Overcurrent tripping unit for a circuit breaker
US4853819A · kind A · utility
4Cited by
3References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 18, 1988 |
| Grant date | Aug 1, 1989 |
| Priority date | — |
| Expiry date | May 18, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/083
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In the overcurrent tripping unit for a circuit breaker, current transformers are provided for detecting currents flowing through respective phases of a main circuit, the secondary outputs of the current transformers are star connected, the primary outputs are polyphase full-wave rectified, the voltage drop based on the rectified positive/negative direct output of each phase is directed by first and second resistances to be applied to the control means, and a ground fault current is detected based on the secondary outputs of the current transformers to be applied to the control means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.