scope:

Applies to dry-type power transformers (including auto-transformers) having values of highest voltage for equipment up to and including 36 kV. Does not cover single-phase transformers rated at less than 1 kVA and polyphase transformers rated at less than 5 kVA, instrument transformers, transformers for static converters, starting transformers, testing transformers, traction transformers mounted on rolling stock, flameproof and mining transformers, welding transformers, voltage regulating transformers, and small power transformers in which safety is a special consideration.