IEC 60794-2-20:2013

IEC 60794-2-20 ®
Edition 3.0 2013-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibre cables –
Part 2-20: Indoor cables – Family specification for multi-fibre optical cables

Câbles à fibres optiques –
Partie 2-20: Câbles intérieurs – Spécification de famille pour les câbles optiques
multifibres
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester.
If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,
please contact the address below or your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite ni
utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les
microfilms, sans l'accord écrit de la CEI ou du Comité national de la CEI du pays du demandeur.
Si vous avez des questions sur le copyright de la CEI ou si vous désirez obtenir des droits supplémentaires sur cette
publication, utilisez les coordonnées ci-après ou contactez le Comité national de la CEI de votre pays de résidence.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.

Useful links:
IEC publications search - www.iec.ch/searchpub Electropedia - www.electropedia.org
The advanced search enables you to find IEC publications The world's leading online dictionary of electronic and
by a variety of criteria (reference number, text, technical electrical terms containing more than 30 000 terms and
committee,…). definitions in English and French, with equivalent terms in
It also gives information on projects, replaced and additional languages. Also known as the International
withdrawn publications. Electrotechnical Vocabulary (IEV) on-line.

IEC Just Published - webstore.iec.ch/justpublished Customer Service Centre - webstore.iec.ch/csc
Stay up to date on all new IEC publications. Just Published If you wish to give us your feedback on this publication
details all new publications released. Available on-line and or need further assistance, please contact the
also once a month by email. Customer Service Centre: csc@iec.ch.

A propos de la CEI
La Commission Electrotechnique Internationale (CEI) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications CEI
Le contenu technique des publications de la CEI est constamment revu. Veuillez vous assurer que vous possédez
l’édition la plus récente, un corrigendum ou amendement peut avoir été publié.

Liens utiles:
Recherche de publications CEI - www.iec.ch/searchpub Electropedia - www.electropedia.org
La recherche avancée vous permet de trouver des Le premier dictionnaire en ligne au monde de termes
publications CEI en utilisant différents critères (numéro de électroniques et électriques. Il contient plus de 30 000
référence, texte, comité d’études,…). termes et définitions en anglais et en français, ainsi que
Elle donne aussi des informations sur les projets et les les termes équivalents dans les langues additionnelles.
publications remplacées ou retirées. Egalement appelé Vocabulaire Electrotechnique
International (VEI) en ligne.
Just Published CEI - webstore.iec.ch/justpublished
Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications de la CEI.
Just Published détaille les nouvelles publications parues. Si vous désirez nous donner des commentaires sur
Disponible en ligne et aussi une fois par mois par email. cette publication ou si vous avez des questions
contactez-nous: csc@iec.ch.
IEC 60794-2-20 ®
Edition 3.0 2013-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibre cables –
Part 2-20: Indoor cables – Family specification for multi-fibre optical cables

Câbles à fibres optiques –
Partie 2-20: Câbles intérieurs – Spécification de famille pour les câbles optiques

multifibres
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX S
ICS 33.180.01 ISBN 978-2-8322-1166-3

– 2 – 60794-2-20 © IEC:2013
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Construction . 7
3.1 General . 7
3.2 Optical fibres . 7
3.3 Buffer . 7
3.4 Ruggedized fibre . 8
3.5 Slotted core . 8
3.6 Tube . 8
3.7 Stranded tube . 8
3.8 Ribbon structure . 8
3.9 Strength and anti-buckling members. 8
3.10 Ripcord . 8
3.11 Sheath . 8
3.12 Sheath marking . 9
3.13 Identification . 9
3.14 Examples of cable constructions . 9
4 Tests . 9
4.1 General . 9
4.2 Dimensions . 9
4.3 Mechanical requirements . 9
4.3.1 Cable tensile performance . 9
4.3.2 Cable crush . 10
4.3.3 Cable impact . 10
4.3.4 Cable bending . 10
4.3.5 Cable repeated bending. 10
4.3.6 Cable bending under tension . 10
4.3.7 Cable bending at low temperature . 11
4.3.8 Cable flexing . 11
4.3.9 Cable torsion . 11
4.3.10 Cable kink . 11
4.4 Environmental requirements – Temperature cycling. 11
4.5 Transmission requirements. 12
4.6 Fire performance . 12
Annex A (informative) Examples of cable constructions . 13
Annex B (informative) Family specification for multi-fibre optical cables – Blank detail
specification and minimum requirements . 17
Bibliography . 22

