Patent ID: 9239368
Filing Date: 2016-01-19
CPC Classification: G01R,H02H

Claim Text:
1. A method to continually self-test a ground fault detector comprising: continuously drawing current for a ground fault detector circuit from a line conductor and a neutral conductor; diverting the current for the ground fault detection circuit to cause a first current imbalance in a sense coil for a first half of a power-line cycle; diverting the current for the ground fault detection circuit to cause a second current imbalance in the sense coil for a second half of the power-line cycle; and monitoring a secondary winding of the sense coil for the current imbalance caused by at least one of the first and second current imbalance or a signal indicative of a fault, wherein causing the first current imbalance comprises: diverting the current from the neutral conductor at a first location, the first location being between a powerline input to the ground fault detector and the sense coil location; and returning the current to the line conductor at a second location being between the sense coil and an output of the ground fault detector.