EN IEC 60794-6-20:2020

Optical fibre cables - Part 6-20: Indoor-outdoor cables - Family specification for flame retardant outdoor cables

IEC 60794-6-20:2020 is a family specification covering optical fibre outdoor cables which are flame retardant and thus also applicable to indoor environments. These cables generally possess the characteristics associated with outdoor cable designs having similar thermal and mechanical robustness that makes them suitable for use in the outside plant, while simultaneously exhibiting the fire performance required in indoor premises. A typical application is for example the extension of a "shorter length" of an outdoor cable into the building.

Lichtwellenleiterkabel - Teil 6-20: Innen-/Außenkabel - Familienspezifikation für flammhemmende Außenkabel

Câbles à fibres optiques - Partie 6-20: Câbles intérieurs/extérieurs - Spécification de famille pour les câbles extérieurs retardateurs de flamme

IEC 60794-6-20:2020 est une spécification de famille qui couvre les câbles extérieurs à fibres optiques ayant un caractère ignifugeant et qui s'applique donc également aux environnements intérieurs. Ces câbles possèdent généralement les caractéristiques associées à des conceptions de câbles extérieurs, présentant une robustesse thermique et mécanique similaire qui les rend appropriés pour une utilisation dans les environnements d'usine extérieurs, tout en présentant le comportement au feu exigé à l'intérieur des locaux. Une application type est par exemple la prolongation d'une longueur de câble extérieur trop courte dans le bâtiment.

Optični kabli - 6-20. del: Notranji ali zunanji kabli - Skupinska specifikacija za zunanje kable, ki zavirajo gorenje (IEC 60794-6-20:2020)

General Information

• Status: Published
• Publication Date: 12-Nov-2020
• ICS: 33.180.10 - Fibres and cables
• Technical Committee: CLC/TC 86A - Optical fibres and optical fibre cables
• Drafting Committee: IEC/SC 86A - IEC_SC_86A
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 13-Nov-2020
• Completion Date: 13-Nov-2020
• Ref Project: SIST EN IEC 60794-6-20:2021 - Optical fibre cables - Part 6-20: Indoor-outdoor cables - Family specification for flame retardant outdoor cables (IEC 60794-6-20:2020)

Overview

EN IEC 60794-6-20:2020 - part of the IEC 60794 suite - is a family specification for flame retardant outdoor optical fibre cables that are also suitable for indoor use. It covers optical fibre cables designed with the mechanical and thermal robustness of outside-plant constructions while meeting the fire-performance requirements needed inside buildings. A typical use case is extending a short length of an outdoor cable into a building without replacing it with a separate indoor-rated cable.

Key topics and technical requirements

This standard defines construction guidance and the tests and performance criteria applicable to indoor‑outdoor, flame‑retardant optical fibre cables. Major technical topics include:

• Cable construction and elements: requirements for fibres, ribbons, tubes and overall cable architecture suitable for both outdoor and indoor deployment.
• Mechanical tests: a comprehensive set of mechanical performance checks such as tensile performance, abrasion, crush, impact, repeated bending, torsion, bend under tension and kink resistance.
• Environmental tests: exposure and durability tests including temperature cycling, water penetration, ageing, UV resistance, environmental stress cracking, external freezing, compound flow and material compatibility.
• Cable element tests: ribbon strippability, ribbon tear/separability, dimensions, torsion, residual twist, tube kinking and element bend tests.
• Fire performance and safety: integration with established fire tests for cables (see referenced fire test standards) to demonstrate flame retardancy and controlled smoke/acid gas emissions for indoor use.
• Family specification approach: defines how variations of a cable family are covered and the test conditions that apply to different designs.

The standard references established test methods (e.g., IEC 60332 series for flame propagation, IEC 60754-2 for acidity and conductivity of combustion gases, IEC 61034 for smoke density), ensuring harmonized fire and safety evaluation.

Applications

EN IEC 60794-6-20 is intended for scenarios where a single cable must serve outdoor deployment and enter indoor premises without compromising safety or performance, for example:

• Extending outdoor optical distribution cables into telecom rooms, equipment cabinets or building entry points.
• Campus, metropolitan and access networks where outdoor-to-indoor transitions occur over short distances.
• Environments requiring robust outside-plant performance combined with indoor fire safety (e.g., data centres, public buildings, multi-dwelling units).

Who uses this standard

• Cable manufacturers and product designers for qualifying indoor‑outdoor flame retardant optical fibre cables.
• Network operators and system integrators specifying cable performance for outside‑to‑inside transitions.
• Test laboratories and conformity assessors conducting mechanical, environmental and fire testing.
• Safety engineers and procurement teams ensuring compliance with European/national regulations.

