1、C.D.U./U.D.C.:621.315.2/.3:621.315.616.96:678.743.22.001.4.(047):620.1(047)31COMMISSION ELECTROTECHNIQUE INTERNATIONALE(affiliee a IOrganisation Internationale de Normalisation-IS0)RAPPORT DE LA CEIINTERNATIONAL ELECTROTECHNICAL COMMISSION(afiliated to the International Organization for Standardizat
2、ion-ISO)IEC REPORTPublication 330Premiere edition-First edition1970Methodes dessai des enveloppes isolantes et gaines de p.c.v.pourles cables electriquesMethods of test for p.v.c.insulation and sheath of electric cablesFOR REFEEENCE ONLYSTANDARDS AND SAFEIY SFCTIONNATIONL ENEENY AUTHORITYDroits de r
3、eproduction reserves-Copyright-all rights reservedAucune partie de cette publication ne peut tre reproduite ni utilisee sous No part of this publication may be reproduced or utilized in anyquelque forme que ce soit et par aucun procde,lectronique ou mca-form or by any means,electronic or mechanical,
4、including photocopyingnique,y compris la photocopie et les microfilms,sans Iaccord crit de Iditeur.I and microfilm,without permission in writing from the publisher.Bureau Central de la Commission Electrotechnique Internationale1,rue de VarembeGeneve,SuissePrix Fr s:40.-IEdPrice S.Fr.VoL.9一3一CONTENTS
5、PageFOREWORD5PREFACE,Clause7l.Scope.72.General notes on tests.3.Tests for determining mechanical properties of insulation before and after ageing.94.Tests for determining mechanical properties of sheaths before and after ageing.175.Electrical tests:,236.Tests for resistance of insulation and sheath
6、to cracking.237.Methods of test for insulation and sheath at low temperatures.278.Behaviour of insulation and sheath at high temperatures.33APPENDIX A-Measurements of thickness and outer diameter of insulation and sheath.39APPENDIX B-Method for determining the density of p.v.c.insulation and sheath.
7、41APPENDIX C-Methods of measuring air flow in ovens4346FIGURES-5INTERNATIONAL ELECTROTECHNICAL COMMISSIONMETHODS OF TEST FOR P.V.C.INSULATION AND SHEATH OFELECTRIC CABLESFOREWORD1)The formal decisions or agreements of the IE C on technical matters,prepared by Technical Committees on which all theNat
8、ional Committees having a special interest therein are represented,express,as nearly as possible,an internationalconsensus of opinion on the subjects dealt with.2)They have the form of recommendations for international use and they are accepted by the National Committees in thatsense.3)In order to p
9、romote this international unification,the IEC expresses the wish that all National Committees having asyet no national rules,when preparing such rules,should use the IE C recommendations as the fundamental basis for theserules in so far as national conditions will permit.4)The desirability is recogn
10、ized of extending international agreement on these matters through an endeavour to harmonizenational standardization rules with these recommendations in so far as national conditions will permit.The NationalCommittees pledge their influence towards that end.PREFACEThis Report has been prepared by IE
11、C Technical Committee No.20,Electric Cables.A first draft was discussed at the meeting held in Ankara in 1967,as a result of which a new draft wassubmitted to National Committees for approval under the Six Months Rule in January 1969.The following countries voted explicitly in favour of the publicat
12、ion:AustraliaNetherlandsAustriaPolandBelgiumRomaniaCzechoslovakiaSwedenDenmarkSwitzerlandFinlandTurkeyGermanyUnion of Soviet Socialist RepublicsIsraelUnited KingdomItalyUnited States of AmericaJapanYugoslaviaSince sufficient agreement could not be reached,IEC Technical Committee No.20 decided that t
13、hisPublication should be published as a Report instead of as a Recommendation.This Report is incomplete.The test for determining the weight loss measurement and the acceleratedageing test,together with tests for resistance to cracking and methods of test and behaviour at low andhigh temperatures are
14、 being reconsidered,taking into account the latest knowledge on this subject.Elec-trical tests have been omitted and are under consideration for inclusion in the form of fundamental electricaltests for this material.A second edition will be published later.一7METHODS OF TEST FOR P.V.C.INSULATION AND
15、SHEATH OFELECTRIC CABLES1.ScopeThis Report is a catalogue,incomplete in this first edition,of test methods which are recommendedto be used for testing polyvinyl chloride insulation and sheath of electric cables,wires and cords usedfor power distribution or telecommunications.Full test requirements,g
