The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 12, 2013
Filed:
Jul. 31, 2009
Gregg Lupaczyk, Shirley, MA (US);
Normand Dontigny, Candiac, CA;
Gregg Lupaczyk, Shirley, MA (US);
Normand Dontigny, Candiac, CA;
SimplexGrinnell LP, Westminster, MA (US);
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.