Related standards

Standards referenced in EN IEC 60794-6-20 include (selection):

• IEC 60332 series (vertical flame propagation tests)
• IEC 60754-2 (acidity and conductivity of gases)
• IEC 61034 series (smoke density)
• IEC 60794-1-22 / -1-21 / -1-23 (generic cable test procedures)
• IEC 60794-3 (outdoor cable sectional specification)
• IEC 60811 series (non‑metallic material tests)

EN IEC 60794-6-20:2020 helps bridge outdoor cable robustness and indoor fire safety, guiding manufacturers and specifiers to deliver compliant, high-performance optical fibre indoor‑outdoor cable solutions.

Standards Content (Sample)

SLOVENSKI STANDARD
01-januar-2021
Optični kabli - 6-20. del: Notranji ali zunanji kabli - Skupinska specifikacija za
zunanje kable, ki zavirajo gorenje (IEC 60794-6-20:2020)
Optical fibre cables - Part 6-20: Indoor-outdoor cables - Family specification for flame
retardant outdoor cables (IEC 60794-6-20:2020)
Lichtwellenleiterkabel Teil 6-20: Innen-/Außenkabel - Familienspezifikation für
flammhemmende Außenkabel (IEC 60794-6-20:2020)
Câbles à fibres optiques - Partie 6-20: Câbles intérieurs/extérieurs - Spécification de
famille pour les câbles extérieurs retardateurs de flamme (IEC 60794-6-20:2020)
Ta slovenski standard je istoveten z: EN IEC 60794-6-20:2020
ICS:
33.180.10 (Optična) vlakna in kabli Fibres and cables
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60794-6-20

NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2020
ICS 33.180.10
English Version
Optical fibre cables - Part 6-20: Indoor-outdoor cables - Family
specification for flame retardant outdoor cables
(IEC 60794-6-20:2020)
Câbles à fibres optiques - Partie 6-20: Câbles Lichtwellenleiterkabel - Teil 6-20: Innen-/Außenkabel -
intérieurs/extérieurs - Spécification de famille pour les Familienspezifikation für flammhemmende Außenkabel
câbles extérieurs retardateurs de flamme (IEC 60794-6-20:2020)
(IEC 60794-6-20:2020)
This European Standard was approved by CENELEC on 2020-11-03. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60794-6-20:2020 E

European foreword
The text of document 86A/2037/FDIS, future edition 1 of IEC 60794-6-20, prepared by SC 86A "Fibres
and cables" of IEC/TC 86 "Fibre optics" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN IEC 60794-6-20:2020.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2021-08-03
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2023-11-03
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice
The text of the International Standard IEC 60794-6-20:2020 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 60794-1-2 NOTE Harmonized as EN 60794-1-2
IEC 60794-1-219 NOTE Harmonized as EN IEC 60794-1-219

