Draft for Public Comment

Transcription

1 Draft for Public Comment Form 36 Version 6.1 DPC: 03/ DC Head Office 389 Chiswick High Road London W4 4AL Telephone: +44(0) Fax: +44(0) Date: 27 March 2003 Origin: National Latest date for receipt of comments: Project no.: 2002/00768 Responsible committee: JPEL/64 Electrical Installations of Buildings Joint Committee Interested committees: Title: BS 7671 Requirements for electrical installations Draft Amd 2 - Identification by colours Supersession information: If you are aware of a current national standard which may be affected, please notify the secretary (contact details below). WARNING: THIS IS A DRAFT AND MUST NOT BE REGARDED OR USED AS A BRITISH STANDARD. THIS DRAFT IS NOT CURRENT BEYOND This draft is issued to allow comments from interested parties; all comments will be given consideration prior to publication. No acknowledgement will normally be sent. See overleaf for information on commenting. No copying is allowed, in any form, without prior written permission from BSI except as permitted under the Copyright, Designs and Patent Act 1988 or for circulation within a nominating organization for briefing purposes. Electronic circulation is limited to dissemination by within such an organization by committee members. Further copies of this draft may be purchased from BSI Customer Services, Tel: +44(0) or orders@bsi-global.com. British, International and foreign standards are also available from BSI Customer Services. British Standards on CD or Online are available from British Standards Publishing Sales Limited. Tel: or bsonline@techindex.co.uk. Information on the co-operating organizations represented on the committees referenced above may be obtained from the responsible committee secretary. Cross-references The British Standards which implement International or European publications referred to in this draft may be found via the British Standards Online Service on the BSI web site Responsible Committee Secretary: Mr P R L Cook (IEE) (BSI) Direct tel: pcook@iee.org.uk a

2 Introduction Your comments on this draft are welcome and will assist in the preparation of the consequent British Standard. If no comments are received to the contrary, this draft may be implemented unchanged as a British Standard. Submission The guidance given below is intended to ensure that all comments receive efficient and appropriate attention by the responsible BSI committee. Annotated drafts are not acceptable and will be rejected. All comments must be submitted, preferably electronically, to the Responsible Committee Secretary at the address given on the front cover. Comments should be compatible with Version 6.0 or Version 97 of Microsoft Word for Windows, if possible; otherwise comments in ASCII text format are acceptable. Any comments not submitted electronically should still adhere to these format requirements. All comments submitted should be presented as given in the example below. Further information on submitting comments and how to obtain a blank electronic version of a comment form are available from the BSI web site at: Date Document National Committee Clause/ subclause Paragraph/ Figure/ Table Type of comment (General/ technical/editorial) COMMENTS Proposed change OBSERVATIONS OF THE SECRETARIAT 3.1 1st definition Editorial Definition is ambiguous and needs clarifying. Amend to read... so that the mains connector to which no connection Technical The use of the UV photometer as an alternative cannot be supported as serious problems have been encountered in its use in the UK. Microsoft and MS-DOS are registered trademarks, and Windows is a trademark of Microsoft Corporation. Delete reference to UV photometer. b

3 DRAFT AMENDMENT NO 2: 2004 to BS 7671 Identification by Colours Introduction Amendment No 2:2004 to BS 7671:2001 implements the cable colours introduced in the revision of European Harmonisation document HD 308S2: Identification of cores in cables and flexible cords, and agrees with BS EN 60446:2000 Basic and safety principles for the man-machine interface identification of conductors by colours or numerals. The single-phase colours of red phase, black neutral and green-and-yellow earth are replaced by brown phase, blue neutral and green-and-yellow earth. These colours have been used in appliance flexible cables for 28 years Three-phase phase colours will be brown black and grey with a blue neutral instead of red, yellow, and blue with a black neutral. To assist in implementation a new Appendix F is included to advise on marking at the interface between old and new colours and to provide general guidance on the extended range of colours that may be used for line (not neutral or protective) conductors. Implementation Amendment No 2: 2004 to BS7671:2001:Identification of colours, is issued on the 1 st April Installations commencing on site on or after 1 st April 2006 shall be in accordance with Amendment No 2 and, as appropriate, cores shall be identified with the new colours. Installations commencing on site on or after 1 st April 2004 and before 1 st April 2006 may be installed in accordance with Amendment No 2: 2004 or Amendment No1:2002; that is they may use the new colours or the old colours, but NOT both. Immediate use of the new colours is allowed to reduce the number of mixed installations. Page 1 of 7

