Patent · US Expired

Method and apparatus for protecting electrical systems

US5475557A · kind A · utility

10Cited by
8References
27Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 30, 1991
Grant dateDec 12, 1995
Priority date
Expiry dateJul 30, 2011

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02H3/04
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

Apparatus for providing an electrical system with protection against electrical shock in the event of a ground fault. The electrical system supplies power from a central mains inlet to at least one local electrical device. The central mains inlet includes a central ground fault detector and interrupter actuatable upon detection of a first predetermined level of current imbalance to interrupt the central mains inlet. A local ground fault detector is associated with the at least one local electrical device and is actuatable upon detecting a current imbalance of a second predetermined level which is lower than the first predetermined level. Controls are effective upon actuation of the local ground fault interrupter to actuate the central ground fault detector to cause it to interrupt the central mains inlet.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.