The safe, economical and reliable operation and output of the transformer depends on its own manufacturing quality and operating environment as well as the quality of the repair. This chapter attempts to answer the measures to effectively prevent sudden faults in the transformer during the operation and maintenance of the transformer.
 
The power grid is often short-circuited due to lightning strikes, relay protection malfunctions or refusal. The strong impact of the short-circuit current may damage the transformer. Therefore, efforts should be made to improve the short-circuit resistance of the transformer from various aspects.

The statistical results of transformer short-circuit shock accidents show that 80% of the causes are caused by manufacturing, and only about 10% are caused by operation and maintenance. This chapter focuses on the measures that should be taken during the operation and maintenance process.
 
During the operation and maintenance process, on the one hand, the short-circuit fault should be minimized, thereby reducing the number of times the transformer is subjected to impact; on the other hand, the deformation of the transformer winding should be tested in time to prevent it from happening.