4 Amend to as follows: 514 IDENTIFICATION AND NOTICES General Except where there is no possibility of confusion, a label or other suitable means of identification shall be provided to indicate the purpose of each item of switchgear and controlgear. Where the operation of switchgear and controlgear cannot be observed by the operator and where this might lead to danger, a suitable indicator, complying with BS EN where applicable, shall be fixed in a position visible to the operator As far as is reasonably practicable; wiring shall be so arranged or marked that it can be identified for inspection, testing, repair or alteration of the installation Conduit Where an electrical conduit is required to be distinguished from a pipeline or another service, orange shall be used as the basic identification colour in compliance with BS Identification of Conductors Except where identificatin is not required by regulation cores of cables shall be identified by one of the following methods: (i) By colour as or (ii) By numbering and/or lettering as Every core of a cable shall be identifiable at its terminations and preferably throughout its length. Binding and sleeving for identification shall comply with BS 3858 where applicable Identification of conductors by colour Neutral or mid-point conductor Where a circuit includes a neutral or mid-point conductor identified by colour, the colour used shall be blue. Protective conductor The bi-colour combination green-and-yellow is reserved exclusively for identification of a protective conductor and this combination shall be used for no other purposes. In this combination one of the colours shall cover at least 30% and at most 70% of the surface being coloured, while the other colour covers the remainder of the surface. A bare conductor or busbar used as a protective conductor shall be identified, where necessary, by equal green-and-yellow stripes, each not less than 15 mm and not more than 100 mm wide, close together, either throughout the length of the conductor or in each compartment and unit and at each accessible position. If adhesive tape is used, it shall be bi-coloured. PEN conductor PEN conductors shall, when insulated, be marked by one of the following methods: i) Green-and-yellow throughout their length wit h, in addition, blue markings at the terminations, or ii) throughout their length with, in addition, green-and-yellow markings at the terminations. Page 2 of 7

5 The additional markings at the terminations may be omitted in wiring systems for the distribution of energy to the public and similar distribution systems, e.g. those used in industry. Other conductors Other conductors shall be identified by colours taking into account the requirements of table Identification of conductors by numbers or letters The numbering or lettering system applies to identification of individual conductors and of conductors in a group. The identification shall be clearly legible and durable. All numerals shall be in strong contrast to the colour of the insulation. The identification shall be given in Arabic numerals or Arabic letters. In order to avoid confusion, unattached numerals 6 and 9 shall be underlined Conductors with green-and-yellow colour identification shall not be numbered Numbers may be used to identify the cores of cables provided that the number 0 shall signify the neutral conductor Omission of Identification by colour or marking Identification by colour or marking is not required for: (i) Concentric conductors of cables; (ii) Metal sheath or armour of cables used as a protective conductor; (iii) Bare conductors where permanent identification is not practical; (iv) Extraneous-conductive-parts used as a protective conductor; (v) Exposed-conductive-parts used as a protective conductor Deleted by amendment No 2: 2004 Page 3 of 7

6 TABLE 51 Colour identification of cores of cables and bare conductors for fixed wiring Function Earthing conductors Protective Functional Colour identification Green-and-yellow Cream a.c. circuit Phase of a.c. single-phase power circuit Neutral of a.c. single- or three-phase circuit Phase R of three-phase a.c. circuit Phase Y of three-phase a.c. circuit Phase B of three-phase a.c. circuit Black Grey Two-wire unearthed d.c. power circuits Positive of d.c, two-wire circuit Negative of d.c. two-wire circuit Grey Three-wire d.c. circuits Outer (positive or negative) of d.c. two-wire circuit derived from three-wire system Positive of three-wire d.c. circuit Middle wire of three-wire d.c. circuit (1) Negative of three-wire d.c. circuit Grey Two-wire earthed d.c. circuits Positive (of negative earthed) circuit Negative (of negative earthed) circuit Positive (of positive earthed) circuit Negative (of positive earthed) circuit Grey Control circuits and ELV Line conductor Neutral or middle conductor (2), Black, Red Orange, Yellow, Violet, Grey, White, Pink, Turquoise NOTES: (1) (2) Only the middle wire of three-wire circuits may be earthed. An earthed PELV conductor is blue Page 4 of 7

