IEC 60794-2-50:2023
(Main)Optical fibre cables - Part 2-50: Indoor cables - Family specification for simplex and duplex cables for use in terminated cable assemblies
Optical fibre cables - Part 2-50: Indoor cables - Family specification for simplex and duplex cables for use in terminated cable assemblies
IEC 60794-2-50:2023 specifies requirements for simplex and duplex optical fibre cables for use in terminated cable assemblies or as used for termination of passive components. This third edition cancels and replaces the second edition published in 2020. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) added IEC 60793-1-46 and IEC 60794-1-211 to the normative references;
b) changed the load duration for the tensile test from 5 min to 10 min;
c) clarified the distance between the clamps for torsion test to 125 times cable diameter, but not less than 0,3 m;
d) recommended the temperatures –10 °C and +60 °C for indoor simplex and duplex cables and included the low and high temperatures for category C, CHD, OP and OPHD according to the operating service environments in IEC 61753-1 for temperature cycling and shrinkage testing;
e) updated the shrinkage test standard to IEC 60794-1-211, F11A, and changed the requirement to maximum 20 mm;
f) replaced the text for the fire performance with an improved description.
Câbles à fibres optiques - Partie 2-50: Câbles intérieurs - Spécification de famille pour les câbles simplex et duplex utilisés dans les câbles assemblés équipés
L'IEC 60794-2-50:2023 spécifie les exigences pour les câbles simplex et duplex à fibres optiques utilisés dans des câbles assemblés équipés ou comme terminaison pour des composants passifs.Cette troisième édition annule et remplace la deuxième édition parue en 2020. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l’édition précédente:
a) ajout de l’IEC 60793-1-46 et de l’IEC 60794-1-211 dans les références normatives;
b) modification de la durée d’application des charges pour l’essai de traction qui est portée de 5 min à 10 min;
c) clarification de la distance entre les pinces pour l’essai de torsion de 125 fois le diamètre du câble, mais pas moins de 0,3 m;
d) recommandation des températures –10 °C et +60 °C pour les câbles intérieurs simplex et duplex et inclusion des températures hautes et basses pour les catégories C, CHD, OP et OPHD conformément aux environnements de service ou de fonctionnement de l’IEC 617531 pour les essais de cycles de température et de rétraction;
e) mise à jour de la norme d’essai de rétraction conformément à l’IEC 60794-1-211, F11A, et modification de l’exigence à 20 mm au maximum;
f) remplacement du texte du comportement au feu par une description améliorée.
General Information
Relations
Standards Content (Sample)
IEC 60794-2-50 ®
Edition 3.0 2023-03
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Optical fibre cables –
Part 2-50: Indoor cables – Family specification for simplex and duplex cables for
use in terminated cable assemblies
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.
IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
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 corrigendum or an amendment might have been published.
IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always have
committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 19 additional languages.
a month by email.
Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: sales@iec.ch.
IEC 60794-2-50 ®
Edition 3.0 2023-03
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Optical fibre cables –
Part 2-50: Indoor cables – Family specification for simplex and duplex cables for
use in terminated cable assemblies
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.180.10 ISBN 978-2-8322-6746-2
– 2 – IEC 60794-2-50:2023 RLV © IEC 2023
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Construction . 8
4.1 General . 8
4.2 Optical fibres and primary coating . 8
4.3 Buffer . 8
4.4 Tube . 9
4.5 Strength and anti-buckling members . 9
4.6 Sheath . 9
4.7 Sheath marking . 9
4.8 Examples of cable constructions . 9
5 Tests . 10
5.1 General . 10
5.2 Dimensions . 10
5.3 Mechanical requirements . 11
5.3.1 Tensile performance . 11
5.3.2 Crush . 11
5.3.3 Impact . 12
5.3.4 Repeated bending . 12
5.3.5 Bend . 12
5.3.6 Torsion . 13
5.3.7 Bend at low temperature . 13
5.3.8 Kink . 14
5.3.9 Sheath pull-off force . 14
5.3.10 Abrasion resistance of cable marking . 14
5.3.11 Buffered fibre movement under compression . 14
5.4 Environmental requirements . 15
5.4.1 Temperature cycling . 15
5.4.2 Sheath shrinkage (informative) . 16
6 Transmission requirements . 17
7 Fire performance . 17
Annex A (informative) Examples of types of cable constructions . 18
Annex B (informative) Guidance on the selection of tests applicable to optical fibre
cables for use in patchcords terminated cable assemblies . 24
Bibliography . 27
Figure A.1 – Simplex loose non-buffered fibre cable .
