SIST EN 3197:2011

SLOVENSKI STANDARD
SIST EN 3197:2011
01-maj-2011
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Aerospace series - Design and installation of aircraft electrical and optical
interconnection systems
Luft- und Raumfahrt - Konstruktion und Installation elektrischer und optischer
Verkabelung in Luftfahrzeugen
Série aérospatiale - Conception et installation des organes de raccordements électriques
et à fibres optiques sur avions
Ta slovenski standard je istoveten z: EN 3197:2010
ICS:
49.090 2SUHPDLQLQVWUXPHQWLY On-board equipment and
]UDþQLKLQYHVROMVNLKSORYLOLK instruments
SIST EN 3197:2011 en,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 3197:2011

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SIST EN 3197:2011


EUROPEAN STANDARD
EN 3197

NORME EUROPÉENNE

EUROPÄISCHE NORM
December 2010
ICS 49.060; 49.090
English Version
Aerospace series - Design and installation of aircraft electrical
and optical interconnection systems
Série aérospatiale - Conception et installation des organes Luft- und Raumfahrt - Konstruktion und Installation
de raccordements électriques et à fibres optiques sur elektrischer und optischer Verkabelung in Luftfahrzeugen
avions
This European Standard was approved by CEN on 30 July 2010.

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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3197:2010: E
worldwide for CEN national Members.

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SIST EN 3197:2011
EN 3197:2010 (E)
Contents Page
Foreword .3
ORGANISATION OF THIS STANDARD (Detailed organisation may be found in Annex A) .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .6
4 Limitations .6
5 General requirements .6
6 Selection of EWIS and OFIS Components . 19
7 EWIS Components Identification . 45
8 Separation and principles to apply . 48
9 Installation and manufacturing principles . 60
10 Modification and repairs by STC applicants . 84
11 EWIS and OFIS Safety . 86
Annex A (informative) EN 3197 detailed content . 87
Annex B (normative) Main normative references and ASD-STAN Technical Reports per family
of products . 95
B.1 Quality and General standards . 95
B.2 Wires and cables. 96
B.3 Optical fibre cables, connectors and contacts . 98
B.4 Connectors and contacts . 99
B.5 Protective devices . 102
B.6 Switching devices . 103
B.7 Terminal junctions . 103
B.8 Terminal lugs and in-line splice . 104
B.9 Ties . 104
B.10 Solder sleeves . 104
B.11 Bonding leads . 105
B.12 Clamps . 105
B.13 Protective parts . 105
B.14 Identification parts . 106
B.15 Installation Components . 106
B.16 Lamps . 107
Annex C (informative) Differences of electrochemical potentials between some conductive
materials (in mV) . 108

