For determining the cause of the moving contact jamming of three-position disconnector for a 252 kV HGIS bus coupler and avoiding reoccurrence of the fault

the cause of the fault is analyzed in detail three-station disconnector and avoid the recurrence of similar incidents

this paper makes a detailed analysis in this paper by such measures as site detection

disassembly and test at the factory as well as theoretical calculation. The analysis shows that the jamming of the moving contact conductor and unbale operation is due to excessive tolerance of the moving contact and the stationary contact holder

which eventually result in the result that the moment borne by the flat key

which is engaged between the gear shaft and the gear

is higher than the allowable shear force and is finally cut off.