ASD-STAN PREN 2591-326-2017 Aerospace series Elements of electrical and optical connection Test methods Part 326 Fire immersion test (Edition P 1).pdf

1、ASD-STAN STANDARD NORME ASD-STAN ASD-STAN NORM ASD-STAN prEN 2591-326 Edition P 1 April 2017 PUBLISHED BY THE AEROSPACE AND DEFENCE INDUSTRIES ASSOCIATION OF EUROPE - STANDARDIZATION Rue Montoyer 10 - 1000 Brussels - Tel. 32 2 775 8126 - Fax. 32 2 775 8131 - www.asd-stan.org ICS: Descriptors: ENGLIS

2、H VERSION Aerospace series Elements of electrical and optical connection Test methods Part 326: Fire immersion test Luft- und Raumfahrt Elektrische und optische Verbindungselemente Prfverfahren Teil 326: Feuereintauchtest Srie arospatiale Organes de connexion lectrique et optique Mthodes dessais Par

3、tie 326 : Immersion au feu This “Aerospace Series“ Prestandard has been drawn up under the responsibility of ASD-STAN (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

4、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 examination and

5、review by users and formal agreement of ASD-STAN, the ASD-STAN prEN 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 natio

6、nal level by giving the EN the status of a national standard and by withdrawing any national standards conflicting with the EN. ASD-STAN Technical Committee approves that: “This document is published by ASD-STAN for the needs of the European Aerospace Industry. The use of this standard is entirely v

7、oluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefrom, is the sole responsibility of the user.” ASD-STAN reviews each standard and technical report at least every five years at which time it may be revised, reaffirmed, stabilized

8、or cancelled. ASD-STAN invites you to send your written comments or any suggestions that may arise. All rights reserved. No parts of this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or other

9、wise, without prior written permission of ASD-STAN. Order details: E-mail: salesasd-stan.org Web address: http:/www.asd-stan.org/ Edition approved for publication 1st April 2017 Comments should be sent within six months after the date of publication to ASD-STAN Electrical Domain Copyright 2017 ASD-S

10、TAN prEN 2591-326:2017 (E) 2 Contents Page Foreword 2 1 Scope 3 2 Normative references 3 3 Test method 3 4 Preparation of specimens 4 5 Apparatus. 6 6 Test fixtures 10 7 Testing 11 8 Inspection after tests . 14 Annex A (normative) Monitoring diagram . 15 Foreword This standard was reviewed by the Do

11、main Technical Coordinator of ASD-STANs Electrical Domain. After 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. prEN 2591-326:2017 (E) 3 1 Scope This standard specifies a metho

12、d of determining a components resistance to a liquid fuelled fire and the elements of connection. It shall be used together with EN 2591-100. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. Fo

13、r dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 2234, Aerospace series Cable, electrical, fire resistant Technical specification EN 2591-100, Aerospace series Elements of electrical and o

14、ptical connection Test methods Part 100: General EN 2591-202, Aerospace series Elements of electrical and optical connection Test methods Part 202: Contact resistance at rated current EN 2997 (all parts), Aerospace series Connectors, electrical, circular, coupled by threaded ring, fire-resistant or

15、non fire-resistant, operating temperatures 65 C to 175 C continuous, 200 C continuous, 260 C peak EN 3645 (all parts), Aerospace series Connectors, electrical, circular, scoop proof, triple start threaded coupling, operating temperature 175 C or 200 C continuous EN 3660 (all parts), Aerospace series

16、 Cable outlet accessories for circular and rectangular electrical and optical connectors ISO 2685, Aircraft Environmental test procedure for airborne equipment Resistance to fire in designated fire zones 3 Test method EN 2591-326 is composed of two tests on 2 sample groups: 1) Liquid fuelled fire im

17、mersion test: The purpose of this test is to verify the ability of a couple of connectors installed in the same area, to sustain a fire for at least 5 min, without electrical discontinuity. 2) Liquid fuelled fire containment test: The purpose of this test is to verify the ability of a couple of conn

18、ectors installed on a wall dividing 2 areas, to sustain a fire for at least 5 min, without electrical discontinuity and to contain the flame on the side exposed to fire for 20 min. prEN 2591-326:2017 (E) 4 4 Preparation of specimens 4.1 Layout For EN 2997: 8-06 for contact size 22; 10-06 for contact

19、s size 20; 18-08 for contact size 12; 24-30 for contact size 16. In case of non-availability of one or more of above mentioned layout, equivalent layouts will be assessed and justified by the mandated body representative. For EN 3645: 9-35 for contact size 22; 11-98 for contacts size 20; 17-06 for c

