Maintenance of surge arrester by a portable arrester leakage current detector

An instrument is described that detects leakage current without disconnecting the arrester ground wire. Better means were developed for detecting deterioration of a surge arrester than the existing appearance inspection, insulation resistance measurement, and leakage current measurement. The device measures only the in component of the current, which is proportional to the power loss. The change of the latter is the recognized measure of deterioration.<>