ASD-STAN PREN 2812-2016 Aerospace series Stripping of electric cables (Edition P 4).pdf

1、ASD-STAN STANDARD NORME ASD-STAN ASD-STAN NORM ASD-STAN prEN 2812 Edition P 4 September 2016 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATION Rue Montoyer 10 - 1000 Brussels - Tel. 32 2 775 8126 - Fax. 32 2 775 8131 - www.asd-stan.org ICS: Supersedes edition

2、P 3 of September 2008 and will supersede EN 2812:2009 Descriptors: ENGLISH VERSION Aerospace series Stripping of electric cables Luft- und Raumfahrt Abisolieren von elektrischen Leitungen Srie arospatiale Dnudages des cbles lectriques This “Aerospace Series“ Prestandard has been drawn up under the r

3、esponsibility of ASD-STAN (The AeroSpace and Defence Industries Association of Europe - Standardization). It is published for the needs of the European Aerospace Industry. It has been technically approved by the experts of the concerned Domain following member comments. Subsequent to the publication

4、 of this Prestandard, the technical content shall not be changed to an extent that interchangeability is affected, physically or functionally, without re-identification of the standard. After examination and review by users and formal agreement of ASD-STAN, the ASD-STAN prEN will be submitted as a d

5、raft European Standard (prEN) to CEN (European Committee for Standardization) for formal vote and transformation to full European Standard (EN). The CEN national members have then to implement the EN at national level by giving the EN the status of a national standard and by withdrawing any national

6、 standards conflicting with the EN. ASD-STAN Technical Committee approves that: “This document is published by ASD-STAN for the needs of the European Aerospace Industry. The use of this standard is entirely voluntary, and its applicability and suitability for any particular use, including any patent

7、 infringement arising therefrom, is the sole responsibility of the user.” ASD-STAN reviews each standard and technical report at least every five years at which time it may be revised, reaffirmed, stabilized or cancelled. ASD-STAN invites you to send your written comments or any suggestions that may

8、 arise. All rights reserved. No parts of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission of ASD-STAN. Order details: E-mail: salesasd-stan.org

9、 Web address: http:/www.asd-stan.org/ Edition approved for publication 1st September 2016 Comments should be sent within six months after the date of publication to ASD-STAN Electrical Domain Copyright 2016 ASD-STAN prEN 2812:2016 (E) 2 Contents Page Foreword 2 1 Scope 3 2 Normative references 3 3 S

10、tripping processes and associated tools. 3 4 Identification, inspection and calibration 6 5 Qualification 8 6 Health, safety and environmental aspects . 10 Annex A (normative) Defects illustrations . 12 Annex B (informative) Mechanical stripping . 16 Annex C (informative) Laser stripping . 17 Annex

11、D (informative) Thermal stripping . 18 Foreword This standard was reviewed by the Domain Technical Coordinator of ASD-STANs Electrical Domain. After inquiries and votes carried out in accordance with the rules of ASD-STAN defined in ASD-STANs General Process Manual, this standard has received approv

12、al for Publication. prEN 2812:2016 (E) 3 1 Scope This standard specifies the conditions for stripping and inspection of stripping tools and the stripped ends of electric cables for aerospace applications. Various stripping processes exist. The choice of a process depends upon the properties of the p

13、articular cables to be stripped and/or on the specific requirements for the end product to be achieved. The processes specified today in this document are: a) manual stripping; b) mechanical stripping; c) laser stripping; d) thermal stripping. 2 Normative references The following documents, in whole

14、 or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 2083, Aerospace series Copper or copp

15、er alloy conductors for electrical cables Product standard EN 3475-701, Aerospace series Cables, electrical, aircraft use Test methods Part 701: Strippability and adherence of insulation to the conductor EN 3719, Aerospace series Aluminium or aluminium alloy conductors for electrical cables Product

16、standard EN 4434, Aerospace series Copper or copper alloy lightweight conductors for electrical cables Product standard (Normal and tight tolerances) EN 4651, Aerospace series Copper-clad aluminium alloy conductors for electrical cables Product standard 3 Stripping processes and associated tools 3.1

