The heating of clamp of disconnector can reduce the current carrying capacity of the equipment and affect safety and reliability of power grid. The traditional thermal fault analysis of clamp is only to perform a macro analysis of contact resistance measurement and

however

the deep micro analysis and the its root cause have not been analyzed and studied. In this paper

the thermal fault of the clamp in phase B of 110 kV 8053 disconnector of one substation in Jiangsu is taken as an example and

on the base of traditional macro analysis

such micro analysis as morphology

metallography and energy spectrum are performed by means of science and technology. And the causes of heating of clamp of the disconnector is systemically studied. From the macro point of view

the increase of contact resistance on the clamp surface of disconnector leads thermal fault. While

from the micro point of view

the clamp surface of the disconnector has corrosion and dimples on the surface and the grain boundary is weakened. A large number of carbides are dispersed in the crystal and the oxidation resistance is decreased. In the oxidation corrosion products

the content of such plasma as O

Cl

S plasma is larger and the total amount is more than 50%. In addition

based on the analysis process

the cause analysis scheme and preventive measures for the thermal fault of clamp for the disconnector at above 110 kV are proposed in this paper.