EN 3475-408:2025

SLOVENSKI STANDARD
01-februar-2026
Aeronavtika - Električni kabli za uporabo v zračnih plovilih - Preskusne metode -
408. del: Požarna odpornost
Aerospace series - Cables, electrical, aircraft use - Test methods - Part 408: Fire
resistance
Luft- und Raumfahrt - Elektrische Leitungen für Luftfahrtverwendung - Prüfverfahren -
Teil 408: Feuerbeständigkeit
Série aérospatiale - Câbles électriques à usage aéronautique - Méthodes d’essais -
Partie 408: Résistance au feu
Ta slovenski standard je istoveten z: EN 3475-408:2025
ICS:
29.060.20 Kabli Cables
49.060 Letalska in vesoljska Aerospace electric
električna oprema in sistemi equipment and systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 3475-408
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2025
EUROPÄISCHE NORM
ICS 49.060 Supersedes EN 3475-408:2005
English Version
Aerospace series - Cables, electrical, aircraft use - Test
methods - Part 408: Fire resistance
Série aérospatiale - Câbles électriques à usage Luft- und Raumfahrt - Elektrische Leitungen für
aéronautique - Méthodes d'essais - Partie 408 : Luftfahrtverwendung - Prüfverfahren - Teil 408:
Résistance au feu Feuerbeständigkeit
This European Standard was approved by CEN on 26 October 2025.

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-CENELEC 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-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3475-408:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Preparation of specimens . 4
5 Apparatus . 4
5.1 General. 4
5.2 Burner . 4
5.2.1 Method A – Liquid combustible (kerosene) . 4
5.2.2 Method B – Gas combustible . 5
5.2.3 Burner calibration . 5
5.3 Test fixture . 10
5.4 Test fluids . 11
6 Test method . 12
6.1 Preparation . 12
6.1.1 General. 12
6.1.2 Single core cable . 12
6.1.3 Multi-core and screen cables . 12
6.2 Procedure . 13
7 Requirements . 14

European foreword
This document (EN 3475-408:2025) has been prepared by ASD-STAN.
After enquiries and votes carried out in accordance with the rules of this Association, this document has
received the approval of the National Associations and the Official Services of the member countries of
ASD-STAN, prior to its presentation to CEN.
This document shall be given the status of a national standard, either by publication of an identical text
or by endorsement, at the latest by June 2026, and conflicting national standards shall be withdrawn at
the latest by June 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 3475-408:2005.
EN 3475-408:2005:
— editorial improvements, update of Clause 2 and introduction of liquid burner requirements with test
setup configuration.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this document: Austria, Belgium, Bulgaria, Croatia, Cyprus,
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
1 Scope
This document specifies a method of testing the fire resistance of “fire-proof” electrical cables.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 2234, Aerospace series — Cable, electrical, fire resistant — Technical specification
EN 3909, Aerospace series — Test fluids and test methods for electrical and optical components and sub-
assemblies
EN 4608-001, Aerospace series — Cable, electrical, fire resistant — Single and twisted multicore assembly,
screened (braided) and jacketed — Operating temperatures between −65 °C and 260 °C — Part 001:
Technical specification
ISO 2685:1998, Aircraft — Environmental test procedure for airborne equipment — Resistance to fire in
designated fire zones
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
4 Preparation of specimens
Six test specimens, 0,75 m minimum length, shall be selected at random from a quantity of cable.
5 Apparatus
5.1 General
The following shall be required for this test: a burner, a burner calibration, a test fixture, and test fluids.
5.2 Burner
5.2.1 Method A – Liquid combustible (kerosene)
The burner shall be as specified in ISO 2685:1998, Clause A.2, or any other burner or assembly of burners
satisfying the following conditions:
— liquid combustible type of kerosene shall be in accordance with EN 3909;
— the burner outlet shall be equipped with an extension of 318 mm, 152 mm high and 280 mm width;
— cable length exposed to the flame: 280 mm;
— flame characteristics according to ISO 2685:1998:
— temperature: 1 100 °C ± 80 °C;
— heat flux density received by the calorimeter specified in ISO 2685:1998, Annex B:
2 2
116 kW/m ± 10 kW/m .
5.2.2 Method B – Gas combustible
The burner shall be as specified in ISO 2685:1998, Clause A.1, or any other burner or assembly of burners
satisfying the following conditions:
— cable length exposed to the flame: 152 mm;
— diameter or width of the flame at the base of the burner(s) ≥ 2 D (D: diameter of the cable under test);
— flame characteristics according to ISO 2685:1998:
— temperature: 1 100 °C ± 80 °C;
— heat flux density received by the calorimeter specified in ISO 2685:1998, Annex B:
2 2
116 kW/m ± 10 kW/m .
5.2.3 Burner calibration
5.2.3.1 Temperature
5.2.3.1.1 Temperature measurement
The calibration in temperature of the burner consists 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 uniformity between tests.
Before calibrating the burner, allow the apparatus to run for at least 5 min for stabilizing the
heating conditions.
During and after calibration, the burner shall not be extinguished until the end of the fire test.
The surface calibrated is only valid as long as the burner settings was not changed or turned off.
The temperature of each thermocouple shall be recorded at least every 5 s intervals during
minimum 3 min.
5.2.3.1.2 Temperature measuring equipment
It is important that the temperature measuring equipment (including the thermocouple and the
acquisition tools) ensures an accuracy and compatible reactivity with the values sought.
The temperature-measuring tool is composed of thermal
...