Figure A.1 – Example of cross-section of a 12 fibre cable . 13
Figure A.2 – Example of cross-section of a 36 fibre cable . 13
Figure A.3 – Example of cross-section of a 6 fibre break-out cable . 14
Figure A.4 – Example of cross-section of a 24 fibre break-out cable . 14
Figure A.5 – Example of cross-section of a slotted core type indoor cable with 4 fibre
ribbons . 15

60794-2-20 © IEC:2013 – 3 –
Figure A.6 – Example of cross-section of an SZ (reverse oscillating lay) slotted core
type indoor cable with 2 fibre ribbons . 15
Figure A.7 – Example of cross-section of an SZ (reverse oscillating lay) slotted core
type indoor cable with 4 fibre bundles . 16
Figure A.8 – Example of multi-fibre unitube cable . 16
Figure A.9 – Example of multi-fibre cable . 16

Table 1 – Dimensions of buffered fibres . 8
Table 2 – Sample temperature cycling values . 12
Table B.1 – Cable description (1 of 2) . 17
Table B.2 – Cable element . 18
Table B.3 – Cable construction . 19
Table B.4 – Installation and operating conditions . 20
Table B.5 – Tests applicable . 20

– 4 – 60794-2-20 © IEC:2013
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRE CABLES –
Part 2-20: Indoor cables –
Family specification for multi-fibre optical 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 60794-2-20 has been prepared by sub-committee 86A: Fibres and
cables, of IEC technical committee 86: Fibre optics.
This third edition cancels and replaces the second edition published in 2008 and constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– removal of Annex C;
– reference to the most recent fibre standards;
– reference to the new series IEC 60794-1-2X.
This standard is to be used in conjunction with IEC 60794-1-1, IEC 60794-1-2 and
IEC 60794-2.
60794-2-20 © IEC:2013 – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
86A/1513/FDIS 86A/1549/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of IEC 60794 series, published under the general title Optical fibre cables,
can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication 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 – 60794-2-20 © IEC:2013
OPTICAL FIBRE CABLES –
Part 2-20: Indoor cables –
Family specification for multi-fibre optical cables

1 Scope
This part of IEC 60794 is a family specification covering multi-fibre optical cables for indoor
use. The requirements of the sectional specification IEC 60794-2 are applicable to cables
covered by this standard. Annex B contains a Blank Detail Specification and general guidance
in case the cables are intended to be used in installation governed by the MICE table of
ISO/IEC 24702 (Industrial premises) [11] .
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
NOTE These reference complete the normative references already listed in the generic specification
(IEC 60794-1-1 and IEC 60794-1-2).
IEC 60189-1, Low-frequency cables and wires with PVC insulation and PVC sheath – Part 1:
General test and measuring methods
IEC 60304, Standard colours for insulation for low-frequency cables and wires
IEC 60793-1-20, Optical fibres – Part 1-20: Measurement methods and test procedures –
Fibre geometry
IEC 60793-1-21, Optical fibres – Part 1-21: Measurement methods and test procedures –
Coating geometry
IEC 60793-2-10, Optical fibres – Part 2-10: Product specifications – Sectional specification for
category A1 multimode fibres
IEC 60793-2-50, 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 60794-1-2, Optical fibre cables – Part 1-2: Generic specification – Basic optical cable test
procedures
IEC 60794-1-20, Optical fibre cables – Part 1-20: Generic specification – Basic optical cable
test procedures – General and definitions
___________
Figures in square brackets refer to the Bibliography.
2 To be published.
60794-2-20 © IEC:2013 – 7 –
IEC 60794-1-22, 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 60794-2:2002, Optical fibre cables – Part 2: Indoor cables – Sectional specification
IEC 60794-3:2001, Optical fibre cables – Part 3: Sectional specification – Outdoor cables
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 60811-504, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 504: Mechanical tests – Bending tests at low temperature for insulation and sheaths
IEC/TR 62222, Fire performance of communication cables installed in buildings
3 Construction
3.1 General
In addition to the constructional requirements in IEC 60794-2, the following considerations
apply to multi-fibre indoor cables.
The cable shall be designed and manufactured for an expected operating lifetime of at least
15 years. In this context, the attenuation at the operational wavelength(s) of the optical fibres
contained in the installed cable shall not exceed values agreed between customer and
supplier. The materials in the cable shall not present a health or environmental hazard within
its intended use.
There shall be no fibre splice in a delivery length unless otherwise agreed by customer and
supplier.
It shall be possible to identify each individual fibre throughout the length of the cable.
3.2 Optical fibres
Class A1 multimode fibres which meet the requirements of IEC 60793-2-10 or class B sub-
categories B1.1, B1.3, B6_a, and B6_b single-mode optical fibres which meet the
requirements of IEC 60793-2-50 shall be used. The linear coefficient of optical fibre
attenuation and attenuation point discontinuity may be affected by the cable manufacturing
process. Maximum values for these optical characteristics shall be agreed between customer
and supplier.
3.3 Buffer
If a tight or semi-tight (loosely applied) buffer is required, it shall consist of one or more layers
of inert material. The buffer shall be easily removable. For tight buffers, the buffer and fibre
primary coating shall be removable in one operation over a length of 15 mm to 25 mm,
depending on customer requirements. For semi-tight buffers, the buffer shall be easily
removable over a length of 0,3 m to 2,0 m.
Buffer dimensions are shown in Table 1.

