1、ASD STANDARD NORME ASD ASD NORM prEN 3475-605 Edition P 2 June 2009 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATIONAvenue de Tervuren, 270 - B-1150 Brussels - Tel. + 32 2 775 8126 - Fax. + 32 2 775 8131 - www.asd-stan.orgICS: 49.060 Supersedes edition P 1 of
2、 October 1997 and will supersede EN 3475-605:2002 Descriptors: Aerospace industry, aircraft equipment, electrical cable test ENGLISH VERSION Aerospace series Cables, electrical, aircraft use Test methods Part 605: Wet short circuit test Srie arospatiale Cbles lectriques usage aronautique Mthodes des
3、sais Partie 605 : Essai de court-circuit humide Luft- und Raumfahrt Elektrische Leitungen fr Luftfahrtverwendung Prfverfahren Teil 605: Verhalten nach Kurzschlu, feucht This “Aerospace Series“ Prestandard has been drawn up under the responsibility of ASD-STAN (The AeroSpace and Defence Industries As
4、sociation 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 of this Prestandard, the technical content shall not be changed t
5、o 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, it will be submitted as a draft European Standard (prEN) to CEN (European Committee for Standardization) for
6、 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 standards conflicting with the EN. Edition approved for publication 10 June 2009
7、 Comments should be sent within six months after the date of publication to ASD-STAN Electrical Domain Copyright 2009 by ASD-STAN Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-605:2009 2 Conten
8、ts Page Foreword Erreur ! Signet non dfini. 1 Scope 3 2 Normative references 3 3 Specimen requirements 3 4 Preparation of specimen.4 5 Apparatus .5 6 Method 7 7 Requirements.8 Foreword This standard was reviewed by the Domain Technical Coordinator of ASD-STANs Electrical Domain. After inquiries and
9、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. Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-
10、prEN 3475-605:2009 3 1 Scope This standard specifies a method for appraising the behaviour of cable insulation subjected to an electric arc initiated and maintained by a contaminating fluid. This standard shall be used together with EN 3475-100. The primary aim of this test is: to produce, in a cont
11、rolled 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 such that electrical arcing occurs, between cables, and to examine the aptitude of the insulation to track, to p
12、ropagate 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 specified for
13、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 Normative ref
14、erences 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 document (including any amendments) applies. EN 2350, Aerospace series Circuit breaker
15、s Technical specification. EN 3197, Aerospace series Installation of aircraft electrical and optical interconnection systems.1)EN 3475-100, Aerospace series Cables, electrical, aircraft use Test methods Part 100: General. EN 3475-302, Aerospace series Cables, electrical, aircraft use Test methods Pa
16、rt 302: Voltage proof test. A-A-52083, Tape, lacing and tying, glass. 2)3 Specimen requirements Cables to be tested shall be of traceable origin and shall have passed the high voltage dielectric test defined in the product standard. 1) Published as ASD Prestandard at the date of publication of this
17、standard. 2) Published by : Department of Defense Industrial Supply Center, ATTN: DISC-BBEE, 700 Robbins Avenue, Philadelphia, PA 19111-5096 USA. Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-6
18、05:20094 4 Preparation of specimen 4.1 Cut seven separate lengths of approximately 0,5 m consecutively from one length of cable, and strip one 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
19、. 4.2 Lay up the seven cables as follows: a) Form 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 ties such that they are in continuous contact at least within the test zone. c) Position the ties
20、at 50 mm spacing toward the end of the specimen as shown in Figure 2. The first tie shall be at no more than 5 mm behind the dripping point. The tie material shall be PTFE glass lacing tape conforming to A-A-52083 type IV, finish D, size 3. d) Position the ties at 50 mm spacing toward the end of the
21、 specimen as shown in Figure 2. The first tie shall be at no more than 5mm behind the dripping point. The tie material shall be PTFE glass lacing tape conforming to A-A-52083 type IV, finish D, size 3. Key 1 Drop needle A1-A2 : Phase A B1-B2 : Phase B C1-C2 : Phase C N : Neutral cable connected to e
22、arth Figure 1 Specimen configuration 1 (10 2) mm C2 N C1 B1 A1 B2 A2 Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-605:20095 Key 1 Cable tie 2 Drop needle 3 Drops 4 10 mm to 20 mm 5 Ends of the
23、 7 cables in the same plane Figure 2 Test configuration 5 Apparatus 5.1 Electrical equipment Connect the seven cables of the test sample within a circuit as shown in Figure 3. This circuit shall have the following requirements: a) The The provision of adjustable levels of prospective fault currents
24、for the six A, B and C cables. 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 rotary machine capable of sustaining the maximum prospective fault current given in Table 1 for at least sufficient tim
25、e for circuit protection to operate. In any case the generator shall have a sufficient rating to provide these prospective fault currents. c) 115 Vac or 230 Vac circuit breakers shall be single pole units rated at the values specified in Table 2. They shall have trip characteristics in accordance wi
