Transformers, and the cooling system they are equipped with, are designed with the actual ambient temperature in mind such that the temperature of the hottest spots in the windings and structural parts does not exceed certain temperature limits. This ensures full life of the transformer insulation even if it is fully loaded 24 hrs / day. For example, transformers for hot weather are designed for a 50 degrees C ambient. The solar radiation is not in itself taken care of in this case but the ambient temperature is specified considering the time of the day when it is hottest. The sun radiation probably adds a little more heating but this is balanced by the fact that the average temperature that the transformer is operating in throughout the year is much lower than the hottest temperature in the summer with the sun radiation. Also, the transformer is typically loaded far less than full load.
Large and medium power transformers
If you want to purchase a product, need any pricing information or need help or support from ABB, please contact your local partner.