Resin encapsulated distribution transformers

The paper-and-oil insulation system of distribution transformers, which has served the industry well for many decades, is now being challenged by resin encapsulation. It is not yet clear whether encapsulated transformers will eventually supersede oil-filled pole-type designs, or will be limited to specialty applications such as installations in or adjacent to buildings. A field trial of encapsulated transformers is in progress to gain experience in manufacturing, to proof test radical design concepts, and to promote study by the industry of the application potentialities and desired characteristics for encapsulated transformers.