Patent ID: 8907678
Filing Date: 2014-12-09
Classification: G01R,H02H

Abstract:
1. An apparatus, comprising: a leakage current sensor configured to measure leakage current from a source of AC power on a primary side of an electrical isolation boundary, which provides power to at least one load circuit on said primary side of said electrical isolation boundary; a control circuit on a secondary side of the electrical isolation boundary configured to: (i) receive measured leakage current values from the leakage current sensor at least at some times other than during a self test of the leakage current sensor, (ii) compare the measured leakage current values against a plurality of predetermined thresholds at least at some times other than during a self test of the leakage current sensor; (iii) provide a status output indicating the status of leakage current with respect to said plurality of thresholds; and (iv) perform a self test to determine whether the leakage current sensor is operative by providing said test control signal.