BS-6007-1993.pdf

BRITISH STANDARD BS 6007:1993 Incorporating Amendment No. 1 Specification for Rubber-insulated cables for electric power and lighting Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 06:58:03 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6007:1993 This British Standard, having been prepared under the direction of the Cables and Installation Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 November 1993 © BSI 12-1999 First published August 1969 Second edition January 1976 (dated 1975) Third edition December 1983 Fourth edition October 1991 Fifth edition November 1993 The following BSI references relate to the work on this standard: Committee reference CIL/20 Draft for comment 92/32695 DC ISBN 0 580 22552 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Cables and Insulation Standards Policy Committee (CIL/-) to Technical Committee CIL/20, upon which the following bodies were represented: Association of Consulting Engineers Association of Manufacturers of Domestic Electrical Appliances BECCAMA (Beama Electrical Cable Connector and Accessories Manufacturers Association) British Approvals Service for Cables British Cable Makers Confederation British Plastics Federation British Steel Industry Department of the Environment (Property Services Agency) Department of Trade and Industry (Consumer Safety Unit, CA Division) Electricity Association Engineering Equipment and Materials Users Association Institution of Electrical Engineers London Regional Transport The following bodies were also represented in the drafting of the standard, through subcommittees and panels: Association of Manufacturers Allied to the Electrical and Electronic Industry (BEAMA Ltd.) British Electrical Systems Association (BEAMA Ltd.) British Non-Ferrous Metals Federation British Steel plc Chartered Institution of Building Services Engineers ERA Technology Ltd. Electrical Installation Equipment Manufacturers Association (BEAMA Ltd.) Engineering Industries Association GAMBICA (BEAMA Ltd.) Institution of Incorporated Executive Engineers Lighting Industry Federation Ltd. London Underground Ltd. National Association of Lift Makers Portable Electric Tool Manufacturers Association Transmission and Distribution Association (BEAMA Ltd.) Amendments issued since publication Amd. No.DateComments 8214November 1995 Indicated by a sideline in the margin Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 06:58:03 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6007:1993 © BSI 12-1999i Contents Page Committees responsibleInside front cover Forewordiii 1Scope1 2References1 3Definitions1 4Voltage designation1 5Conductors2 6Insulation2 7Core identification2 8Filler3 9Braid3 10Sheath4 11Marking5 12Construction and overall dimensions5 13Electrical requirements6 14Test under fire conditions6 15Flexing text6 Appendix A Guide to the use of rubber-insulated cables and flexible cables16 Appendix B Guidance on procedure for routine tests on rubber-insulated cables of rated voltages Uo/U up to 450/750 V17 Appendix C Solderability test for plain conductors19 Appendix D Electrical tests19 Appendix E Method for checking the efficacy of the method of spark testing21 Appendix F Core identification by numbers22 Figure 1 Spark test check: removal of insulation21 Figure 2 Spark test check: covering with tape21 Figure 3 Axial arrangement of core-numbering marks22 Figure 4 Transverse arrangement of core-numbering marks23 Table 1 Rubber-insulated, textile-braided and compound cable, 450/750 V single core6 Table 2 Rubber-insulated and sheathed cable, 300/500 V flat twin7 Table 3 Rubber-insulated and sheathed flexible cable, 300/500 V 3-core and 4-core7 Table 4 Rubber-insulated and sheathed flexible cable, 450/750 V single core, circular twin, 3-core, 4-core and 5-core8 Table 4A Rubber-insulated and sheathed flexible cable, 450/750 V, having more than 5 cores (multicore cables)9 Table 5 Rubber-insulated, HOFR-sheathed flexible cable, 450/750 V single core, circular twin, 3-core, 4-core and 5-core10 Table 6 Rubber-insulated, braided, heat-resistant flexible cable, 300/500 V single core and twisted twin11 Table 7 Heat-resistant, rubber-insulated single core cables, 450/750 V for internal wiring11 Table 7A Heat-resistant, rubber-insulated single core cables, 300/500 V for internal wiring12 Table 8 Unbraided, silicone-rubber-insulated cables, 300/500 V for internal wiring13 Table 9 Summary of electrical tests14 Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 06:58:03 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6007:1993 ii © BSI 12-1999 Page Table 10 List of tests applicable to the various types of cable15 Table 11 Guide to the use of rubber-insulated cables and flexible cables16 Table 12 Spark test voltage17 