IEC 60726:1982

Specifies requirements for dry-type power transformers (including auto-transformers) having values of highest voltage for equipment up to and including 36 kV. The following small and special dry-type transformers are not covered by this standard:
-instrument transformers (covered by IEC 60185 and 60186);
-transformers for static convertors (covered by IEC 60084, 60119 and 60146).
Where IEC standards do not exist for other special transformers, this standard may be applicable as a whole or in part.