Figure A.2 – Simplex fibre cable .
Figure A.3 – Duplex loose non-buffered fibre cable .
Figure A.4 – Duplex fibre cable .
Figure A.5 – Duplex fibre zip cord .
Figure A.6 – Duplex flat cable .
Figure A.7 – Duplex round cable (breakout cable) .
Figure A.1 – Simplex non-buffered cable . 21
Figure A.2 – Simplex cable . 21
Figure A.3 – Duplex non-buffered cable . 21
Figure A.4 – Duplex cable . 22
Figure A.5 – Duplex zip cord cable . 22
Figure A.6 – Duplex flat cable . 23
Figure A.7 – Duplex round cable (breakout cable) . 23
Table 1 – Outer dimensions of buffered fibres . 9
Table 2 – Temperature cycling ranges according to the application environment.
Table 2 – Preferred low and high temperatures . 16
Table B.1 – Cable test method summary . 24
Table B.2 – Blank detail specification for cable testing agreement . 26
– 4 – IEC 60794-2-50:2023 RLV © IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRE CABLES –
Part 2-50: Indoor cables – Family specification for simplex
and duplex cables for use in terminated cable assemblies
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.
This redline version of the official IEC Standard allows the user to identify the changes
made to the previous edition IEC 60794-2-50:2020. A vertical bar appears in the margin
wherever a change has been made. Additions are in green text, deletions are in
strikethrough red text.
IEC 60794-2-50 has been prepared by subcommittee 86A: Fibres and cables, of IEC technical
committee 86: Fibre optics. It is an International Standard.
This third edition cancels and replaces the second edition published in 2020. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) added IEC 60793-1-46 and IEC 60794-1-211 to the normative references;
b) changed the load duration for the tensile test from 5 min to 10 min;
c) clarified the distance between the clamps for torsion test to 125 times cable diameter, but
not less than 0,3 m;
d) recommended the temperatures –10 °C and +60 °C for indoor simplex and duplex cables
HD HD
and included the low and high temperatures for category C, C , OP and OP according
to the operating service environments in IEC 61753-1 for temperature cycling and shrinkage
testing;
e) updated the shrinkage test standard to IEC 60794-1-211, F11A, and changed the
requirement to maximum 20 mm;
f) replaced the text for the fire performance with an improved description.
The text of this International Standard is based on the following documents:
Draft Report on voting
86A/2284/FDIS 86A/2316/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all the parts in the 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 document will remain unchanged until the
stability date indicated on the IEC website under 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 60794-2-50:2023 RLV © IEC 2023
INTRODUCTION
This document includes test methods according to IEC 60794-1-21, IEC 60794-1-22 and
IEC 60794-1-23 that will be split into single documents and individually renumbered in the
IEC 60794-1-1xx series, IEC 60794-1-2xx series and IEC 60794-1-3xx series. Full cross-
reference details are given in IEC 60794-1-2.
OPTICAL FIBRE CABLES –
Part 2-50: Indoor cables – Family specification for simplex
and duplex cables for use in terminated cable assemblies
1 Scope
This part of IEC 60794 is a family specification that specifies requirements for simplex and
duplex optical fibre cables for use in terminated cable assemblies or as used for termination
with optical fibre of passive components.
