BS 7727-1994 Code of practice for installation and inspection of pre-insulated compression terminals and connectors for cables with copper conductors up to 6 mm2《铜导体面积达6平方毫米(10AWG).pdf

1、BRITISH STANDARDBS 7727:1994Incorporating Amendment No. 1Code of practice forInstallation and inspection of pre-insulated compression terminals and connectors for cables with copper conductors up to 6 mm2ICS 29.120.20anufacturers Association)itish Approvals Service for CablesBS 7727:1994Committees r

2、esponsible for this British StandardThInsulation CIAssociaAssociation of BECCAMBrThis British Standard, having been prepared under the direction of the Cables and Insulation Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on 15 May 1994 BSI

3、2006The following BSI references relate to the work on this standard:Committee reference CIL/20Draft for comment 93/207110 DCISBN 0 580 22809 6British Cable Makers ConfederationBritish Plastics FederationBritish Steel IndustryDepartment of Trade and Industry (Consumer Safety Unit, CA Division)Electr

4、icity AssociationEngineering Equipment and Materials Users AssociationInstitution of Electrical EngineersLondon Regional TransportThe following bodies were also represented in the drafting of the standard, through subcommittees and panels:Electrical Contractors AssociationElectrical Installation Equ

5、ipment Manufacturers Association (BEAMA Ltd.)ERA Technology Ltd.Institution of Lighting EngineersLondon Underground Ltd.Transmission and Distribution Association (BEAMA Ltd.)Amendments issued since publicationAmd. No. Date Comments16445 29 September 2006 See foreword. Also deletion of AWG values fro

6、m title and Clause 1e preparation of this British Standard was entrusted by the Cables and Standards Policy Committee (CIL/-) to Technical Committee L/20, upon which the following bodies were represented:tion of Consulting EngineersManufacturers of Domestic Electrical AppliancesMA (BEAMA Electrical

7、Cable Connector and Accessories BS 7727:1994 BSI 2006ContentsPageCommittees responsible Inside front coverForeword ii1Scope 12 References 13 Definitions 14 Marking 15 Selection of styles 26 Compression tools 27 Current rating 28 Preparation 29 Compression 410 Inspection 4Annex A (informative) Constr

8、uction of pre-insulated terminals, splices and connectors 7Annex B (informative) Maintenance, testing and certification of tooling 9Figure 1 Example of identification marking 2Figure 2 Examples of styles 2Figure 3 Examples of compression tools 3Figure 4 Example of correct and incorrect stripping of

9、insulation 3Figure 5 Example of correct bare conductor protrusion 3Figure 6 Example of a tool with a locator fitted 3Figure 7 Example of tool with insulation thickness adjustment 3Figure 8 Example of correct insertion into a compression tool 5Figure 9 Examples of correct compression 6Figure 10 Examp

10、les of common faults 6Figure A.1 Examples of pre-insulated compression terminals 8Figure A.2 Examples of pre-insulated splices 8Figure A.3 Examples of pre-insulated disconnect connectors 9List of references Inside back coveriBS 7727:1994iiBS 7727 is intended to give guidance to manufacturers and con

11、tractors who use compression terminals and connectors of the pre-insulated type to enable cables to be terminated using good engineering practice and to provide quality control guidance for the compression tooling.A similar code of practice for uninsulated connectors is !BS 7609“.As a code of practi

12、ce, this British Standard takes the form of guidance and recommendations. It should not be quoted as if it were a specification and particular care should be taken to ensure that claims of compliance are not misleading.The start and finish of text introduced or altered by Amendment No. 1:2006 is ind

13、icated in the text by tags !“. Minor editorial changes are not tagged.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Summary of pagesThis document comprises a front cover, an inside front cover, pages i and

14、ii, pages 1 to 10, 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 Compliance with a British Standard cannot confer immunity from legal obligations.ForewordThis Britis

15、h Standard has been prepared under the direction of the Cables and Insulation Standards Policy Committee. BSI 2006the inside front cover.BS 7727:19941 ScopeThis British Standard recommends methods and procedures applicable to installation and inspection of pre-insulated terminals and connectors for

