The ambient temperature rating is a 24 hour average. In desert applications we have succesfully installed transformers at 55 degree ambient temperatures and I specify a 45 degree rise on a 50 degree ambient. If your loads are linear and there are no expectations for large harmonic content you...
In our applications transformer heating is a huge issue. After researching the problem I have come to understand a couple of things in regard to the handling of heat and its affect on the life span of transformers.
The temperature rise is a figure the transformer is designed to operate...