16、iving all the limiting values for test results,are not specified in this Report:it is intended that these should be specified in the Recommendations for the various types of cable.Any test requirements which are given in this Report should be considered as examples only andmay be modified to suit th
17、e needs of a particular type of cable.Conditioning values and testing parameters are specified for the most common types of pounds and of cables,wires and cords.It is intended that the values of these parameters should bemodified for use in various applications,particularly for pounds for operation
18、at tempera-tures higher than 70 C.Notes 1.-The term polyvinyl chlorideis used to denote compounds of polyvinyl chloride or suitable co-polymersbased on vinyl chloride or of mixtures of p.v.c.and such co-polymers.2.-This Report is intended as a guide to IEC Technical Committees in drafting Recommenda
19、tions for electriccables and to the National Committees in drafting specifications for use in their own countries.TheseCommittees should select from this general Report the tests appropriate to the particular application withwhich they are concerned,and reproduce these tests in their cable specifica
20、tions after adding the limitingvalues for test results.This Report is not intended to be used as a guide in drafting purchasing specifications,which should bebased on the relevant national specifications for electric cables or,where these do not exist,on the relevantIEC Recommendations for electric
21、cables.2.General notes on tests2.1 The tests described in this Report are type tests.Note.-The definition of a type test is given in IEC Publication 189-1,Low-frequency Cables and Wires withp.v.c.Insulation and p.v.c.Sheath,Part 1:General Test and Measuring Methods.2.2 If the methods of sampling are
22、 not given in the following tests,these should be specified in therelevant cable Recommendation.2.3 Unless otherwise specified,tests shall be made at an ambient temperature of 20+5C.2.4 Unless otherwise specified,test voltages shall be a.c.40 Hz to 62 Hz of approximately sine-waveform,the ratio peak
23、 value/r.m.s.value being within the limits 2+7%.The values quoted are r.m.s.values.2.5 If a marking is stamped into the insulation or sheath,thus giving rise to a local thickness smallerthan the specified thickness,the samples used for the tests shall be taken so as to include such marking.2.6 Where
24、 the term median valueis used in this Report,it means either the middle value,if an oddnumber of values is obtained,or the mean of both the middle values if an even number of values isobtained,after the values have been arranged in order of increasing value.93.Tests for determining mechanical proper
25、ties of insulation before and after ageing.The tests shall determine the tensile strength and elongation at break of the insulating materialtaken from pieces of cable in the following conditions:a)as received(i.e.without any ageing treatment);b)after an accelerated ageing treatment;c)after another a
26、geing treatment,different from b),if required.3.1SamplingThree samples of each core to be tested shall be taken,each not less than I m from the other two.The cores of flat cords are not separated.Each sample shall be at least 60 cm long,and shall becut into six small pieces,two of which shall be use
27、d for each of the tests a),b)and c),so that sixsmall pieces of insulated core are provided for each of these tests.If it is possible to take two test pieces from the circumference of the core,the sample shall be40 cm long and shall be cut into four small pieces.Note.-In general,this type of sample i
28、s applicable to a conductor of cross-sectional area of 50 mm2 and above.If the samples of core are taken from the three places x,y and z,they shall be marked consecutively:X0,X1,X2,X3,X4,X5;y0,y1,y2,y3,y4,y5;Z0,Z1,Z2,Z3,Z4,Z5.When two test pieces are taken from the circumference of the core,the numb
29、ering shall be:XX。The procedure shall be the same for test pieces y and z.The numbering of the samples shall corres-pond to their original places in the sample of the core.Those numbered:I and 3 shall be subjected to the preparation and determination of the cross-sectional area,asspecified in Sub-cl
30、auses 3.2 and 3.3 respectively,and to the test specified in Sub-clauses 3.4and 3.5 without an ageing treatment.2 and 4 to the test after an ageing treatment,as specified in Sub-clause 3.7.0 and 5 to the test after another ageing treatment,if required.The tensile test on the unaged pieces shall be made at the same time as the test on the aged pieces.3.2 Preparation of test piecesTest pieces may be of two types,tubular and dumb-bell.