16、use on copper conductors of insulated cables conforming to !BS EN 60228:2005, up to 6 mm2cross-sectional area“, using hand application tooling.This standard does not apply to installations which are required to comply with BS 5G 178-1:1993 and BS 4G 178-2:1986.2 References2.1 Normative referencesThi

17、s British Standard incorporates, by dated or undated reference, provisions from other publications. These normative references are made at the appropriate places in the text and the cited publications are listed on the inside back hover. For dated references, only the edition cited applies; any subs

18、equent amendments to or revisions of the cited publication apply to this standard only when incorporated in the reference by amendment or revision. For undated references, the latest edition of the cited publication applies, together with any amendments.2.2 Informative referencesThis British Standar

19、d 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 the inside back cover, but reference should be made to the latest editions.3 DefinitionsFor the purposes of this British Standard, the follo

20、wing definitions apply.3.1 pre-insulated compression jointan electrical connection made by compressively forming the insulated barrel of a terminal or connector around one or more conductors3.2 terminal luga connector comprising a palm and a barrel, for connecting a conductor to an equipment termina

21、l3.3 splicea device used to permanently connect conductors to each otherNOTE This is also known as a through connector or a closed end 3.4 disconnect connectora device used to connect a conductor to another conductor or equipment terminal fitted with a similar connector having mating parts of opposi

22、te gender. Such connection or disconnection may only be suitable for a limited number of operations3.5 barrelpart of a connector designed to accommodate the conductor3.6 palmpart of a terminal lug formed flat to make a bolted connection to an equipment terminal3.7 insulation sleevecylindrical insula

23、tion sleeve surrounding the compression barrel and through which the compressed connection is made. The insulation may be extended to protect the mating part of a connector3.8 insulation grip sleevean optional metal sleeve interposed between the compression barrel and insulation for the purpose of p

24、roviding a positive retention of the wire insulation within the insulation compression area3.9 compression sleevea metal sleeve often used to improve compression properties of the spring material when using mating disconnect devicesNOTE Such a sleeve may also be extended to provide retention of wire

25、 insulation.4 MarkingEach compression connector and its packaging should be clearly marked with the suppliers identification (Figure 1). Reference should be made to the manufacturers literature in order to establish wire size ranges which are identified by insulation colour and sometimes also by mar

26、king upon the palm. BSI 2006 1connector (see A.2)BS 7727:19945 Selection of stylesThere are various styles of terminals and connectors available; some of these are described in Annex A . If there is any doubt about correct selection, advice should be sought from the supplier or manufacturer.Insulati

27、on entry diameter should be checked to ensure that the selected wire insulation can be accommodated. Flared and straight entry variants are available (Figure 2).6 Compression toolsAdvice should be sought from the terminal supplier or manufacturer, if there is any doubt about the correct selection of

28、 the tool, cavity in a multicavity tool, or where applicable, dies. Compression tools (Figure 3) should have full closure mechanisms and be designed to compress both the conductor and insulation areas simultaneously, forming the insulation sleeve closely around the wire insulation (see clause 10).Lo

29、cators are available for various terminal types and, as they facilitate precise location during compression, they promote consistently good results. The use of locators is recommended particularly on connectors without brazed seams. The use of simple tools capable only of compressing the conductor a

30、nd insulation areas in two separate operations, and without locators or full closure Tools should be regularly maintained, tested and where required, certified. Further information on maintenance, testing and certification is given in Annex B .7 Current ratingCurrent ratings are dependent upon the c

31、onductors in use, the environment and the permitted temperature rise. Correctly designed copper compression terminals and splices, correctly applied to annealed high-conductivity copper conductors will have at least as high current ratings as those conductors. However, with disconnect connectors, wh

32、ich are made from copper alloy, the current ratings are governed by different criteria and advice should be sought from the supplier or manufacturer. For flat blade push-on male/female connectors BS 5057:1992 provides current/temperature ratings.8 PreparationCable should be cut to length and strippe

33、d squarely and cleanly without damage to conductors or insulation (Figure 4). There should be no missing conductor strands. Stripped length should allow for protrusion of conductor witness (Figure 5) of approximately 1 mm from the barrel end when fully inserted. Where a conductor stop is provided, t

