1、BRITISH STANDARD BS EN 61234-1:1994 IEC 1234-1: 1994 Method of test for Hydrolytic stability of electrical insulating materials Part 1: Plastic films The European Standard EN 61234-1:1994 has the status of a British Standard UDC 621.315.6:620.193BSEN 61234-1:1994 This British Standard, having been p
2、repared under the directionof the Cables and Insulation Standards Policy Committee, was published underthe authority of the Standards Board and comesintoeffect on 15 August 1994 BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference CIL/15 Special announcem
3、ent in BSINews May 1994 ISBN 0 580 23395 2 Cooperating organizations The European Committee for Electrotechnical Standardization (CENELEC), under whose supervision this European Standard was prepared, comprises the national committees of the following countries: Austria Italy Belgium Luxembourg Denm
4、ark Netherlands Finland Norway France Portugal Germany Spain Greece Sweden Iceland Switzerland Ireland United Kingdom Amendments issued since publication Amd. No. Date CommentsBSEN 61234-1:1994 BSI 11-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 I
5、ntroduction 3 1 Scope 3 2 Normative references 3 3 Definitions 3 4 Test specimens 4 5 Conditioning 4 6 Apparatus 4 7 Procedure 4 8 Measurements and test results 5 9 Report 5 Annex ZA (normative) Other international publications quotedinthisstandardwith the references of the relevant Europeanpublicat
6、ions 6 National annex NA (informative) Committees responsible Inside back cover National annex NB (informative) Cross-references Inside back coverBSEN 61234-1:1994 ii BSI 11-1999 National foreword This British Standard has been prepared under the direction of the Cables and Insulation Standards Poli
7、cy Committee and is the English language version of EN 61234-1:1994 Method of test for the hydrolytic stability of electrical insulatingmaterials Part 1: Plastic films, published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC 1234-1:1994 published
8、by the International Electrotechnical Commission (IEC). A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from lega
9、l obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the
10、 amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN61234-1 March1994 UDC 621.315.6:620.193 Descriptors: Electrical insulating materials, solid electrical insulating materials, insulating films, plastic sheets, tests, immersion tests, stability tests, hydro
11、lytic tests, measurements, tensile strength, breakdown voltage English version Method of test for the hydrolytic stability of electrical insulating materials Part 1: Plastic films (IEC 1234-1:1994) Mthode dessai pour la stabilit hydrolytique des matriaux isolants lectriques Partie1:Films en matire p
12、lastique (CEI 1234-1:1994) Prfverfahren fr die Hydrolysebestndigkeit von Elektroisolierstoffen Teil 1: Kunststoffolien (IEC 1234-1:1994) This European Standard was approved by CENELEC on 1993-12-08. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the con
13、ditions 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
14、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 electrotech
15、nical committees of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrote
16、chnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B-1050 Brussels 1994 Copyright reserved to CENELEC members Ref. No. EN 61234-1:1994 EEN61234-1:1994 2 BSI 11-1999 Foreword The text of document 15A(CO)67, as prepared by Sub-Committee 15A: Short-time te
17、sts, of IECTechnical Committee 15: Insulating materials, was submitted to the IEC-CENELEC parallel vote in May 1993. The reference document was approved by CENELEC as EN 61234-1 on 8 December 1993. The following dates were fixed: Annexes designated “normative” are part of the body of the standard. I
18、n this standard, Annex ZA is normative. latest date of publication ofan identical national standard (dop) 1995-03-01 latest date of withdrawal ofconflicting national standards (dow) 1995-03-01EN61234-1:1994 BSI 11-1999 3 Introduction This part of IEC 1234 is one of a series which deals with tests fo
19、r the determination of hydrolytic stability of solid insulating materials. Part 1 describes the method of test for plastic films. This test method investigates the combined effect of water and elevated temperature in appropriate vessels, but does not impose any mechanical stress on the test specimen
20、s during their immersion in water. A test for assessing the effect of mechanical stress during immersion in water at high temperature will be recommended later. In addition, it is intended to publish other parts in this series, detailing methods of test for rigid materials, laminates and varnishes.
