dry type transformer aging

[nehring]

I am looking for information to help determine the life expectancy of dry type transformers. What clues, tests or history is there as to life expectancy of a transformer.

 

[mpparent]

The best signs of degradation are periodic maintenance, ......Doble testing would be a good start.

 

[busbar]

IEEE Standard 493 (gold book) lists transformer reliability and failure data.