oSIST prEN 3475-603:2024

SLOVENSKI STANDARD
01-december-2024
Aeronavtika - Električni kabli za uporabo v letalih - Preskusne metode - 603. del:
Ugotavljanje odpornosti proti obloku v vlažnih razmerah
Aerospace series - Cables, electrical, aircraft use - Test methods - Part 603: Resistance
to wet arc tracking
Luft- und Raumfahrt - Elektrische Leitungen für Luftfahrtverwendung - Prüfverfahren -
Teil 603: Lichtbogenfestigkeit, feucht
Série aérospatiale - Câbles électriques à usage aéronautique - Méthodes d’essais -
Partie 603 : Résistance à l’amorçage et à la propagation d’arc électrique, essai humide
Ta slovenski standard je istoveten z: prEN 3475-603
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 3475-603:2018
English Version
Aerospace series - Cables, electrical, aircraft use - Test
methods - Part 603: Resistance to wet arc tracking
Série aérospatiale - Câbles électriques à usage Luft- und Raumfahrt - Elektrische Leitungen für
aéronautique - Méthodes d'essais - Partie 603 : Luftfahrtverwendung - Prüfverfahren - Teil 603:
Résistance à l'amorçage et à la propagation d'arc Lichtbogenfestigkeit, feucht
électrique, essai humide
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 3475-603:2024 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 . 8
6.1 Electrical equipment. 8
6.2 Test equipment . 9
6.3 Test protocol . 10
6.4 Test rig set-up . 10
7 Method . 10
7.1 Test procedure . 10
7.2 Examination . 11
7.3 Test report . 11
8 Requirements . 12
Bibliography . 15

European foreword
This document (prEN 3475-603:2024) 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 3475-603:2018.
EN 3475-603:2018:
— EN 3475-603 (P5), 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 of assessing the behaviour of cable insulation subject to an electric
arc initiated and maintained by contaminating fluid along the surface of the insulation.
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 and subjected to aqueous fluid
contamination. Electrical arcing occurs along the surface of the insulation between damage sites on
adjacent cables;
— 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 sizes larger than 051 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 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
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.
Damage two (2) lengths of the cable by inflicting a cut around the total circumference at the mid-point
of the length, taking care to ensure that the cut penetrates to the conductor around the full
circumference and has a width of 0,5 mm to 1,0 mm.
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) displace the damaged cables longitudinally such that a separation of (10 ± 0,5) mm of undamaged
insulation is provided as shown in Figure 2. This is called the test zone;
c) ensure that cables are straight and geometrically parallel, and restrained by lacing tapes such that
they are in continuous contact within the test zone;
d) position the lacing tapes (4 ± 1,0) mm away from outer each notch and then at 15 mm to 20 mm
spacing towards the ends of the specimen as show in Figure 2. The tie material used adjacent to the
notch shall be PTFE glass lacing tape in accordance with A-A-52083 type IV, finish D, size 3;
e) number the cables as shown in Figure 1 such that the fault cables are numbers A1 and B1 and the
centre is N. Cables C1, A2, B2 and C2 are grouped around N.
Key
1 Drop needle
A1-A2 Phase A
B1-B2 Phase B
C1-C2 Phase C
N Neutral cable connected to earth
Figure 1 — Specimen configuration
Key
1 Test zone (10 ± 0,5) mm
2 Notch 0,5 mm to 1 mm
3 15 mm to 20 mm
4 Lacing tape
5 Drop needle
Figure 2 — Test 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 six (6) A, B and C cables and
an electrical return path for the 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) the (115 Ω - 115 W per phase for 115 VAC network or 230 Ω - 230 W per phase for 230 VAC
network) ballast resistors R1, are fitted in order to prevent over voltage during the arc extinction
phases (opening of an inductive circuit);
d) 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.
e) the electrical power source shall be appropriately protected, and it shall be established that no
combination of test circuit events would activate this protection;
f) 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;
g) cables A, B and C shall be connected to indication and open circuit detectors (R) 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;
h) an automatic shutdown facility shall be provided, which shall, upon the detection of any open
circuit during the test and after a 10 s delay, shut down the flow of electrolyte and electrical power.
An open circuit in this case means either a physical break in the specimen or a thermal breaker trip.
The facility to override this shutdown facility shall be provided so as to restore the power whilst
still inhibiting the flow of electrolyte.
The physical break in the specimen shall be indicated by lamps in series with resistor R;
i) appropriate instrumentation, recording and switching control shall be installed in accordance with
good laboratory practice;
j) adjust re
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