1、BRITISH STANDARD AEROSPACE SERIES BS2G180: 1974 Superseding British Standard G180 Specification for Permanent splicing of aircraft electrical cables UDC 629.7.064.5:621.315.687.1BS2G180:1974 This British Standard, having been approved by the AerospaceIndustry Standards Committee, was published under
2、the authority of the Executive Board on 29November1974 BSI10-1999 The following BSI references relate to the work on this standard: Committee reference ACE/6/1 Draft for comment72/36973 ISBN 0 580 08620 8 Foreword This British Standard has been prepared to define approved methods of making and insta
3、lling joints in copper conductors of aircraft electrical cables and wires by the use of crimped splices. It also covers the repair of such cables and wires using the same techniques, and details certain design requirements to supplement those given in British Standard G178. Appendix A provides infor
4、mation about the types of device currently manufactured, to assist the definition of the subject. This standard makes reference to the following British Standards: 3G100, General requirements for equipment for use in aircraft Part1:Identification, declaration and construction Part2: All equipment. G
5、178, Crimped joints for aircraft electrical cables and wires. 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 fro
6、m legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to4 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 fro
7、nt cover. Amendments issued since publication Amd. No. Date CommentsBS2G180:1974 BSI 10-1999 i Contents Page Foreword Inside front cover Section 1. General 1 Scope 1 2 Definitions 1 Section 2. Application 3 Selection and use of splices 1 4 Restrictions on splicing 1 Section 3. Installation 5 Stagger
8、ing of splices 2 6 Location of splices 2 7 Support of splices 2 8 Post-insulation of splices 2 9 Tools 2 10 Recording 2 Section 4. Design requirements 11 General 2 12 Protective treatment 2 13 Insulation 3 14 Environmental requirements 3 Appendix A Types of splice currently manufactured 4ii blankBS2
9、G180:1974 BSI 10-1999 1 Section 1. General 1 Scope This British Standard defines the essential parameters for achieving acceptable jointing of the copper conductor of one cable to that of another, or the multiple connection of such conductors by means of permanent crimped splices. This standard does
10、 not cover the splicing of coaxial cables or of aluminium cables. 2 Definitions For the purposes of this British Standard the definitions contained in British Standard G178 and the following apply. 2.1 cable and wire a single core electrical cable or wire or an individual core of a multicore cable o
11、r wire 2.2 in-line splice a connecting device with a barrel or socket at each end to accommodate electrical cable conductors, with or without additional provision to accommodate and support the cable insulation. With this type of splice two separate crimping operations are normally necessary to join
12、 the conductors of the cables 2.3 parallel splice a connecting device with a single conducting barrel in which the electrical cable conductors lie side by side, whether inserted from the same end or from opposite ends of the barrel. With this type of splice only one crimping operation is normally ne
13、cessary to join the conductors of two or more cables 2.4 pre-insulated splice an in-line or parallel splice in which the conducting barrel is insulated by a sleeve which extends beyond the ends of the barrel, which remains firmly fixed to the barrel before, during and after the crimping operations,
14、and through which the crimping operations must be performed 2.5 post-insulated splice an in-line or parallel splice insulated after the crimping operation by the addition of a sleeve, which extends beyond the ends of the barrel 2.6 declaration of design and performance (DDP) the standard form specif
15、ied in British Standard3G100-1 2.7 Air Form100D a standard form relating to instrument and electrical equipment intended for United Kingdom Ministry of Defence aircraft, whereby the manufacturer or design authority certifies compliance with the specification for that equipment or, if necessary, stat
16、es any limitations in performance Section 2. Application 3 Selection and use of splices The selection and use of splices for given cable sizes, type and installation shall be made in accordance with the data supplied by the relevant design authority 1) . It is recognized that splices are occasionall
17、y used to effect an urgent repair of damaged wiring when specific instruction from an approved design authority is not available. In such cases, particular regard shall be given to the requirements of clause4, in addition to the general requirements of this standard. Any such splicing of cables shal
