1、BRITISH STANDARD AEROSPACE SERIES BSG246:1991 Specification for Cable ties for installation under controlled tension on aircraft electric cable harnessesBSG246:1991 This BritishStandard, having been prepared under the directionof the Aerospace Standards Policy Committee, waspublished under the autho
2、rityof the Board of BSI andcomes into effect on 28February1991 BSI 01-2000 The following BSI references relate to the work on this standard: Committee referenceACE/6 Draft for comment89/77936DC ISBN 0 580 19121 4 Committees responsible for this BritishStandard The preparation of this BritishStandard
3、 was entrusted by the Aerospace Standards Policy Committee(ACE/-) to Technical CommitteeACE/6, upon which the following bodies were represented: Association of Manufacturers allied to the Electrical and Electronic Industry (BEAMA Ltd.) British Airways British Cable Makers Confederation British Rubbe
4、r Manufacturers Association Civil Aviation Authority (Airworthiness Division) Electronic Components Industry Federation Ministry of Defence Society of British Aerospace Companies Limited Amendments issued since publication Amd. No. Date of issue CommentsBSG246:1991 BSI 01-2000 i Contents Page Commit
5、tees responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Classification 1 4 Design requirements 1 5 Type testing 2 6 Production and quality testing 3 7 Packaging and identification 3 8 Tests 3 Appendix A Storage recommendations 13 Appendix B Ordering procedure 13 Figure 1 Design o
6、f cable ties with provision for marking 9 Figure 2 Loop tensile strength test mandrel 10 Figure 3 Test condition random vibration test curve envelope 11 Figure 4 Assembly of components, wire bundle and fixture 11 Figure 5 Suggested cold flow and high temperature performance test fixture 12 Table 1 D
7、esign requirements 2 Table 2 Type tests 7 Table 3 Production routine tests 7 Table 4 Production quality tests 7 Table 5 List of test fluids 8 Table 6 Wire harness construction 12 Publications referred to Inside back coverBSG246:1991 ii BSI 01-2000 Foreword This BritishStandard has been prepared unde
8、r the direction of the Aerospace Standards Policy Committee at the request of the British Aerospace Industry to improve the reliability of aircraft electrical cable harnesses. In addition to achieving a satisfactory cable tie, the correct tensioning of the tie using the recommended application tool
9、is considered to be important for a successful installation. With this in view, a code of practice is in course of preparation which will cover the selection and installation of ties. The importance of toxic fume emission when burning occurs has been recognized, but no suitable test has been found t
10、o date which has proved acceptable for this standard. Pending the development of such a test, the materials from which the ties are manufactured should present the minimum hazard from toxic fumes and smoke emission when burning occurs. WARNING NOTE. This standard calls for the use of substances and/
11、or test procedures that may be injurious to health if adequate precautions are not taken. It refers only to technical suitability and in no way absolves either the supplier or the user from statutory obligations relating to health and safety at any stage of manufacture or use. A British Standard doe
12、s 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 from legal obligations. Summary of pages This document comprises a front cover, an insi
13、de front cover, pagesi andii, pages1 to14, 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.BSG246:1991 BSI 01-2000 1 1 Scope This BritishStanda
14、rd specifies the design, performance, quality assurance requirements and test procedures for cable ties for installation under controlled tension on aircraft electric cable harnesses. Ties which have provision for marking are covered but the standard does not include accessories such as mounting bra
15、ckets, separate identification tags, reuseable ties or application tools. Guidance on the storage of finished ties is given inAppendix A, and a recommended ordering procedure is given inAppendix B. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2
16、 Definitions For the purposes of this BritishStandard, the following definitions apply. 2.1 application tools the tools used in completing and correctly tensioning the tie joint 2.2 cable the complete assembly of conductor, insulation and metal braid, if any 2.3 harness (or bundle) a number of cable
