This International Standard applies to power transformers as defined by and in the scope of IEC 60076-1. It gives details of the applicable dielectric tests and minimum dielectric test levels. Recommended minimum external clearances in air between live parts and between live parts and earth are given for use when these clearances are not specified by the purchaser. For categories of power transformers and reactors which have their own IEC standards@ this standard is applicable only to the extent in which it is specifically called up by cross reference in the other standards.