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 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 60793-1-32, Optical fibres – Part 1-32: Measurement methods and test procedures –
Coating strippability
IEC 60793-1-40, Optical fibres – Part 1-40: Attenuation measurement methods
IEC 60793-1-46, Optical fibres – Part 1-46: Measurement methods and test procedures –
Monitoring of changes in optical transmittance
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 – General guidance
IEC 60794-1-211, Optical fibre cables – Part 1-211: Generic specification – Basic optical cable
test procedures – Environmental test methods – Sheath shrinkage, method F11
IEC 60794-1-21, Optical fibre cables – Part 1-21: Generic specification – Basic optical cable
test procedures – Mechanical tests methods
IEC 60794-1-22, Optical fibre cables – Part 1-22: Generic specification – Basic optical cable
test procedures – Environmental tests methods
– 8 – IEC 60794-2-50:2023 RLV © IEC 2023
IEC 60794-1-23, Optical fibre cables – Part 1-23: Generic specification – Basic optical cable
test procedures – Cable element test methods
IEC 60794-2, Optical fibre cables – Part 2: Indoor cables – Sectional specification
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
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60794-1-1 and the
following 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
3.1
terminated cable assembly
short length of cable provisioned with a connector at both ends
cable terminated with connectors
Note 1 to entry: Examples from the ISO/IEC 11801 series are optical fibre optic cords used to establish connections
on patch panels, equipment and at work areas or to connect outlets to the terminal equipment.
Note 2 to entry: A so called patch cord or jumper is one type of a terminated cable assembly.
4 Construction
4.1 General
In addition to the constructional requirements in IEC 60794-2, the following considerations
apply to simplex and duplex indoor cables for use in terminated cable assemblies.
It is not the intention of this document to specify the finished terminated cable assembly
complete with terminations.
There shall be no fibre splice in a delivery length. It shall be possible to identify each individual
fibre throughout the length of the cable.
4.2 Optical fibres and primary coating
Multimode or single-mode optical fibres meeting the requirements of IEC 60793-2-10
sub-categories A1-OM1 and or A1-OM2 to A1-OM5 or IEC 60793-2-50 class B shall be used.
4.3 Buffer
If a tight or semi-tight (loosely applied) buffer is required, it shall consist of one or more layers
of inert material. Unless otherwise specified, the tight buffer shall be removable removed in one
operation together with fibre coating over the specified length. Semi-tight tubes may be filled.
For semi-tight and loose buffer, the buffer material is stripped off removed for a specified length
leaving the primary coating of the fibre intact.
Specified buffer strippability minimum lengths:
– tight: 15 mm;
– semi tight: 300 mm;
– loose: 1,0 m minimum.
Strip force shall comply to the values stated in the relevant specification and the evaluation
shall be carried out according to IEC 60793-1-32.
Buffer dimensions are shown in Table 1.
Table 1 – Outer dimensions of buffered fibres
Nominal outer diameter Tolerance
mm mm
0,3 to 0,9 ±0,05
Lower tolerance levels can be a requirement for buffered fibres having a low nominal diameter
within the specified range. In such cases, tolerance values shall be agreed between supplier
and customer.
4.4 Tube
One or two primary coated or buffered fibres are packaged (loosely or not) in a tube construction
which may be filled. A tube is a cable element that is not covered in 4.3 and typically has a
larger outer diameter than what is specified in 4.3. The tube may be reinforced with a composite
wall.
If required, the suitability of the tube shall be determined by an evaluation of its kink resistance
in accordance with IEC 60794-1-23, method G7.
4.5 Strength and anti-buckling members
The cable shall be designed with sufficient strength members to meet the requirements of this
document.
The strength and/or anti-buckling member 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.
4.6 Sheath
The cable shall have a uniform overall protective sheath. The cable diameter shall be specified
in the relevant detail specification (or product specification). Sheath removal is an important
feature of these cables. Sheath pull-off force shall be determined in accordance with
IEC 60794-1-21, method E21.
4.7 Sheath marking
If required, the cable shall be marked as agreed between the customer and supplier. The
marking shall be resistant to abrasion, which shall be verified in accordance with
IEC 60794-1-21, method E2B, method 2.
