Reaffirmed 2023

NATIONAL FOREWORD

This Indian Standard (Part 3) (Fourth Revision) which is identical with IEC 60076-3 : 2013 ‘Power Transformers — Part 3: Insulation levels, dielectric tests and external clearances in air’ issued by the International Electrotechnical Commission (IEC) was adopted by the Bureau of Indian Standards on the recommendation of the Transformers Sectional Committee and approval of the Electrotechnical Division Council.

This standard was originally published in 1962 and subsequently revised in 1977, 1981 and 2009. The fourth revision of this standard has been undertaken to align it with the latest IEC 60076-3 : 2013.

The text of IEC Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain terminologies and conventions are, however, not identical to those used in Indian Standards. Attention is particularly drawn to the following:

a) Wherever the words ‘International Standard’ appear referring to this standard, they should be read as ‘Indian Standard’.

b) Comma (,) has been used as a decimal marker, while in Indian Standards, the current practice is to use a point (.) as the decimal marker.