In view of the high repair rate of the high voltage isolator switch thermal defects in Xuejiawan area

the paper analyzes the causes from the aspects of skill level

cleaning method

welding process and coating repair process

etc.

concludes that the main causes of thermal defect repair are the bad cleaning method

the backward welding process

the rough coating repair process and the delay in tracking contact resistance change

at last

proposes the laser cleaning

cold welding and cyanide-free brush silver plating technology.After the adoption of the new technology

the repair rate has decreased significantly.