Closing grounding switch to energized live part is one of the five serious misoperation accident

which must be resolutely against.This article introduces a closing grounding switch to energized live part accident of HGIS equipment

including its operation

analysis

treatment process in a 500 kV substation.The cause is a screw drop off from disconnector operating mechanism in HGIS chamber

resulting in the switch has not disconnect actually.This paper emphatically put forward to four preventive measures

that is

improving measures to be taken by the manufacturers

establishing a perfect five prevention misoperation system

tagging HGIS close-open position clearly

strictly executing indirect electrical inspection procedures.It provides a reference to prevent similar incidents.