New Standard from Last Update.

NATIONAL FOREWORD

This Indian Standard (Part 9) which is identical with IEC 60099-9 : 2014 ‘Surge arresters — Part 9: Metal-oxide surge arresters without gaps for HVDC converter stations’ issued by the International Electrotechnical Commission (IEC) was adopted by the Bureau of Indian Standards on recommendation of the Surge Arrestors Sectional Committee and approval of the Electrotechnical Division Council.

This Indian Standard is published in several parts. The other parts in this series are:

Part 3 Artificial pollution testing ofsurge arresters

Part 4 Metal-oxide surge arresters without gaps for a.c. systems

Part 5 Selection and applicationrecommendations

Part 8 Metal oxide surge arresters with external series gap (EGLA) for overhead transmission and distribution lines of a.c. systems above 1 kv

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.