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SIST EN 3197:2011
EN 3197:2010 (E)
Foreword
This document (EN 3197:2010) 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 June 2011, and conflicting national standards shall be withdrawn at
the latest by June 2011.
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, Croatia, 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.
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SIST EN 3197:2011
EN 3197:2010 (E)
ORGANISATION OF THIS STANDARD
(Detailed organisation may be found in Annex A)
1 Scope page 5
Description of the aim of this document.
2 Normative references page 5
List of Normative references used.
3 Terms and definitions page 6
List of particular definitions or mentions of particular applicable documents.
4 Limitations page 6
Applicability of this document.
5 General requirements page 6
General and important considerations, plus specific requirements linked to particular areas of use.
6 Selection of EWIS and OFIS Components page 19
Guideline for the choice of necessary components.
7 EWIS and OFIS Components Identification page 45
Description of necessary identifications for components, bundles, equipements and repairs.
8 Separation and principles to apply page 48
Rules to satisfy for a good integration and behaviour of systems.
9 Installation and manufacturing principles page 60
Description of installation and manufacturing principles.
10 Modification and repairs by STC applicants page 84
11 EWIS and OFIS Safety page 86
Safety analysis.
NOTE Inside this standard, texts in italic come from official texts and cannot be modified without verification.
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SIST EN 3197:2011
EN 3197:2010 (E)
1 Scope
This European standard provides instructions on the methods to be used when designing, selecting,
manufacturing, installing, repairing or modifying the aircraft electrical and optical interconnection networks,
now called Electrical Wiring Interconnection System (EWIS), and Optical Fibre Interconnection Systems
(OFIS), subjects to the limitations defined in Clause 4 of this standard.
The general content of this standard is described in page 2.
A detailed content of this standard is given in Annex A.
This standard lists all the relevant European standards related to EWIS and OFIS in Annex B.
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 60270, High-voltage test techniques — Partial discharge measurements (IEC 60270:2000)
ISO 2574, Aircraft — Electrical cables — Identification marking
ISO 2685, Aircraft — Environmental test procedure for airborne equipment — Resistance to fire in designated
fire zones
ISO 4046-1, Paper, board, pulps and related terms — Vocabulary — Part 1: Alphabetical index
ISO 7137, Aircraft — Environmental conditions and test procedures for airborne equipment
1)
MIL-DTL-22520G, Revision G General Specification for Crimping Tools, Wire Termination — Entire Set
1)
MIL-STD-202, Test method standard electronic and electrical component parts
1)
MIL-T-43435B, Military specification tape, lacing and tying
2)
TR 4684, Aerospace series — Electrical technology and components definitions
2)
TR 9535, Aerospace series — Substance declaration
2)
TR 9536, Aerospace series — Declarable Substances Recommended Practice
3)
AS 81824/1, Splice, electric, permanent, crimp style copper, insulated, environment resistant, class 1
AS 83519, Shield termination, solder style, insulated, heat-shrinkable, environment resistant with pre installed
3)
leads for cables having tin or silver plated shields (class I)

1) Published by: Department of Defense (DoD), http://www.defenselink.mil/.
2) Published as ASD-STAN Technical Report at the date of publication of this standard by Aerospace and Defence
Industries Association of Europe-Standardization (ASD-STAN), (www.asd-stan.org).
3) Published by: Society of Automotive Engineers (SAE), (www.sae.org).
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SIST EN 3197:2011
EN 3197:2010 (E)
ASTM D 1868, Standard Test Method for Detection and Measurement of Partial Discharge (Corona) Pulses in
4)
Evaluation of Insulation Systems
NOTE Related to EWIS and OFIS, all today existing ASD Normative references per family of products may be found
in Annex B.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in TR 4684 and the following apply.
3.1
Design Authority
in this document, this term covers the Companies, in charge of the original design or to give the design
agreement for which Certification will be required from the Regulatory Authorities
3.2
Regulatory Authority
in this document, this term covers the Organisations in charge to write rules to satisfy, to survey the design
and to grant Navigability Certificate, like EASA and FAA
4 Limitations
It is recognized that the installation practices contained in this standard do not necessarily represent the full
requirements for a safe and satisfactory electrical and optical interconnection system.
In the event of a conflict between the text of this document and the references cited herein, the text of this
document takes precedence. However, nothing written in this standard shall override the specific
requirements of a Design Authority, the Airworthiness Requirements, applicable laws or any regulation from
the regulatory authorities, unless a specific exemption has been obtained.
5 General requirements
5.1 Applicable Rulemaking
The main rulemakings to satisfy for the definition of the various possible electrical installations on large
aircrafts are coming from:
 Design technical requirements
From the EASA European Aviation Safety Agency (CS 25) and the FAR Federal Aviation Regulation (14CFR –
Part 25).
 Organisation requirements
From the EASA European Aviation Safety Agency (IR 21) and the FAR Federal Aviation Regulation (14CFR –
Part 21).

