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1、BRITISH STANDARD AEROSPACE SERIES BS 2G 180: 1974 Superseding British Standard G 180 Specification for Permanent splicing of aircraft electrical cables UDC 629.7.064.5:621.315.687.1 Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:14:59 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 180:1
2、974 This British Standard, having been approved by the Aerospace Industry Standards Committee, was published under the authority of the Executive Board on 29 November 1974 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference ACE/6/1 Draft for comment 72/3
3、6973 ISBN 0 580 08620 8 Foreword This British Standard has been prepared to define approved methods of making and installing 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
4、, and details certain design requirements to supplement those given in British Standard G 178. Appendix A provides information about the types of device currently manufactured, to assist the definition of the subject. This standard makes reference to the following British Standards: 3G 100, General
5、requirements for equipment for use in aircraft Part 1: Identification, declaration and construction Part 2: All equipment. G 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 Stand
6、ards 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 and ii, pages 1 to 4 and a back cover. This standard has been updat
7、ed (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:14:59 GMT+00:00 2006, Uncontrolled Copy, (c) B
8、SI BS 2G 180:1974 BSI 10-1999i Contents Page ForewordInside front cover Section 1. General 1Scope1 2Definitions1 Section 2. Application 3Selection and use of splices1 4Restrictions on splicing1 Section 3. Installation 5Staggering of splices2 6Location of splices2 7Support of splices2 8Post-insulatio
9、n of splices2 9Tools2 10Recording2 Section 4. Design requirements 11General2 12Protective treatment2 13Insulation3 14Environmental requirements3 Appendix A Types of splice currently manufactured4 Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:14:59 GMT+00:00 2006, Uncontrolled Copy, (c) B
10、SI ii blank Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:14:59 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 180:1974 BSI 10-19991 Section 1. General 1 Scope This British Standard defines the essential parameters for achieving acceptable jointing of the copper conductor of one cable
11、to that of another, or the multiple connection of such conductors by means of permanent crimped splices. This standard does 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 G 178 and
12、 the following apply. 2.1 cable and wire a single core electrical cable or wire or an individual core of a multicore cable or 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 accommodat
13、e and support the cable insulation. With this type of splice two separate crimping operations are normally necessary to join 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 inserte
14、d from the same end or from opposite ends of the barrel. With this type of splice only one crimping operation is normally necessary 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 extend
15、s beyond the ends of the barrel, which remains firmly fixed to the barrel before, during and after the crimping operations, 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
16、sleeve, which extends beyond the ends of the barrel 2.6 declaration of design and performance (DDP) the standard form specified in British Standard 3G 100-1 2.7 Air Form 100D a standard form relating to instrument and electrical equipment intended for United Kingdom Ministry of Defence aircraft, whe
17、reby the manufacturer or design authority certifies compliance with the specification for that equipment or, if necessary, states 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 b
18、e made in accordance with the data supplied by the relevant design authority1). It is recognized that splices are occasionally 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 giv
19、en to the requirements of clause 4, in addition to the general requirements of this standard. Any such splicing of cables shall be recorded in the aircraft technical log (or equivalent) as a “temporary repair”. The information recorded shall include that listed in clause 10 and at the first opportun
20、ity the splice(s) shall be replaced or duly authorized by an approved procedure. It should be noted that the crimping of multiple conductors in a splice with simultaneously crimped insulation support does not provide the normal insulation support. The installer should recognize this limitation and c
21、are should be taken to prevent compression of the insulation of multiple cables. 4 Restrictions on splicing 4.1 Joints shall not be made for repair purposes in the following cables unless specifically approved by a design authority: a) h.t. cables (greater than 600 V (r.m.s.) to earth); b) multicore
22、 cables; c) cables within a fire zone; d) thermocouple cables; 1) For aircraft subject to British civil or military airworthiness requirements, a design authority is an organization approved by the Airworthiness Division of the Civil Aviation Authority, or by the Ministry of Defence (Procurement Exe
23、cutive) (A.D.Elec.), as appropriate. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:14:59 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 180:1974 2 BSI 10-1999 e) cables in vital circuits declared by the aircraft constructor and listed in the aircraft manual; f) cables larger than size
24、10; 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 except as a direct replacement for an existing item. Section
25、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 between splices, or from splice to earth. 6 Location of splices 6.
26、1 Splices shall not be located under clips or ties. 6.2 The minimum distance between splices in any one cable shall be 500 mm and not more than two splices shall be used in 3 m of cable. 6.3 Splices shall be so positioned that they can be visually inspected after installation. 6.4 Splices shall not
27、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 cables, splices shall not be positioned in an unsupported l
28、ength exceeding 500 mm. 7.2 Splices in loomed cables shall be supported, e.g. by strapping within 50 mm of each end of the splice. 8 Post-insulation of splices Uninsulated splices shall be insulated with materials which maintain the performance of the cables to be spliced. When shrink-on sleeves are
29、 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 Form 100D for the particular size and type of splice and which have been shown to com
30、ply with the requirements of clause 11 shall be used in the crimping operation. All tools shall be checked regularly in accordance with 3.4 of British Standard G 178. 10 Recording Any temporary use of splices as detailed in clause 3 shall be recorded in the aircraft technical log (or equivalent). Th
31、e 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. Section 4. Design requirements 11 General Splices s
32、hall provide conductor crimps that conform to the requirements of British Standard G 178 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 largest and the smallest conductor sizes inclu
33、ded 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 contact resistance, having regard to the finish of
34、 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 G 178. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:14:59 GMT
35、+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 180:1974 BSI 10-19993 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 insulat
36、ion of the insulated splice shall be of a material that is non-corrosive, resistant to fungus and to aircraft fluids when tested in accordance with the relevant requirements of British Standards 3G 100-2 and G 178. The material and form of the insulation shall minimize abrasion to adjacent cables an
37、d shall comply with the relevant dielectric strength tests specified in 3.2.9.4 of G 178. 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
38、in accordance with British Standard G 178. 14 Environmental requirements 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
39、with the temperature rating of the cables to be spliced. For splices which are declared as suitable for use in conditions of high humidity, samples of the completed splice joint shall be completely immersed in a 5 % aqueous sodium chloride solution. A potential of 1500 V r.m.s. at a frequency of 50
40、Hz to 60 Hz shall be applied between the conductor assembled to the spliced joint and an electrode in contact with the liquid. The voltage shall be applied for 1 min without breakdown. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:14:59 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2G 18
41、0:1974 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 for 105 C cables; b) uninsulated nickel-plated copper splice for 260 C cables; c) uninsulated silver-plated
42、 copper splice for 190 C cables; d) uninsulated gold-plated copper splice for 260 C cables. These four basic types are also available in pre-insulated and post-insulated form. The insulation material will vary; generally it will be nylon or polytetrafluoroethylene dependent upon temperature category
43、. 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 multi-conductor applications, it may be necessary to use collector ferrules in special cases. These ferru
44、les 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 maintained. A.2 Step-down in-line splice An extension of the employment of inserts in the in- line type
45、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 when a conductor of large cross section is desirable to minimize voltage drop over a length of cable, t
46、he 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 in A.1. These four types are also available in post-insulated form but not normally in pre-insulated form except for other than aircr
47、aft 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 therefore greater in diameter than an in-line splice used to connect the same cables, i.e. the overa
48、ll 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 is of greater diameter so that support of the cable insulations is effected. Unless the plastics is t
49、ranslucent 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 clamped 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 similar sizes of screened cable. Normally both centre conductor and braid are crim