1、 - CEN PREN*3475 (PARTx303) 42 rn 3404584 0031,452 792 rn Edition approved for publication 1992-08-31 A. E .C. M .A. STAN DARD NORME A.E.C.M.A. A.E.C.M.A. NORM Comments should be sent within six months after the date of publication decision A.E C.M A. Technopolis - 175, rue Jean-Jacques Rousseau 921
2、 38 Issy-les-Moulineaux Cdex - FRANCE prEN 3475 Part 303 Issue P 1 August 1992 EDITE PAR L ASSOCIATION EUROPEENNE DES CONSTRUCTEURS DE MATERIEL AEROSPATIAL Technopolis - 175 rue JeamJacques Rousseau - F 921 38 Issy-les-Moulineaux Cedex Tel Il 147 36 Y8 76 UDC Key words : ENGLISH VERSION Aerospace se
3、ries Cables, electrical, aircraft use Test methods Part 303 - Insulation resistance Srie arospatiale Cbles lectriques usage aronautique Mthodes dessais Partie 303 - Rsistance disolement Luft- und Raumfahrt Elektrischen Leitungen fr Luftfahrt Verwendung Prfverfahren Teil 303 - Isolationswiderstandes
4、This Aerospace Series. pre-standard has been drawn up under the responsibility of AECMA (Association Europenne des Constructeurs de Matriel Arospatial). It is published on green paper for the needs of AECMA-Members. It has been technically approved by the experts of the concerned Commission followin
5、g comment by the Member countries. Subsequent to the publication of this pre-standard, the 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 signature of the AECMA Stan
6、dard Checking Centre (NPS) and formal agreement of the Official Services of the Member countries it will be submitted as a draft European Standard to CEN (European Committee for Standardization) for final vote. Nota - Extra copies can be supplied by B N.A E. - Technopolis 54 - 199. rue Jean-Jacques
7、Rousseau - 92138 ISSY-LES-MOULINEAUX CEDEX I I C2 Chairman M. J. LE CUNFF prEN 3475-303 Page 3 1 Scope and field of application This standard specifies a method of measuring the insulation resistance of finished cables. It shall be used together with EN 3475-100. 2 References EN 3475-100 Aerospace s
8、eries - Cables, electrical, aircraft use - Test methods - Part 1 O0 - General 1) 3 Preparation of specimens The specimens, of at least 10 m length, shall be taken from finished cables. The solution used for the immersion test shall have the following composition : - sodium chloride 30 g ; - distille
9、d water 1000 g ; - wetting agent 2 9. 4 Immersion test The specimens shall be immersed in the solution defined in 3 with their ends protruding at least 150 mm. The immersed length L shall be known and shall exceed 10 m. After one hours immersion at test temperature (20 f 2) OC and (95 I 2) OC, a vol
10、tage of between 200 Vd.c. and 500 Vd.c., shall be applied for 1 min as shown below : - insulated conductor : between solution and conductor ; - screened and jacketed cables : between solution and screen. The insulation resistance, in MR.km calculated from the formula - RL where R is the 1 O00 resist
11、ance of L (m) shall be at least equal to : - insulated conductor : the value stated in the technical specification, - screened and jacketed cables : the value shown for the jacket in the technical specification. 1) Published as AECMA pre-standard at the date of publication of the present standard. .
12、- Previous page is blank CE“ PRENr3475 (PART*303) 32 = 3404583 O033454 565 prEN 3475-303 Page 4 5 Dry test The insulation resistance shall be measured between each insulated conductor of length L and all the others connected together and to the screen if present. A voltage of between 200 Vd.c. and 500 Vd.c., shall be applied for 1 min at ambient temperature. The insulation resistance in MQ.km calculated from the formula - RL where R is the -loo0 resistance of length L (m), shall be at least equal to the value given in the technical specification.
