1、BRITISH STANDARD AEROSPACE SERIES BS G 256:1995 ISO 8668-6: 1994 Specification for Type 4 terminal junction systemsBSG256:1995 This BritishStandard, having been prepared under the directionof the Engineering SectorBoard (E/-), was publishedunder the authority ofthe Standards Board and comes into eff
2、ect on 15February1995 BSI 02-2000 The following BSI references relate to the work on this standard: Committee reference ACE/6 Draft for comment 91/83230 DC ISBN 0 580 23700 1 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted by the Engineering Sect
3、or Board to Technical Committee ACE/6, upon which the following bodies were represented: British Airways British Cable Makers Confederation British Rubber Manufacturers Association Civil Aviation Authority (Airworthiness Division) Federation of the Electronics Industry Ministry of Defence Society of
4、 British Aerospace Companies Ltd. Amendments issued since publication Amd. No. Date CommentsBSG256:1995 BSI 02-2000 i Contents Page Committees responsible Inside front cover National foreword iii 1 Scope 1 2 Normative references 1 3 Requirements 1 4 Test methods 2 5 Designation 4 6 Marking, packagin
5、g and ordering 5 Annex A (normative) Specification sheets 6 Annex B (normative) Test samples for qualification approval 40 Annex C (normative) Contacts, test methods 41 Figure A.1 Module sizes 22, 20 and16 7 Figure A.2 Size 12 module 8 Figure A.3 Bussing arrangements 9 Figure A.4 Module sizes OW, OX
6、 and OZ 11 Figure A.5 Size OY module 12 Figure A.6 Component designator 13 Figure A.7 Module 14 Figure A.8 Grommet cavity identification marking 15 Figure A.9 Stud-mounted grounding module, type S 24 Figure A.10 Flange-mounted grounding module, type F 25 Figure A.11 Flange-mounted grounding module,
7、type F, block size 12 26 Figure A.12 Type 4 S and F 27 Figure A.13 Grounding stud 28 Figure A.14 Flat washer 29 Figure A.15 Wire in-line junction, type 2 30 Figure A.16 Wire in-line junction splice, type 1 30 Figure A.17 In-line electronic junctions 31 Figure A.18 Feed-back rail 33 Figure A.19 Modul
8、e mounting bracket 35 Figure A.20 Module extraction tool, type 1 36 Figure A.21 Module extraction tool, type 2 37 Figure A.22 Contacts 38 Figure A.23 Sealing plug 39 Table 1 Terminal junction system components 1 Table 2 Current rating 2 Table 3 Voltage rating 2 Table 4 Contact resistance 3 Table 5 C
9、ontact retention force 3 Table 6 Contact insertion force 3 Table 7 Contact resistance stability 3 Table 8 Wire size 3 Table A.1 Bussing details and dimensions 10 Table A.2 Accessories 10 Table A.3 Bussing details and dimensions 13 Table A.4 Accessories 13 Table A.5 Module electronic component descri
10、ption 19 Table A.6 Module types and accessories 27BSG256:1995 ii BSI 02-2000 Page Table A.7 Dimensions 28 Table A.8 Dimensions 30 Table A.9 Dimensions 30 Table A.10 Electronic junction components description 31 Table A.11 Dimensions 34 Table A.12 Dimensions 38 Table A.13 Dimensions 39 Table A.14 Too
11、l details 40 Table B.1 Specimens for general tests 40 Table B.2 Specimens for fluid resistance tests 41 List of references Inside back coverBSG256:1995 BSI 02-2000 iii National foreword This BritishStandard has been prepared under the direction of the Engineering Sector Board. It is identical with I
12、SO8668-6:1994, Aircraft Terminal junction systems Part6: Detail specification for type4 system, published by the International Organization for Standardization (ISO). The Technical Committee has reviewed the provisions of ISO1966:1973, ISO8668-1:1986, ISO8668-2:1986 and Mil-I-81969:1982, to which no
13、rmative reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. 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 w
14、ith a British Standard does not of itself confer immunity from legal obligations. Cross-reference International Standard Corresponding BritishStandard ISO 7137:1992 BS3G229:1993 Schedule for environmental conditions and test procedures for airborne equipment (Identical) Summary of pages This documen
15、t comprises a front cover, an inside front cover, pagesi toiv, pages1to42, 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.iv blankBSG256:1995
16、BSI 02-2000 1 1 Scope This part of ISO8668 specifies the specific characteristics of a Terminal Junction System (TJS), designated as type4 and particularly designed for aircraft applications. It shall be read in conjunction with ISO8668-1 and ISO8668-2. 2 Normative references The following standards
17、 contain provisions which, through reference in this text, constitute provisions of this part of ISO8668. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO8668 are encouraged to investigate the po
18、ssibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 1966:1973, Crimped joints for aircraft electrical cables. ISO 7137:1992, Aircraft Environmental conditions and test procedures fo
19、r airborne equipment. ISO 8668-1:1986, Aircraft Terminal junction systems Part1: Characteristics. ISO 8668-2:1986, Aircraft Terminal junction systems Part 2: Tests. MIL-I-81969:1982, Connector and electrical contact General specification for installing and removing tools 1) . 3 Requirements 3.1 Desc
