Douglas E Frushour

US Patent:

6888708, May 3, 2005

Filed:

Jun 20, 2002

Appl. No.:

10/175618

Inventors:

William T. Brungs - North Bend OH, US
Thomas R. Yingling - Batavia OH, US
Douglas E. Frushour - Burlington KY, US

Assignee:

Post Glover Resistors, Inc. - Erlanger KY

International Classification:

H02H003/16

US Classification:

361 42, 361 44

Abstract:

A ground fault detector for use in resistance grounded electrical systems. In one embodiment, the system includes a digital processor to monitor an electrical parameter of the resistance to determine and indicate whether a ground fault has occurred. Data regarding the ground fault occurrence can then be digitally stored transmitted, or processed, such as by an external computer. In another embodiment, the ground fault detector includes a filter to remove the harmonic components of the monitored electrical parameter, to avoid false alarms. In addition, in another embodiment, the ground fault detector can also determine whether a high harmonic condition is present in the monitored electrical system. The phase of the electrical system can be grounded by pressing a test switch, thereby causing a ground fault and allowing the harmonic components of the signal in the electrical system to be monitored.

US Patent:

59634200, Oct 5, 1999

Filed:

Sep 22, 1997

Appl. No.:

8/934881

Inventors:

James Rodney Bailey - Brevard NC
Douglas Eugene Frushour - Asheville NC
Alfred Lee Randall - Horshshoe NC

Assignee:

Eaton Corporation - Cleveland OH

International Classification:

H02B 11133
H05K 502
H05K 503
H01H 920

US Classification:

361616

Abstract:

An electrical apparatus housing having a door for accessing the apparatus within the interior of the housing and a switch for activating the apparatus accessible from the exterior of the housing. When in the on position, the switch is operable to block the door from being opened; thus functioning as an interlock to prevent access to the interior of the housing when the apparatus is activated. The invention includes a key for bypassing the interlock so that under certain circumstances the housing door can be opened while the equipment is operating, so it can be tested in its energized state.