1、BRITISH STANDARDBS EN 50497:2007Recommended test method for assessment of the risk of plasticizer exudation from PVC insulated and sheathed cablesThe European Standard EN 50497:2007 has the status of a British StandardICS 29.035.20g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g
2、40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 50497:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 December 2007 BSI 2007ISBN 978 0 580 57097 1
3、National forewordThis British Standard is the UK implementation of EN 50497:2007.The UK participation in its preparation was entrusted by Technical Committee GEL/20, Electric cables, to Subcommittee GEL/20/17, Low voltage cables.A list of organizations represented on this committee can be obtained o
4、n request to its secretary.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 cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date Comm
5、entsEUROPEAN STANDARD EN 50497 NORME EUROPENNE EUROPISCHE NORM November 2007 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 200
6、7 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 50497:2007 E ICS 29.035.20 English version Recommended test method for assessment of the risk of plasticizer exudation from PVC insulated and sheathed cables Mthode dessai recomman
7、de pour lvaluation du risque dexsudation de plastifiant des gaines des cbles et des isolants en PVC Empfohlenes Prfverfahren zur Einschtzung des Risikos von Weichmacherausschwitzungen bei PVC-isolierten und -ummantelten Kabeln und Leitungen This European Standard was approved by CENELEC on 2007-11-0
8、1. 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 obtain
9、ed 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 Centra
10、l Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Mal
11、ta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN 50497:2007 - 2 - Foreword This European Standard was prepared by the Technical Committee CENELEC TC 20, Electric cables, in response to CLC/TC 20 (AT) 42. The text of the
12、 draft was submitted to the formal vote and was approved by CENELEC as EN 50497 on 2007-11-01. 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) 2008-11-01 latest date by which
13、the national standards conflicting with the EN have to be withdrawn (dow) 2009-11-01 _ - 3 - EN 50497:2007 Contents Introduction . 4 1 Scope 5 2 Normative references . 5 3 Terms and definitions 5 4 Test method. 5 4.1 Apparatus. 5 4.2 Sampling 6 4.3 Conditioning of samples. 6 4.4 Test method 6 5 Eval
14、uation of results 6 6 Test report . 6 Bibliography 7 EN 50497:2007 - 4 - Introduction PVC, by its nature, requires the addition of chemical agents (plasticizers, extenders) in order to generate useful and effective electrical grade materials for cable insulation and sheathing having suitable flexibi
15、lity. Use over many decades has shown that exceptional and unexpected circumstances, coupled with particular installation conditions, may generate unfavourable conditions in which the plasticizer or extender dissociates from the body of the cable material and exudes from it. This is undesirable as i
16、t progressively alters the characteristics of the PVC and, in extreme cases, may lead to cracking, or it could damage surrounding components. It is also aesthetically unpleasing and, if it drips or drains in discrete amounts, may become a serious nuisance and may cause concern. In practice the pheno
17、menon is rare, because material suppliers and cable manufacturers have developed controls for cable grade PVC compounds. These controls begin with material selection tests to screen out unsuitable additives. Such tests are described, for example, in ASTM D3291-97:2003. Furthermore, PVC insulated and
18、 sheathed cables made to recognised standards are required to conform to the compatibility test in EN 60811-1-2, 8.1.4. In the vast majority of cases these actions are sufficient to prevent exudation in service. It is not possible to determine every type of assembly into which a cable may be placed,
19、 nor every installation condition, including thermal condition, that may be experienced. However, where additional assurances and tests are deemed necessary, it is recommended that the method in this European Standard should be used. - 5 - EN 50497:2007 1 Scope The test method described in this Euro
20、pean Standard shows, by the use of accelerated testing, discrete exudation of plasticizer from PVC insulated and sheathed cables. It is for use in circumstances where the manufacturer determines that there may be a specific risk that cannot be assessed only by use of the compatibility test in EN 608
21、11-1-2, 8.1.4. This method is intended as a qualitative test on the completed product and not an individual material test. NOTE 1 Information on the background to use of the test is given in the Introduction. NOTE 2 Although any exudation is most likely to be of plasticizer, other components may als
22、o exude and, for the purposes of this standard, are treated equally in this test. NOTE 3 The method has been developed with special reference to PVC/PVC cables. No recommendation is given as to its use with cables based on other insulation and sheathing materials. 2 Normative references The followin
23、g referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 60811-1-2 1995 Insulating and sheathing materials of elect
24、ric cables Common test methods Part 1-2: General application Thermal ageing methods (IEC 60811-1-2:1985 + A1:1989 + corr. May 1986) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 compatibility ability of the plasticizer to be retained by the
25、 bulk compound or base resin NOTE High compatibility indicates good retention by the bulk compound. 3.2 plasticizer substance incorporated into a material to increase its flexibility, softness, distensibility, or workability NOTE Plasticizers typically consist of high boiling point , oily, organic l
26、iquids. 3.3 exudation visible presence of plasticizer on the surface of the cable, or dripping from the cable 3.4 operating temperature maximum permitted conductor temperature of the completed product 4 Test method 4.1 Apparatus The apparatus includes the ordinary laboratory apparatus, and a) air ci
27、rculating oven in accordance with EN 60811-1-2, b) filter or cigarette paper, c) chamber capable of sub-zero temperatures. EN 50497:2007 - 6 - 4.2 Sampling Take two representative samples of the completed cable. Cut the two cables so that each of them forms a test sample (200 10) mm long. If a manuf
28、acturer produces the full range of the relevant product to a specific standard, testing is only necessary on one representative size if identical materials are used. 4.3 Conditioning of samples The test samples shall be conditioned at (23 2) C for a period of 24 h prior to testing. 4.4 Test method T
29、he two conditioned test samples shall be suspended vertically, with filter paper positioned underneath, in an air oven. The bottom edge of each sample shall be (15 5) mm above the filter paper. The test samples shall be suspended in the air oven for a duration of 7 days, at a temperature of 10 C abo
30、ve the maximum permitted conductor temperature of the cable, but at a minimum temperature of (80 2) C. Immediately after this period of 7 days in the air oven, the test samples shall be separated as follows: one test sample shall be kept at an ambient temperature of (23 2) C; one test sample shall b
31、e kept at -(5 2) C. In both cases the test sample, suspended vertically with the filter paper positioned underneath at the distance previously described, shall be kept at the respective condition for 21 days. The test samples shall be checked at regular periods for symptoms of plasticizer exudation
32、for the duration of 28 days (7 days + 21 days). 5 Evaluation of results The examination shall be done with normal or corrected vision, without magnification, for plasticizer exudation. There shall be no greasy film on the surface of the cable, drops at the cable ends, marks on the filter paper. The
33、findings shall be recorded. 6 Test report The test report shall contain the following minimum information: a) the type and identification of the tested cable; b) the reference to this document; c) the date of the test; d) the result of the test. - 7 - EN 50497:2007 Bibliography ASTM D3291-97:2003, S
34、tandard Practice for Compatibility of Plasticizers in Poly(Vinyl Chloride) Plastics Under Compression BS EN 50497:2007BSI389 Chiswick High RoadLondonW4 4ALBSI British Standards InstitutionBSI is the independent national body responsible for preparing British Standards. It presents the UK view on sta
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