– 8 – 60794-2-20 © IEC:2013
Table 1 – Dimensions of buffered fibres
Buffer type Nominal diameter Tolerances
mm mm
Semi-tight buffer 0,3 to 1,4 ± 0,05
Tight buffer 0,3 to 1,0
± 0,05
3.4 Ruggedized fibre
Further protection can be provided to tight or semi-tight buffered fibres by surrounding them
with non-metallic strength members within a sheath of suitable material.
3.5 Slotted core
The slotted core is obtained by extruding a suitable material with a defined number of slots,
providing helical or SZ (reverse-oscillating lay) configuration along the core. One or more
primary coated fibres or optical elements such as ribbons or fibre bundles are located in each
slot.
3.6 Tube
One or more primary coated or buffered fibres or ribbons are packaged (loosely or not) in a
tube construction which may be filled. The tube may be reinforced with a composite wall.
3.7 Stranded tube
Multiple tubes, containing one or more primary coated or buffered fibres or ribbons, are
stranded around a central member. For the sake of preserving cable geometry, some tubes
may be "filler" or "empty" elements not containing optical fibres.
3.8 Ribbon structure
Ribbon structures shall conform to 6.5 and 8.2.3 of IEC 60794-3:2001. Fibres shall be
arranged to be parallel and formed into ribbons so that the fibres remain parallel and do not
cross over. Unless otherwise specified, each ribbon shall be uniquely identified with a printed
legend or by uniquely colouring the reference fibre and/or by colouring the matrix material of
the ribbon.
3.9 Strength and anti-buckling members
The cable shall be designed with sufficient strength members to meet installation and service
conditions so that the fibres are not subjected to strain in excess of limits agreed between
customer and supplier.
The strength and/or anti-buckling members may be either metallic or non-metallic and may be
located in the cable core and/or under the sheath and/or in the sheath.
3.10 Ripcord
If required, a ripcord may be provided beneath the sheath.
3.11 Sheath
The cable shall have an overall protective sheath. The cable diameter shall be specified in the
relevant blank detail specification (or product) specification.

