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:
Sep. 24, 2019
Filed:
Dec. 20, 2017
Schneider Electric Usa, Inc.;
Kevin M. Jefferies, Raleigh, NC (US);
Benjamin W. Edwards, Rolesville, NC (US);
Matthew L. White, Cary, NC (US);
Alan E. Freeman, Raleigh, NC (US);
Richard K. Weiler, Wake Forest, NC (US);
SCHNEIDER ELECTRIC USA, INC., Andover, MA (US);
Abstract
In accordance with an example embodiment of the invention, in an overload relay for a three-phase motor, an adjusted threshold for detected current phase unbalance is dynamically determined at which the relay will be tripped. The adjusted threshold is a function of a ratio of an average of currents in the three-phases to the rated full load current of the motor, i.e., motor load. As the motor load decreases, the adjusted current phase unbalance threshold is increased, causing the resulting trip time to increase, thereby increasing motor run time and reducing downtime.