1、AECMA STANDARD NORME AECMA AECMA NORM Edition approved for publication Comments should be sent within six months after the date of publication to 31 December 2004 AECMA-STAN prEN 3475-302 Edition P 2 December 2004 Electrical Domain ICs: 49.060 Supersedes issue P 1 of August 1992 and will supersede E
2、N 3475-302:2002 Descriptors: ENGLISH VERSION Aerospace series Cable, electrical, aircraft use Test methods Part 302: Voltage proof test Srie arospatiale Luft- und Raumfahrt Mthodes dessais Prfverfahren Cbles lectriques a usage aronautique Partie 302 : Tenue en tension Elektrische Leitungen fr Luftfa
3、hrtverwendung Teil 302: Spannungsfestigkeit This “Aerospace Series“ Prestandard has been drawn up under the responsibilify of AECMA-STAN (The European Association of Aerospace Industries - Standardization). It is published for the needs of the European Aerospace Industry. It has been technically app
4、roved 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 interchangeability is affected, physically or functionally, without re-identification of the standard. After examina
5、tion and review by users and formal agreement of AECMA-STAN, it will be submitted as a draft 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
6、level by giving the EN the status of a national standard and by withdrawing any national standards conflicting with the EN. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without
7、license from IHS-,-,-Page 2 prEN 3475-302:2004 Foreword This standard was reviewed by the Domain Technical Coordinator of AECMA-STANS Electrical Domain. After inquiries and votes carried out in accordance with the rules of AECMA-STAN defined in AECMA- STANS General Process Manual, this standard has
8、received approval for Publication. Contents Page 1 Scope 3 2 Normative references . 3 3 Immersion test . 3 4 Dry spark test (in production) 3 5 Dry impulse test (test in production as an alternative to 4) 4 6 Method . 5 7 Voltage test of components (screened cables) . 5 Copyright Association Europee
9、ne des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Page 3 prEN 3475-302:2004 1 Scope This standard specifies a method of performing voltage proof tests on finished cables and cables i
10、n course of production. It shall be used together with EN 3475-100. 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 doc
11、ument (including any amendments) applies. EN 3475-100, Aerospace series - Cables, electrical, aircraft use - Test methods - Part 700: General 3 Immersion test The specimens, each 15 m long, shall be immersed in the solution so that their ends are at least 150 mm from the surface of the solution. The
12、 composition of the solution, at a temperature of between 15 OC and 25 OC, shall be as follows: - sodium chloride 30 g - distilled water 1 O00 g - wetting agent 2g After immersion for 1 h, the voltage specified by the technical specification with a frequency of 40 Hz to 60 Hz, shall be applied betwe
13、en the conductor of the cable and the screen, if present, or an electrode in contact with the liquid for 5 min. Single and multicore (jacketed) without shield: - between the conductor(s) and an electrode in contact with the liquid Shielded and jacketed cables - between the shield and an electrode in
14、 contact with the liquid The voltage rise time shall be between 300 V per second and 500 V per second. There shall be no perforation of the insulation or jacket. 4 Dry spark test (in production) All the finished cables shall pass, without flash-over, through the electrode of a suitable dry tester, a
15、t the voltage stated in the technical specification at a frequency of 40 Hz to 60 Hz. The electrode consists of an assembly of small chains or other metallic feelers suitable for making close contact with practically the whole surface of the cable. The length of the electrode and speed of the cable
16、shall be such that each portion of the insulation or jacket is subjected to the test voltage for at least 0,20 s. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license fr
17、om IHS-,-,-Page 4 prEN 3475-302:2004 The voltage shall be applied: Single and multicore (jacketed) without shield: - between the conductor(s) and the electrode Shielded and jacketed cables - between the shield and the electrode There shall be no perforation of the insulation or jacket. NOTE If a def
18、ect is found, a minimum length of 30 mrn shall be cut away from each side of the defective point. 5 Dry impulse test (test in production as an alternative to 4) Apparatus The electrode through which the cable passes when subjected to the voltage test shall be formed of beaded chains so that effectiv
19、ely the whole surface of the cable insulator is in contact with the beads. The characteristics and ancillary apparatus of the impulse test shall be as follows. Impulse test The form of the signal shall be negative pulse with a peak value of the cable test voltage followed by a damped oscillation. Th
