I have an old tube device whose power transformer gets very hot. With a common thermometer I found that it reaches 200º C. What is the maximum recommended temperature for this component?
The transformers are classified according to the type of insulation. A class 180 transformer, for example, withstands a maximum temperature of 180º but in operation it is not recommended to go beyond 115º. Thus, for normal applications, we have the following division according to classes.
Class 220 - Maximum recommended temperature 150º C
Class 180 - Maximum recommended temperature 115º C
Class 150 - Maximum recommended temperature 80º C
Class 105 - Recommended maximum temperature 50º C
Certainly, your transformer must not be above class 220, which means it is overheating.