4.8 Examples of cable constructions
Examples of some main types of cable constructions are shown in Annex A.
– 10 – IEC 60794-2-50:2023 RLV © IEC 2023
Other configurations are not excluded if they meet the mechanical, environmental, transmission
and termination requirements given in this document.
5 Tests
5.1 General
Compliance with the specification requirements shall be verified by carrying out tests selected
from Clause 5. It is not intended that all tests be carried out in all cases, and Annex B provides
guidance on the selection of applicable tests. The tests to be applied and the frequency of
testing shall need to be agreed between the customer and supplier.
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 making it possible to detect permanent changes in
attenuation. As a general requirement for the tests specified in this document, the spirit goal is
to keep "no change in attenuation" criteria at the end of each evaluation, although the
parameters specified in this document may be affected by measurement uncertainty arising
either from measurement errors or calibration errors. The optical total uncertainty of
measurement for this document shall be ±0,05 dB for single-mode fibres and ±0,2 dB for
multimode fibres. Any measured value within this range shall be considered as "no change in
attenuation".
Cabled Single-mode fibres cables are measured at 1 550 nm or 1 625 nm and the measuring
wavelength shall be agreed between the customer and supplier. Cabled Multimode fibres cables
are measured at 850 nm or 1 300 nm and the measuring wavelength shall be agreed between
the customer and supplier. Measurements of attenuation shall be carried out according to
IEC 60793-1-40. Change in attenuation measurements shall be carried out according to
IEC 60793-1-46.
NOTE The optimized wavelength for multimode fibres A1-OM3 and A1-OM4 is 850 nm and for A1-OM5 fibre, the
targeted operational wavelength(s) range is between in the vicinity of 850 nm and to 950 nm.
If loops are used within a test to fix the ends of a cable, the loop diameter shall be equal or
greater than the specified minimum cable bend diameter to avoid cable damage and excessive
mode filtering in multimode fibre.
Unless otherwise specified, all tests shall be carried out at expanded test conditions as
specified in IEC 60794-1-2.
5.2 Dimensions
The fibre dimensions and tolerances shall be checked in accordance with test method
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 60811-202
and IEC 60811-203.
The nominal outer cable diameter is abbreviated as "d" in this document. "d" for the different
cable constructions is defined as follows:
– for simplex cable, "d" is the outer diameter;
– for zip cord cable, "d" is the outer diameter of the simplex cable which is used to be combined
with another simplex cable to form a zip cord;
– for duplex flat cable, "d" is the outer diameter of the inner cables which include the optical
fibre, the buffer, the strength members and the sheath;
– for duplex round cable, "d" is the outer diameter of the inner cables which include the optical
fibre, the buffer, the strength members and the sheath.
The cable diameter tolerance shall be ±0,2 mm.
The deviation of the average sheath thickness shall be within the tolerance of ±0,1 mm for
100 % of the cable length.
5.3 Mechanical requirements
5.3.1 Tensile performance
Method: IEC 60794-1-21, E1
Diameter of chuck drums and transfer devices: not less than the minimum loaded bending
diameter specified for the cable, at least 250 mm diameter.
Load for 5 10 min:
– simplex cables d < 1,2 mm at 50 N; simplex cables 1,2 mm ≤ d ≤ 2,0 mm at 70 N; simplex
cables d > 2,0 mm at 100 N;
– duplex round cables at 100 N;
– zipcord and duplex flat cables d ≤ 2,0 mm at 140 N; zipcord and duplex flat cables d
> 2,0 mm at 200 N.
Length of sample: sufficient to achieve the desired accuracy of measurement of attenuation
change shall be agreed between the customer and supplier.
Requirements:
– in all cases, fibre strain shall be less than 0,6 % not exceed 60 % of the proof strain (equals
to absolute 0,6 % strain for 1 % proof-tested fibres);
– the maximum allowable increase in attenuation during the test shall be specified in the
product relevant specification;
– there shall be no change in attenuation after the test.