7 Add an appendix: APPENDIX F to BS Introduction Alterations and additions to installations wired in the old cable colours The requirements of BS 7671 have been harmonized with the technical intent of CENELEC Harmonization Document : identification, including :identification of conductors. The cable standards have been harmonised with CENELEC Harmonization Document HD 308 S2: identification of cores in cables and flexible cords. These documents specify the cable core marking including cable core colours to be implemented in the CENELEC countries. This appendix provides guidance as to how cables manufactured to the old and new standards are to be marked to comply with the requirements of BS British Standard fixed and flexible cable standards have been harmonized with the colours in HD 308 S2. BS 7671 has been modified to align with these cable colours, but it also allows other suitable methods of marking connections by coloured tapes, sleeves or discs or by numbering or lettering. Methods may be mixed within an installation. 2. Alterations on additons to existing installations 2.1 Alterations or additons made to single-phase installations or parts of installations need not be marked at the interface providing that: i) the old cables are correctly coloured throughout their length by the correct single phase colours or red phase and black neutral; and ii) the new cables are correctly coloured brown and blue, (see Table 7A below): TABLE 7A Single -phase installations Conductor marking for extensions and alterations to installationsidentified with the old cable colours Function Old Conductor New Conductor Phase of a.c. Red Neutral of a.c. Black Earth Green-and-Yellow Green-and-Yellow 2.2 Alterations or additions made to Two- and Three-phase installations When alterations or additions are made to two- and three-phase installations wired in the old core colours with cable to the new core colours, unambiguous identification is required. For example, cores should be marked as follows: Neutral and mid point conductors old and new installation conductors: blue Line conductors (phase for a.c.) old and new line conductors: brown, see Table7B or old and new phase conductors shall be marked brown, black, grey or old and new phase conductors shall be numbered L1, L2, L3. Page 5 of 7

8 Function TABLE 7B Two- and Three-phase installations Conductor marking for extensions and alterations to installations identified with the old cable colours Insulation colour Old Conductor Marking Marking New Conductor Insulation Colour Phase of a.c. Red Yellow Black Grey Neutral of a.c. Black 3 Switch wires in new installations Where two-core cables with a brown and a blue conductor are used as switch wires, both conductors being line (phase for a.c.) conductors, the blue conductor is to be marked brown at its terminations. 4 Intermediate and two-way switch wires in new installations Where three-core cables with cores coloured brown, black and grey are used for switch wires, all conductors being line (phase for a.c.) conductors further marking is not required in new installations. 5 Single core cables in new installations Single core cables in conduit, trunking or ducting Neutral, PEN, and protective conductors should be identified throughout their length by the colours of Regulations that is blue, blue/green and yellow, and green-and-yellow. Other conductors may be brown, black, grey, red, orange, yellow, violet, white, pink or turquoise. Power circuits line conductors should be coloured as Table 51. Typically they should be brown, black and grey. They may be all of any one colour marked brown black and grey at their termination to show the phases, 6 Changes to cable core colour identification Table 7C Standard house wiring cable to BS 6004 (flat cable with bare earth) Cable type Old core colours New core colours Single core + bare earth Red or Black or 2 core + bare earth Red, Black, Alt. 2 core + bare earth Red, Red, 3 core + bare earth Red, Yellow,, Black, Grey Table 7D Standard 600/1000 V armoured cable BS 6346 / BS 5467 / BS 6724 Cable type Old core colours New core colours Single core Red or Black or 2 core Red, Black, 3 core Red, Yellow,, Black, Grey 4 core Red, Yellow,, Black, Black, Grey, 5 core Red, Yellow,, Black, Green-and-Yellow, Black, Grey,, Green-and-Yellow No change in the statement in the standard The cores of all cables shall be identified either by colour or by numbers. See 1(iii) Page 6 of 7

9 Table 7E Flexible cable to BS 6500 The changes made to the colour identification requirements for flexible cables and colours are slight and apply only to 5 core cables where one of the black conductors is now coloured grey Cable type Old core colours New core colours 2 core, No change 3 core,, Green-and- No change Yellow 4 core Black,,, Greenand-Yellow No change 5 core Black,,, Black, Green-and-Yellow Black,,, Grey, Green-and-Yellow Page 7 of 7