60794-2-20 © IEC:2013 – 9 –
3.12 Sheath marking
If required, the cable shall be marked as agreed between customer and supplier.
3.13 Identification
Optical fibres, buffers and sub-unit sheaths shall be easily and uniquely identifiable through
the use of a suitable colour code (i.e. IEC 60304) and/or an easily visible numbering scheme
to be agreed between customer and supplier.
3.14 Examples of cable constructions
Examples of some main types of cable construction are shown in Annex A. Other
configurations (e.g. multi-layer constructions) are not precluded if they meet the mechanical,
environmental and transmission requirements given in this specification.
4 Tests
4.1 General
Compliance with relevant detail specification requirements shall be verified by carrying out
tests selected from the following subclauses. It is not intended that all tests be carried out; the
frequency of testing shall be agreed between customer and supplier.
Unless otherwise specified, all tests shall be carried out at room temperature: (23 ± 5) °C.
Attenuation measurements shall be conducted at the highest specified wavelength.
Some of the following tests can be performed on a short sample length of cable which is still
an integral part of a longer length. Thus it becomes possible to detect permanent changes in
attenuation within the measurement uncertainty of the equipment used (see 4.8.2,
Assessment of uncertainties in IEC 60794-1-20:201X). The wavelength and maximum value of
this attenuation change shall be agreed between customer and supplier.
4.2 Dimensions
The fibre dimensions and tolerances shall be verified in accordance with test method C of
IEC 60793-1-20 or IEC 60793-1-21. The diameter of the buffer and of the cable, as well as the
thickness of the sheath, shall be measured in accordance with the methods of IEC 60189-1.
4.3 Mechanical requirements
4.3.1 Cable tensile performance
Method: IEC 60794-1-21-E1A and/or E1B [4]
Diameter of chuck drums
and transfer devices:  not smaller than the minimum bending diameter specified
for the cable under load
Velocity of transfer device: either 100 mm/min or 100 N/min
Load and duration: 400 N or the weight of 1 km of cable, whichever is greater,
and for a minimum period of 5 min
Length of sample: sufficient to achieve the desired accuracy of measurement
of attenuation change (typically 300 m) and shall be
agreed between customer and supplier
Requirements: for E1A there shall be no change in attenuation after the
test
– 10 – 60794-2-20 © IEC:2013
for E1B allowed fibre strain to be agreed between supplier
and customer
There shall be no visible damage to the cable elements
Fibre strain above 60 % of the proof test of the all-glass fibre while under test load is not
recommended.
NOTE For certain applications specifying MICE classification of ISO/IEC 24702 and related standards, different
load and duration values may be agreed between customer and supplier.
4.3.2 Cable crush
Method: IEC 60794-1-21-E3
Force during installation: 500 N
Duration during installation: 1 min
Force during operation: 300 N
Duration during operation: 15 min
Length between test locations: 500 mm
Requirements: no change in attenuation during the operational test and
after the installation test. There shall be no visible damage
to the cable elements
NOTE For certain applications specifying MICE classification of ISO/IEC 24702 and related standards, different
force values may be agreed between customer and supplier.
4.3.3 Cable impact
Method: IEC 60794-1-21-E4
Radius of striking surface: 12,5 mm
Impact energy: 1,0 J
Number of impacts: at least 3, each separated at least 500 mm
Requirements: no fibre breakage
NOTE For certain applications specifying MICE classification of ISO/IEC 24702 and related standards, impact
energy values may be agreed between customer and supplier.
4.3.4 Cable bending
Method: IEC 60794-1-21-E11A
Mandrel diameter: 20 times cable diameter
Number of turns per helix: 6
Number of cycles: 10
Requirements: no fibre breakage
NOTE For certain applications specifying MICE classification of ISO/IEC 24702 and related standards, different
mandrel diameter values may be agreed between customer and supplier.
4.3.5 Cable repeated bending
Method: IEC 60794-1-21-E6
Bending radius: 20 times cable diameter
Number of cycles: 25
Mass of weights: 4 kg
Requirements: under visual examination without magnification there shall
be no damage to the sheath and to the cable elements
4.3.6 Cable bending under tension
Method: IEC 60794-1-21-E18
60794-2-20 © IEC:2013 – 11 –
Bending radius: 20 times cable diameter
Load: 400 N or weight of 1 km of cable, whichever is greater
Requirements: no change in attenuation after the test, and
there shall be no visible damage to the cable elements
4.3.7 Cable bending at low temperature
Method: IEC 60794-1-21-E11A (see IEC 60811-504)
Bending radius: 10 times cable diameter
Test temperature: 0 °C, –10 °C or –15 °C depending on application and
customer requirements.
Number of turns per helix: according to IEC 60811-504
Number of cycles: 2
Requirements: in addition to the requirements of IEC 60811-504, no fibre
shall break during the test
4.3.8 Cable flexing
Method: IEC 60794-1-21-E8
Number of cycles: 100
Pulley diameter: 20 times cable diameter
Mass of weights: 2 kg (minimum)
Requirements: no fibre breakage
NOTE For certain applications specifying MICE classification of ISO/IEC 24702 and related standards, different
pulley diameter values may be agreed between customer and supplier.
4.3.9 Cable torsion
Method: IEC 60794-1-21-E7
Number of cycles: 10
Distance between fixed and 125 times cable diameter but not more than 2,0 m
rotation clamp:
Tension load: 20 N
Requirements: no fibre breakage
NOTE For certain applications specifying MICE classification of ISO/IEC 24702 and related standards, different
values for the number of cycles may be agreed between customer and supplier.
4.3.10 Cable kink
Method: IEC 60794-1-21-E10
Minimum loop diameter: 20 times cable diameter
Requirement: no kink shall occur
4.4 Environmental requirements – Temperature cycling
Method: IEC 60794-1-22-F1
– 12 – 60794-2-20 © IEC:2013
Table 2 – Sample temperature cycling values
Low temperature High temperature
TA TB
*
a) 0 °C +50 °C
b)
–5 °C +50 °C
c)
–20 °C +60 °C
d) –40 °C +60 °C
*
Condition a), b) c) or d) shall be selected depending on application and
customer requirements, for example condition c) is appropriate for applications to
ISO/IEC 11801 [10].
Period: t = sufficient time such that the cable has reached
thermal stability throughout its entire length at the
specified temperature (e.g. 8 h ≤ t ≤ 24 h)
Number of cycles: 2
Length of sample: sufficient to achieve the desired accuracy of measurement
of attenuation
Requirements: the wavelength and maximum increase in attenuation both
at T and T and after returning to thermal stability at
A B
ambient temperature shall be agreed between the
customer and supplier
4.5 Transmission requirements
The transmission requirements shall be verified in accordance with IEC 60793-2-10 or
IEC 60793-2-50 and shall be agreed between customer and supplier. Maximum cable
attenuation shall comply with values stated in the relevant detail specification.
4.6 Fire performance
IEC/TR 62222 provides recommendations for the requirements and test methods to be
specified for the fire performance of communication cables when installed in buildings.
The recommendations relate to typical applications and installation practices and also take
into account legislation and regulation applicable to the fire performance of cables that govern
the tests to be performed.
Tests to be performed shall be agreed between the customer and the supplier.

