www bzfxw com BS EN 3475 417 2009 ICS 49 060 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Aerospace series — Cables, electrical, aircraft use — Test methods[.]
Trang 1BS EN 3475-417:2009
ICS 49.060
NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW
BRITISH STANDARD
Aerospace series —
Cables, electrical,
aircraft use — Test
methods
Part 417: Fire resistance of cables
confined inside a harness
Trang 2This British Standard
was published under the
authority of the Standards
Policy and Strategy
Committee on 30 April
2009
© BSI 2009
ISBN 978 0 580 63187 0
Amendments/corrigenda issued since publication
Date Comments
BS EN 3475-417:2009
National foreword
This British Standard is the UK implementation of EN 3475-417:2009 The UK participation in its preparation was entrusted to Technical Committee ACE/6
A list of organizations represented on this committee can be obtained on request to its secretary
This publication does not purport to include all the necessary provisions
of a contract Users are responsible for its correct application
Compliance with a British Standard cannot confer immunity from legal obligations.
Trang 3BS EN 3475-417:2009
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
EN 3475-417
March 2009
ICS 49.060
English Version
Aerospace series - Cables, electrical, aircraft use - Test methods - Part 417: Fire resistance of cables confined inside a
harness
Série aérospatiale - Câbles électriques à usage
aéronautique - Méthodes d'essais - Partie 417: Tenue au
feu des câbles confinés dans un harnais
Luft- und Raumfahrt - Elektrischen Leitungen für Luftfahrt Verwendung - Prüfverfahren - Teil 417: Feuerbeständigkeit
von Leitungen eingebunden in Bündeln
This European Standard was approved by CEN on 30 August 2008.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
C O M I T É E U R O P É E N D E N O R M A L I S A T I O N
E U R O P Ä I S C H E S K O M I T E E F Ü R N O R M U N G
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved
worldwide for CEN national Members.
Ref No EN 3475-417:2009: E
Trang 4BS EN 3475-417:2009
EN 3475-417:2009 (E)
2
Foreword 3
1 Scope 4
2 Normative references 4
3 Preparation of specimens 4
4 Apparatus 4
5 Method 5
6 Requirements/Acceptance criteria 6
Annex A (normative) Circuit diagram principle for measurement of equipotentials 7
Trang 5BS EN 3475-417:2009
EN 3475-417:2009 (E)
3
Foreword
This document (EN 3475-417:2009) has been prepared by the Aerospace and Defence Industries Association
of Europe - Standardization (ASD-STAN)
After enquiries and votes carried out in accordance with the rules of this Association, this Standard has received the approval of the National Associations and the Official Services of the member countries of ASD,
prior to its presentation to CEN
This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 2009, and conflicting national standards shall be withdrawn at the latest by September 2009
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom
Trang 6BS EN 3475-417:2009
EN 3475-417:2009 (E)
4
1 Scope
This standard specifies a method of testing the fire resistance of fire resistance or fire-proof electrical cables
inside a harness
The objective of this test is to qualify these cables when they are confined inside harnesses defined
hereafter Described configurations try to be representative of various cables configuration installed in Aircraft
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
document (including any amendments) applies
EN 2346-002, Aerospace series — Cable, electrical, fire resistant — Operating temperatures between − 65 °C
and 260 °C — Part 002 : General
EN 3475-100, Aerospace series — Cables, electrical, aircraft use — Test methods — Part 100: General
EN 3475-408, Aerospace series — Cables, electrical, aircraft use — Test methods — Part 408: Fire resistance
ISO 2685, Aircraft — Environmental test procedure for airborne equipment — Resistance to fire in designated
fire zones
3 Preparation of specimens
Three specimens per configuration 0,75 m length shall be tested See Figure 1
4 Apparatus
The test equipment shall be as required in EN 3475-408
Reminder of apparatus requirements:
a) Burner: according with ISO 2685 or any other burner or assembly of burners satisfying the following
conditions:
The minimum width of the burner shall be 50 mm;
Cable length exposed to the flame: 152 mm;
Diameter or width of the flame at the base of the burner ≥ 2 D (D= diameter of the harness under test);
Flame temperature: (1 100 ± 80) °C;
Heat flux density received by the calorimeter: (116 ± 10) kW/m2
b) Test fixture: according with ISO 2685:
The frame of the test fixture shall be vibrated with the following characteristics:
Direction perpendicular to the axis of the cable;
Frequency : (30 ± 5) Hz;
Minimum acceleration: 4 g
c) Circuit diagram (see Annex A, Figures A.1 and A.2)
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EN 3475-417:2009 (E)
5
5 Method
5.1 Preparation of test specimens
Unless otherwise specified in the product standard, 3 types of homogeneous harnesses of respective code 002
(AWG 24), 006 (AWG 20) and 020 (AWG 14) shall be tested
The cable used to build the harnesses is a three-core cable EN2346-xxxCyyy (see EN 2346-002)
The composition of the harnesses will be 4, 12 and 19 cables connected in series as in example for 4 cables
These cables shall be twisted with a lay length of 12 to 16 times the outer diameter of the harness
E1
E2
E3 E4
Figure 1 — Schema
All first conductors of each three-core together in series (1 st equipotential E1)
All second conductors of each three-core together in series (2 nd equipotential E2)
All third conductors of each three-core together in series (3 rd equipotential E3)
An external protection [Nickel coated or tin coated copper (85 % minimum coverage) sheath plus a Nomex braid (80 % minimum coverage)] (4th equipotential E4)
Each sample shall be mounted onto a frame as defined in EN 3475-408 The sample shall be loaded with a force defined in Table 1
Table 1
In daN Gage 24
(002)
Gage 20
(006)
Gage 14
(020) n1 1,5 4 8 n2 4 8 8 n3 8 8 8
"n" is the number of three-cores wires EN2346-xxxCyyy
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EN 3475-417:2009 (E)
6
5.2 Procedure
The test shall be performed according to EN 3475-408, without fluid immersion
Each sample shall be simultaneously subjected to the combined flame and vibration test during 5 min, then
the flame will be removed and vibration still maintained during the following 10 min
The insulation resistance measurements must be performed simultaneously between equipotential 1/2 (E1/E2)
and equipotential 3/4 (E3/E4)
6 Requirements/Acceptance criteria
Check the electrical continuity and insulation resistance of the cables during the test
The minimum insulation resistance shall be 10 000 Ω, unless otherwise specified in the product standard
Trang 9BS EN 3475-417:2009
EN 3475-417:2009 (E)
7
A
mA
50 mA
0 mA – 100 mA
62,5 A
0 A – 5 A
~ 125 V
L
N
5 k Ω
5 A
A
50 mA
0 mA – 100 mA
62,5 A
0 A – 5 A
~ 125 V
L
N
5 k Ω
5 A
mA
Annex A
(normative)
Circuit diagram principle for measurement of equipotentials
Figure A.1 — Circuit diagram principle for measurement of equipotentials 1 / 2
Figure A.2 — Circuit diagram principle for measurement of equipotentials 3 / 4
Trang 10BS EN
3475-417:2009
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