18、l be recorded in the aircraft technical log (or equivalent) as a “temporary repair”. The information recorded shall include that listed in clause10 and at the first opportunity the splice(s) shall be replaced or duly authorized by an approved procedure. It should be noted that the crimping of multip
19、le conductors in a splice with simultaneously crimped insulation support does not provide the normal insulation support. The installer should recognize this limitation and care should be taken to prevent compression of the insulation of multiple cables. 4 Restrictions on splicing 4.1 Joints shall no
20、t be made for repair purposes in the following cables unless specifically approved by a design authority: a) h.t. cables (greater than600V (r.m.s.) to earth); b) multicore cables; c) cables within a fire zone; d) thermocouple cables; 1) For aircraft subject to British civil or military airworthiness
21、 requirements, a design authority is an organization approved by the Airworthiness Division of the Civil Aviation Authority, or by the Ministry of Defence (Procurement Executive) (A.D.Elec.), as appropriate.BS2G180:1974 2 BSI 10-1999 e) cables in vital circuits declared by the aircraft constructor a
22、nd listed in the aircraft manual; f) cables larger than size10; g) cable or loom installations specifically designed to permit movement between aircraft stations in a predetermined manner. 4.2 Unless specifically approved by a design authority parallel splices shall not be used for repair purposes e
23、xcept as a direct replacement for an existing item. Section 3. Installation 5 Staggering of splices Where there is a loom or bundle of cables or cable core to be spliced, the splices shall be staggered to avoid an excessive increase in bulk of the loom and with due regard to possible tracking betwee
24、n splices, or from splice to earth. 6 Location of splices 6.1 Splices shall not be located under clips or ties. 6.2 The minimum distance between splices in any one cable shall be500mm and not more than two splices shall be used in3m of cable. 6.3 Splices shall be so positioned that they can be visua
25、lly inspected after installation. 6.4 Splices shall not be located on bends so that the natural lay of the loom is impaired. 6.5 Splices which are not moisture proof shall be installed horizontally or otherwise protected against the ingress of fluids. 7 Support of splices 7.1 For single unloomed cab
26、les, splices shall not be positioned in an unsupported length exceeding500mm. 7.2 Splices in loomed cables shall be supported, e.g.by strapping within50mm of each end of the splice. 8 Post-insulation of splices Uninsulated splices shall be insulated with materials which maintain the performance of t
27、he cables to be spliced. When shrink-on sleeves are used for post-insulation, the diameter of the cable should, where necessary, be built up to provide an adequate insulation support. 9 Tools Only those tools listed in the relevant aircraft manual and/or DDP or Air Form100D for the particular size a
28、nd type of splice and which have been shown to comply with the requirements of clause11 shall be used in the crimping operation. All tools shall be checked regularly in accordance with3.4 of British Standard G178. 10 Recording Any temporary use of splices as detailed in clause3 shall be recorded in
29、the aircraft technical log (orequivalent). The following information shall be given: a) location; b) cable identification where possible, circuit or other identification; c) cable size and type; d) the make and part numbers of the splice: e) identification reference of the crimping tool used. Sectio
30、n 4. Design requirements 11 General Splices shall provide conductor crimps that conform to the requirements of British Standard G178 and shall be used only in conjunction with tools that conform to the requirements of Appendix D of that standard. Where multiple conductor splicing is employed, the la
31、rgest and the smallest conductor sizes included in the crimped joint shall meet the requirements for those particular sizes of conductor in respect of voltage drop and tensile strength. 12 Protective treatment Splices shall be suitably treated during manufacture to resist corrosion and reduce contac
32、t resistance, having regard to the finish of the strands of the cable conductors with which they are to be used. The protective treatment and surface finish shall be of such a quality that the crimped joint complies with the requirements of this British Standard and of G178.BS2G180:1974 BSI 10-1999
33、3 13 Insulation 13.1 Pre-insulated splices shall be so designed that adequate engagement of the stripped conductor(s) in the crimping region of the barrel can be established before and after the crimped joint is made. 13.2 The insulation of the insulated splice shall be of a material that is non-cor
