Power transformers - Part 20: Energy efficiency

IEC TS 60076-20:2017(E) is applicable to transformers in the scope of IEC 60076-1. It proposes two methods of defining an energy efficiency index and introduces three methods of evaluating the energy performance of a transformer. The appropriate method is chosen by agreement between purchasers and manufacturers or according to local regulations.
The contents of the corrigendum of January 2018 have been included in this copy.