oSIST prEN 3475-604:2024

SLOVENSKI STANDARD
01-december-2024
Aeronavtika - Električni kabli za uporabo v zračnih plovilih - Preskusne metode -
604. del: Odpornost proti električnemu obloku v suhih razmerah
Aerospace series - Cables, electrical, aircraft use - Test methods - Part 604: Resistance
to dry arc propagation
Luft- und Raumfahrt - Elektrische Leitungen für Luftfahrtverwendung - Prüfverfahren -
Teil 604: Lichtbogenfestigkeit, trocken
Série aérospatiale - Câbles électriques à usage aéronautique - Méthodes d’essais -
Partie 604 : Résistance à l’amorçage et à la propagation d’arc électrique, essai à sec
Ta slovenski standard je istoveten z: prEN 3475-604
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.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2024
ICS 49.060 Will supersede EN 3475-604:2018
English Version
Aerospace series - Cables, electrical, aircraft use - Test
methods - Part 604: Resistance to dry arc propagation
Série aérospatiale - Câbles électriques à usage Luft- und Raumfahrt - Elektrische Leitungen für
aéronautique - Méthodes d'essais - Partie 604 : Luftfahrtverwendung - Prüfverfahren - Teil 604:
Résistance à l'amorçage et à la propagation d'arc Lichtbogenfestigkeit, trocken
électrique, essai à sec
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee ASD-
STAN.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 3475-604:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Specimen requirements . 5
5 Preparation of specimen . 5
6 Apparatus . 6
6.1 Electrical equipment. 6
6.2 Test equipment . 7
6.3 Test protocol . 9
6.4 Test rig set-up . 10
7 Method . 10
7.1 Test procedure . 10
7.2 Examination . 11
7.3 Test report . 12
8 Requirements . 12
Bibliography . 15

European foreword
This document (prEN 3475-604:2024) 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 is currently submitted to the CEN Enquiry.
This document will supersede EN 3475-604:2018.
The main changes with respect to the previous edition are as follows:
— EN 3475-604 (P3), 01/2018:
o scope: addition of a specification regarding 230 VAC test condition;
o revision of test method to update the electrical schematic circuit and add the tripping curve.
1 Scope
This document specifies a method for appraising the behaviour of cable insulation when an electric arc
is initiated and maintained by two (2) powered cables rubbing against a blade.
This document is intended to be used together with EN 3475-100.
The primary aim of this test is:
— to produce, in a controlled fashion, continuous failure effects, which are representative of those,
which can occur in service when a typical cable bundle is damaged by abrasion such that electrical
arcing occurs, both between the cables and conductive structure; and
— to examine the aptitude of the insulation to track, to propagate electric arc to the electrical origin.
Originally defined for 115 VAC network, this test also proposes conditions for 230 VAC network.
However, for 230 VAC test condition only, the test EN 3475-605 can overrule and be applied as test
governance as it has been demonstrated that test EN 3475-605 is more stringent, repeatable and
reproductible.
Unless otherwise specified in the product standard, only 115 VAC conditions are satisfied.
Six levels of prospective fault current have been specified for concerned cable sizes (see Clause 8). It is
agreed that larger sizes need not be assessed since the short-circuit phenomenon becomes dominant at
low line impedances.
Unless otherwise specified in the technical/product standard, sizes 002, 006 and 020 cable are
assessed.
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 2350, Aerospace series — Circuit breakers — Technical specification
EN 2702, Aerospace series — Aluminium alloy AL-P6061 — T6 or T62 — Drawn or extruded bar and
section — a or D ≤ 200 mm
EN 3475-302, Aerospace series — Cable, electrical, aircraft use — Test methods — Part 302: Voltage
proof test
A-A-52083, Tape, lacing and tying, glass
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/

