Circuit interrupter with digital trip unit and potentiometers for parameter entry
US4331997A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1980 |
| Grant date | May 25, 1982 |
| Priority date | — |
| Expiry date | Apr 15, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/006
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit interrupter includes a microprocessor-based trip unit, a numeric display, and a plurality of potentiometers each associated with one parameter of the time-current trip characteristic of the circuit interrupter. The trip unit provides a sequential display of the present setting values of the time-current trip characteristic parameters. Adjustment of any of the potentiometers is operable to interrupt the sequential display and to cause the present setting of the parameter associated with the adjusted potentiometer to be displayed. Adjustment of the potentiometer to either limit of its travel causes the most conservative setting value for that parameter to be selected. A hysteresis feature is provided to require a significant adjustment of the potentiometer before a different parameter setting will be selected. Although the potentiometers are continuously variable, operator adjustment thereof results in the selection of one of eight predetermined discrete values stored in the trip unit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.