回路電流の信号処理によるコードプラグトラッキング検出方法の検討

抄録

Tracking of a cord plug caused by leakage current between its electrodes, which is occasionally observed under contaminated and wetted conditions, is attributed to one of the causes of fire accidents. It is generally difficult to detect the leakage current itself because its magnitude is much smaller than that of load current of a typical household appliance. Some detection methods have been proposed based on results of laboratory experiments. However, it seems that no reliable method, which detects tracking and shuts off circuit, has been realized at site due to technical and economical problems.
In this paper, a novel method is proposed, where characteristics of leakage current is extracted from circuit current (i.e. sum of load and leakage currents) based on signal processing and by using a physical quantity introduced. It was confirmed by laboratory experiments that the method was satisfactory to detect tracking of a cord plug regardless of the extent of tracking and kind of loads connected.