20、e peak voltage is stated in the technical specification. The rise time of the negative pulse of the signal between O % and 90 % of the peak voltage specified shall not be greater than 75 ps. The peak value of the first positive overshoot of the signal and each of the damped oscillations which flow f
21、rom it shall be less than the initial negative pulse. The time during which each pulse and its damped oscillation (positive and negative) remain at a voltage equal to 80 % or higher than the specified peak voltage shall be between 20 ps and 100 ps. The pulse rate shall be between 200 pulses and 500
22、pulses per second inclusive. Apart from regulation of the peak voltage, conformity with the impulse test parameters shall be defined without capacitance load applied to the electrode. Capacity tolerance As far as the capacitive load is concerned, the suitable tolerance for the apparatus shall be suc
23、h that where there is an increase in the capacitive load between electrode and earth, the peak voltage shall not be reduced by more than 12 % from an initial load of 123 pF/25 mm to 25 pF/25 mm electrode length. Voltmeter A voltmeter allowing continuous reading of the voltage at the electrode termin
24、als is connected. The voltmeter shall be capable of showing a total deviation for a voltage not exceeding 15 kV and shall be accurate to within a minimum of 4 % of the test voltage. Error detection circuit The test apparatus shall consist of an error detection circuit with visual or audible indicati
25、on of an insulation fault automatically cutting off the supply to the electrode and stopping the passage of the cable. The detection circuit shall be sensitive enough to show the fault at 75 % of the specified test voltage when an arc occurs between the electrode and earth through a resistance of 20
26、 k!2; it shall also be capable of detecting a fault with a duration corresponding to that of a pulse. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-P
27、age 5 prEN 3475-302:2004 Calibration of apparatus The voltmeter shall be calibrated by comparison with another voltmeter capable of detecting the peak voltage of the electrode with or without auxiliary circuit. During calibration, the calibrated voltmeter shall be directly connected to one of the el
28、ectrodes or through a calibrated attenuator circuit. The pulse generator shall be switched on and the control voltage of the generator regulated until the voltage reading on the calibrated voltmeter corresponds to the specified voltage; at this moment the voltage reading on the voltmeter to be calib
29、rated shall be noted. The calibration shall be repeated for each peak voltage at which it is intended to operate the equipment. A calibrated oscilloscope can also be used connected to the electrode through an attenuator. Thus the value of the negative pulse peak can be read directly on the wave form
30、 indicator. An oscilloscope connected to the electrode at appropriate different points can also be used to check the conformity of the other waveform parameters specified for the impulse test. Method The finished cable shall be passed through the electrode and the conductor(s) earthed at one or both
31、 ends. The voltage shall be applied: Single and multicore (jacketed) without shield: - between the conductor(s) and the electrode Shielded and jacketed cables - between the shield and the electrode The electrode shall be supplied with the specified voltage and after a final voltage adjustment the ca
32、ble shall be passed from the pay-off reel to the take-up reel through the electrode. The line speed shall be such that the cable is subjected to no fewer than three pulses and no more than 100 pulses at any given point. During the test, which includes the insertion of new lengths of cable, the cable
33、 shall be tested over its total length, including the ends, complying with the procedure. Any ends or other parts of the cable not tested in accordance with this method shall be withdrawn. There shall be no perforation of the insulation or jacket. NOTE If a defect is found, a minimum length of 50 mr
34、n shall be cut away from each side of the defective point. 6 Voltage test of components (screened cables) The cables shall be subjected to a voltage test at ambient temperature. The r.m.s. value of the voltage shall be specified in the technical specification at a frequency between 40 Hz and 60 Hz.
35、The voltage shall be applied for at least 1 min between one component and the other components and the screen connected together. There shall be no perforation of the insulation. Copyright Association Europeene des Constructeurs de Materiel Aerospatial Provided by IHS under license with AECMANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