17、 General recommendations Precise definition of tools to use on a particular wire or cable standard is under the responsibility of the user. It is particularly important to know from which ASD Product Norm conductors are coming (for examples: EN 2083, EN 3719, EN 4434, EN 4651) for the mechanical str

18、ipping process. Availability of a common tool able to strip different gauges or cable sizes is recommended. If tools are designed for particular applications, differentiation by colours is recommended. Size and weight of tools has to be appropriate for the envisaged use. prEN 2812:2016 (E) 4 When it

19、 is essential to control the length of insulation to be removed an adjustable abutment must be part of the tool. 3.2 Manual stripping 3.2.1 Use The use of this process must be strictly limited to insulations and jackets of the cables for which other methods are impractical. Nevertheless, with therma

20、l stripping and the arrival of small laser machines, this manual practice must be progressively eliminated for aerospace use and stay permissible only for small batches. 3.2.2 Application Manual stripping by scalpel, razor blade or other cutting tool is carried out on cables over 5 mm cross-section,

21、 sheaths of shielded cables, fire-resistant cables and coaxial cables, unless another stripping process is specified. 3.3 Mechanical stripping 3.3.1 Use This process is generally the most used in particular for single wires. Various power tools are also adapted to strip round cables, such as single

22、wire screened jacketed and coaxial, and flat cables. The simplicity of manual pliers makes these tools ideal for work in the field. For illustration, see Annex B (informative). 3.3.2 Stripping with manual tools The blades of tools can have different profiles and dimensions. Various assembly shapes a

23、re now available. A blade can have several marked cavities of different sizes. When the tool is closed, the edges of the blades shall be in the same plane and form a cutting circumference whose diameter is greater than the maximum diameter of the conductor of the cable to be stripped. Blades must be

24、 replaced as pairs. The manual stripping tools with V shaped cutting blades or shearing type blades are forbidden (see Figure 1 and Figure 2). Figure 1 V shaped cutting blades Figure 2 Shearing type blades prEN 2812:2016 (E) 5 3.3.3 Stripping with power tools These tools use blades with the same gen

25、eral characteristics as those defined in 3.3.2. Particular care is necessary during the use of rotating blades, and their depth shall be adjustable to adapt the cutting diameter to the need. 3.4 Laser stripping 3.4.1 Use Laser wire stripping can be carried out on wires and cables of any gauge and on

26、 jackets. This process is particularly suitable for use in applications where damage of any sort to the conductor or the screen is unacceptable and when the external geometry of the cable to strip is incompatible with mechanical processes. More specifically, laser wire stripping is recommended: 1) T

27、o process single core wires where the batch to batch variation in conductor diameter exceeds the tight cutting tolerances compatible with mechanical stripping tools 2) To process the jackets of multi-core shielded cables having a non-circular cross section 3) To provide operator-independent high str

28、ipping quality with a high level of repeatability. For illustration, see Annex C (informative). 3.4.2 Application Two technologies are currently available: Carbon Dioxide (CO2) laser technology and blue-violet semiconductor lasers technology. Other laser types may be applicable for certain applicati

29、ons. Low power RF excited CO2 laser and CW (continuous wave) laser types are recommended. In this context “low power” typically means 30 Watts average power. The system shall be designed to guarantee that the laser beam cannot cause damage to the plated metallic conductor or shield at any time. Beam

30、 power and displacement speed shall be adjustable to be able to cut properly all various types of insulation and shapes. 3.5 Thermal stripping 3.5.1 Use Thermal wire stripping can be carried out on wires and cables of any gauge and on jackets. This process is particularly suitable when the external

31、geometry of the cable to strip is incompatible with mechanical process and when the size of tooling equipment investment must be limited. This process may not be suitable for all types of insulation or in particular environmental conditions such as where flammable vapours may be present. For illustr

32、ation, see Annex D (informative). prEN 2812:2016 (E) 6 3.5.2 Application Generally the tool is in two parts, a generator to control the required temperature and a hand unit. The hand unit can be equipped with various shapes of blades. 4 Identification, inspection and calibration 4.1 Manual stripping