60794-2-20 © IEC:2013 – 13 –
Annex A
(informative)
Examples of cable constructions

Figures A.1 to A.9 provide examples of cable constructions.

Coated fibre
Thermoplastic buffer
Strength member
Dielectric central member
Overcoat
Sheath
IEC  2648/13
Figure A.1 – Example of cross-section of a 12 fibre cable
Buffered fibre
Subunit sheath
Strength member
Overcoat
Dielectric central member
Strength member
Dielectric central member
Ripcord
Sheath
IEC  2649/13
Figure A.2 – Example of cross-section of a 36 fibre cable

– 14 – 60794-2-20 © IEC:2013
Coated fibre
Thermoplastic buffer
Strength member
Subunit sheath
Strength member
Dielectric central member
Overcoat
Sheath
IEC  2650/13
Figure A.3 – Example of cross-section of a 6 fibre break-out cable
Dielectric central member
Single fibre subunit
6 fibre unit
Dielectric central member
Strength member
Sheath
Ripcord
IEC  2651/13
Figure A.4 – Example of cross-section of a 24 fibre break-out cable

60794-2-20 © IEC:2013 – 15 –
Sheath
4 fibre ribbon
Slotted core
Strength member
Ripcord
IEC  2652/13
Figure A.5 – Example of cross-section of a
slotted core type indoor cable with 4 fibre ribbons
Sheath
2 fibre ribbon
SZ slotted rod
Strength member
Ripcord
IEC  2653/13
Figure A.6 – Example of cross-section of an SZ (reverse oscillating lay)
slotted core type indoor cable with 2 fibre ribbons