20、ription This part of ISO8668 defines a range of multicontact connecting devices, comprising terminal junctions with their associated rails, electronic modules, grounding junctions and studs, wire in-line junctions and electronic in-line junctions, for d.c. and a.c. low-frequency use in aircraft and
21、airframe applications. These devices form part of a common interconnecting wiring system. The devices are environmentally sealed and the removable single wire crimp-type contacts are of female form. The contacts are inserted and removed by use of the appropriate tools. Each group of contacts within
22、a device is clearly marked and, when used with its appropriate rail, terminal and distribution junctions, has individual markings for each contact. A range of terminal junction frames is provided for housing the modules. The frames are of aluminium alloy with anodised finish and are marked in such a
23、 way that when modules are mounted, every individual contact is uniquely identified. Individual terminal junction modules are removable and insertable from their frames using the appropriate removal tool. Grounding junctions (a device in which individual wires may be terminated to a common bus, whic
24、h is in turn attached to a grounding plate or stud, and then attached to the airframe or equipment) also have unique contact marking. In-line junctions may form part of a cable loom or be separately mounted. Contacts for the above devices are available in four sizes,22,20,16 and12, and use insertion
25、/removal tools and crimping tools as used for a common interconnecting wiring system. The devices are designed to operate over a temperature range of65 C to+200 C, to be light in weight, and are capable of satisfactory performance during or after subjection to the defined environmental conditions. E
26、lectronic modules and special individual modules have a reduced performance and reference should be made to the individual specification sheet. The terminal junction system shall comprise the components given in Table 1 and design details shall be in accordance with Figure A.1 to Figure A.23. Table
27、1 Terminal junction system components 1) May be obtained from: Naval Publications and Forms Center 5801 Tabor Avenue Philadelphia, PA19120 USA Specification sheet No. (seeAnnex A) Component 8668-6AA 8668-6BB 8668-6CC 8668-6DD 8668-6EE 8668-6FF 8668-6GG 8668-6HH 8668-6JJ 8668-6KK 8668-6LL 8668-6MM 86
28、68-6NN 8668-6PP Bussing modules, feed-back Distribution modules Electronic modules Grounding modules Grounding studs Wire in-line junctions In-line electronic junctions Rack assembly, rail, feed-back type Module mounting brackets Module extraction tools Contacts, female, crimp-removable Sealing plug
29、s Insertion and extraction tools Crimping toolsBSG256:1995 2 BSI 02-2000 3.2 Ratings 3.2.1 Electrical 3.2.1.1 Current Table 2 gives the current rating. Table 2 Current rating The continuous current rating of any contact or group of contacts is governed by the heating effects of the electric loading
30、and ambient temperature. Devices may have any combination of electric loading and ambient temperature, provided the housing insert or contact temperature does not exceed+200 C. 3.2.1.2 Voltage Table 3 gives the voltage rating. Table 3 Voltage rating 3.2.2 Environmental a) Temperature range:65 C to+2
31、00 C b) Altitude: 24 km c) Low air pressure: ISO8668-2:1986, test No.14 (immersion at1kPa) d) Vibration: ISO8668-2:1986, test No.10(10Hz to2000 Hz,10g, duration12h) e) Mechanical shock: ISO8668-2:1986, test No.9981m/s 2 (100g), duration6ms f) Climatic test: ISO8668-2:1986, test No.11 g) Salt spray:
32、ISO8668-2:1986, test No.16 h) Flammability: test under consideration i) Magnetic effect: to satisfy the test procedure given in ISO7137-3.1 j) Resistance to fluids: ISO8668-2:1986, testNo.18 The wired specimens shall be subjected to immersion in the fluids specified for fluid susceptibility, test pr
33、ocedure ISO7137-1.6, for the time and temperature conditions stated therein. k) Endurance temperature:1000h at200 C mechanical: complies with ISO8668-2:1986, test No.7, except that the number of insertions and extractions shall be100. 3.3 Characteristics a) Module frames: seeAnnex A, Sections HH and
34、 JJ of this part of ISO8668. b) Accessories: contacts and sealing plugs: seeAnnex A, Section LL of this part of ISO8668. Contacts must comply with Annex C. c) Tools: crimping, insertion and extraction: seeAnnex A, Sections PP and NN. d) Electrical 1) Maximum contact resistance: ISO8668-2:1986, test
35、No.5 (seeTable 4) 2) Minimum insulation resistance: ISO8668-2:1986, test No.3 initially,5000M7 after conditioning,100M7 e) Mechanical 1) Contact retention force: ISO8668-2:1986, test No.8 (seeTable 5) 2) Contact insertion force: ISO8668-2:1986, test No.1 (seeTable 6) 3) Contact resistance stability:
36、 ISO8668-2:1986, test No.17 (seeTable 7) f) Conductor accommodation and wire seal (seeTable 8) 4 Test methods 4.1 Type approval This shall be in accordance with ISO8668-1:1986, Section 2. 4.1.1 Measurement group The range of samples chosen to represent terminal junction systems is shown in Annex B.