To be published. Stage at the time of publication: prEN IEC 60794-1-219:2020.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60332-1 series Tests on electric and optical fibre cables EN 60332-1 series
under fire conditions - Part 1: Test for
vertical flame propagation for a single
insulated wire or cable
IEC 60332-3 series Tests on electric and optical fibre cables EN IEC 60332-3 series
under fire conditions - Part 3: Test for
vertical flame spread of vertically-mounted
bunched wires or cables
IEC 60754-2 - Test on gases evolved during combustion EN 60754-2 -
of materials from cables - Part 2:
Determination of acidity (by pH
measurement) and conductivity
IEC 60793-2-10 2019 Optical fibres - Part 2-10: Product EN IEC 60793-2-10 2019
specifications - Sectional specification for
category A1 multimode fibres
IEC 60793-2-50 2018 Optical fibres - Part 2-50: Product EN IEC 60793-2-50 2019
specifications - Sectional specification for
class B single-mode fibres
IEC 60794-1-1 - Optical fibre cables - Part 1-1: Generic EN 60794-1-1 -
specification - General
IEC 60794-1-21 - Optical fibre cables - Part 1-21: Generic EN 60794-1-21 -
specification - Basic optical cable test
procedures - Mechanical tests methods
IEC 60794-1-22 2017 Optical fibre cables - Part 1-22: Generic EN IEC 60794-1-22 2018
specification - Basic optical cable test
procedures - Environmental test methods
Publication Year Title EN/HD Year
IEC 60794-1-23 - Optical fibre cables - Part 1-23: Generic EN IEC 60794-1-23 -
specification - Basic optical cable test
procedures - Cable element test methods
IEC 60794-1-24 - Optical fibre cables - Part 1-24: Generic EN 60794-1-24 -
specification - Basic optical cable test
procedures - Electrical test methods
IEC 60794-1-31 2018 Optical fibre cables - Part 1-31: Generic EN IEC 60794-1-31 2018
specification - Optical cable elements -
Optical fibre ribbon
IEC 60794-1-215 - Optical fibre cables - Part 1-215: Generic EN IEC 60794-1-215 -
specification - Basic optical cable test
procedures - Environmental test methods -
Cable external freezing test, Method F15
IEC 60794-3 2014 Optical fibre cables - Part 3: Outdoor EN 60794-3 2015
cables - Sectional specification
IEC 60794-3-10 2015 Optical fibre cables - Part 3-10: Outdoor EN 60794-3-10 2015
cables - Family specification for duct,
directly buried and lashed aerial optical
telecommunication cables
IEC 60794-4 2018 Optical fibre cables – Part 4: Sectional EN IEC 60794-4 2018
specification - Aerial optical cables along
electrical power lines
IEC 60794-5 2014 Optical fibre cables - Part 5: Sectional EN 60794-5 2016
specification - Microduct cabling for
installation by blowing
IEC 60811-202 - Electric and optical fibre cables - Test EN 60811-202 -
methods for non-metallic materials - Part
202: General tests - Measurement of
thickness of non-metallic sheath
IEC 60811-203 - Electric and optical fibre cables - Test EN 60811-203 -
methods for non-metallic materials - Part
203: General tests - Measurement of
overall dimensions
IEC 60811-406 - Electric and optical fibre cables - Test EN 60811-406 -
methods for non-metallic materials - Part
406: Miscellaneous tests - Resistance to
stress cracking of polyethylene and
polypropylene compounds
IEC 61034 series Measurement of smoke density of cables EN 61034 series
burning under defined conditions
ISO 4892-2 2013 Plastics - Methods of exposure to EN ISO 4892-2 2013
laboratory light sources - Part 2: Xenon-arc
lamps
IEC 60794-6-20 ®
Edition 1.0 2020-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibre cables –
Part 6-20: Indoor-outdoor cables – Family specification for flame retardant

outdoor cables
Câbles à fibres optiques –
Partie 6-20: Câbles intérieurs/extérieurs – Spécification de famille pour

les câbles extérieurs retardateurs de flamme

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.10 ISBN 978-2-8322-8908-2

– 2 – IEC 60794-6-20:2020 © IEC 2020
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviated terms . 7
4 General specifications . 7
4.1 Optical fibres . 7
4.2 Cable elements . 7
5 Specifications for flame retardant outdoor cables – Construction . 8
6 Details of family specifications and test conditions for flame retardant outdoor
cables. 8
6.1 Applicable tests . 8
6.2 Mechanical tests . 9
6.2.1 General . 9
6.2.2 Tensile performance . 10
6.2.3 Abrasion . 10
6.2.4 Crush . 11
6.2.5 Impact . 11
6.2.6 Repeated bending . 11
6.2.7 Torsion . 12
6.2.8 Bend . 12
6.2.9 Bending under tension . 12
6.2.10 Kink . 12
6.2.11 Rip cord functional test . 12
6.3 Environmental tests . 13
6.3.1 Temperature cycling . 13
6.3.2 Water penetration . 13
6.3.3 Ageing . 14
6.3.4 UV resistance . 14
6.3.5 Environmental stress cracking . 14
6.3.6 Cable external freezing . 14
6.3.7 Compound flow . 15
6.3.8 Bleeding and evaporation . 15
6.3.9 Material compatibility . 15
6.4 Cable element tests . 15
6.4.1 Ribbon strippability . 15
6.4.2 Ribbon tear (separability) . 15
6.4.3 Ribbon dimensions and geometry . 16
6.4.4 Ribbon torsion . 16
6.4.5 Ribbon residual twist . 16
6.4.6 Tube kinking . 16
6.4.7 Bend test for optical cable elements . 16
6.4.8 Stripping force stability of cabled fibres . 16
6.5 Other tests . 17
6.5.1 Fire performance . 17
6.5.2 Electrical continuity of cable metallic elements . 17
6.5.3 Thickness of non-metallic sheath . 17
6.5.4 Overall dimensions . 17

IEC 60794-6-20:2020 © IEC 2020 – 3 –
Annex A (informative) Examples of flame retardant (FR) outdoor cables . 19
Bibliography . 20

