Question

What is a difference between indoor transformer and outdoor transformer of same rating?

Answer 1

Large oil-filled transformers are rarely installed indoors because people worry about fire and the like. They go outdoors in locked enclosures with a bund wall to contain leakage if the oil escapes. They are designed to be wetherproof as a consequence.

large dry resin transformers are normaly air cooled, and will be installed either indoors or in a large enclosure which effectively puts them indorrs.

Answer 2

Explanation:

Transformers Based on the Place of Use

These are classified as indoor and outdoor transformers. Indoor transformers are covered with a proper roof like as in the process industry. The outdoor transformers are nothing but distribution type transformers.