34、he conductor should reach it without there being any inclusion of insulation within the barrel. Care should be taken to ensure that the conductor surface is kept clean. If the conductor surface is tarnished or otherwise contaminated, it may be cleaned, taking care not to damage any strands. Otherwis

35、e, it should be shortened sufficiently to reveal clean strands. Chemical cleansing, with substances which may react with the material or plating of either the conductor or the terminal, should not be used.If the compression tool is fitted with a locator (Figure 6) it should be appropriate to the sty

36、le of terminal being compressed. If fitted with an insulation thickness adjustment (Figure 7), this should be set according to the tool manufacturers instructions.Figure 1 Example of identification markingFigure 2 Examples of styles2 BSI 2006mechanisms, is likely to give rise to inconsistent results

37、 and is not recommended for production equipment.BS 7727:1994Figure 3 Examples of compression toolsFigure 4 Example of correct and incorrect stripping of insulationFigure 5 Example of correct bare conductor protrusionFigure 6 Example of a tool with a locator fittedFigure 7 Example of a tool with ins

38、ulation thickness adjustment BSI 2006 3BS 7727:19949 CompressionThe connector should be inserted into the tool die-space (Figure 8); if a locator is present it should be used. If a locator is not present, the compression barrel should be inserted in the correct plane as shown in Figure 8. The connec

39、tor should then be retained by means of a light partial closure of the handles. Continued light pressure of the full closure mechanism will then retain the terminal in place while inserting the wire. Care should be taken to fully insert the wire ensuring that the conductor strands abut the locator/c

40、onductor stop. Care should be taken to ensure thin wires do not pass the stop and enter the conductor barrel.The handles should then be closed until the full closure device permits them to be opened, releasing the compressed connector.10 InspectionFigure 9 shows correct compression features and Figu

41、re 10 shows common faults.The compressed connector should be inspected to check the following.a) The correct connector has been used for the conductor size (see clause 4).b) Compression die identifier markings show that the correct dies have been used for the connector size.c) Correct positioning of

42、 compressed areas, ensuring that the conductor compression is central to the conductor barrel length and in the correct plane.d) Approximately 1 mm of conductor shows at the barrel end or that, if a wire stop is present, the conductor abuts it.e) The wire insulation is fully inserted into the entry

43、of the insulation sleeve and is adequately secured or supported, depending upon the connector construction.f) There is no apparent damage to conductors or insulation and that no stray strands of conductor are visible.NOTE When inspecting fully insulated connectors, the use of an illuminated torch st

44、yle magnifier can be helpful.Quality control procedures should include the periodic sampling of completed work for tensile testing and voltage drop testing as required by the appropriate user standard. When installing assembled and compressed connectors and terminals, care should be taken to avoid u

45、ndue stress caused by tension in the connected wiring on the weight of heavy cableforms. Where significant vibration or movement of wiring is likely to occur, the connection should be protected by securing the wiring in a suitable manner.4 BSI 2006BS 7727:1994 BSI20065Figure 8 Example of correct ins

46、ertion into a compression toolBS 7727:1994Figure 9 Examples of correct compressionFigure 10 Examples of common faults6 BSI 2006BS 7727:1994Annex A (informative) Construction of pre-insulated terminals, splices and connectorsA.1 Pre-insulated copper compression terminals (see Figure A.1)The compressi

47、on area is a cylindrical barrel formed from tightly butted sheet copper, the seam of which may be brazed. One end of the barrel is integral with a connecting palm which is usually a flat ring, blade or spade/fork shape suitable for connecting to an equipment terminal. Optionally, the palm may be cra

48、nked and/or hook ended, or formed into a circular or rectangular section pin for pinch screw clamping. The product is normally annealed followed by electroplating for protection.A tubular insulating sleeve is fitted around the barrel, usually flush with the junction of barrel and palm, extending pas

49、t the opposite end of the barrel to provide cable insulation support. The insulation may be parallel or have a flared wire entry portion; it may also be formed so as to present a wire entry funnel for easy application. Various insulation materials are available and should be selected with the following in mind: operating temperature; exposure to certain fluids; environmental requirements concerning products of combustion.PVC is commonly used; it has excellent insulation and mechanical properties and is little affected by moistur