Table 13 Insulation test voltage17 Table 14 Insulation resistance constant (K value) at 20 °C18 Table 15 Temperature correction factor18 Table 16 Axial marks22 Table 17 Transverse marks22 List of references24 Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 06:58:03 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6007:1993 © BSI 12-1999iii Foreword This edition of BS 6007 has been prepared under the direction of the Cables and Insulation Standards Policy Committee and it supersedes BS 6007:1991 which is withdrawn. This edition includes alterations introduced by Amendment No. 1 to BS 6007:1991 (published in May 1993) together with some further technical changes to bring the standard up to date but it does not reflect a full review of the standard which will be undertaken in due course. This new edition is aligned with Amendments 8, 9, 10 and 11 to HD 22.1 S2, Amendment 3 to HD 22.2 S2 and Amendment 5 to HD 22.4 S2. Where Harmonized Code Designations are given, the requirements are in conformity with those of all countries which accept the basic principles of harmonization in accordance with the requirements of CENELEC1). Designs shown as recognized national types are not harmonized but are regarded as representing a particular requirement in the UK which is not reflected in other countries. Colours for core identification as agreed with CENELEC have been included in Table 1 to Table 8, as appropriate. Differences in the text between this edition and BS 6007:1991 are indicated by a sideline in the margin. Certification. Attention is drawn to the certification services (see inside back cover) of the British Approvals Service for Cables (BASEC)2). These services include licensing manufacturers to use BASEC certification trade marks as independent assurance that cables or cords have been designed and manufactured to appropriate British Standards. BASEC is a subscriber to an agreement in CENELEC whereby cables or cords coming within Harmonized Code Designations and manufactured under a BASEC licence, can carry marks acceptable to other signatory countries (CENELEC “Common Marking”). 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 legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 24, 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 amendment table on the inside front cover. 1) European Committee for Electrotechnical Standardization. 2) British Approvals Service for Cables, Silbury Court, 360 Silbury Boulevard, Milton Keynes, Buckinghamshire MK9 2AF. Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 06:58:03 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 06:58:03 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6007:1993 © BSI 12-19991 1 Scope This British Standard specifies requirements for the construction, electrical properties, mechanical properties and dimensions of non-armoured rubber-insulated cables and flexible cables for operation at voltages up to and including 450 V a.c. to earth and 750 V a.c. between conductors. The types of cables included in the standard are: A guide to the use of rubber-insulated cables is given in Appendix A. Guidance to manufacturers on procedures for routine testing is given in Appendix B. 2 References 2.1 Normative references This British 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 on page 24. For dated references, subsequent amendments to or revisions of any of these publications apply to this British Standard only when incorporated in it by amendment or revision. For undated references, the latest edition of the publications referred to applies. 2.2 Informative references This British Standard refers to other publications that provide information or guidance. Editions of these publications current at the time of issue of this standard are listed on page 24, but reference should be made to the latest editions. 3 Definitions For the purposes of this British Standard, the definitions given in BS 4727-2:Group 08 apply together with the following. 3.1 rated voltage Uo the power-frequency voltage to earth for which the cable is designed 3.2 rated voltage U the power-frequency voltage between conductors for which the cable is designed 4 Voltage designation The rated voltage of a cable is the reference voltage for which the cable is designed and which serves to define the electrical tests and shall be expressed, in volts, by the following expression: Uo/U where In an alternating current system, the rated voltage of a cable shall be at least equal to the nominal voltage of the system for which it is intended and this applies both to the value Uo and to the value U. a) Table 1.Rubber-insulated, textile-braided and compound cable, single core 450/750 V; b) Table 2.Rubber-insulated and sheathed cable, flat twin300/500 