Published by Department of Defense (DoD), available at: https://assist.dla.mil/online/start/.
4 Specimen requirements
Cables to be tested shall be of traceable origin and shall have passed the high voltage dielectric test
specified in the product standard.
5 Preparation of specimen
5.1 Cut seven (7) separate lengths approximately 0,5 m consecutively from one (1) length of cable,
and strip each of the ends of insulation to permit electrical connection. Clean each length of cable with a
clean cloth moistened with propan-2-ol (isopropyl alcohol) fluid.
5.2 Lay up the seven (7) cables as follows:
a) form the cables in a six (6) around one (1) configuration as shown in Figure 1;
b) ensure that all cables are straight and geometrically parallel, and restrained by lacing tapes such
that they are in continuous contact for at least a 75 mm continuous length around the mid-point of
the loom length. This is called the test zone;
c) position the lacing tapes at 15 mm to 20 mm spacing within the test zone. The tie material shall be
PTFE glass lacing tape in accordance with A-A-52083 type IV, finish D, size 3;
d) number the cables as shown in Figure 1 such that the cables in contact with the blade are numbers
A1 and B1.
Test blade
Key
1 Original position
2 Final position
A1-A2 Phase A
B1-B2 Phase B
C1-C2 Phase C
N1-N2 Inactive cables connected to earth
Figure 1 — Specimen configuration
6 Apparatus
6.1 Electrical equipment
Connect the seven (7) cables of the test specimen within the circuit shown in Figure 3. This circuit shall
have the following requirements:
a) the provision of adjustable levels of prospective fault currents for the five (5) A, B and C cables and
an electrical return path for the two (2) N cable;
b) a three (3) phase 115/200 V 400 Hz (115 VAC network) or 230/400 V 400 Hz (230 VAC network)
star (Y) connected supply shall be derived from a dedicated rotary machine capable of sustaining
the maximum prospective fault current given in Table 1 (115 VAC network) or Table 2 (230 VAC
network) for at least sufficient time for the circuit protection to operate. In any case, the generator
shall have a sufficient rating to provide these prospective fault currents;
c) 115 VAC or 230 VAC circuit breakers (D2) shall be tri-pole units rated at the values specified in
Table 3.
They shall have trip characteristics in accordance with EN 2350 or as required in the product
specification.
Reference of circuit breakers used shall be recorded;
NOTE In particular cases, other ratings of thermal breaker protection could be employed in accordance with
aircraft manufacturer rules.
d) the electrical power source shall be appropriately protected, and it shall be established that no
combination of test circuit events would activate this protection;
e) the ballast resistors shall be non-inductive and of appropriate power rating. Care shall be taken to
position all laboratory wiring such that inductive effects are reduced to a practical minimum.
Supply cables shall be as short as possible;
f) cables A, B and C shall be connected to indication and open circuit detectors at the entry into the
grounded star point. These components shall limit the standing current to no more than 10 % of
the circuit breaker rating;
g) the automatic shutdown facility shall provide, upon the detection of any open circuit during test
and after a 10 s delay, removal of the blade from the specimen and for electrical power to be
removed. Open circuit in this case means either a physical break in the specimen or a thermal
breaker trip;
NOTE In the case of the automatic shutdown facility is not used, the physical break in the specimen are
detected by lamps in series with the rheostat R.
h) a heavy-duty electrical bonding strap shall be connected between the blade of the test rig and the
electrical star point of the generator;
i) appropriate instrumentation, recording and switching control shall be installed in accordance with
good laboratory practice;
j) a rheostat R adjusting current (I) in the circuit to a value equal to 10 % of the circuit
breaker current.
Key
1 Phase A
2 Phase B
3 Phase C
4 Supply protection
5 Test bundle
6 Indicators (lamp) + R
7 Test blade
Figure 2 — Test schematic circuit
The electrical test setup method configuration has been modified as per Figure 1 for ensuring identical
current value over each phase (by an introduction of resistance on each conductor line A1, A2, B1, B2…)
as previous electrical schematic circuit definition was implying only half of current default over each
conductor due to 1 resistance for 2 phases (i.e. when 6x In was injected, only 3x In was flowing into
each conductor phase).
NOTE Further detail, explanation and justification evolutions are provided in TR 4901.
6.2 Test equipment
Construct an apparatus
...