Method of determining contact wear in a trip unit
US6231227A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 28, 1998 |
| Grant date | May 15, 2001 |
| Priority date | — |
| Expiry date | Dec 28, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2071/044
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of determining contact wear in a trip unit of a circuit breaker is presented. The trip unit includes a microcontroller and associated memories. An algorithm (program) stored in a memory of the trip unit measures temperatures relative to circuit breaker contacts and cumulative energy dissipated in the breaker contacts, and utilizes them in a variety of analysis techniques within the trip unit to determine contact wear. These techniques include, by way of example, differential temperature analysis, measurement of cumulative energy dissipated in the breaker contacts, and calculated contact wear using sampled electrical currents and voltage and Ohm's law.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.