Routine inspection of dry-type transformer

Compared with oil-immersed transformer, dry-type transformer is small in volume, light in weight, easy to install, easy to maintain, no danger of fire and explosion.

The normal checks in operation are maintained as follows： 

(1) no overheating of high and low voltage side connector, no leakage and creepage of cable head. 
(2) the monitoring temperature rise shall not exceed the specified value according to the insulation grade used in the transformer. 
(3) there is no odor in the transformer room, the sound is normal, and the indoor ventilation is good. 
(4) no crack and no discharge trace of the supporting insulator.

Depends on the heat rating of your transformer

　　Transformers can be divided into a class E class B Class F class H class according to the heat resistance grade

　　Maximum allowable temperature (OC)105120130155180

　　Winding temperature rise limit (k)607580100125

　　Performance reference temperature (OC)8095100120145

　　There's also a C class, which allows for higher temperatures