– there shall be no damage to the cable elements.
5.3.2 Crush
Method: IEC 60794-1-21, E3A
Force short-term:
– 300 N for simplex/duplex cables with d ≤ 2,0 mm;
– 500 N for simplex/duplex cables with d > 2,0 mm.
Duration short-term: 1 min
Number of crushes short-term: 1
Force long-term:
– 100 N for simplex/duplex cables with d ≤ 2,0 mm;
– 200 N for simplex/duplex cables with d > 2,0 mm.
Duration long-term: 10 min
Number of crushes long-term: 1, separated at least 500 mm to any other loaded position.
Requirements:
– 12 – IEC 60794-2-50:2023 RLV © IEC 2023
– the maximum increase in attenuation during the test with a long-term force shall be specified
in the product relevant specification;
– there shall be no change in attenuation after the test with short-term and long-term force;
– there shall be no damage to the cable elements; any flattening of cable elements is not
considered as damage.
For cables having a non-circular cross section, the force shall be applied in the direction of the
minor axis (perpendicular to the major axis), as shown in Figure A.6 as an example.
5.3.3 Impact
Method: IEC 60794-1-21, E4
– impact energy: 0,5 J for simplex/duplex cables with d ≤ 2,0 mm; 1,0 J for simplex/duplex
cables with d > 2,0 mm;
– number of impacts: at least 3, each separated at least 500 mm.
Requirements:
– there shall be no change in attenuation after the test;
– there shall be no damage to the cable elements; any flattening of cable elements is not
considered as damage.
– any imprint of the striking surface on the cable sheath is not considered mechanical damage.
For cables having a non-circular cross section, the force shall be applied in the direction of the
minor axis (perpendicular to the major axis), as shown in Figure A.5 and Figure A.6.
5.3.4 Repeated bending
Method: IEC 60794-1-21, E6
Bending diameter:
– 60 mm for simplex and non-circular duplex cables (consider the cable diameter is the minor
dimension);
– 40 times cable diameter for circular round duplex cables but not less than 60 mm.
Number of cycles: 200
Mass of weights: sufficient to contour the apparatus, for example 1 kg to 2 kg.
Requirements:
– the maximum increase in attenuation during the test shall be specified in the product
relevant specification;
– there shall be no change in attenuation after the test;
– there shall be no damage to the cable elements; any flattening of cable elements is not
considered as damage.
NOTE For cables having a non-circular cross section, the bend requirements are determined using the minor axis
as the cable diameter with bending in the direction of the preferential bend, as shown in Figure A.5 and Figure A.6.
5.3.5 Bend
Method: IEC 60794-1-21, E11A
Bending diameter: 20 times cable diameter, but not less than 60 mm (for non-circular cables
see note below).
NOTE A cable with smaller bend diameter than specified above can be required for an application. Such a cable
can contain bending loss insensitive (enhanced macrobend loss) fibre(s). A smaller bending diameter can be agreed
between customer and supplier.
Number of turns per helix: 6
Number of cycles: 3
Length of sample: sufficient to carry out the test.
Prior to bending: at both ends of the sample, all the cable components shall be fixed together,
for example by loops clamps or glue.
Requirements:
– the maximum increase in attenuation during the test shall be specified in the product
relevant specification;
– there shall be no change in attenuation after the test;
– there shall be no damage to the cable elements; any flattening of cable elements is not
considered as damage.
NOTE For cables having a non-circular cross section, the bend requirements are determined using the minor axis
as the cable diameter with bending in the direction of the preferential bend, as shown in Figure A.5 and Figure A.6.
5.3.6 Torsion
Method: IEC 60794-1-21, E7
Number of cycles: 10
Distance between fixed and rotating clamps: greater than 0,3 m or 125 times cable diameter
(for non-circular cables, the cable diameter is the minor dimension) but not less than 0,3 m.
Length of sample: sufficient to carry out the test.
