ASD-STAN PREN 3475-604-2016 Aerospace series Cables electrical aircraft use Test methods Part 604 Resistance to dry arc propagation (Edition P 3).pdf

1、ASD-STAN STANDARD NORME ASD-STAN ASD-STAN NORM prEN 3475-604 Edition P 3 June 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: 49.060 Supersedes edition P 2

2、 of June 2009 and will supersede EN 3475-604:2010 Descriptors: ENGLISH VERSION Aerospace series Cables, electrical, aircraft use Test methods Part 604: Resistance to dry arc propagation Luft- und Raumfahrt Elektrische Leitungen fr Luftfahrtverwendung Prfverfahren Teil 604: Lichtbogenfestigkeit, troc

3、ken Srie arospatiale Cbles lectriques usage aronautique Mthodes dessais Partie 604 : Rsistance lamorage et la propagation darc lectrique, essai sec This “Aerospace Series“ Prestandard has been drawn up under the responsibility of ASD-STAN (The AeroSpace and Defence Industries Association of Europe -

4、 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 of this Prestandard, the technical content shall not be changed to an extent that inte

5、rchangeability is affected, physically or functionally, without re-identification of the standard. After examination and review by users and formal agreement of ASD-STAN, it will be submitted as a draft European Standard (prEN) to CEN (European Committee for Standardization) for formal vote and tran

6、sformation 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 standards conflicting with the EN. ASD-STAN Technical Committee approves that: “This document is publ

7、ished 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 infringement arising therefrom, is the sole responsibility of the user.” ASD-STAN reviews each standa

8、rd 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 arise. All rights reserved. No parts of this publication may be reproduced, stored in a retrieval sys

9、tem 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 Web address: http:/www.asd-stan.org/ Edition approved for publication 1st June 2016 Comments should b

10、e sent within six months after the date of publication to ASD-STAN Electrical Domain Copyright 2016 ASD-STAN prEN 3475-604:2016 (E) 2 Contents Page Foreword 2 1 Scope 3 2 Normative references 3 3 Specimen requirements 3 4 Preparation of specimen 4 5 Apparatus . 5 6 Method 9 7 Requirements 11 Forewor

11、d 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 approval for Publication. prEN 3475-604:2016 (E) 3 1

12、 Scope This standard specifies a method for appraising the behaviour of cable insulation when an electric arc is initiated and maintained by two powered cables rubbing against a blade. This standard shall be used together with EN 3475-100. The primary aim of this test is: to produce, in a controlled

13、 fashion, continuous failure effects which are representative of those which may occur in service when a typical cable bundle is damaged by abrasion such that electrical arcing occurs, both between cables and between cables and conductive structure, and to examine the aptitude of the insulation to t

14、rack, to propagate electric arc to the electrical origin. Originally defined for 115 Vac network, this test also proposes conditions for 230 Vac network. Unless otherwise specified in product standard, only 115 Vac conditions shall be satisfied. Six levels of prospective fault current have been spec

15、ified for concerned cable sizes (see Clause 7). It is generally agreed that larger sizes need not be assessed since the short-circuit phenomenon becomes dominant at low line impedances. Unless otherwise specified in the technical/product standard sizes 002, 006 and 020 cable shall be assessed. 2 Nor

16、mative references The following documents, in whole 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

17、) applies. EN 2350, Aerospace series Circuit breakers Technical specification EN 2702, Aerospace series Aluminium alloy AL-P6061 T6 or T62 Drawn or extruded bar and section a or D 200 mm EN 3197, Aerospace series Design and installation of aircraft electrical and optical interconnection systems EN 3

18、475-100, Aerospace series Cables, electrical, aircraft use Test methods Part 100: General EN 3475-302, Aerospace series Cables, electrical, aircraft use Test methods Part 302: Voltage proof test A-A-52083, Tape, lacing and tying, glass 1) 3 Specimen requirements Cables to be tested shall be of trace

19、able origin and shall have passed the high voltage dielectric test defined in the product standard. 1) Published by: Department of Defense Industrial Supply Center, ATTN: DISC-BBEE, 700 Robbins Avenue, Philadelphia, PA 19111-5096 USA. prEN 3475-604:2016 (E) 4 4 Preparation of specimen 4.1 Cut seven

