Water is one of the worst enemies of a transformer
1. A transformer with low moisture content is like a person in good condition
(1) A transformer can be used at high load without risk for catastrophic failure.
(2) A person can work hard without risk for heart attack.
2. A wet transformer is like an overweight person in bad condition
(1) The transformer owner has to limit load to avoid bubbling (may lead to catastrophic failure).
(2) Moisture in insulation increases the rate of aging.
(3) The person can not run the marathon.
3. Water/moisture and (high) temperature will sooner or later kill the transformer.