Unless otherwise specified in the detail relevant specification, specimen sample sag or bend
may be minimized by applying tension sufficient to keep the specimen sample straight.
Requirements:
– the maximum increase in attenuation during the test shall be specified in the product
relevant specification;
– there shall be no change in attenuation after the test;
– there shall be no damage to the cable elements.
5.3.7 Bend at low temperature
Method: IEC 60794-1-21, E11A
Bending diameter: 20 times cable diameter (for non-circular cables, the cable diameter is the
minor dimension) but not less than 60 mm.
NOTE A cable with smaller bend diameter than specified above can be required for an application. Such a cable
can contain bending loss insensitive (enhanced macrobend loss) fibre(s). A smaller bending diameter can be agreed
between customer and supplier.
Number of cycles: 2
Number of turns per helix: 4
– 14 – IEC 60794-2-50:2023 RLV © IEC 2023
HD
Test temperature: 0 °C for applications at category C and C environment;
The acronyms for the categories are specified in IEC 61753-1. A suitable category should be
selected according to the application. See Table 2.
Requirements:
– the maximum increase in attenuation during the test shall be specified in the product
relevant specification;
– there shall be no change in attenuation after the test;
– there shall be no damage to the cable elements; any flattening of cable elements is not
considered as damage.
5.3.8 Kink
Method: IEC 60794-1-21, E10
Inner loop diameter (for non-circular cables, the cable diameter is the minor dimension):
5 times cable diameter.
– for cables with outer diameter ≤ 3,0 mm, to be 15 mm;
– for cables with outer diameter > 3,0 mm, to be 5 times the cable outer diameter.
NOTE This is not an operational parameter; this is to address short-term installation/handling performance.
Requirement: no kink on cable shall occur when submitted to the specified loop diameter.
5.3.9 Sheath pull-off force
Method: IEC 60794-1-21, E21
Rate of separation: ≤ 200 mm/min
Strip length: 50 mm
Requirement: the force to strip the sheath shall not be greater than 15 N.
5.3.10 Abrasion resistance of cable marking
Method: IEC 60794-1-21, E2B, method 2
Number of cycles: 50
Requirement: the marking shall be legible on completion of the test, after the number of
specified cycles.
5.3.11 Buffered fibre movement under compression
Method: IEC 60794-1-21, E22
Compression distance: 1 mm
Number of movements: 5
Requirements:
– the maximum increase in attenuation during the test shall be specified in the product
relevant specification;
– the reaction force shall be less than 1 N at 0,4 mm.
5.4 Environmental requirements
5.4.1 Temperature cycling
Method: IEC 60794-1-22, Method F12
Period t and the number of cycles shall be according Table 2.
Length of sample: 10 m
At both ends of the sample, all components of the cable shall be fixed together, for example
with loops or glue.
The temperature cycling range used for the test shall be taken from the intended application
environment of the final assembly as described in Table 2.
Requirements:
– the maximum change in attenuation during the test shall be specified in the relevant product
specification;
– there shall be no change in attenuation after the test.
Table 2 – Temperature cycling ranges according to the application environment
a
Environment description Temperature Temperature Soak Number of
Category
extreme extreme time cycles
T T t
A B 1
°C °C h
C Indoor controlled −10 +60 1 5
HD
Indoor controlled with heat
C
−10 +70 1 5
dissipation
a
The acronyms for the categories are specified in IEC 61753-1. A suitable category should be selected
according the application.
Method: IEC 60794-1-22, method F12
Length of device under test (DUT): 10 m
NOTE The length of the DUT is the length between the fixing points of all components of the cable. The cable
sample length is longer to allow for connection to the optical measurement device outside the temperature chamber.
At both ends of the length of the DUT, all components of the cable shall be fixed together, for
example with clamps or glue.
For indoor simplex and duplex cables, –10 °C and +60 °C are the recommended low and high
temperatures. Specific operating temperatures can be agreed between customer and supplier.
Table 2 gives the preferred operating temperatures.
