NATIONAL FOREWORD

This Indian Standard which is identical with IEC 60305 : 1995 ‘Insulators for overhead lines with a nominal voltage above 1 000 V — Ceramic or glass insulator units for a.c. systems — Characteristics of insulator units of the cap and pin type’ issued by International Electrotechnical Commission (IEC) was adopted by the Bureau of Indian Standards on the recommendation of the Electrical Insulators and Accessories Sectional Committee and approval of the Electrotechnical Division Council.

After publication of this standard, IS 3188 : 1980 ‘Characteristics of string insulator units’ shall be withdrawn, the requirements of which have now been covered in this standard.

The text of IEC Standard has been approved as suitable for publication as an Indian Standard without deviations. Certain terminology 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.