Ground fault detection
US8373420B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2009 |
| Grant date | Feb 12, 2013 |
| Priority date | — |
| Expiry date | Nov 20, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B25/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A ground fault detection system detects an earth fault or ground fault in a network device. The network device may be used in a fire alarm network. The ground fault detection system includes a power device that electrically isolates the ground fault detection system. A controller sequences a series of switches or relays to charge an energy storing element, such as a capacitor, with the isolated power supply. The capacitor is placed in communication with each port of the network device one at a time. If the connected port includes an inadvertent connection to ground, a detection circuit will detect the bias on the earth ground. The detection circuit may then output an indication of the inadvertent connection to ground to either a workstation or a fire alarm control panel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.