21、1 Scope This part of IEC 1234 describes the method of test for the determination of the hydrolytic stability of plastic films subjected to the simultaneous influence of water and temperature. With this test method, the irreversible changes of the mechanical and electrical properties are measured. Th
22、e test method is applicable to films up to 250 4m thick. Although this method was developed for electrically insulating plastic films, as specified, for example, in the series of IEC 674, it may be appropriate for other types of plastic films. 2 Normative references The following normative documents
23、 contain provisions which, through reference in this text, constitute provisions of this part of IEC 1234. At the time of publication, the edition indicated was valid. All normative documents are subject to revision, and parties to agreement based on this part of IEC 1234 are encouraged to investiga
24、te the possibility of applying the most recent editions of the normative documents indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. IEC 243-1:1988, Methods of test for electric strength of solid insulating materials Part 1: Tests at power frequen
25、cies. IEC 296:1982, Specification for unused mineral insulating oils for transformers and switchgear. Amendment 1 (1986) IEC 584-1:1977, Thermocouples Part 1: Reference tables. Amendment 1 (1989) IEC 584-2:1982, Thermocouples Part2:Tolerances. Amendment 1 (1989) IEC 674-1:1980, Specification for pla
26、stic films for electrical purposes Part 1: Definitions and general requirements. IEC 674-3-2:1992, Specification for plastic films for electrical purposes Part 3: Specifications for individual materials Sheet 2: Requirements for balanced biaxially oriented polyethylene terephthalate (PET) films used
27、 for electrical insulations. IEC 674-3-4 to 6:1993, Specification for plastic films for electrical purposes Part 3: Specifications for individual materials Sheets 4 to 6: Requirements for polyimide films used for electrical insulation. ISO 1184:1983, Plastics Determination of tensile properties of f
28、ilms. 3 Definitions For the purpose of this standard, the following definitions apply: 3.1 breakdown voltage the voltage at which electrical breakdown occurs measured in accordance with 8.1 3.2 tensile strength the tensile strength of the films measured in accordance with ISO 1184EN61234-1:1994 4 BS
29、I 11-1999 4 Test specimens 4.1 Number of test specimens Five specimens shall be used for each property at each test temperature and time. For the determination of the properties of the untreated film 10 specimens shall be used for each property. 4.2 Test specimens for the determination of tensile st
30、rength The specimens shall be taken in the machine direction. The recommended dimensions for the specimens are15 mm wide, 150 mm long, with a test gauge length of 100 mm. If other dimensions are used they shall be reported. 4.3 Test specimens for the determination of breakdown voltage The recommende
31、d dimensions for the specimens are100 mm by 100 mm. If other dimensions are used they shall be reported. 5 Conditioning Specimens shall be conditioned, prior to both treatment and testing, for not less than 60 min at60 C 2K in a vacuum oven at a pressure less than 1,5 Pa. Specimens shall then be tes
32、ted immediately, or stored in a dessicator before testing. 6 Apparatus 6.1 Ageing vessel The ageing vessel shall have a minimum volume of1 l per five specimens. Not more than 5 % loss of water is permissible after 1 000 h at the test temperature. The material of the ageing vessel must be chosen so t
33、hat the ageing vessel is able to satisfy the following calibration test. Demineralized water according to 7.2 is heated at the highest test temperature (140 C 2 K) for 1 000 h. The pH of the water shall then not change from 7,0 0,5 to more than 7,0 1,5 and the conductivity shall not increase by more
34、 than 500 4S/m. National regulations for the use of pressure vessels shall be observed. 6.2 Device for measuring the film thickness The instrument for measuring the thickness of thefilm shall be capable of measuring to a tolerance of 24m. 6.3 Temperature measuring device The temperature shall be mea
