This International Standard applies to traction transformers installed on board rolling stock and to the various types of inductors inserted in the power and auxiliary circuits of electric vehicles. The inductors mentioned in the first paragraph may be: - filter inductors; smoothing inductors; commutation inductors; protection inductors in static power converters; inductive shunts for traction motors; inductors used for transition between tap changer notches; braking circuit inductors and interference suppression inductors. This standard can also be applied, after agreement between user and manufacturer, to the traction transformers of three-phase a.c. line-side powered vehicles and to the transformers inserted in the single-phase or polyphase auxiliary circuits of vehicles, except for instrument transformers and transformers of a rated output below 1 kVA single-phase or 5 kVA polyphase. This standard does not cover accessories such as tap changers, resistors, heat exchangers, fans, etc., intended for mounting on the transformers or inductors, which shall be tested separately according to relevant rules. When tap changers are an integral part of the transformers, they cannot be separated while the latter are tested. For service conditions, refer to IEC 60077-1.