scope:

This Standards Publication is generally applicable to commercial, institutional and industrial dry-type transformers rated above 600 volts up to 15 kilovolts and covers the following kVA ratings:

1. Self-cooled-ventilated, sealed atmospheric pressure, and compound-filled types-above 500 kVA up through 7500 kVA.

2. Forced-cooled-ventilated-above 500 kVA up through 10000 kV A.

For transformers with a self-cooled rating of 500 kVA and below, see the NEMA Standards Publication for Dry-type Transformers for General Applications, ST 20-1972.