35、sured inside the pressure vessel with a thermocouple in accordance with IEC584-1 and IEC 584-2. 6.4 pH-meter The pH-meter shall have an accuracy of at least 0,05 pH. 7 Procedure 7.1 Outline The principle of this test is that dried film samples are immersed in water for different times and at differe
36、nt temperatures. The specimens are then dried again, according to clause 5 and tested to determine the electrical and mechanical properties. The per cent retention of those electrical and mechanical properties, in comparison to the untreated film, is reported. 7.2 Treatment medium Demineralized wate
37、r is used which, before treatment commences, shall have a conductivity of less than5004S/m and a pH of 7,0 0,5. 7.3 Treatment procedure Test specimens as in 4.2 and 4.3 are prepared, and then completely immersed in water in the treatment vessel. It is important to avoid mechanical load on the specim
38、ens, and to avoid direct contact between the specimens. Only one type of film shall be tested in each volume of water.EN61234-1:1994 BSI 11-1999 5 7.4 Temperature of treatment The temperatures which shall be used for thetreatment are 90 C 2 K, 120 C 2 K, and140 C 2 K. The temperature shall be measur
39、ed inside the pressure vessel with a thermocouple in accordance with 6.3. 7.5 Duration of the treatment The recommended times for the treatment at eachtemperature are 48, 168 and 500 h; optionally1 000 h or even longer times of duration may be used but shall be reported. The interruption of the trea
40、tment caused by removal of samples from the vessel for testing shall be as short as possible. Any water lost in this process should be replaced. 8 Measurements and test results 8.1 Breakdown voltage The breakdown voltage shall be measured in accordance with 6.2 of IEC 243-1. Both treated and untreat
41、ed specimens, defined by4.1, shall be measured in insulating oil conforming to IEC 296 as the preferred medium, in accordance with 6.2 of IEC 243-1, and the mean initial and mean retained values reported. Optionally, measurements in air medium are permissible, but shall be reported. The preferred el
42、ectrode arrangement is as in 4.1.1.2 of IEC 243-1, with a recommended parallel plate diameter of 25 mm. Other parallel electrode arrangements are permissible, but should be reported. Ten untreated specimens shall be tested and the initial mean value noted. Five treated specimens are to be tested for
43、 each combination of time and temperature and the mean retained value noted. 8.2 Tensile strength The tensile strength is measured according to ISO1184 after conditioning in accordance with clause 5, ontreated and untreated specimens. Thetest speed shall be 100 mm/min, and the test temperature23 C 1
44、 K. Ten untreated specimens are to be tested and the initial mean value noted. Five treated specimens shall be tested for each combination of time and temperature, and the retained mean value noted. 8.3 Calculation of the results The results are reported as the retention of the property, compared to
45、 the initial value, and expressed as a percentage of the initial value. Results are calculated using the following equations: Retained tensile strength (t, T)= Retained breakdown voltage (t, T) = where 9 Report Unless otherwise specified, the report shall include the following: a) a complete identif
46、ication of the material tested, a description of the specimens, and the method of preparation; b) the nominal thickness of the test specimens; c) the time-temperature treatment of the test specimens; d) the per cent retention of the breakdown voltage; e) the per cent retention of the tensile strengt
47、h. B(t, T) is the mean value of tensile strength at time t and at temperature T; B(c) is the mean value for the tensile strength of untreated specimens; U(t, T) is the mean value of breakdown voltage at time t and at temperature T; U(c) is the mean value for the breakdown voltage of untreated specim
48、ens. B tT , () B c () -100 %() UtT , () Uc () -100 %() EN61234-1:1994 6 BSI 11-1999 Annex ZA (normative) Other international publications quoted in this standard with the references of the relevant European publications This European Standard incorporates by dated or undated reference, provisions fr
49、om other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. NOTEWhen the international publication has been modified by CENELEC common