37、Each different component of the samples chosen shall be measured to verify that it complies with the manufacturing drawings. Each sample shall consist of a complete assembly from the verified components. The interchangeability characteristics of each sample shall be verified. Contact size Maximum te
38、st current at25 C a A 22 20 16 12 5 7,5 13 13 a For largest size of conductor accommodated by contact. Voltage rating Sea level 101,1kPa V Altitude 3kPa(24000m) V Working voltage, nominal, d.c. or a.c. peak 600 300 Proof voltage, d.c. or a.c. peak 1500 600 NOTEThe establishment of an electrical safe
39、ty factor is the responsibility of the user.BSG256:1995 BSI 02-2000 3 4.1.2 Test group 4.1.2.1 Bussing modules A specimen shall consist of four fully wired modules, one of each contact size, mounted in their associated rail. SeeAnnex B. 4.1.2.2 Grounding junctions A specimen shall consist of four fu
40、lly wired modules, one of each contact size, mounted in a mounting plate representing aircraft practice. SeeAnnex B. 4.1.2.3 Wire in-line junctions A specimen shall consist or four fully wired in-line junctions, one of each contact size, mounted in the form of a loom representing aircraft practice.
41、SeeAnnex B. Table 4 Contact resistance Table 5 Contact retention force Table 6 Contact insertion force Table 7 Contact resistance stability Table 8 Wire size 4.1.2.4 Electronic junctions and blocks Qualification of dimensional and material requirements may be by similarity to a qualified bussed comp
42、onent. Electronic junctions shall be rated at the electronic component level or the bussed junction level whichever has the lesser requirement. 4.1.3 Wiring of specimens Annex B shows the components to be used to make up a specimen. Specimens1,2,3,7,9 and11 shall be wired with extruded sheath PTFE w
43、ire of maximum external diameter. Specimens4,5,6,8,10,12,13,14,15,16,17 and18 shall be wired with extruded sheath PTFE wire of minimum external diameter for75% of the cavities, and sealing plugs shall be fitted to the remaining25% of cavities. Specimens with wired contacts, the contact resistance of
44、 which are to be measured, shall be submitted to the special preparations defined, in ISO8668-2:1986, Annex A. 4.1.4 Contacts The contacts used for testing shall be taken from batches tested to and complying with Annex C. 4.1.5 Sealing plugs Sealing plugs shall be in accordance with Annex A, Section
45、 MM. 4.1.6 Crimping The tools used for crimping the wires to the contacts shall produce crimped joints complying with ISO1966. 4.1.7 Test conditions These shall be in accordance withISO8668-1:1986, clause10. 4.1.8 Measurements When measurements are necessary, the precise figures obtained shall be no
46、ted in the type approval test report. Contact size Resistance m7 22 20 16 12 5 4 3 2 Contact size Maximum retention force N 22 20 16 12 44 67 111 111 Contact size Maximum insertion force N 22 20 16 12 45 68 68 68 Contact size Maximum variation m7 22 20 16 12 2,5 1,75 1,25 1 Contact size Wire size AW
47、G Finished wire outside diameter mm min. max. 22 26, 24, 22 0,76 1,52 20 24, 22, 20 1,01 2,10 16 20, 18, 16 1,65 2,76 12 14, 12 2,46 3,60BSG256:1995 4 BSI 02-2000 4.1.9 Test details Subject the test specimens to their tests concurrently. Specimens1 to12 shall be subjected to the tests stated and in
48、the order shown in the table of type approval tests of ISO8668-1:1986. Specimens13 to18 shall be used for immersion influids and shall be subjected to tests1,3,4,5a,18,4 and3, in that order, of the same table. Fluids and temperatures of immersion are as stated in3.2.2. 4.2 Production tests Productio
49、n control tests comprise the production acceptance100% test and batch sampling tests. 4.2.1 Acceptance tests,100% inspection Each component shall be examined visually without magnification. Construction, workmanship, finish and marking shall comply with the requirements of the manufacturing drawings. a) Internal electrical continuity: ISO8668-2:1986, test No.2 b) Withstanding voltage: ISO8668-2:1986, testNo.4 4.2.2 Batch sampling tests To be applied
