What is the definition of an industrial transformer?

Answer 1

A transformer is a transformer, for the most part. The use of "industrial" here may just mean the transformer in question is constructed a little more robustly than a "regular" transformer. One generalization about Transformers is that they are generally built pretty tough 'cause they are usually a bit more expensive to construct than most basic components and the manufacturer doesn't want it to fail. But the "industrial" version may be even tougher to withstand more punishment because of the application.