– 16 – IEC 60794-2-50:2023 RLV © IEC 2023
Table 2 – Preferred low and high temperatures
Low High Sources of temperatures (informative) Remark
temperature temperature
Performance categories Environmental
T T
of connectors, classification
A B
components and of customer
a
premises
protective housings
b
°C °C
cabling
–10 +60 C M I C E Recommended
x x 1 x
HD
–10 +70 -
C
–25 +70 OP M I C E
x x 2 x
HD
–25 +85 -
OP
A suitable operating service environment (performance category) or environmental classification should be
selected according to the application. A complete list of operating service environments can be found in
IEC 60794-1-1.
a
Included in IEC 61753-1. The abbreviations represent:
C: indoor controlled environment;
OP: outdoor protected environment;
HD
: indicates an extended upper temperature necessary due to additional dissipation by active electronics.
b
Included in ISO/IEC 11801-1. For an introduction to the MICE environmental classification system, use
ISO/IEC TR 29106. The abbreviation MICE represents: mechanical, ingress, climatic, electromagnetic.
Soak time t : 1 h
Number of cycles: 5
Requirements:
– the maximum change in attenuation during the test shall be specified in the relevant
specification;
– there shall be no change in attenuation after the test.
5.4.2 Sheath shrinkage (informative)
Information on cable shrinkage characterization of optical fibre cables, related test methods
and guidance for shrinkage grade classification are given in IEC TR 62959 . Following an
example for characterization.
Method: IEC 60794-1-22, F11
Exposure temperature: the highest operation temperature specified for the cable according to
the performance category in Table 2.
Exposure duration: according to the performance category in Table 2.
Number of cycles: according to the performance category in Table 2.
Nominal length of samples: 1 m.
___________
Under preparation. Stage at the time of publication: IEC/PCC 62959:2019.
On completion of the corresponding number of cycles, report the maximum shrinkage of the
cable samples. Requirements shall be specified in the product specification.
Method: IEC 60794-1-211, F11A
Low and high temperature: One pair should be selected in Table 2 according to the application.
Nominal length of samples: 1 m
: 1 h
Soak time t
Number of cycles: 5
Requirement: The maximum sheath shrinkage shall be equal or less than 20 mm.
NOTE IEC TR 62959 provides information on cable shrinkage characterisation of optical fibre cables that consist
of standard glass optical fibres for telecommunication applications. The characterisation is directed to the effects of
cable shrinkage or cable element shrinkage on the termination of cables.
6 Transmission requirements
The transmission requirements shall be verified in accordance with IEC 60793-1-40
IEC 60793-2-10 or IEC 60793-2-50 and shall be agreed between customer and supplier.
Maximum cable attenuation shall comply with IEC 60794-1-1.
7 Fire performance
All cables according to this document shall pass fire performance specifications. The
requirements may differ in different regions (e.g. North America, EU). But they also can differ
from country to country.
NOTE 1 IEC TR 62222 provides guidance and recommendations for the requirements and test methods for the fire
performance of communication cables when installed in buildings. The recommendations relate to typical applications
and installation practices, and an assessment of the fire hazards presented. Account is also taken of applicable
legislation and regulation.
IEC TR 62222 references several IEC fire performance test methods and also other test methods that may can be
required by local or national legislation and regulation. It is important that the tests to be applied fulfil the national
legislation and regulation and the specific requirements by its intended use.
Products placed on the EU or UK market should determine whether harmonised EN 50575 is
applicable after checking with local regulations.
– 18 – IEC 60794-2-50:2023 RLV © IEC 2023
Annex A
(informative)
Examples of types of cable constructions
Figure A.1 to Figure A.7 shows examples of types of cable constructions. The main dimensions
depend on agreement between customer and supplier.