– 16 – 60794-2-20 © IEC:2013
Sheath
4 fibre bundles
SZ slotted rod
Strength member
Ripcord
IEC  2654/13
Figure A.7 – Example of cross-section of an SZ (reverse oscillating lay)
slotted core type indoor cable with 4 fibre bundles
Fibres (loose or bundled)
Tube
Strength member
Sheath
IEC  2655/13
Figure A.8 – Example of multi-fibre unitube cable
Coated fibres
Thermoplastic buffer
Strength member
Sheath
IEC  2656/13
Figure A.9 – Example of multi-fibre cable

60794-2-20 © IEC:2013 – 17 –
Annex B
(informative)
Family specification for multi-fibre optical cables –
Blank detail specification and minimum requirements
B.1 Blank detail specification
B.1.1 Cable description
Table B.1 – Cable description (1 of 2)
(1) Prepared by (2) Document No:
Issue:
Date:
(3) Available from (4) Generic specification: IEC 60794-1-1
Sectional specification: IEC 60794-2
(5) Additional references: ISO/IEC 24702 if required
(6) Cable description:
(7) Cable construction:
Optical fibres
Range of fibre count
Modularity
Construction Additional remarks
– single coloured fibre
– tube – filled
– tube – unfilled
– slotted core – filled
– slotted core – unfilled
– tight or semi-tight buffer
– ribbon in slotted core
– ribbon in tube
– strength elements – non metallic
– strength elements – metallic
Lay-up
– stranding (helical or reverse oscillating/SZ)
– single unit
– hybrid configuration
– other
Insulated copper conductors
– AWG
– solid/stranded
– insulation material
Inner sheath
material
– minimum wall thickness
Peripheral strength member
– metallic
– non-metallic
– 18 – 60794-2-20 © IEC:2013
Table B.1 (2 of 2)
Outer sheath
– material
– minimum wall thickness
Additional armouring
– non-metallic armouring
– metallic armouring
Marking identification
– customer requirement
– identification of supplier
(8) Application information:
Application
Maximum outer diameter (d) mm
Rated maximum tensile load N
Minimum bending radius for operation mm or nxd
Minimum bending radius under load mm or nxd
Temperature range:
– transport and storage ºC
– installation ºC
– operation ºC
Manufacturing cable length
– typical m
– nominal/tolerances:
+1
%
B.1.2 Cable element
Table B.2 – Cable element
IEC 60794-2 Family
Characteristics Test methods Remarks
Clause/subclause requirements
(9) (12) (13)
(10) (11)
Cable element
Tight/semi-tight buffer
Slotted core
Tube
Compound flow and
evaporation
Outer diameter
Ribbon
Filler
Insulated copper conductor
Central strength member
60794-2-20 © IEC:2013 – 19 –
B.1.3 Cable construction
Table B.3 – Cable construction
IEC 60794-2
Family
Characteristics Clause/ Test methods Remarks
requirements
(9) subclause (12) (13)
(11)
(10)
a
Lay-up 6.2 According to DS Visual inspection
Cable core 6.3 According to DS
Strength member 6.4 According to DS Visual inspection
– central
– peripheral
Outer cable sheath 6.6
Material 6.6.3 of
IEC 60794-2:2002
Minimum sheath According to DS IEC 60811-202
thickness
Outer diameter According to DS IEC 60811-203
Optional protection According to DS
Sheath marking 6.7
Configuration, According toDS Visual inspection
dimensions
Abrasion resistance According to DS IEC 60794-1-21,
Method E2B, Method 1
Or
IEC 60794-1-21,
Method E2B, Method 2
Sheath abrasion 8.10 According to DS IEC 60794-1-21,
Method E2A
Cable length
a
Detail specification.
– 20 – 60794-2-20 © IEC:2013
B.1.4 Installation and operating conditions
Table B.4 – Installation and operating conditions
Characteristics IEC 60794-2 Family Test methods Remarks
(9) Clause/subclause requirements (12) (13)
(10) (11)
General requirements
Bend of cable element  IEC 60794-1-21,
Method G1
Tube kinking  IEC 60794-1-21,
Method G7
Ribbons:
– dimensions  IEC 60794-1-23,
Method G2, G3 or G4
– separability of  IEC 60794-1-21,
individual fibres Method G5
from ribbon or acc. DS
– ribbon stripping
– torsion  IEC 60794-1-21,
Method G6
B.1.5 Mechanical and environmental tests
Table B.5 – Tests applicable
Characteristics (9) IEC 60794-2 Family Test methods Remarks
Clause/subclause requirements (12) (13)
(10) (11)
Tensile performance  IEC 60794-1-2,
Method E1A and E1B
Installation capability
selection from the
following:
– bending under  IEC 60794-1-21,
tension Method E18
– repeated bending  IEC 60794-1-21,
Method E6
– impact  IEC 60794-1-21,
Method E4
– kink  IEC 60794-1-21,
Method E10
– torsion  IEC 60794-1-21,
Method E7
Cable bend  IEC 60794-1-21,
Method E11
Crush  IEC 60794-1-21,
Method E3
Temperature cycling  IEC 60794-1-22,
Method F1
Ageing
– coating adhesion  IEC 60794-1-22,
stability Method E5
– finished cable
60794-2-20 © IEC:2013 – 21 –
B.2 Cables subject to the MICE environmental classification (ISO/IEC 24702
and related standards)
Cables intended for installation in conformity with ISO/IEC 24702 and related standards may
require the specification of additional tests to ensure their suitability in the applicable
environments defined by the mechanical, ingress, climatic and chemical, and electromagnetic
(MICE) classification. Such tests are outside of the scope of IEC 60794 cable specifications,
and MICE criteria are not part of the requirements for IEC 60794 specifications. The MICE
tests may be the same as, similar to, or substantially different from, the tests required by
IEC 60794 specifications. Cables manufactured per IEC 60794 specifications may or may not
meet the MICE criteria. For supplemental guidance see IEC/TR 62362 [9].

