1、CEN PREN*3475 (PART*305) 92 I 3404589 0033459 047 Edition approved for publication 1992-08-31 A. E. C. M. A. STAN DAR D NORME A.E.C.M.A. A.E.C.M.A. NORM Comments should be sent within six rnont9s C2 Chairman after the date of publication decision AECMA Technopolis - 175. rue Jean-Jacques Rousseau 92
2、138 Issy les-Moulineaux Cdex - FRANCE M. J. LE CUNFF prEN 3475 Part 305 Issue P 1 August 1992 EDITE PAR LASSOCIATION EUROPEENNE DES CONSTRUCTEURS DE MATERIEL AEROSPATIAL Technopolis - 175. rue Jean-Jacques Rousseau - F-92138 Issy-les-Moulineaux Cdex - T1 (1) 47 36 98 76 UDC : Key words : ENGLISH VER
3、SION Aerospace series Cables, electrical, aircraft use Test methods Part 305 - Overload resistance Srie arospatiale Cbles lectriques usage aronautique Mthodes dessais Partie 305 - Tenue aux surcharges Luft- und Raumfahrt Elektrischen Leitungen fr Luftfahrt Verwendung Prfverfahren Teil 305 - berlastb
4、arkeit 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
5、following comment by the Member countries. Subsequent to the publication of thispre-standard, the technical content shallnot be changed to an extent that interchangeability is affected, physically or functionally, without re-identification of the standard. After examination and signature of the AECM
6、A Standard 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. CEN PREN*I475 (PART*305) 72 E 3404587 083l14b 8b E prEN 3475-305 Page 3 1 Scope and
7、 field of application This standard specifies a method of measuring the resistance to overload of finished cables. It shall be used together with EN 3475-100. 2 References EN 3475-100 Aerospace series - Cables, electrical, aircraft use - Test methods - Part 100 - General 1) 3 Preparation of specimen
8、s Each specimen having 0,75 m to 1 m useful length between the supports, shall be installed horizontally in front of a screen and lightly stretched at the ends to avoid any slack during the test. The test shall be carried out at ambient temperature in a chamber where the whole unit shall be sheltere
9、d from draughts. An extraction shall be provided but only operated after completion of the test. To identify the appearance of smoke, a screen with black and white horizontal bands or any other device shall be used. 4 Method The purpose of this test shall be to check that there is no smoke emission
10、for an overload level bringing the conductor to a temperature TI, and that for an overload bringing the conductor to a temperature 12, there is neither ignition nor disappearance of the insulation. The temperatures Ti and T2 shall be specified in the product standard. The test shall be performed on
11、size 0,60 mm2 only. The temperatures shall be determined by measuring the variation of the voltage drop in the central part of the cable (2/3 of the useful length maximum) between the voltage application points. = i + 0,004 (8-20) - 5 *“e *u20 R20 - First regulate the current to a value Il, which ra
12、ises the temperature of the conductor to TI, for a period of 30 min (temperature defined in the product standard). The current shall then be increased to a second value I2 for 15 min, bringing the temperature of the conductor to T2 (temperature defined in the product standard). 1) Published as AECMA
13、 pre-standard at the date of publication of the present standard. Previous page is blank prEN 3475-305 Page 4 5 Requirements At TA : no visible smoke or smell or appreciable change of colour ; At T2: no visible deterioration of the insulation (peeling, cracking, stripping of the conductor) no spontaneous combustion and no visible smoke.
