BS-EN-60674-2-1998.pdf

BRITISH STANDARD BS EN 60674-2:1998 Incorporating Amendments Nos. 1 and 2 to BS 7290-2:1990 (Amendment No. 2 renumbers the BS as BS EN 60674-2:1998) and Amendment No. 3 Specification for plastic films for electrical purposes Part 2: Methods of test The European Standard EN 60674-2:1998, with the incorporation of amendment A1:2001, has the status of a British Standard ICS 29.035.20 ? Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 10 07:04:48 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 60674-2:1998 This British Standard, having been prepared under the direction of the Cable and Insulation Standards Policy Committee, was published under the authority of the Board of BSI and comes into effect on 31 July 1990 © BSI 22 August 2002 The following BSI references relate to the work on this standard: Committee reference CIL/15 Draft for comment 89/25808 DC ISBN 0 580 18241 X Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Cable and Insulation Standards Policy Committee (CIL/-) to Technical Committee CIL/15, upon which the following bodies were represented: Adhesive Tape Manufacturers Association British Ceramic Research Limited British Industrial Ceramic Manufacturers Association British Paper and Board Industry Federation Department of Trade and Industry, National Measurement Accreditation Service ERA Technology Limited Electrical and Electronic Insulation Association (BEAMA Ltd.) Electricity Supply Industry in England and Wales Ministry of Defence Rotating Electrical Machines Association (BEAMA Ltd.) Telecommunication Engineering and Manufacturing Association Transmission and Distribution Association (BEAMA Ltd.) The following bodies were also represented in the drafting of the standard, through sub-committees and panels: British (AC) Capacitor Manufacturers Association (BEAMA Ltd.) British Plastics Federation EBEA (the Electronics and Business Equipment Association) Packaging and Industrial Films Association Amendments issued since publication Amd. No.DateComments 9101July 1996Indicated by a sideline in the margin 10106October 1998Implements the European Standard 1366122 August 2002 Replacement of Clause 16 and addition of Figure 7 and Figure 8 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 10 07:04:48 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 60674-2:1998 © BSI 22 August 2002 i Contents Page Committees responsibleInside front cover National forewordii Foreword 2 Introduction3 1Scope3 2General notes on tests3 3Thickness3 4Density3 5Width4 6Windability (bias/camber and sag)4 7Surface roughness7 8Coefficient of friction7 9Wetting tension (polyolefine films)7 10Tensile properties9 11Edge tearing resistance9 12Tear resistance9 13Stiffness of film9 14Surface resistivity9 15Volume resistivity10 16Dissipation factor and permittivity11 17Dissipation factor under impregnated conditions13 18Electric strength13 19Electrical weak spots14 20Resistance to breakdown by surface discharges15 21Electrolytic corrosion15 22Melting point16 23Dimensional change 16 24Dimensional stability under tension with rising temperature16 25Dimensional stability under pressure with rising temperature16 26Resistance to penetration at elevated temperature17 27Volatile content (loss of mass on heating)17 28Thermal endurance17 29Burning characteristics 17 30Water absorption in a damp atmosphere19 31Absorption of liquid20 32Ionic impurities 21 33Effect of insulating varnishes21 34Effect of polymerisable resinous compounds in a liquid state22 Annex ZA (normative) Normative references to international publications with their corresponding European publications28 Figure 1 Windability of film. Measurement of bias/camber; Method A22 Figure 2 Windability of film. Apparatus for measurement of sag; Method A23 Figure 3 Windability of film. Measurement of sag; Method A24 Figure 4 Equipment for testing for electrical faults by Method A24 Figure 5 Equipment for testing for electrical faults by Method B25 Figure 6 Equipment for testing for electrical weak spots by method C26 Figure 7 Three-terminal electrode system for low frequencies (up to 50 kHz)26 Figure 8 Two-terminal electrode system for high frequencies (above 50 kHz)27 Table I 8 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 10 07:04:48 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 60674-2:1998 ii© BSI 22 August 2002 National foreword This part of this British Standard is the English language version of EN 60674-2:1998, including amendment A1:2001. It is identical with IEC Publication 60674-2:1988, Specification for plastic films for electrical purposes Part 2: Methods of test, together with its Corrigendum November 1995 and amendment 1:2001, published by the International Electrotechnical Commission (IEC). Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index” or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. The Technical Committee has reviewed the provisions of IEC 60343:1970 and ISO/DIS 6824, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. Related British Standards to IEC 60243:1967 and IEC 60454-2:1974 are BS 2918:1957 and BS 3924:1978, respectively. Related British Standards to IEC 60250:1969 are BS 2067:1953 and BS 4542:1970. Related British Standards to ISO 1183:1987 are BS 2782-6:Method 620A:1980 and BS 3715:1964. A related British Standard to ISO 1184:1983 is BS 2782-3:Method 326:1977. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 29 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 10 07:04:48 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 60674-2 April 1998 + A1 December 2001 ICS 29.035.20 Descriptors: Electrical insulating materials, solid electrical insulating materials, insulating films, plastic films, tests English version Specification for plastic films for electrical purposes Part 2: Methods of test (includes amendment A1:2001) (IEC 60674-2:1988 + corrigendum 1995 + A1:2001) Spécification pour les films en matière plastique à usages électriques Partie 2: Méthodes dessai (inclut lamendement A1:2001) (CEI 60674-2:1988 + corrigendum 1995 + A1:2001) Bestimmung for Isolierfolien für elektrotechnische Zwecke Teil 2: Prüfverfahren (enthält Änderung A1:2001) (IEC 60674-2:1988 + corrigendum 1995 + A1:2001) This European Standard was approved by CENELEC on 1998-04-01. Amendment A1 was approved by CENELEC on 2001-12-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels © 1998 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 60674-2:1998 + A1:2001 E Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 10 07:04:48 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60674-2:1998 © BSI 22 August 2002 2 Foreword The text of the International Standard IEC 60674-2:1988 and its corrigendum November 1995, prepared by SC 15C, Specifications, of IEC TC 15, Insulating materials, was submitted to the formal vote and was approved by CENELEC as EN 60674-2 on 1998-04-01 without any modification. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. In this standard, Annex ZA is normative. Annex ZA has been added by CENELEC. Foreword to amendment A1 The text of document 15C/1263/FDIS, future amendment 1 to IEC 60674-2:1988, prepared by SC 15C, Specifications, of IEC TC 15, Insulating materials, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as amendment A1 to EN 60674-2:1998 on 2001-12-01. The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 1998-12-01 latest date by which the national standards conflicting with the EN have to be withdrawn(dow) 1998-12-01 latest date by which the amendment has to be implemented at national level by publication of an identical national standard or by endorsement(dop) 2002-09-01 latest date by which the national standards conflicting with the amendment have to be withdrawn(dow) 2004-12-01 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 10 07:04:48 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60674-2:1998 © BSI 22 August 2002 3 Introduction This standard is one of a series which deals with plastic films for electrical purposes. The series will consist of three parts: Part 1: Definitions and general requirements (IEC Publication 60674-1); Part 2: Methods of test; Part 3: Specifications for individual materials (IEC Publication 60674-3). 1 Scope This standard is applicable to plastic films used for electrical purposes. This Part 2 gives methods of test. 2 General notes on tests 2.1 Discard at least the first three layers of film from the roll to be tested before removing test specimens. 2.2 Sample rolls shall be exposed for at least 24 h to the standard atmosphere 23 ± 2 ?C and 50 ± 5 % r.h. before test specimens are removed for test. Unless otherwise specified, all individual test specimens shall be conditioned for 1 h and tested in the same standard atmosphere. 3 Thickness Thickness shall be measured by any one or more of the methods given below as required by the future IEC Publication 60674-3. 3.1 Determination of thickness by mechanical scanning 3.1.1 Principle The method is based on ISO Standard 4593 using a precision micrometer to measure the thickness of a single sheet test specimen. 3.1.2 Test specimens and measuring points Cut three strips about 100 mm wide across the width of the sample. The test strips shall not contain creases or other defects. Determine the thickness of the test strips in accordance with the requirements of ISO Standard 4593 using a micrometer having plane or radiused measuring surfaces. Measurements shall be made at nine points at approximately equally spaced intervals along the length of the test strips. In the case of samples less than 300 mm wide make the measurements every 50 mm along the length of the test strips. In the case of untrimmed rolls, readings shall not be taken within 50 mm of the edges. 3.1.3 Result The thickness is the central value of all the measurements, the highest and lowest values on each strip being reported. 3.2 Determination of gravimetric thickness of a sample Principle: calculation of the thickness of a sample from measurements of mass, area and density in accordance with Section 1 of ISO Standard 4591. 3.3 Determination of average gravimetric thickness of a roll Principle: calculation of the average thickness from measurements of the length, average width and net mass of the roll and the density of the film in accordance with Section 2 of ISO Standard 4591. 3.4 Crosswise thickness profile and lengthwise variation in thickness (Under consideration.) 4 Density To be determined in accordance with ISO Recommendation 1183. The particular method will be specified in IEC Publication 60674-3. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 10 07:04:48 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 60674-2:1998 4© BSI 22 August 2002 5 Width To be determined in accordance with ISO Standard 4592, except that a 5 m sample length is used. Determine the width five times along the length at equal intervals after the film has relaxed for one hour. Record each width measured and report the central value as the width of the roll. 6 Windability (bias/camber and sag) 6.1 Principle An assessment is made of the distortion of the film as supplied in the roll. Two forms of distortion may be apparent in the film which can impair its subsequent winding characteristics. These distortions are: 1) the film may exhibit bias or camber and therefore its edges may not be straight (see Figure 1); 2) the film may sag below its general level in areas where it has been stretched (see Figure 2 and Figure 3). 6.2 Introduction Two methods are given. Method A is appropriate for narrow (i.e. less than 150 mm) films where distortion is apparent mainly as bias/camber and also for the measurement of sag for very thick films where the tension required for extension by Method B is excessive. Method B is appropriate for wider (i.e. greater than 150 mm) films where distortion is apparent, mainly as sag. 6.3 Method A 6.3.1 Principle To assess bias/camber, a length of film is unwound and laid on a flat surface and the deviation of each of its edges from a straight line is measured (see Figure 1). To assess sag, a length of film is unwound and laid orthogonally over two parallel bars under defined conditions and the deviation from a uniform catenary is measured (see Figure 2). It may sometimes be convenient to make this measurement using the rollers of a winding machine, but in cases of dispute the dimensions and distances shall be as given below. 6.3.2 Measurement of bias/camber 6.3.2.1 Apparatus A flat, horizontal table of any suitable material having a satin finish (not polished) of sufficient width to accommodate the maximum width of film to be tested and of length 1 500 ± 15 mm