1、? I BRITISH STANDARD C ommu nicat ion cables - Specifications for test methods - Part 1-5: Electrical test methods - Capacitance The European Standard EN 50289-1-52001 has the status of a British Standard ICs 33.120.10 BS EN 50289-1-5:2001 O NO COPYJNG WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY C
2、OPYRIGHT LAW I BS EN 50289-1-5:2001 National foreword This British Standard is the official English language version of The UK participation in its preparation was entrusted by Technical Committee EPW46, Cables, wire and waveguides, RF connectors and accessories for communication and signalling to S
3、ubcommittee EPL/46/1, Communication cables, which has the responsibility to: EN 50289-1-5:2001. - - 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 in
4、ternational and European developments and promulgate them in the UK. - 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
5、be found in the BSI Standards Catalogue under the 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 St
6、andards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. This British Standard, having been prepared under the direction of the Electrotechnical Sector Committee, was published under the authority of the Stan
7、dards Committee and comes into effect on 15 September 2001 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. Amendments issued
8、 since publication Amd. No. (Date 1 Comments O BSI 08-2001 ISBN O 580 38298 2 EUROPEANSTANDARD EN 50289-115 NORME EUROPENNE EUROPISCHE NORM June 2001 ICs 33.120.20 English version Communication cables - Specifications for test methods Part 1-5: Electrical test methods - Capacitance Cbles de communic
9、ation - Spcifications des mthodes dessais Partie 1-5: Mthodes dessais lectriques - Kommunikationskabel - Spezifikationen fr Prfverfahren Teil 1-5: Elektrische Prfverfahren - 0 Capacit Kapazitt This European Standard was approved by CENELEC on 2001-03-01. CENELEC members are bound to comply with the
10、CENKENELEC 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 t
11、o 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
12、 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 El
13、ectrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels O 2001 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
14、Ref. No. EN 50289-1-5:2001 E EN 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
15、 CENELEC as EN 50289-1-5 on 2001-03-01. 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
16、 to be withdrawn (dow) 2004-04-01 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 met
17、hod 6 4.1 Equipment 6 4.2 Test sample . 6 4.3 Procedure 6 4.3.1 Unsymmetrical cables . 6 4.3.2 Symmetrical cables . 6 Capacitance unbalance to earth 6 4.3.3 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 . 7 EN
18、 50289-1-5:2001 -4- 1 Scope Part 1-5 of 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 app
19、lication. 2 Normative references This European 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
20、 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 (including amendments). EN 50289-1-1 2001 Communication cables - Specifications for tests
21、 methods - Part 1-1 : Electrical test methods - General requirements EN 50290-1 -2 - 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 capaci
22、tance/km (Cmu) of a pair (or with respect to the side of a quad) is the effective capacitance under balanced conditions, see Figure 1. Cmu = CAB + (CAG x CBG /(CAG + CEG) (nF/km) (1) It can be measured directly with balanced bridges. 3.1.1 measure of a pair under unbalanced conditions alternatively,
23、 the mutual capacitance/km (CmU) can be determined from the asymmetrical capacitances and calculated using the following formula : (nF/km) where Cl = capacitance/km between conductor “a” and conductor “b with conductor “b connected to all other conductors, screen, if any, and earth. Accordingly, to
24、the figure below, CI = CAB + CAG; ) At draft stage -5- EN 50289-1-5:2001 C2 = capacitance/km between conductor ?b and conductor ?a? with conductor ?a? connected to all other conductors and screen, if any. a Accordingly, to the figure below, C2 = CAB + CBG; C3 = capacitance/km between the conductors
25、of the pair connected together and all other conductors connected to the screen, if any, and earth Accordingly, to the figure below, C3 = CAG + CBG. T Figure 1 - Mutual capacitance 3.1.2 coaxial cables the capacitance between inner and outer conductor with outer conductor connected to earth (when me
26、asuring). 3.2 capacitance unbalance to earth the capacitance unbalance/km (Cu) to earth of a pair (or with respect to the side of a quad) is defined as It can be measured directly with balanced bridges. e 3.2.1 measurement under unbalanced conditions using asymmetrical test equipment the capacitance
27、 unbalance/km (Cu) to earth of a pair (or with respect to the side of a quad) is defined as where Cu = capacitance unbalance of reference length and reference temperature; Ct = capacitance between conductor ?a? and conductor ?b? with conductor ?b? connected to all other conductors, to the screen and
28、 to earth; C2 = 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 capacitance and capacitance unbalance to earth shall be performed with
29、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 conditions. The accuracy shall be better than 1 %. 4.2 Test sample Th
30、e 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 test. The measuring equipment shall be calibrated according to
31、the manufacturers specification. Test leads shall be involved in the calibration procedure. 4.3.1 Unsymmetrical cables For coaxial cables C, is measured between the inner and the outer conductor with the outer conductor connected to earth. For multicore cables C, shall be measured with one conductor
32、 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 pair or side of a quad with all other conductors and screens, if any,
33、connected to earth. 4.3.2.2 Mutual capacitance measured under unbalanced conditions Measure Cl, Cp, and CJ in accordance with 3.1.1. 4.3.3 Capacitance unbalance to earth The capacitance unbalance to earth shall be measured in accordance with 3.2. All screens shall be earthed. 5 Expression of test re
34、sults 5.1 Expression of mutual capacitance The test result of the mutual capacitance shall be normalised to the reference length of 1 km. Clll c =-xl O00 0 L -7- (nF/km) EN 50289-1 -5:2001 (5) where C = mutual capacitance normalised to the reference length (1 km); C, = measured capacitance, in nF, o
35、f 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. C, = capacitance unbalance corrected to the reference length (1 km); Cu, = L = length of sample in m. measured
36、 capacitance unbalance, in pF, of CUT; 6 Test report The test report shall include: e- tem perature, test frequency, balanced or unbalanced measurement, sample length, the mutual capacitance and the capacitance unbalance for the reference length derived from the measured value as required. BS EN 502
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