Abstract
Because of active introduction of IEC standards into the JIS standards and the viewpoint of the lightning protection，grounding systems are diversified.
When grounding systems are considered from a viewpoint of a ground fault accident，one point need to be concerned is the influence of ground fault accidents on faultless circuits. Specifically，the potential rise of faultless circuits and unnecessary operation of earth leakage breakers should be concerned. It is thought that these phenomena by ground accidents depend on a grounding system adopted. However，there have been only a few studies into this point. Therefore，the authors built a high-voltage power receiving equipment to a test site, and the authors verified the difference in the phenomenon by the classification of grounding systems. This paper discusses the results of them.
