This course focuses on distribution transformers, with an emphasis on selection. There is a detailed discussion of transformer winding connections, including various combinations of wye and delta connections, and of how to determine secondary transformer voltages using a transformer's winding ratio. This course offers practical information that will help guide the selection of distribution transformers tailored to meet the customer's needs for three-phase delivery, single-phase delivery, or a combination of the two. The course concludes with a discussion of fault tolerance for distribution transformers as compared to other types of transformers.