4) Published by: American Society For Testing and Materials (ASTM), http://www.astm.org/.
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SIST EN 3197:2011
EN 3197:2010 (E)
Important advices:
a) From the P2 issue, this standard includes the EWIS concept and associated consequences which were
introduced in the regulation by the FAA in November 2007 and by the EASA in autumn 2008. This was
also the opportunity for the authorities to group all the electrical requirements: the rules 25.17xx.
b) CS or FAR 23, 27 and 29 which concern small aircraft, small and large helicopters were not updated
in-line.
5.2 EWIS Definition
The definition of the aircraft electrical interconnection network, now called Electrical Wiring Interconnection
System (EWIS) is now given in the regulation. The retained text, coming from the EASA, is the following:
«CS 25.1701 Electrical Wiring Interconnection System Definition
(a) Electrical wiring interconnection system (EWIS) means any wire, wiring device, or combination of these,
including termination devices, installed in any area of the airplane for the purpose of transmitting electrical
energy between two or more intended termination points. Except as provided for in Subclause (c) of this
Subclause, this includes:
1) Wires and cables.
2) Bus bars.
3) The termination point on electrical devices, including those on relays, interrupters, switches,
contactors, terminal blocks and circuit breakers, and other circuit protection devices.
4) Connectors, including feed-through connectors.
5) Connector accessories.
6) Electrical grounding and bonding devices and their associated connections.
7) Electrical splices.
8) Materials used to provide additional protection for wires, including wire insulation, wire sleeving, and
conduits that have electrical termination for the purpose of bonding.
9) Shields or braids.
10) Clamps and other devices used to route and support the wire bundle.
11) Cable tie devices.
12) Labels or other means of identification.
13) Pressure seals.
(b) The definition in Subclause (a) of this Subclause covers EWIS components inside shelves, panels, racks,
junction boxes, distribution panels, and back-planes of equipment racks, including, but not limited to, circuit
board back-planes, wire integration units and external wiring of equipment.
(c) Except for the equipment indicated in Subclause (b) of this Subclause, EWIS components inside the
following equipment, and the external connectors that are part of that equipment, are excluded from the
definition in Subclause (a) of this Subclause:
1) Electrical equipment or avionics that is qualified to environmental conditions and testing procedures
when those conditions and procedures are:
i) Appropriate for the intended function and operating environment, and
ii) Acceptable to the Agency.
2) Portable electrical devices that are not part of the type design of the aeroplane. This includes
personal entertainment devices and laptop computers.
3) Fibre optics».
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SIST EN 3197:2011
EN 3197:2010 (E)
5.3 OFIS Definition
The definition of the aircraft optical fibre interconnection network, now called Optical Fibre Interconnection
System (OFIS) was created by similarity. The retained text is the following:
"OFIS means any fibre or cable, including termination devices, installed in any area of the aircraft for the
purpose of transmitting optical signals between two or more intended termination points. Except as provided
for in Subclause (c) of this Subclause, this includes:
1) Fibres and cables.
2) Optical Data buses.
3) The termination point on fibre optic transmitting sources and receiving devices protection devices.
4) Connectors, including feed-through connectors.
5) Connector accessories.
6) Fibre optic splices.
7) Materials used to provide additional protection for fibres and cables, including insulation, and conduit.
8) Clamps and other devices used to route and support the cable bundle.
9) Cable tie devices.
10) Labels or other means of identification.
11) Pressure seals.
a) The definition in Subclause (a) of this Subclause covers OFIS components inside shelves, panels, racks,
junction boxes, distribution panels, and back-planes of equipment racks.
b) Except for the equipment indicated in Subclause (b) of this Subclause, OFIS components inside the
following equipment, and the external connectors that are part of that equipment, are excluded from the
definition in Subclause (a) of this Subclause:
1) Fibre optic equipment or avionics that is qualified to environmental conditions and testing procedures
when those conditions and procedures are:
i) Appropriate for the intended function and operating environment, and
ii) Acceptable to the Agency"
Particular information on OFIS may be found in EN 4533-001 to EN 4533-004. (See also particular Annex B3).