17、s or looms specifically formed and terminated to suit a particular installation 2.4 loom any number of cables running together 2.5 breakout any number of cables branching out from the main harness 2.6 tail the portion of the tie removed after fixing 2.7 head the portion of the tie containing the tie
18、 locking system 2.8 strap the portion of the tie between its head and tail 3 Classification 3.1 General Ties shall be classified by type according to the temperature range within which they are designed to operate and by class according to their resistance to flame, see3.2 and3.3. 3.2 Operating temp
19、erature range (type) 3.3 Flame resistance (class) 4 Design requirements 4.1 General 4.1.1 Ties shall be designed for installation under controlled tension by the use of an application tool. The head design, locking system and strap cross-sectional dimensions shall be such that the requirements of th
20、e tests given in clause8 are met. NOTETies are available with either internal or external serrations. 4.1.2 Ties shall comply with the design requirements given inTable 1. 4.2 Materials Ties shall be made from materials which ensure that the finished tie complies with the appropriate requirements gi
21、ven in clause8. NOTEA material known to comply with clause8 requirements for type1 ties is heat stabilized nylon66. A nominal2% carbon black is required in nylon66 to provide the UV resistance capability of type1W ties. The inclusion of carbon black in nylon is known to increase the brittleness of c
22、able ties particularly at low temperatures and it is recommended that the use of such ties be restricted to areas where UV resistance is essential. 4.3 Finish The finish shall prevent abrasion to the harness and to adjacent harnesses or breakouts. In completing the joint, no sharp or abrasive edges
23、shall be formed that could damage the cable insulation of the loom or any adjacent looms, or that could cause injury to an operator. Type1: 55 C to+105 C Type1W: 55 C to+105 C ultraviolet (UV) resistant Type2: 55 C to+150 C Type2W: 55 C to+150 C ultraviolet (UV) resistant Class1: after removal of th
24、e burner(see8.5) any flame shall extinguish within5s. Class2: after removal of the burner(see8.5) any flame shall extinguish within5s and no burning or flaming particles shall fall.BSG246:1991 2 BSI 01-2000 Table 1 Design requirements 4.4 Temperature ratings The ties shall be capable of use within t
25、he following temperature ranges. Type1: 55 C to+105 C Type2: 55 C to+150 C Type2 ties shall have the number2 embossed on or near the head. 4.5 Colour 4.5.1 Type1 and2 ties shall have either: a) a natural material finish; or b) a colour complying with BS6746C. NOTEThe requirement for colouring and th
26、e colour required should be stated in the purchasers contract or order. 4.5.2 Type1W and2W ties shall be black. 4.5.3 The colour shall be uniform throughout any coloured tie. 5 Type testing 5.1 Type tests 5.1.1 The manufacturer shall submit evidence to the satisfaction of the Approving Authority 1)t
27、hat ties complying with this standard satisfy the tests listed inTable 2. 5.1.2 In the event of a failure of a specimen to satisfy any test, two further sets of samples shall be tested. Both sets shall satisfy the appropriate tests, otherwise the ties shall be deemed not to comply with this standard
28、. 5.1.3 The manufacturer shall inform the Approving Authority if any changes are made in the techniques or materials used in the production of the ties. NOTEFollowing such changes, the Approving Authority may require a repetition of type testing. 5.1.4 Type tests shall be carried out every five year
29、s. 5.2 Test conditions Unless otherwise specified in clause8 the tests shall be carried out under the following normal atmospheric conditions: a) a temperature of20 5 C. In the event of a dispute, the tests shall be conducted at23 2 C; b) relative humidity (r.h.) not greater than80%. 5.3 Conditionin
30、g of specimens Before submission to type approval tests, the specimens shall be placed in a chamber maintained at a temperature ofwith a relative humidity of20 5% for24h. Immediately upon removal from the chamber the specimens shall be stored at20 5 C in an airtight container for a minimum of30min.