20、ontact size 12; 23-21 for contact size 16; 21-48 for contacts size 8. In case of non-availability of one or more of above mentioned layout, equivalent layouts will be assessed and justified by the mandated body representative. 4.2 Specimen preparation 4.2.1 Model without integrated accessory The con

21、nector shall be fitted with a straight backshell, unsealed with clamp strain relief type EN 3660-XXX or equivalent on both sides. Cables in the area between the clamps and rear grommet shall be exposed to the flame without protection, see Figure 1 and Figure 2. Glass fibre sheath or equivalent shall

22、 be installed where the cables contact the clamp, to avoid any electrical breakdown in this area. Cables shall be clamped between 200 mm to 250 mm of the rear of the grommet in both sides. prEN 2591-326:2017 (E) 5 Figure 1 Figure 2 4.2.2 Model with integrated accessory Cables and rear grommet shall

23、be exposed to the flame without protection and without a metallic braid. See Figure 3. Cables shall be clamped between 200 mm to 250 mm of the rear of the grommet in both sides of the test assembly. Figure 3 4.3 Wiring Specimens shall be wired with cable bundles 450 mm min. in length. All cavities s

24、hall be fitted with wired contacts. Two circuits shall be connected in series, one using the even-numbered contacts and the other using the odd-numbered contacts, see Figure A.1. In case of alphabetical identification of contact cavities, the following rule shall apply: A, C, E, G are considered odd

25、 number contacts; B, D, F, H are considered even number contacts. prEN 2591-326:2017 (E) 6 4.4 Recommendation Unless specified in the technical specification, the following details shall be stated: mounting method, type of fire-resistant cable (EN 2234 or MIL qualified equivalent) and definition of

26、specimen wiring; initial measurements (if applicable); value of leakage current (phase 1); nominal current to be applied to contacts (phase 1); Angle and position of burner. 5 Apparatus 5.1 General The rig shall allow movement/rotation of the burner between the calibration and test phases, without t

27、urning off the burner, nor modifying the intended distance and relative positioning of the specimen. See Figure 4. The spatial positioning of the burner shall ensure that the centre of the temperature measuring tool and the centre of the heat flux measuring tool are within a tolerance from the centr

28、e of the expected impinged specimen surface. The distance “X” from the burner nozzle to the connector shall be calibrated according to ISO 2685 (see 5.2). Figure 4 Example of fuel burner providing the standard flame 5.2 Burner calibration 5.2.1 General The temperature calibration of the burner consi

29、sts of adjusting the mixing ratio of air and combustible, until the flame is delivering a standard flame. A flame is characterized by its temperature and its heat flux. As the quantitative value is directly dependent on the instrumentation, it is necessary to respect a common tool to ensure uniformi

30、ty between tests. prEN 2591-326:2017 (E) 7 The overall calibration process shall consist of the following operations (see Figure 5): Positioning of the specimen (distance X and Y); Flame Temperature calibration and stabilization; Heat flux calibration and stabilization. Key 1 Flame temperature calib

31、ration (see Figure 6 and Figure 7) 2 Heat flux calibration (see Figure 8) 3 Position for test 4 Specimen 5 Temperature calibration 6 Heat flux calibration 7 Temperature calibration, 7 thermocouples X 100 mm 10 % Y 25 mm 10 % Figure 5 Example of burner calibration process prEN 2591-326:2017 (E) 8 5.2

32、.2 Flame temperature measurement Burner flame temperature is adjusted by increasing or decreasing the air and liquid flows. The flame temperature is measured with 7 (seven) thermocouples type K (Ni-Cr/Ni-Al) positioned over a metallic support at regular intervals of (25 1) mm. The distance between t

33、he burner nozzle and the thermocouples is X = 100 mm 10 %. The thermocouples shall be positioned at a height of Y = 25 mm 10 % over the axial centreline of the burner. For each thermocouple, the flame temperature shall be over 1 020 C. Short excursions above 1 180 C are permissible provided the aver

34、age temperature remains within the range 1 020 C to 1 180 C. The 7 (seven) thermocouples measuring points issued from the comb flame temperature recording shall be (1 100 80) C. 5.2.3 Temperature sensor disposal Due to its flame shape, it is accepted for only a liquid fuel burner, to perform the cal

35、ibration with 7 (seven) thermocouples aligned as shown in Figures 6 and 7. For a liquid fuel burner, the temperature measurement is acceptable with a line of 7 (seven) measuring points aligned within the symmetrical line of the area impingement, spaced with a 25 mm pitch. For a liquid fuel burner, t

