IEEE Standard for Thermal Evaluation of Insulation Systems for Dry-Type Power and Distribution Transformers - Redline

A uniform method is established for determining the temperature classification for the insulation systems for dry-type power and distribution transformers by testing rather than by chemical composition. These insulation systems are intended for use in transformers covered by IEEE Std C57.12.01(TM) and IEEE Std C57.12.91(TM) as they apply to dry-type transformers whose highest voltages exceed nominal 600 V.