33、 tools 4.1.1 Identification An identification number marked on the main body is recommended in order to facilitate the follow-up of the inspection of the cutting blade. 4.1.2 Inspection The inspection of cutting area is carried out visually at regular intervals. The inspection shall be completed by

34、inspection of samples of stripped cable ends, see 5.3.1. 4.2 Mechanical stripping tools 4.2.1 Identification An identification number shall be permanently marked on the main body of the tool and on the blade. In addition, each stripping tool shall have an individual inspection sheet including: its i

35、dentification number; date of first commissioning; dates of successive inspections; dates of rectification or repair; numbers of associated blades. 4.2.2 Inspection The inspection of blades is carried out with the aid of measuring gauges, shadowgraph, calipers or other means permitting confirmation

36、that the cavities are in accordance with the dimensions specified. The inspection shall be completed by checking the mechanical condition of the manual tool or power tool and by stripping tests, followed by inspection of samples of stripped cable ends, see 5.3.2. For the routine inspection of produc

37、tion tools, the gauging of blades may be omitted, provided double stripping is used for the inspection of stripped cable ends. Stripping tools shall be inspected at least every 90 days. If a worn blade requires replacement, the complete blade assembly shall always be replaced together. prEN 2812:201

38、6 (E) 7 4.2.3 Calibration Some particular tools, for coaxial cables for example, may require calibration to obtain the necessary diameter to strip. 4.3 Laser stripping tools 4.3.1 Identification An identification number shall be permanently marked on the main body of the tool. In addition, each tool

39、 shall have an individual inspection sheet including: its identification number; date of first commissioning; dates of successive inspections; dates of rectification or repair; numbers of associated parts. 4.3.2 Inspection The inspection shall be completed by checking the general behaviour of the la

40、ser tool accordingly to the laser tool manufacturer instructions and by stripping tests, followed by inspection of samples of stripped cable ends, see 5.3.3. Laser tools shall be inspected at least every 90 days. 4.3.3 Calibration Periodic system stripping parameter checks shall be made to ensure th

41、ey remain within the limits as defined by the manufacturers specification. These checks can consist in the carrying out of a control sample according to the system manufacturer recommendations. 4.4 Thermal stripping tools 4.4.1 Identification An identification number shall be permanently marked on t

42、he main body of the tool. In addition, each stripping tool shall have an individual inspection sheet including: its identification number; date of first commissioning; dates of successive inspections; dates of rectification or repair; numbers of associated parts. prEN 2812:2016 (E) 8 4.4.2 Inspectio

43、n The inspection shall be completed by checking the general behaviour of the thermal tool according to the thermal tool manufacturer instructions and by stripping tests, followed by inspection of samples of stripped cable ends, see 5.3.4. Thermal tools shall be inspected at least every 90 days. 4.4.

44、3 Calibration Periodic calibration checks of the tool shall be made to ensure power levels, and consequently temperature at the tip of the respective blade remain within the limits as defined by the manufacturers specification. 5 Qualification 5.1 General Wires and cables must be strippable as norma

45、lly defined in their technical specification or product standard. The test method generally used to assess this is EN 3475-701. The stripping operation must remove the insulator from the conductor over a length defined with tolerances, to allow correct connection of cables, without: damaging the cor

46、e strands or the insulator when stripping a single conductor wire. damaging the screen or the inner wire(s) when stripping a shielded cable or coaxial cable. The stripping operation must not reduce the original performances of the wire or cable as defined in its technical specification. The strippin

47、g length depends on the length required to connect the conductor into the end component. Each process must be applied by trained operators. For qualification to a wire and cable standard, there must be an agreement between the wire and cable manufacturer and the qualifying authority on exact tool re

48、ference to use. The exact reference of this tool must be written in the associated test report. 5.2 Method Qualification of a dedicated tool to strip a wire or cable type will be performed by stripping of samples coming from at least two different batches (ideally for manual stripping pliers used fo

49、r single wires, batches shall have conductors not coming from the same conductor batch, and if possible one at the maximum conductor diameter and the other at the minimum). The qualification method of stripping a single conductor wire is the following: The inspection of stripped cable ends, for which the tool will be used, shall be carried out on 10 samples coming from the same manufacturing batch for each wire size. Five samples will h