Fused Grading Shields

The fused grading shield was developed primarily to reduce the number of outages due to insulator flashovers on transmission lines. Recent practise of reducing the insulation adjacent to terminals has increased the number of flashovers in these sections. The fused grading shield while not always economically feasible for entire lines provides a means of obtaining the reduced insulation without increased outages. Laboratory and field data are presented showing the characteristics of the device as well as the results of several years of operating experience.