1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 3475-603:2011Aerospace series Cables,electrical, aircraft use TestmethodsPart 603: Resistance to wet arc trackingIncorporating corrigendum November 2011BS EN 3475-603:2011
2、BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 3475-603:2011,The UK participation in its preparation was entrusted to TechnicalCommittee ACE/6, Aerospace avionic electrical and fibre optictechnology.A list of organizations represented on this committee can beob
3、tained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication.ISBN 978 0 580 77399 0ICS 49.060Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Sta
4、ndard was published under the authority of theStandards Policy and Strategy Committee on 30 June 2011.Amendments/corrigenda issued since publicationDate Text affectedImplementation of CEN corrigendumBS EN 3475-603:2007 which is withdrawn.incorporating corrigendum November 2011. It supersedesNovember
5、 2011: Figure 2 updated The British Standards Institution 201231 January 2012EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 3475-603 May 2011 ICS 49.060 Supersedes EN 3475-603:2007English Version Aerospace series - Cables, electrical, aircraft use - Test methods - Part 603: Resistance to wet a
6、rc tracking Srie arospatiale - Cbles lectriques usage aronautique - Mthodes d essais - Partie 603: Rsistance lamorcage et la propagation darc lectrique, essai humide Luft- und Raumfahrt - Elektrische Leitungen fr Luftfahrtverwendung - Prfverfahren - Teil 603: Lichtbogenfestigkeit, feucht This Europe
7、an Standard was approved by CEN on 20 February 2010. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references co
8、ncerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member
9、into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ir
10、eland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix
11、 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 3475-603:2011: EIncorporating corrigendum November 20112 Contents Page Foreword 31 Scope 42 Normative references 43 Specimen requirements 44 Preparation of s
12、pecimen .55 Apparatus .66 Method 97 Requirements 10BS EN 3475-603:2011 EN 3475-603:2011 (E)3 Foreword This document (EN 3475-603:2011) has been prepared by the Aerospace and Defence Industries Association of Europe - Standardization (ASD-STAN). After enquiries and votes carried out in accordance wit
13、h the rules of this Association, this Standard has received the approval of the National Associations and the Official Services of the member countries of ASD, prior to its presentation to CEN. This document supersedes EN 3475-603:2007. This European Standard shall be given the status of a national
14、standard, either by publication of an identical text or by endorsement, at the latest by November 2011, and conflicting national standards shall be withdrawn at the latest by November 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
15、rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croati
16、a, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 3475-603:2011 EN 3475-60
17、3:2011 (E)4 1 Scope This European standard specifies a method of assessing the behaviour of cable insulation subject to an electric arc initiated and maintained by contaminating fluid along the surface of the insulation. This standard shall be used together with EN 3475-100. The primary aim of this
18、test is: to produce, in a controlled fashion, continuous failure effects, which are representative of those, which may occur in service when a typical cable bundle is damaged and subjected to aqueous fluid contamination. Electrical arcing occurs along the surface of the insulation between damage sit
19、es on adjacent cables; and to examine the aptitude of the insulation to track, 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 s
20、hall be satisfied. Six levels of prospective fault current have been specified for concerned cable sizes (see Clause 7). It is agreed that sizes larger than 051 need not be assessed since the short-circuit phenomenon becomes dominant at low line impedances. Unless otherwise specified in the technica
21、l/product standard sizes 002, 006 and 020 cable shall be assessed. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced docu
22、ment (including any amendments) applies. EN 2350, Aerospace series Circuit breakers Technical specification EN 3197, Aerospace series Design and installation of aircraft electrical and optical interconnection systems EN 3475-100, Aerospace series Cables, electrical, aircraft use Test methods Part 10
23、0: 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 traceable origin and shall have passed the high voltage dielectric test defined in th
24、e product standard. 1) Published by: Department of Defense Industrial Supply Center, ATTN: DISC-BBEE, 700 Robbins Avenue, Philadelphia, PA 19111-5096 USA. BS EN 3475-603:2011 EN 3475-603:2011 (E)5 4 Preparation of specimen Cut seven separate lengths approximately 0,5 m consecutively from one length
25、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. Damage two lengths of the cable by inflicting a cut around the total circumference at the mid-point of the length, t
26、aking care to ensure that the cut penetrates to the conductor around the full circumference and has a width of 0,5 mm to 1,0 mm. Lay up the seven cables as follows: a) Form the cables in a six around one configuration as shown in Figure 1. b) Displace the damaged cables longitudinally such that a se
27、paration of (10 0,5) mm of undamaged insulation is provided as shown in Figure 2. This is called the test zone. c) Ensure that cables are straight and geometrically parallel, and restrained by ties such that they are in continuous contact within the test zone. d) Position the ties or PTFE glass laci
28、ng tape (41,0) mm away from each outer notch and then at 15 mm to 20 mm spacing towards the ends of the specimen as show in Figure 2. The tie material used adjacent to the notch shall be PTFE glass lacing tape conforming to A-A-52083 type IV, finish D, size 3. e) Figure 1 Number the cables as shown
