1、ASD STANDARD NORME ASD ASD NORM prEN 3475-603 Edition P 4 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 3 of
2、 October 2006 and will supersede EN 3475-603:2007 Descriptors: Aerospace industry, aircraft equipment, electrical cable, test ENGLISH VERSION Aerospace series Cables, electrical, aircraft use Test methods Part 603: Resistance to wet arc tracking Srie arospatiale Cbles lectriques usage aronautique Mt
3、hodes dessais Partie 603 : Rsistance lamorage et la propagation darc lectrique, essai humide Luft- und Raumfahrt Elektrische Leitungen fr Luftfahrtverwendung Prfverfahren Teil 603: Lichtbogenfestigkeit, feucht This “Aerospace Series“ Prestandard has been drawn up under the responsibility of ASD-STAN
4、 (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 of this Prestandard, the
5、 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, it will be submitted as a draft European Standard (prEN) to CEN (Eu
6、ropean 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 standards conflicting with the EN. Edit
7、ion approved for publication 10 June 2009 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
8、 from IHS-,-,-prEN 3475-603:2009 2 Contents Page Foreword2 1 Scope 3 2 Normative references 3 3 Specimen requirements 3 4 Preparation of specimen.4 5 Apparatus .5 6 Method 8 7 Requirements.9 Foreword This standard was reviewed by the Domain Technical Coordinator of ASD-STANs Electrical Domain. After
9、 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. Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without licens
10、e from IHS-,-,-prEN 3475-603:20093 1 Scope This 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 primar
11、y aim of this 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 betw
12、een damage sites 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 Va
13、c conditions shall 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 i
14、n the technical/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 r
15、eferenced document (including any amendments) applies. EN 2350, Aerospace series Circuit breakers 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 P
16、art 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. 2)3 Specimen requirements Cables to be tested shall be of traceable origin and shall have passed the high voltage dielectric test defi
17、ned in the product standard. 1) Published as ASD Prestandard at the date of publication of this 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
18、 Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-603:20094 4 Preparation of specimen Cut seven separate lengths approximately 0,5 m consecutively from one length of cable, and strip each of the ends of insulation to permit electrical connection. Clean eac
19、h 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, taking care to ensure that the cut penetrates to the conductor around the full circumference a
20、nd 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 separation of (10 0,5) mm of undamaged insulation is provided as shown in Figure 2. This is cal
21、led 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 (4 1,0) mm away from outer each notch and then at 15 mm to 20 mm spacing towards the ends of the specimen as sh
22、ow 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) Number the cables as shown 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
23、. 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 A1 B1C2 N C1B2 A2(10 2) mm 1Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from
24、IHS-,-,-prEN 3475-603:2009 5 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 th
25、e following requirements: 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 deri
26、ved from a dedicated rotary 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. Copyright ASD-STA
27、N Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-603:20096 c) The (115 - 115 W per phase for 115 Vac network or 230 - 230 W per phase for 230 Vac network) ballast resistors R1, are fitted in order to prevent over
28、voltage during the arc extinction phases (opening of an inductive circuit). d) 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 with EN 2350 or as required by the product specification. NOTE 1
29、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. e) The electrical power source shall be appropriately protected and should be established that no combinatio
30、n of test circuit events would activate this protection. f) The resistors shall be non-inductive and have 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. g) Ca
31、bles A, B and C shall be connected to indication and open circuit detectors (Rg) at the entry into the grounded star point. These components shall 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
32、 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 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
33、 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 with resistor Rg. i) Appropriate instrumentation, recording and switching control shall be installed in accordance with good laboratory practice. j) Adjust
34、resistor Rg so that the current (I) in the circuit is 10 % of value of the circuit breaker rated current. Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-603:20097 Figure 3 Test schematic circuit
35、 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 ready means of connecting test specimens into the circuit as shown in Figure 2. b) A transparent enclosure to protect personnel fr
36、om 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 drops from an 18 gauge needle cut square at the outlet. NOTE The needle wall thickness should be selected such that the specified
37、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 cable sizes 002 to 051 (24 to 10) and for each size six values of prospective maximum fault current to be set by adjustment of resi
38、stances Rf have been defined in Table 1. Performance of the cable at a given fault current shall be determined by testing three specimens. Thus 18 specimens are required for each cable size. Supply protection Test bundle Indicators (lamp)Phase A Phase B Phase C Copyright ASD-STAN Provided by IHS und
39、er license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-603:2009 8 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 an
40、d values of prospective fault currents, the ratings of thermal breaker 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 w
41、ith 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 to the cable type and size to be tested (Table 2). 5.4.2 Heavy-duty electrical con
42、nections shall be fitted in substitution of test specimen 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 desired value is obtained. R
43、e-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 of 10 to the horizontal with the electrical input connections at the higher end and with t
44、he cables forming the test zone uppermost. 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 than 2 mm towards the higher end of the
45、 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 electrical connections as shown in Figure 1 and with
46、 Rf set, as in 5.4.2 above, to give the required fault current specified in 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 should be taken to ensure that the electrolyte flows between the damage sites as the evide
47、nced by the steaming of the electrolyte and the development of scintillation. 6.1.3 Run the test continuously for a period of 8 hours or until an automatic shut down (CB tripping or/and an extinction of lamps occur), whichever is the sooner. 6.1.4 In the event of an automatic shutdown adopt the foll
48、owing 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 the automatic trip circuit deactivated and with no further flow of electrolyte. b) Maintain the power for 15 min to allow any fault condition to develop fully but do not reset any of the thermal circuit breakers. Copyright ASD-STAN Provided by IHS under license with AECMA Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-prEN 3475-603:2009 9 6.1.5 Repeat the test to obtain three tested specimens and then re
