BS EN 50289-1-5-2001 Communication cables - Specifications for test methods - Electrical test methods - Capacitance - SEC5 Capacitance《通信电缆 试验方法规范 电气试验方法 电容 第5节 电容》.pdf

1、BRITISH STANDARD BS EN 50289-1-5:2001 Communication cables Specifications for test methods Part 1-5: Electrical test methods Capacitance The European Standard EN 50289-1-5:2001 has the status of a British Standard ICS 33.120.10 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS

2、 EN 50289-1-5:2001 This British Standard, having been prepared under the direction of the Electrotechnical Sector Committee, was published under the authority of the Standards Committee and comes into effect on 15 September 2001 BSI 08-2001 ISBN 0 580 38298 2 National foreword This British Standard

3、is the official English language version of EN 50289-1-5:2001. The UK participation in its preparation was entrusted by Technical Committee EPL/46, Cables, wire and waveguides, RF connectors and accessories for communication and signalling to Subcommittee EPL/46/1, Communication cables, which has th

4、e responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the

5、section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct applicat

6、ion. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related int

7、ernational and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 7 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendmen

8、ts issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 50289-1-5 NORME EUROPENNE EUROPISCHE NORM June 2001 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretar

9、iat: rue de Stassart 35, B - 1050 Brussels 2001 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 50289-1-5:2001 E ICS 33.120.20 English version Communication cables - Specifications for test methods Part 1-5: Electrical test method

10、s - Capacitance Cbles de communication - Spcifications des mthodes dessais Partie 1-5: Mthodes dessais lectriques - Capacit Kommunikationskabel - Spezifikationen fr Prfverfahren Teil 1-5: Elektrische Prfverfahren - Kapazitt This European Standard was approved by CENELEC on 2001-03-01. CENELEC member

11、s 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

12、 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

13、 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.EN

14、 50289-1-5:2001 2 Foreword This European Standard was prepared by SC 46XC, Multicore, Multipair and Quad Data communication cables, of Technical Committee CENELEC TC 46X, Communication cables. The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50289-1-5 on 2001-

15、03-01. 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) 2002-04-01 - latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2004-04-01

16、 This European Standard has been prepared under the European Mandate M/212 given to CENELEC by the European Commission and the European Free Trade Association. _ 3 EN 50289-1-5:2001 Contents Foreword 1 1 Scope. 4 2 Normative references 4 3 Definitions . 4 4 Test method 6 4.1 Equipment 6 4.2 Test sam

17、ple . 6 4.3 Procedure 6 4.3.1 Unsymmetrical cables . 6 4.3.2 Symmetrical cables . 6 4.3.3 Capacitance unbalance to earth 6 5 Expression of test results. 6 5.1 Expression of mutual capacitance 6 5.2 Expression of capacitance unbalance to earth 7 6 Test report. 7EN 50289-1-5:2001 4 1 Scope Part 1-5 of

18、 EN 50289 details the test methods to determine the capacitance characteristics of the finished cables used in analogue and digital communication systems. It is to be read in conjunction with Part 1-1 of EN 50289, which contains essential provisions for its application. 2 Normative references This E

19、uropean Standard incorporates by dated or undated reference, provisions from 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 publicati

20、ons 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 (including amendments). EN 50289-1-1 2001 Communication cables Specifications for tests methods - Part 1-1: Electrical test meth

21、ods General requirements EN 50290-1-2 1) - Communication cables - Part 1-2: Definitions 3 Definitions For the purpose of this European Standard, the definitions of EN 50290-1-2 apply in addition to the following ones. 3.1 mutual capacitance the mutual capacitance/km (C mu ) of a pair (or with respec

22、t to the side of a quad) is the effective capacitance under balanced conditions, see Figure 1. C mu = C AB+ (C AGx C BG/(C AG+ C BG ) (nF/km) (1) It can be measured directly with balanced bridges. 3.1.1 measure of a pair under unbalanced conditions alternatively, the mutual capacitance/km (C mu ) ca

23、n be determined from the asymmetrical capacitances and calculated using the following formula : () 3 2 2 1 3 2 1 mu C 4 C C 4 C 2 C C C + = (nF/km) (2) where C 1 = capacitance/km between conductor a and conductor b with conductor b connected to all other conductors, screen, if any, and earth. Accord

24、ingly, to the figure below, C 1= C AB+ C AG ;1)At draft stage 5 EN 50289-1-5:2001 C 2 = capacitance/km between conductor b and conductor a with conductor a connected to all other conductors and screen, if any. Accordingly, to the figure below, C 2= C AB+ C BG ; C 3 = capacitance/km between the condu