29、in Figure 1 such that the fault cables are numbers A1 and B1 and the centre is N. Cables C1, A2, B2 and C2 are grouped around N. Key 1 Drop needle A1-A2 : Phase A B1-B2 : Phase B C1-C2 : Phase C N : Neutral cable connected to earth Figure 1 Specimen configuration BS EN 3475-603:2011 EN 3475-603:2011
30、 (E)6 Key 1 Test zone (10 0,5) mm 2 Notch 0,5 mm to 1 mm 3 15 mm to 20 mm 4 Tape lacing 5 Drop needle Figure 2 Test configuration 5 Apparatus 5.1 Electrical equipment Connect the seven cables of the test specimen within the circuit shown in Figure 3. This circuit shall have the following requirement
31、s: a) The provision of adjustable levels of prospective fault currents for the six A, B and C cables and an electrical return path for the N cable. b) A three phase 115/200 V 400 Hz (115 Vac network) or 230/400 V 400 Hz (230 Vac network) star (Y) connected supply shall be derived from a dedicated ro
32、tary machine capable of sustaining the maximum prospective fault current given in Table 1 for at least sufficient time for the circuit protection to operate. In any case the generator shall have a sufficient rating to provide these prospective fault currents. c) The (115 - 115 W per phase for 115 Va
33、c network or 230 - 230 W per phase for 230 Vac network) ballast resistors R1, are fitted in order to prevent over voltage during the arc extinction phases (opening of an inductive circuit). BS EN 3475-603:2011 EN 3475-603:2011 (E)7 d) 115 Vac or 230 Vac circuit breakers shall be single pole units ra
34、ted at the values specified in Table 2. They shall have trip characteristics in accordance with EN 2350 or as required by the product specification. NOTE 1 Reference of circuit breakers used shall be recorded. NOTE 2 In particular case, others ratings of thermal breaker protection could be employed
35、in accordance with aircraft manufacturer rules. e) The electrical power source shall be appropriately protected and should be established that no combination of test circuit events would activate this protection. f) The resistors shall be non-inductive and have appropriate power rating. Care shall b
36、e taken to position all laboratory wiring such that inductive effects are reduced to a practical minimum. Supply cables shall be as short as possible. g) Cables A, B and C shall be connected to indication and open circuit detectors (Rg) at the entry into the grounded star point. These components sha
37、ll limit the standing current to no more than 10 % of the circuit breaker rating. h) An automatic shut down facility shall be provided, which shall upon the detection of any open circuit during the test and after a 10 s delay, shutdown the flow of electrolyte and electrical power. An open circuit in
38、 this case means either a physical break in the specimen or a thermal breaker trip. The facility to override this shut down facility shall be provided so as to restore the power whilst still inhibiting the flow of electrolyte. The physical break in the specimen is to be indicated by lamps in series
39、with resistor Rg. i) Appropriate instrumentation, recording and switching control shall be installed in accordance with good laboratory practice. j) Adjust resistor Rg so that the current (I) in the circuit is 10 % of value of the circuit breaker rated current. BS EN 3475-603:2011 EN 3475-603:2011 (
40、E)8 Key 1 Phase A 2 Phase B 3 Phase C 4 Supply protection 5 Test bundle 6 Indicators (lamp) + Rg Figure 3 Test schematic circuit 5.2 Test equipment Construct an apparatus as shown diagrammatically in Figure 3 which includes the following minimum provisions: a) Electrical terminations to provide a re
41、ady means of connecting test specimens into the circuit as shown in Figure 2. b) A transparent enclosure to protect personnel from ejected molten metal and short wavelength ultra violet light. c) An electrolyte delivery system which provides a constant rate of (100 10) mg per minute and dispenses dr
42、ops from an 18 gauge needle cut square at the outlet. NOTE The needle wall thickness should be selected such that the specified flow rate will be delivered at approximately 6-10 drops per minute. 5.3 Test protocol 5.3.1 The procedure embraces copper cable sizes 001 to 051 (26 to 10) or aluminium cab
43、le sizes 002 to 051 (24 to 10) and for each size six values of prospective maximum fault current to be set by adjustment of BS EN 3475-603:2011 EN 3475-603:2011 (E)9 resistances Rf have been defined in Table 1. Performance of the cable at a given fault current shall be determined by testing three sp
44、ecimens. Thus 18 specimens are required for each cable size. 5.3.2 For the purpose 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 br
45、eaker protection which are typical of aircraft use have been included in Table 1. 5.3.3 It is emphasised that electrical arcing tests are essentially destructive and can be hazardous to personnel. Therefore tests should be undertaken with all observers shielded from direct physical and visual exposu
46、re as noted in 5.2 b). The use of 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 2). 5.4.2 Heavy-duty electrical connections shall be fitted in substitution of test specimen to enab
47、le 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 desired value is obtained. Re-instate the thermal protection. 5.4.3 Prepare an electrolyte so
48、lution made by dissolving (3 0,5) % by weight of sodium chloride in distilled water. 5.4.4 Support the specimen in free air inclined at an angle of 10 to the horizontal with the electrical input connections at the higher end and with the cables forming the test zone uppermost. 5.4.5 Position the del
49、ivery system so that the electrolyte contacts the loom from a height of (10 2) mm above the uppermost cables in the loom at a point which shall position the droplets into the upper cut or no more than 2 mm towards the higher end of the specimen. Ensure that the drops strike the cables in the middle of the test zone, the top centre of the circumference such that they fall into the crevice between cables at A1 and B1. 6 Method 6.1 Test procedure 6.1.1 Install a test specimen with el
