NATIONAL FOREWORD

This Indian Standard (Part 20) (Second Revision) which is identical with IEC 60317-20 : 2013 ‘Specifications for particular types of winding wires — Part 20: Solderable polyurethane enamelled round copper wire, class 155’ issued by the International Electrotechnical Commission (IEC) was adopted by the Bureau of Indian Standards on recommendation of the Winding Wires Sectional Committee and approval of the Electrotechnical Division Council.

This standard was originally published in 1993 and subsequently revised in 2016. First revision was based on IEC 60317-20 : 2000 ‘Specifications for particular types of winding wires — Part 20: Solderable polyurethane enamelled round copper wire, class 155’, issued by the International Electrotechnical Commission. The second revision of this standard has been undertaken to align it with the latest version of IEC 60317-20 : 2013.

The major changes in this revision are as follows:

a) New Clause 3.2.2 containing general notes on winding wire, formerly a part of the scope;

b) Revision to references to first revision of IS 13730 (Part 0/Sec 1) : 2012 to clarify that their application is normative;

c) Modification to Clause 15 to remove specific wire specimen sizes;

d) Consolidation of 17.1 and 17.2 of the solderability requirements;

e) Modification to Clause 19, Dielectric dissipation factor; and

f) New Clause 23, Pin hole test.

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.