25、ctors of the pair connected together and all other conductors connected to the screen, if any, and earth Accordingly, to the figure below, C 3= C AG+ C BG . C AB C BG C AG Figure 1 - Mutual capacitance 3.1.2 coaxial cables the capacitance between inner and outer conductor with outer conductor connec

26、ted to earth (when measuring). 3.2 capacitance unbalance to earth the capacitance unbalance/km (C u ) to earth of a pair (or with respect to the side of a quad) is defined as C u= C AG C BG (pF/km) (3) It can be measured directly with balanced bridges. 3.2.1 measurement under unbalanced conditions u

27、sing asymmetrical test equipment the capacitance unbalance/km (C u ) to earth of a pair (or with respect to the side of a quad) is defined as C u= C 1 C 2 (pF/km) (4) where C u = capacitance unbalance of reference length and reference temperature; C 1 = capacitance between conductor a and conductor

28、b with conductor b connected to all other conductors, to the screen and to earth; C 2 = capacitance between conductor b and conductor a with conductor a connected to all other conductors, to the screen and to earth.EN 50289-1-5:2001 6 4 Test method 4.1 Equipment The measurement of the mutual capacit

29、ance and capacitance unbalance to earth shall be performed with a.c. at a frequency range between 500 Hz and 2 kHz. To measure mutual capacitance a three (3) terminal capacitance bridge shall be used for balanced conditions and a two (2) terminal capacitance bridge shall be used for unbalanced condi

30、tions. The accuracy shall be better than 1 %. 4.2 Test sample The cable under test (CUT) shall have a minimum length of 100 m and both ends of the CUT shall be prepared to avoid stray capacitance. 4.3 Procedure The test shall be carried out on the CUT after the continuity or the conductor resistance

31、 test. The measuring equipment shall be calibrated according to the manufacturers specification. Test leads shall be involved in the calibration procedure. 4.3.1 Unsymmetrical cables For coaxial cables C mu is measured between the inner and the outer conductor with the outer conductor connected to e

32、arth. For multicore cables C mu shall be measured with one conductor against all others (circulating all conductors) and the screen, if any, connected to the earth. 4.3.2 Symmetrical cables 4.3.2.1 Mutual capacitance measured under balanced conditions The measuring voltage shall be applied to the pa

33、ir or side of a quad with all other conductors and screens, if any, connected to earth. 4.3.2.2 Mutual capacitance measured under unbalanced conditions Measure C 1 , C 2 , and C 3in accordance with 3.1.1. 4.3.3 Capacitance unbalance to earth The capacitance unbalance to earth shall be measured in ac

34、cordance with 3.2. All screens shall be earthed. 5 Expression of test results 5.1 Expression of mutual capacitance The test result of the mutual capacitance shall be normalised to the reference length of 1 km. 7 EN 50289-1-5:2001000 1 L C C m = (nF/km) (5) where C = mutual capacitance normalised to

35、the reference length (1 km); C m = measured capacitance, in nF, of CUT; L = length of sample in m. 5.2 Expression of capacitance unbalance to earth The test result of the capacitance unbalance to earth shall be normalized to the reference length of 1 km. L 000 1 C C um u = (pF/km) (6) where C u = ca

36、pacitance unbalance corrected to the reference length (1 km); C um = measured capacitance unbalance, in pF, of CUT; L = length of sample in m. 6 Test report The test report shall include: - temperature, - test frequency, - balanced or unbalanced measurement, - sample length, - the mutual capacitance

37、 and the capacitance unbalance for the reference length derived from the measured value as required.BS EN 50289-1-5:2001 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK vie

38、w on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve th

39、e quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: 020 8996 9000. Fax: 020 89

40、96 7400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards. Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel: 020 8996

41、9001. Fax: 020 8996 7001. Standards are also available from the BSI website at http:/www.bsi-. In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as British Standards, unless otherwise requested. Information on stand

42、ards BSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Various BSI electronic information services are also available which give details on all its products and services. Contact the Information

43、 Centre. Tel: 020 8996 7111. Fax: 020 8996 7048. Subscribing members of BSI are kept up to date with standards developments and receive substantial discounts on the purchase price of standards. For details of these and other benefits contact Membership Administration. Tel: 020 8996 7002. Fax: 020 89

44、96 7001. Further information about BSI is available on the BSI website at http:/www.bsi-. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the international standardization bodies. Except as permitted under the Copyright, Designs a

45、nd Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without prior written permission from BSI. This does not preclude the free use, in the course of implementing the standard, of ne

46、cessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel: 020 8996 7070.