20、separate lengths of approximately 0,5 m consecutively from one length of cable, and strip each of the ends of insulation to permit electrical connection. Clean each length of cable with a clean cloth moistened with propan-2-ol (isopropyl alcohol) fluid. 4.2 Lay up the seven cables as follows: a) For

21、m the cables in a six around one configuration as shown in Figure 1. b) Ensure that all cables are straight and geometrically parallel, and restrained by lacing tapes such that they are in continuous contact for at least a 75 mm continuous length around the mid point of the loom length. This is call

22、ed the test zone. c) Position the lacing tapes at 15 mm to 20 mm spacing within the test zone. The tie material shall be PTFE glass lacing tape conforming to A-A-52083 type IV, finish D, size 3. d) Number the cables as shown in Figure 1 such that the cables in contact with the blade are numbers A1 a

23、nd B1. Key 1 Original position 2 Final position A1-A2 : Phase A B1-B2 : Phase B C1-C2 : Phase C N1-N2 : Inactive cables connected to earth Figure 1 Specimen configuration prEN 3475-604:2016 (E) 5 5 Apparatus 5.1 Electrical equipment Connect the seven cables of the test sample within a circuit as sho

24、wn in Figure 2. This circuit shall have the following requirements: a) The provision of adjustable levels of prospective fault currents for the five A, B and C cables and an electrical return path for the two N cables. b) A three phase 115/200 V 400 Hz (115 Vac network) or 230/400 V 400 Hz (230 Vac

25、network) star (Y) connected supply shall be derived from a dedicated rotary machine capable of sustaining the maximum prospective fault current given in Table 1 (115 Vac network) or Table 2 (230 Vac network) for at least sufficient time for circuit protection to operate. In any case the generator sh

26、all have a sufficient rating to provide these prospective fault currents. c) 115 Vac or 230 Vac circuit breakers (D2) shall be single pole units rated at the values specified in Table 3. They shall have trip characteristics in accordance with EN 2350 or as required in the product specification. NOTE

27、 1 Reference of circuit breakers used shall be recorded. NOTE 2 In particular case, others ratings of thermal breaker protection could be employed in accordance with aircraft manufacturer rules. d) The electrical power source shall be appropriately protected and it shall be established that no combi

28、nation of test circuit events would activate this protection. e) The ballast resistors shall be non-inductive and of appropriate power rating. Care shall be taken to position all laboratory wiring such that inductive effects are reduced to a practical minimum. Supply cables shall be as short as poss

29、ible. f) Cables A, B and C shall be connected to indication and open circuit detectors at entry into the grounded star point. These components shall limit the standing current to no more than 10 % of the circuit breaker rating. g) The automatic shut down facility shall provide, upon the detection of

30、 any open circuit during test and after a 10 s delay, removal of the blade from the specimen and for electrical power to be removed. Open circuit in this case means either a physical break in the specimen or a thermal breaker trip. NOTE 3 In the case of the automatic shut down facility is not used,

31、the physical break in the specimen are detected by lamps in series with the rheostat Rg. h) A heavy duty electrical bonding strap shall be connected between the blade of the test rig and the electrical star point of the generator. i) Appropriate instrumentation, recording and switching control shall

32、 be installed in accordance with good laboratory practice. j) A rheostat Rg adjusting current (I) in the circuit to a value equal to 10 % of the circuit breaker current. prEN 3475-604:2016 (E) 6 Key 1 Phase A 2 Phase B 3 Phase C 4 Supply protection 5 Test bundle 6 Indicators (lamp) + Rg 7 Test blade

33、 Figure 2 Test schematic circuit 5.2 Test equipment Construct an apparatus as shown diagrammatically in Figures 3a, 3b and 3c which includes the following minimum provisions: a) A lightweight, freely pivoting test fixture to hold the blade at a 90 angle to the specimen and to exert a controlled forc

34、e on the specimen. NOTE Generally a mounting on 50 mm centres shall hold the individual cables of the specimen in close proximity. b) Electrical terminations to provide a ready means of connecting test specimens into the circuit as shown in Figure 2. c) An aluminium blade complying with material spe

35、cification T6061-T6 (EN 2702) and Figure 3c. d) A mechanism to provide a minimum oscillating stroke of 15 mm excursion at a frequency of (8 2) Hz. e) A blade carrier to give a downward force at the blade of (2,5 0,1) N. prEN 3475-604:2016 (E) 7 f) A mechanical stop to limit the fall of the oscillati