34、rosive, resistant to fungus and to aircraft fluids when tested in accordance with the relevant requirements of British Standards3G100-2 and G178. The material and form of the insulation shall minimize abrasion to adjacent cables and shall comply with the relevant dielectric strength tests specified
35、in3.2.9.4 of G178. 13.3 Pre-insulated crimp sizes shall be indicated by a colour code which shall be defined on the manufacturers approved drawings. 13.4 The action of crimping a pre-insulated splice shall cause positive marking in accordance with British Standard G178. 14 Environmental requirements
36、 Environmental proofing may be achieved by the use of sleeves fitted under tension or by thermal shrinking, with or without adhesives or meltable interiors. The temperature of any necessary heating operation shall be compatible with the temperature rating of the cables to be spliced. For splices whi
37、ch are declared as suitable for use in conditions of high humidity, samples of the completed splice joint shall be completely immersed in a5% aqueous sodium chloride solution. Apotential of1500V r.m.s. at a frequency of50Hz to60Hz shall be applied between the conductor assembled to the spliced joint
38、 and an electrode in contact with the liquid. The voltage shall be applied for1min without breakdown.BS2G180:1974 4 BSI 10-1999 Appendix A Types of splice currently manufactured A.1 In-line splice Four basic types of in-line splice are in current use, namely: a) uninsulated tin-plated copper splice
39、for105 C cables; b) uninsulated nickel-plated copper splice for260 C cables; c) uninsulated silver-plated copper splice for190 C cables; d) uninsulated gold-plated copper splice for260 C cables. These four basic types are also available in pre-insulated and post-insulated form. The insulation materi
40、al will vary; generally it will be nylon or polytetrafluoroethylene dependent upon temperature category. Heat-shrink material is also used for post-insulating this type of splice. In-line splices are suitable for single cable-to-cable or multi-conductor splicing. When in-line splices are used for mu
41、lti-conductor applications, it may be necessary to use collector ferrules in special cases. These ferrules gather the strands of the multiple conductors and contain them for insertion into the crimping barrel, while ensuring that the correct volume of material for the particular crimping barrel is m
42、aintained. A.2 Step-down in-line splice An extension of the employment of inserts in the in- line type of splice is to provide an item which will connect two conductors of widely differing cross section, i.e.a difference not normally accommodated by one barrel size. This type of splice is utilized w
43、hen a conductor of large cross section is desirable to minimize voltage drop over a length of cable, the actual current carrying requirement being relatively low. A.3 Parallel splice Four basic types of parallel splice are available, as detailed for the in-line splice inA.1. These four types are als
44、o available in post-insulated form but not normally in pre-insulated form except for other than aircraft usage. Heat-shrink material can also be used for post-insulation. NOTEBecause one crimp barrel only is used in this type of splice it has to accommodate all conductor strands to be spliced and is
45、 therefore greater in diameter than an in-line splice used to connect the same cables, i.e.the overall splice connection is bulkier. A.4 Closed end connector This type of splice utilizes a parallel type crimp barrel insulated by a plastics thimble closed at one end. The opposite end of the thimble i
46、s of greater diameter so that support of the cable insulations is effected. Unless the plastics is translucent this type of splice cannot offer the facility of post-crimping inspection. A.5 Moisture-sealed splice With this splice the crimping barrel is of the parallel type and sealing grommets are c
47、lamped under the post-insulation sleeve to seal around the insulation of the individual cables being spliced. Both single cable-to-cable and multiple conductor splice applications can be accommodated. A.6 Screened cable splice These splices are intended to make a permanent connection between two sim
48、ilar sizes of screened cable. Normally both centre conductor and braid are crimped in one operation. Splices of this type are not intended for use in r.f. circuits requiring accurate impedance matching. Post-insulation is achieved by the use of end bushings and plastics tubing held in place by clamp
49、ing rings crimped into position. Again, heat-shrink tubing may be used for post-insulation. The splicing of multiple screened conductors is also possible using similar crimping techniques both for conductors and for post-insulation.blankBS2G180: 1974 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions BritishStandards are updated by amendment or rev