V; c) Table 3.Rubber-insulated and sheathed flexible cable, 3-core and 4-core 300/500 V; d) Table 4.Rubber-insulated and sheathed flexible cable, single core, circular twin, 3-core, 4-core and 5-core 450/750 V; d1) Table 4A. Rubber-insulated and sheathed flexible cable, having more than 5-core (multicore cables)450/750 V; e) Table 5.Rubber-insulated, HOFR-sheathed flexible cable, single core, circular twin, 3-core, 4-core and 5-core 450/750 V; f) Table 6.Rubber-insulated, braided, heat-resistant flexible cable, single core and twisted twin300/500 V; g) Table 7.Heat-resistant, rubber-insulated, single core cables for internal wiring 450/750 V; g1) Table 7A. Heat-resistant, rubber-insulated, single core cables for internal wiring300/500 V; h) Table 8.Unbraided, silicone-rubber-insulated cables for internal wiring300/500 V. Uois the r.m.s. value between any insulated conductor and earth, i.e. the metal covering of the cable or the surrounding medium; Uis the r.m.s. value between any two phase-conductors of a multicore cable or of a system of single-core cables. Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 06:58:03 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6007:1993 2 © BSI 12-1999 In a direct current system, the nominal voltage of the system shall be not higher than 1.5 times the rated voltage of the cable. NOTEThe operating voltage of a system may permanently exceed the nominal voltage of such a system by 10 %. A cable can be used at 10 % higher operating voltage than its rated voltage if the latter is at least equal to the nominal voltage of the system. The rated voltages recognized for the purpose of this standard shall be 300/500 V and 450/750 V. 5 Conductors 5.1 Construction The conductors shall be annealed copper conductors complying with BS 6360. Unless otherwise given in Table 1 to Table 8, as appropriate, the individual wires of conductors shall be plain or covered with an effective layer of commercial tin. For cables specified in Table 7 and Table 7A, where the wires are plain, a separator tape made of suitable material shall be placed between the conductor and the insulation. NOTEFor cables specified in tables other than Table 7 and Table 7A, a separator tape made of suitable material may be applied around each conductor. The application of a separator is left to the discretion of the manufacturer. The solderability of plain conductors, except for the cables whose properties are given in Table 6, shall be tested as described in Appendix C. The part of the conductor that has been immersed in the solder bath shall be adequately tinned. 5.2 Class The class of the conductor shall be as given in Table 1 to Table 8, inclusive. 6 Insulation 6.1 Type of insulation The insulation shall be one of the following types, as given in Table 1 to Table 8, as appropriate: a) type GP 1 rubber insulation complying with BS 6899; b) types EI 2, EI 3 and EI 4 rubber insulation complying with BS 7655-1.1. Compliance shall be checked by carrying out the appropriate tests listed in Table 10. 6.2 Application The insulation shall be closely applied to the conductor or separator as follows: a) types EI 3 and GP 1: unless applied by the extrusion process, the insulation shall consist of at least two layers; b) types EI 2 and EI 4: the insulation shall be extruded in a single layer. It shall be possible to remove the insulation easily, without damage to the insulation itself, the conductor or the tin coating, if any. Compliance shall be checked by examination and by a manual test. 6.3 Thickness The mean value of the thickness of the insulation shall be not less than the value given for each type and cross section of cable in Table 1 to Table 8, as appropriate. However, it shall be permissible for the thickness at any place to be less than the value specified provided that the difference does not exceed 0.1 mm + 10 % of the value specified. Compliance shall be checked by the measurements described in 8.1 of BS 6469-1.1:1992. From each core to be tested, one sample of core shall be taken from each of three places separated by at least 1 m. The mean of all the values obtained on the three pieces of insulation shall be calculated to two decimal places and then rounded off to obtain the mean value of insulation thickness. If the calculation gives 5 or more for the second decimal figure, the first figure shall be raised to the next number: thus, for example, 1.75 shall be rounded to 1.8 and 1.74 to 1.7. The smallest of all the values obtained shall be taken as the minimum thickness of insulation at any place. 6.4 Addition of tape Where stated in Table 1 to Table 8, it shall be permissible for a proofed textile tape to be applied over the insulation. The tape shall be applied helically with a