5.4 Design precedence
Design of the EWIS and OFIS shall conform to the following precedence:
st
1 – Safety;
nd
2 – System requirements;
rd
3 – The ease of maintenance, removal and replacement of the cabling;
th
4 – Cost effective aircraft production.
Cabling shall be fabricated and installed so as to achieve the following:
a. Maximum reliability;
b. Minimum interference and coupling between systems;
c. Accessibility for inspection and maintenance including cleaning;
d. Prevention of damage.
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SIST EN 3197:2011
EN 3197:2010 (E)
5.5 Selection considerations
Parts, materials, directives and procedures covered by existing European Standards shall be given preference
by Design Authorities for all new European projects wherever suitable.
This standard lists all the relevant European standards related to EWIS and OFIS in Annex B.
Otherwise the parts, materials, directives and procedures shall meet the levels of performance and safety as
required by the regulatory authorities.
5.6 Service life
In normal use conditions, the airframe electrical and fibre optic interconnection systems and its EWIS and
OFIS components shall be selected and installed so that their service life is not less than that of the aircraft
structure, which for a civil plane is generally 60 000 flying hours or 20 years, unless otherwise specified.
It shall not, however, be assumed that all EWIS and OFIS components will always achieve this life and
installations should be designed to permit a satisfactory level of inspection, test and repair according to rule
25.1725.
Similarly, for engines/power plants and undercarriages which normally have a minimum service life of
10 000 hours, but where, due to their modular construction, the interconnection system, or parts thereof, are
required to have longer service lives, the system design shall permit satisfactory inspection, test and repair.
For devices and sub-systems which are designed to be disconnected, the number of acceptable mating
unmating operations shall be specified in the relevant technical specifications.
5.7 Smoke and Fire Hazards
Components of the interconnection systems defined in this standard have been designed with an awareness
of the hazards of smoke and toxic products under failure conditions. General test requirements may be found
in EN 2825 and EN 2826 and dedicated test method may be found in the relevant component specifications
(for example: for electrical cables see EN 3475-601 and EN 3475-602).
It is the responsibility of the designer to avoid the use of materials which, in any likely conditions of use or
abuse, could create a severe failure condition.
When necessary the design of EWIS and OFIS installations shall recognize the need to provide adequate
protection or separation of cables and cable harnesses.
Flammability and self-extinguishing requirements shall be specified for all EWIS and OFIS components and it
shall be noted that these requirements are intended to minimize, for example, the transmission of fire along
cables or the propagation of fire by the release of flaming droplets.
Nevertheless, the installation of EWIS and OFIS shall recognize that severe overheating of electrical cables is
a possibility, therefore the maximum number and size of cables with associated loads within the cable harness
shall be considered, see EN 2853 for calculation.
Particular care shall be given to the torqueing of terminal lug screws.
When considering the acceptability of wire or fibre optic, reference should be made to EN 3475 or EN 3745
respectively, or alternative standards acceptable to the design authority, defining acceptable test methods,
including arc-tracking test methods (see next Subclause).
Damaged wire and insulation can cause electrical arcing, providing the spark that can cause fire. It should be
noted that contamination by materials such as dust, dirt, lint, vapours, etc. can provide fuel for fire.
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SIST EN 3197:2011
EN 3197:2010 (E)
Owing to potential fire hazard, silver-plating shall not be used in areas where they are subject to
contamination by ethylene glycol solutions unless suitable protection features are employed.
CASE OF SMALL NON METALLIC PARTS
Small parts are those that would not contribute significantly to the propagation of a fire as knobs, handles,
rollers, fasteners, clips, grommets, rub strips, pulleys, and small electrical parts.
When these parts are grouped together in the same zone, virtual volume are equivalent and shall be taken
into consideration. Verification of flammability behaviour shall be done, for example on a reference
homogenous material specimen of 50 mm wide and 30 cm length.
Shall be taken into account in particular:
