scope:

This test procedure is intended to establish a uniform method for determining the temperature classification of solid-cast and resin-encapsulated power and distribution transformer insulation systems by testing rather than by chemical composition.

These insulation systems are intended for use in transformers covered by IEEE Std C57.12.01-1989¹ and IEEE Std C57.12.91-1995 as they apply to solid-cast and resin-encapsulated transformers whose highest voltages exceed nominal 600 V.

NOTE - In this guide, the term transformer means solid-cast and resin-encapsulated transformer, unless qualified by other descriptive terms.

¹Information on references can be found in Clause 2.