31、When required, the specimens shall be installed on the test fixtures immediately on removal from the airtight container. 5.4 Type test sequence and number of specimens Tests shall be carried out in accordance with the sequence given inTable 2 for each tie for which approval is being sought. The numb
32、er of specimens for each test shall be as given inTable 2. Size code Loop tensile strength (min.) Recommended bundle diameter Strap length (min.) Strap width (min.) min. max. 1 2 3 4 5 6 7 8 9 10 11 N 80 130 130 220 220 220 220 360 360 530 530 mm 1.5 1.5 1.5 1.5 1.5 1.5 1.5 5.0 5.0 5.0 5.0 mm 16 28
33、44 28 39 63 93 47 86 89 102 mm 90 140 180 140 180 250 270 200 330 340 360 mm 2.0 3.3 3.3 4.0 4.0 4.0 4.0 7.3 7.3 7.3 7.3 1MA a 1MB a 5MC a 80 80 220 5.0 1.5 10.0 16 16 39 90 90 180 2.0 2.0 4.0 NOTEThe length of the tie will depend on the maximum permissible harness diameter and the method of applica
34、tion. In some cases, additional length may be provided to facilitate application. a Ties with provision for marking (M). SeeFigure 1 for details of designs A, B, and C. 1) The Approving Authority for civil aircraft applications is the Civil Aviation Authority, Airworthiness Division or an organizati
35、on approved by them, and for Ministry of Defence applications, information is available from the Procurement Executive, Ministry of Defence, Directorate General of Defence Quality Assurance, Directorate of Standardization, Kentigern House, 65 Brown Street, Glasgow G28EX. 49 +3 0C BSG246:1991 BSI 01-
36、2000 3 5.5 Declaration A declaration shall be made in the form of a declaration of design and performance specified in BS3G100-1. The declaration shall include particulars of: a) approved drawings; b) materials and colours; c) type; d) application tool type and application tension values; e) size co
37、de. 6 Production and quality testing 6.1 Production routine tests Production routine tests shall be applied to samples taken at random from every batch, and shall be as given inTable 3. 6.2 Production quality tests Production quality tests shall be applied to samples taken at random from batches, an
38、d shall be as given inTable 4. NOTEThe frequency of application of each production quality test should be agreed with the Approving Authority and will depend on the maintenance of the basic formulation of the material and the manufacturing conditions. 6.3 Batch A batch of ties shall consist of that
39、quantity produced from one batch of basic material, or by one shift from any one machine, whichever is the smaller. 6.4 Test conditions and conditioning of specimens Test conditions shall comply with5.2. Conditioning of specimens shall comply with5.3. NOTEManufacturers may use alternative methods fo
40、r conditioning specimens for production routine quality tests, but they should ensure that the samples have similar moisture levels to those that would be achieved by the method given in5.3. 7 Packaging and identification Each packet shall be identified with the following information: a) number of t
41、his BritishStandard, i.e.BSG246 2) ; b) type; c) size code; d) colour; e) manufacturers name; f) manufacturers part number; g) quantity; h) batch number and date of manufacture; i) recommended installation tool part number. NOTEPackaging requirements will vary and should be specified by the purchase
42、r in the contract or order. For UK Government Services these instructions will be based on DEF/STAN81-41 “Packaging of Defence Materiel Part1:General requirements”, available from Ministry of Defence, Directorate of Standardization, Kentigern House, 65 Brown Street, Glasgow G28EX. 8 Tests NOTEThe nu
43、mber of specimens to be used in each type test is given inTable 2. 8.1 Inspection 8.1.1 Procedure. Inspect all specimens used for testing for compliance with the approved drawings. For each installation required by the test procedures apply the ties using the manufacturers recommended tool at the re
44、commended tension setting. Visually inspect each installed specimen. 8.1.2 Requirements. All specimens shall comply with their approved drawings. All specimens shall show: a) completion of application cycle, i.e.tail severed cleanly and locking device secure; b) freedom from fracture and rough or sh
45、arp edges. 8.2 Loop tensile strength 8.2.1 Procedure. Individually apply test specimens to a suitable tensile test fixture as shown in Figure 2 ensuring that the head is positioned on the mandrel split line. Separate the jaws of the tensile tester at a constant rate of traverse of25mm/min. Apply suf
46、ficient force to break the strap or release the locking device. Conduct the tests with ties applied in accordance with8.1 to mandrels of a diameter equal to the maximum permissible harness diameter for which the tie is designed and width greater than the maximum width of the tie. Record the maximum
47、force obtained. 2) Marking BSG246 on or in relation to a product represents a manufacturers declaration of conformity, i.e.a claim by or on behalf of the manufacturer that the product meets the requirements of the standard. The accuracy of the claim is therefore solely the responsibility of the pers
48、on making the claim. Such a declaration is not to be confused with third party certification of conformity, which may also be desirable.BSG246:1991 4 BSI 01-2000 8.2.2 Requirements. Force to failure for each specimen shall be the following. 8.3 Resistance to fluids 8.3.1 Procedure. Mount the specime
49、ns as shown inFigure 2 on appropriate size mandrels as given in8.2. Completely immerse the specimens in each of the fluids given inTable 5 for a period of4h 10min at the immersion temperatures given inTable 5. Not later than60min after completion of the immersion period submit the specimens, mounted on the mandrels, to the loop strength test specified in8.2. WARNING NOTE. Some test fluids may have a critical flash point temperature. Testing should always be undertaken in a suitable vessel if that temperature is excee
