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. 07, 2017
Filed:
Jul. 06, 2015
Emprimus, Llc, St. Louis Park, MN (US);
Frederick R. Faxvog, Long Lake, MN (US);
Wallace Jensen, Centerville, MN (US);
Terrence R. Noe, Sebastopol, CA (US);
Craig Eid, Santa Rosa, CA (US);
David Blake Jackson, Excelsior, MN (US);
Greg Fuchs, River Falls, WI (US);
Gale Nordling, Excelsior, MN (US);
Emprimus, LLC, St. Louis Park, MN (US);
Abstract
Systems and methods for protecting an electrical component in an alternating current system that includes a transformer are disclosed. In one aspect, a circuit includes a switch assembly connected between a transformer neutral of a transformer and a ground and having an open position and a closed position. In normal operation, the switch remains in a closed position. The circuit further includes a DC blocking component positioned in parallel with the switch assembly and connected between the transformer neutral and the ground, a voltage probe connected between the transformer neutral and ground and configured to monitor an instantaneous voltage level at the transformer neutral, and a control circuit configured to control the switch assembly, the control circuit including a sensor configured to actuate the switch assembly to an open position at least upon detection of a harmonic signal in at least one phase of the transformer or a predetermined threshold of DC or quasi DC current between the transformer neutral and the ground.