36、ng blade to within an accuracy of 0,2 mm measured at the point of contact. g) Means of separating the blade from the specimen, both manually and automatically if used. h) An electrical connection of the aluminium blade to the neutral of the test power supply (see 5.1 h). i) A transparent enclosure t

37、o protect personnel from ejected molten metal and short wavelength ultra violet light. Key 1 Blade carrier guide 2 Aluminium blade 3 Bundle 4 Heat insulation (e.g.:PTFE) 5 Aluminium support Figure 3a prEN 3475-604:2016 (E) 8 Key 1 Blade 2 Bundle 3 Stop 4 Cable tie 5 Spring 6 Contact pressure adjustm

38、ent 7 Depth adjustment shim Figure 3b Key 1 Sharpen edge with 60 grit aluminium disc sander directed “towards the blade“ (i.e. to avoid feathered edge) 2 Aluminium square (10 mm) Figure 3c prEN 3475-604:2016 (E) 9 5.3 Test protocol 5.3.1 The procedure embraces copper cable sizes 001 to 050 (26 to 10

39、) or aluminium cable sizes 002 to 090 (24 to 8), and for each cable size six values of prospective fault current have been defined. Performance of a cable size at a given fault intensity shall be determined by testing three samples. Thus 18 samples are required for every cable size. 5.3.2 For the pu

40、rposes of cable qualification at least sizes 002, 006 and 020 shall be tested. Additional testing of other sizes may be deemed necessary in particular cases and values of prospective fault currents, the ratings of thermal breaker protection which are typical of aircraft use and the blade form to be

41、employed have been included in this specification. 5.3.3 It is emphasised that electrical arcing tests are essentially destructive and can be hazardous to personnel. Therefore tests shall be undertaken with all observers shielded from direct physical and visual exposure as noted in 5.2 i). The use o

42、f video recording for all tests is required. 5.4 Test rig set-up 5.4.1 Install the rating of circuit breaker appropriate to the cable type and size to be tested (Table 3). Fit a blade to the reciprocating head of the test rig of the appropriate type shown in Figures 3a and Figure 3b. 5.4.2 Heavy dut

43、y electrical shorting connections shall be fitted in substitution of a test sample to enable prospective fault currents to be set by adjustment of resistances Rf. Because these currents would trip the thermal breakers very rapidly these shall be shunted to permit the pulsing of current until the des

44、ired value is obtained. Re-instate the thermal protection. 5.4.3 With electrical power removed adjust the test apparatus to give the correct conditions of blade stroke, frequency and downwards force. Ensure that the test fixture is correctly positioned and that the method of holding the specimen pro

45、vides satisfactory restraint. 5.4.4 Modify a verification sample by removing a section of cables A1 and B1 in the test zone. Adjust the blade depth stop such that the final blade position is at least half the conductor diameter of A1 or B1, from wires A2, B2 and C1, as shown by Figure 1. 6 Method 6.

46、1 Test procedure 6.1.1 Install a test specimen with electrical connections as shown in Figure 1 and with Rf set, as in 5.4.2 above, to give the required current from Table 1 or Table 2. 6.1.2 Apply electrical power to the specimen and gently make contact with the blade. Arm the automatic blade lifti

47、ng circuit, if used, and start the abrading action. NOTE 1 Only blades in good condition shall be used on new samples. If the abrading edge of a blade becomes significantly degraded after a circuit breaker trip at any stage it shall be replaced. NOTE 2 Before each test series check that thermal brea

48、kers are operating within their specified trip limits when subjected to 100 % overload. NOTE 3 Shall it be established that the mechanical attack of the blade does not penetrate the insulation within 3 min, then it is permissible for a fine cut to be made on the test specimens at the point on the up

49、per surface of cables A1 and B1 where the blade is to make contact. No material shall be removed and the cut shall not penetrate to the conductor. prEN 3475-604:2016 (E) 10 6.1.3 Actuation of the abrader shall create failure effects which shall be processed as follows: NOTE 1 If the automatic shut down is not used, switch off the power and the removal of the blade manually. NOTE 2 If the automatic shut down is not used, reset the power and