26、th EN 2350 or as required in 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 in accordance with aircraft manufacturer rules. d) The electrical power source shall be appro
27、priately protected and it shall be established that no combination of test circuit events would activate this protection. 50 mm 1 10 23455 mm max.Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-6
28、05:20096 e) The ballast Rb 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 possible. The ballast resistor Rb is in order to preve
29、nt over voltage (115 - 115 W per phase for 115 Vac network or 230 - 230 W per phase for 230 Vac network) during the arc extinction phases (opening of an inductive circuit). f) A rheostat, Rf, limiting maximum short-circuit current per phase by simulating a line length. g) Appropriate instrumentation
30、, recording and switching control shall be installed in accordance with good laboratory practice. Figure 3 Test schematic circuit 5.2 Test equipment Construct an apparatus as shown diagrammatically in Figure 2, which includes the following minimum provisions: a) Electrical terminations to provide a
31、ready means of connecting test specimens into the circuit as shown in Figure 3. 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/min and dispenses drops f
32、rom an 18 gauge needle, cut of square at the outlet. NOTE The needle wall thickness shall be selected such that the specified flow rate shall be delivered at approximately 6 drops per minute. RfV V N U V A2A1C1C2D2B1B2NSupply protection Test bundle Rb Copyright ASD-STAN Provided by IHS under license
33、 with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-605:2009 7 5.3 Test protocol 5.3.1 The procedure embraces copper cable sizes 001 to 051 (26 to 10) or copper clad aluminum cable sizes 002 to 090 (24 to 8), and for each cable size six values of
34、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 purposes of cable qualification at least sizes 002, 006 and 020 shall be tested. Addition
35、al 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 have been included in this specification. 5.3.3 It is emphasized that electrical arcing tests are essentially de
36、structive 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 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
37、to the cable type and size to be tested (Table 2). 5.4.2 Heavy duty 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 the
38、se 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 solution 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
39、 of 10 to the horizontal with the electrical input connections at the higher end. 5.4.5 Position the delivery 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
40、than 2 mm towards the higher end of the specimen. Ensure that the drops strike the cables at the top centre of the circumference such that they fall into the crevice between cables A1 and B1. 6 Method 6.1 Test procedure 6.1.1 Install a test specimen with electrical connections as shown in Figure 1 a
41、nd with Rf set, as 5.4.2 above, to give the required current from Table 1. 6.1.2 Apply electrical power to the specimen and start the flow of electrolyte at a rate of (100 10) mg/min. Particular care shall be taken to ensure that the electrolyte flows between the damage sites as evidenced by steamin
42、g of the electrolyte and the development of scintillation. Shall this not occur, and failure of the cable to wet be determined, then the alternative surfactant described in 5.4.3 may be used. 6.1.3 Run the test continuously for a period of 2 h. If the circuit-breaker(s) of phases A1, A2, B1, B2, C1
43、and C2 do not trip for a duration of 2 h, switch off the power supply and the electrolyte flow. Stop the test. Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-605:20098 6.1.4 Following CB(s) trip
44、ping adopt the following procedure: a) After not less than 3 min, nor more than 10 min, and with all thermal circuit breakers closed, reapply power to the specimen with no further flow of electrolyte. b) Apply power for the time necessary for any fault condition to develop fully but do not reset the
45、 thermal circuit breakers. 6.1.5 Repeat the test to obtain three samples and then reset the circuit for the next highest current overload until all 18 samples have been tested. 6.2 Examination EN 3197, can be used as a guideline to differentiate short-circuit and arc-tracking effects. Noticeable dam
46、ages may come from ever: aptitude of the insulation to become an electrically conducting material (arc-tracking phenomenon), propagation of thermal effects due to established arcs, duration of the test causing electro-erosion, as result of thermal effects due to possible short-circuit. 6.2.1 Careful
47、ly remove the test specimen from the apparatus and photograph the cable bundle. 6.2.2 Examine visually and record the damage to the insulation including the length of char. Also record if there is evidence of tracking effect to the electrical source. 6.3 Test report The test report shall include det
48、ails of the following: a) Clearly mentioned which type of tension was tested (115 Vac or 230 Vac); b) Identity of the cable type and size and details of the origin and release certification permitting traceability to a production batch; c) Identity of circuit breakers used; d) Characteristics of the
49、 power source; e) Operation of individual circuit breakers; f) Record of the damage as required in 6.2.2. 7 Requirements The detail product specification shall define: tension to test if different from 115 Vac, the pass/fail criteria for each cable size, in any series of tests. In any case the cable shall not present evidenc
