GROUND DETECTOR SYSTEM HAVING FAST RESPONSE AND DECOUPLING OF DETECTOR CIRCUIT

摘要

A detector is disclosed which senses ground currents exceeding a predetermined magnitude in either one of a pair of line wires. A counter causes each line to be periodically and alternately connected to the detector for individual sensing of each line. An alarm system is provided which is responsive to a signal from the detector to generate a warning signal when a current exceeding said predetermined magnitude is sensed. The structure includes means for connecting each line to the detector and for responding to the alarm signal by decoupling the detector from the lines to thereby eliminate any contribution to the ground current which might be contributed by the presence of the detector coupled to the lines.