Figure A.1 – Example of a stranded FR outdoor cable design . 19
Figure A.2 – Example of an FR outdoor cable with a central tube design . 19

Table 1 – Tests applicable for mechanical and environmental performance of flame
retardant outdoor cables . 8
Table 2 – Low and high temperatures . 13

– 4 – IEC 60794-6-20:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRE CABLES –
Part 6-20: Indoor-outdoor cables –
Family specification for flame retardant outdoor cables

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60794-6-20 has been prepared by subcommittee SC 86A: Fibres
and cables, of IEC technical committee 86: Fibre optics.
The text of this International Standard is based on the following documents:
FDIS Report on voting
86A/2037/FDIS 86A/2051/RVD
Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60794 series, published under the general title Optical fibre cables,
can be found on the IEC website.

IEC 60794-6-20:2020 © IEC 2020 – 5 –
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

– 6 – IEC 60794-6-20:2020 © IEC 2020
OPTICAL FIBRE CABLES –
Part 6-20: Indoor-outdoor cables –
Family specification for flame retardant outdoor cables

1 Scope
This part of IEC 60794 is a family specification covering optical fibre outdoor cables which are
flame retardant and thus also applicable to indoor environments. These cables generally
possess the characteristics associated with outdoor cable designs having similar thermal and
mechanical robustness that makes them suitable for use in the outside plant, while
simultaneously exhibiting the fire performance required in indoor premises. A typical application
is for example the extension of a "shorter length" of an outdoor cable into the building.
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.
IEC 60332-1 (all parts), Tests on electric and optical fibre cables under fire conditions – Part 1:
Test for vertical flame propagation for a single insulated wire or cable
IEC 60332-3 (all parts), Tests on electric and optical fibre cables under fire conditions – Part 3:
Test for vertical flame spread of vertically-mounted bunched wires or cables
IEC 60754-2, Test on gases evolved during combustion of materials from cables – Part 2:
Determination of acidity (by pH measurement) and conductivity
IEC 60793-2-10:2019, Optical fibres – Part 2-10: Product specifications – Sectional
specification for category A1 multimode fibres
IEC 60793-2-50:2018, Optical fibres – Part 2-50: Product specifications – Sectional
specification for class B single-mode fibres
IEC 60794-1-1, Optical fibre cables – Part 1-1: Generic specification – General
IEC 60794-1-21, Optical fibre cables – Part 1-21: Generic specification – Basic optical cable
test procedures – Mechanical test methods
IEC 60794-1-22:2017, Optical fibre cables – Part 1-22: Generic specification – Basic optical
cable test procedures – Environmental test methods
IEC 60794-1-23, Optical fibre cables – Part 1-23: Generic specification – Basic optical cable
test procedures – Cable element test methods
IEC 60794-1-24, Optical fibre cables – Part 1-24: Generic specification – Basic optical cable
test procedures – Electrical test methods
IEC 60794-1-31:2018, Optical fibre cables – Part 1-31: Generic specification – Optical cable
elements – Optical fibre ribbon

IEC 60794-6-20:2020 © IEC 2020 – 7 –
IEC 60794-1-215, Optical fibre cables – Part 1-215: Generic specification – Basic optical cable
test procedures – Environmental test methods – Cable external freezing test, Method F15
IEC 60794-3:2014, Optical fibre cables – Part 3: Outdoor cables – Sectional specification
IEC 60794-3-10:2015, Optical fibre cables – Part 3-10: Outdoor cables – Family specification
for duct, directly buried and lashed aerial optical telecommunication cables
IEC 60794-4:2018, Optical fibre cables – Part 4: Sectional specification – Aerial optical cables
along electrical power lines
IEC 60794-5:2014, Optical fibre cables – Part 5: Sectional specification – Microduct cabling for
installation by blowing
IEC 60811-202, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 202: General tests – Measurement of thickness of non-metallic sheath
IEC 60811-203, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 203: General tests – Measurement of overall dimensions
IEC 60811-406, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 406: Miscellaneous tests – Resistance to stress cracking of polyethylene and
polypropylene compounds
IEC 61034 (all parts), Measurement of smoke density of cables burning under defined
conditions
ISO 4892-2:2013, Plastics – Methods of exposure to laboratory light sources – Part 2: Xenon-
arc lamps
3 Terms, definitions and abbreviated terms
For the purposes of this document, the terms and definitions given in IEC 60794-1-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 General specifications
4.1 Optical fibres
The optical fibre shall conform to the requirements of IE
...