– 22 – 60794-2-20 © IEC:2013
Bibliography
[1] IEC 60654 (all parts), Industrial-process measurement and control equipment –
Operating conditions
[2] IEC 60721-1, Classification of environmental conditions – Part 1: Environmental
parameters and their severities
[3] IEC 60721-3-3, Classification of environmental conditions – Part 3-3: Classification of
groups of environmental parameters and their severities – Stationary use at
weatherprotected locations
[4] IEC 60794-1-21, Optical fibre cables – Part 1-21: Generic specification – Basic optical
cable test procedures – Mechanical tests methods
[5] IEC/TR 61000-2-5, Electromagnetic compatibility (EMC) – Part 2-5: Environment –
Description and classification of electromagnetic environments
[6] IEC 61000-6-2, Electromagnetic compatibility (EMC) – Part 6-2: Generic standards –
Immunity for industrial environments
[7] IEC 61326 (all parts), Electrical equipment for measurement, control and laboratory use
– EMC requirements
[8] IEC 61918, Industrial communication networks – Installation of communication networks
in industrial premises
[9] IEC/TR 62362, Selection of optical fibre cable specifications relative to mechanical,
ingress, climatic or electromagnetic characteristics – Guidance
[10] ISO/IEC 11801, Information technology – Generic cabling for customer premises
[11] ISO/IEC 24702, Information technology – Generic cabling – Industrial premises

___________
___________
3 Under consideration as a Committee Draft.

– 24 – 60794-2-20 © CEI:2013
SOMMAIRE
AVANT-PROPOS . 26
1 Domaine d'application . 28
2 Références normatives . 28
3 Construction . 29
3.1 Généralités . 29
3.2 Fibres optiques. 29
3.3 Revêtement protecteur . 30
3.4 Fibre renforcée . 30
3.5 Jonc rainuré . 30
3.6 Tube . 30
3.7 Tube toronné . 30
3.8 Structure en ruban. 30
3.9 Renforts de traction et antidéformation . 31
3.10 Filin de déchirement . 31
3.11 Gaine . 31
3.12 Marquage de la gaine .
...