 Self extinguishing,
 Smoke density,
 Gas emission toxicity,
 Dripping must not ignite a flammable product (paper as ISO 4046).
5.8 Short-Circuit and Arc-Tracking
Experience has shown that people examining fault damages may confuse these two phenomena. So the
following Subclauses propose means to differentiate both and give technical information to explain the
Arc-tracking phenomenon.
5.8.1 Short-Circuit description
5.8.1.1 Cause
A phenomenon of electrical origin generating an over current (with or without an electric arc), which causes
local deterioration of one or more cables (conductor and insulation) by thermal effect.
The origin of this phenomenon is direct contact:
 between at least two conductors (cable core)
 of a conductor with the structure
with different electric voltages.
The over current then appears in the damaged circuit thus causing the protection device located upstream
(circuit-breaker, fuse, etc.) to trip.
The duration of the short-circuit is short (a few milliseconds to a few tenths of a second).
5.8.1.2 Effects on electric cable looms
The deterioration depends on the power flowing in the circuit.
With high short circuit current deterioration of collateral cables may occur.
Cable damage generally does not exceed 50 mm length (25 mm on either side of the defect point).
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SIST EN 3197:2011
EN 3197:2010 (E)
5.8.2 Arc-Tracking description
5.8.2.1 Cause
The origin of this phenomenon is contact between at least two conductors (cable core) with different electric
voltages via a wet (liquid) or dry (chafing on structure or between cables) "resistive" circuit.
This results in the appearance of electric arcs limiting the current in the circuit(s) to an integrated value below
the tripping threshold of the circuit breaker located upstream.
In returning to the source, the electric arc causes cable deterioration (conductor and insulation) by thermal
effect.
As the protection devices do not trip immediately the duration of the arc-tracking phenomenon is relatively
longer than that of a short-circuit, and can last for several seconds.
The phenomenon stops when:
 direct contact occurs between adjacent conductors (short-circuit). The over current then appears in the
damaged circuit thus causing the protection device located upstream (circuit-breaker, fuse, …) to trip.
 current flows stops due to separation of cores (lack of maintaining, blow effect, …).
The phenomenon cannot propagate if:
 the insulation is arc-tracking resistant, or
 a specific device is used to accelerate tripping from the very beginning of arcs appearance.
5.8.2.2 Effects on electric cable looms
Arc-tracking can be differentiated from a short-circuit mainly through the following indications:
• The cable insulation is partly or fully transformed into blackish carbonized residue,
• The cable damage is always located between the initial defect and the supply source,
• The cable damage is generally longer than 70 mm and can extend to hundreds millimetres.
Deterioration of collateral cables may occur.
5.8.3 Arc-tracking phenomenon
5.8.3.1 General
This phenomenon is basically a thermal effect resulting in the conversion of some particular insulating polymer
into an electrically conducting material.
There are various ways to initiate this degradation of the insulation, nevertheless once a power arc is
produced the resultant reaction is the same.
In any case the generator shall have a 1-minute rating of not less than 20 kVA. Similar results are obtained
with higher ratings. Location and tightness of cable-ties are of particular importance to obtain repeatable
results.
Present test methodologies are carried out with 115 Va.c. in order to cover all present existing voltage sources
used on aircraft, three main ways exist, classified as wet test, dry test or wet short circuit test.
Current test methods do not cover new voltages such as 230 Va.c. and ± 270 Vd.c. For these new voltages,
appropriate fault protection is essential particularly where d.c., with its absence of zero voltage crossing
points, is involved.
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SIST EN 3197:2011
EN 3197:2010 (E)
Combinations of materials may be employed to optimise the performance of an insulating system.
Use of Arc Fault protection, such as AFCB (Arc Fault Circuit-Breaker) is another solution. It can be used to
accelerate tripping from the very beginning of arcs appearance, thus limiting collateral damages.
5.8.3.2 Wet tracking
This is a surface phenomenon that can act over a significant distance.
When failure occurs the conversion proceeds through the bulk of the insulation and results in more extensive
damage (see note below). A continuing supply of electrolyte is required over the polymer surface, bridging
points at differ
...