses the failure of a relay's contacts to open once it has been commanded to trip. This sensing may directly sense relay conditions, or may indirectly determine the failure by sensing a system parameter that shows the effects of the failure. Once the failure of the relay to open has been determined, the relay is again energized in an attempt to break loose the relay tack weld. If the relay fails to open after this first attempt, the relay may again be repulsed. Preferably a relay check timer is utilized to ensure that the system has stabilized before a repulse is attempted. A relay pulse timer may be used to control the pulse duration during these attempts. The number of attempts may also be limited.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.