Protection system for electric motors
US4288828A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 1980 |
| Grant date | Sep 8, 1981 |
| Priority date | — |
| Expiry date | Jan 17, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/0855
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A solid state protection system for AC electric motors driving high inertia loads requiring long acceleration times. An electroresponsive relay (OL) is separately responsive to permissible acceleration time, circuitry (DT, DC), acceleration overload current circuitry (ACA), and to normal running overload current circuitry (ACR). Up-to-speed detector and latch circuits (USD, USL) deactivate the acceleration time circuitry and overload current circuitry, and activate the running overload current circuitry upon attainment of normal running speed by the motor. The response levels of the overload and time response circuits are individually settable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.