This study addresses the issue of abnormal large-scale heating at the flexible connection conductive strip of the upper and lower conductive tube joints in a GW6-type disconnector at a 500 kV substation.Through comprehensive analysis

including macroscopic observation

chemical composition analysis

scanning electron microscopy (SEM)

and coating thickness testing of the replaced elbow fittings and conductive strips

it was found that insufficient tinning width at the copper conductive strip joints led to direct contact between the copper sheets and aluminum fittings.This caused electrochemical corrosion on the conductive contact surface of the aluminum fittings

increasing the contact resistance and resulting in abnormal heating during operation.To resolve this issue

it is recommended to replace the conductive strips of this disconnector type and install copper-aluminum transition plates.Additionally

regular infrared temperature monitoring should be implemented to reduce the probability of abnormal heating at the joints

ensuring the safe and stable operation of the equipment.