36、he temperature measurement is acceptable if each of the 7 (seven) thermocouples measures a temperature of (1 100 80) C over a 2 min period. Figure 6 Temperature sensor disposal prEN 2591-326:2017 (E) 9 Key 1 Kerosene Burner Cowl 2 7 off thermocouples equally spaced 25 mm ( 2) apart a above burner ce

37、ntre line Horizontal and vertical centrelines shall be within 2 mm of true position. Figure 7 Thermocouple layout 5.2.4 Heat flux density calibration Burner is calibrated by using the continuous flow calorimeter apparatus show here after. A constant head of water (from the domestic network) shall en

38、sure consistent flow conditions. A valve on the outlet pipe enables water flow rate adjusted for the test. Flow conditions are recorded during the calibration step. Water flow passing through the apparatus shall be checked by controlling water volume over a defined time period, see Figure 8. Two Pt

39、100 thermocouples class 1/10 are placed in the inlet and outlet of the device. The heat flux-measuring tool must be at (X; Y) 10 % from the burner surface. Where (X; Y) are the measured distance used for the temperature calibration of the flame. prEN 2591-326:2017 (E) 10 Key 1 Flow-measuring device

40、2 Tail pipe 3 Setting valve 4 Thermometer (to measure T2) 5 Thermometer (to measure T1) 6 Constant head inlet 7 Screens 8 Heat transfer device 9 Burner Figure 8 Heat flux density calibration 6 Test fixtures 6.1 Liquid fuelled fire immersion (Method 1) The test fixture shall ensure the correct positi

41、oning of the specimen. The assembly shall be rigidly secured to a vibration generator. The circuits shall be connected to an electrical installation as shown in Figure A.1. 6.2 Liquid fuelled fire containment (Method 2) The test fixture shall ensure the correct positioning of the specimen. The assem

42、bly shall be rigidly secured to a vibration generator. The circuits shall be connected to an electrical installation as shown in Figure A.1. prEN 2591-326:2017 (E) 11 7 Testing 7.1 Liquid fuelled fire immersion test (Method 1) 7.1.1 Test setup See Figures 9 and 10. Key 1 Burner cone 2 Draft tube 3 R

43、eturn 4 Feed Figure 9 Liquid fuelled fire immersion test setup Key 1 Burner cone 2 Specimen Figure 10 Liquid fuelled fire immersion test setup (top view) 7.1.2 Test monitoring See Figure A.1. prEN 2591-326:2017 (E) 12 7.1.3 Test procedure The specimens shall be simultaneously exposed to the flame an

44、d vibrations at a constant frequency between 30 Hz and 60 Hz of 100 m/s acceleration throughout the tests. During the first 5 min, the contacts shall carry a constant current of the specified nominal value: switch 2 is closed, switch 1 is open (see Figure A.1). After the fifth minute, a potential of

45、 200 Vrms. to 260 Vrms., 40 Hz to 60 Hz, shall be applied for 1 min between each of the circuits and 100 V to 130 V potential between each circuit and the housing (shell): switch 1 is closed, switch 2 is open (see Figure A.1). 7.1.4 Test acceptance criteria There shall be no electrical discontinuity

46、 during the first 5 min and no leakage current higher than the specified value (2A) during the sixth minute. 7.2 Liquid fuelled fire containment test (Method 2) 7.2.1 Test setup See Figures 11 and 12. Key 1 Burner cone 2 Draft tube 3 Return 4 Feed Figure 11 Liquid fuel fire containment test setup pr

47、EN 2591-326:2017 (E) 13 Key 1 Burner cone 2 Specimen Figure 12 Liquid fuel fire containment test setup (top view) 7.2.2 Test procedure 7.2.2.1 Phase 1 The specimens shall be simultaneously exposed to the flame and vibrations at a constant frequency between 30 Hz and 60 Hz of 100 m/s acceleration thr

48、oughout the tests. During the first 5 min, the contacts shall carry a constant current of the specified nominal value: switch 2 is closed, switch 1 is open (see Figure A.1). After the fifth minute, a potential of 200 Vrms. to 260 Vrms., 40 Hz to 60 Hz, shall be applied for 1 min between each of the

49、circuits and 100 V to 130 V potential between each circuit and the housing (shell): switch 1 is closed, switch 2 is open (see Figure A.1). 7.2.2.2 Phase 2 The flame shall be maintained for an additional 14 min with no voltage on the circuits, to reach a total of 20 min. 7.2.3 Test monitoring See Figure A.1. 7.2.4 Test acceptance criteria 7.2.4.1 Phase 1 There shall be no electrical d