Figure A.1 – Simplex loose non-buffered fibre cable
Figure A.2 – Simplex fibre cable
Figure A.3 – Duplex loose non-buffered fibre cable
Figure A.4 – Duplex fibre cable
Figure A.5 – Duplex fibre zip cord
– 20 – IEC 60794-2-50:2023 RLV © IEC 2023
Figure A.6 – Duplex flat cable
Figure A.7 – Duplex round cable (breakout cable)
Figure A.1 – Simplex non-buffered cable
Figure A.2 – Simplex cable
Figure A.3 – Duplex non-buffered cable
– 22 – IEC 60794-2-50:2023 RLV © IEC 2023
Figure A.4 – Duplex cable
Figure A.5 – Duplex zip cord cable
Figure A.6 – Duplex flat cable
Figure A.7 – Duplex round cable (breakout cable)
Connectors for indoor use are usually not terminated to a duplex flat cable shown in Figure A.6
and not to a duplex round cable (breakout cable) shown in Figure A.7 directly, but terminated
to each sub-unit that contains an optical fibre (simplex cable).
– 24 – IEC 60794-2-50:2023 RLV © IEC 2023
Annex B
(informative)
Guidance on the selection of tests applicable to
optical fibre cables for use in patchcords terminated cable assemblies
Annex B provides guidance on the selection of the tests to be applied according to the
description in Clause 5.
Table B.1 summarizes all cable test methods used for patchcords terminated cable assemblies
and provides information on the purpose of the various test methods.
Table B.1 – Cable test method summary
Clause/ Test method Purpose
Subclause
5.2 Dimensions
The check of fibre dimensions and tolerances ensures that the cable mates
with other patchcord components (e.g. connectors) to support processing and
installation.
5.3 Mechanical requirements
5.3.1 Tensile Determines the optical transmission and mechanical changes that typically
performance occur due to tensile loading, primarily as a result of installation or re-patching
related forces.
Cables used in patchcord applications are not likely to see high tensile forces
due to the relatively sho
...
IEC 60794-2-50 ®
Edition 3.0 2023-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibre cables –
Part 2-50: Indoor cables – Family specification for simplex and duplex cables for
use in terminated cable assemblies
Câbles à fibres optiques –
Partie 2-50: Câbles intérieurs – Spécification de famille pour les câbles simplex
et duplex utilisés dans les câbles assemblés équipés
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 l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.
IEC Secretariat Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
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 corrigendum or an amendment might have been published.
IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always have
committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 19 additional languages.
a month by email.
Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) 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 IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.
Recherche de publications IEC - Découvrez notre puissant moteur de recherche et consultez
webstore.iec.ch/advsearchform gratuitement tous les aperçus des publications. Avec un
La recherche avancée permet de trouver des publications IEC abonnement, vous aurez toujours accès à un contenu à jour
en utilisant différents critères (numéro de référence, texte, adapté à vos besoins.
comité d’études, …). Elle donne aussi des informations sur les
projets et les publications remplacées ou retirées. Electropedia - www.electropedia.org
Le premier dictionnaire d'électrotechnologie en ligne au monde,
IEC Just Published - webstore.iec.ch/justpublished
avec plus de 22 300 articles terminologiques en anglais et en
Restez informé sur les nouvelles publications IEC. Just
français, ainsi que les termes équivalents dans 19 langues
Published détaille les nouvelles publications parues.
additionnelles. Egalement appelé Vocabulaire
Disponible en ligne et une fois par mois par email.
Electrotechnique International (IEV) en ligne.
Service Clients - webstore.iec.ch/csc
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
IEC Products & Services Portal - products.iec.ch
IEC 60794-2-50 ®
Edition 3.0 2023-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibre cables –
Part 2-50: Indoor cables – Family specification for simplex and duplex cables for
use in terminated cable assemblies
Câbles à fibres optiques –
Partie 2-50: Câbles intérieurs – Spécification de famille pour les câbles simplex
et duplex utilisés dans les câbles assemblés équipés
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.10 ISBN 978-2-8322-6711-0
– 2 – IEC 60794-2-50:2023 © IEC 2023
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 Construction . 8
4.1 General . 8
4.2 Optical fibres and primary coating . 8
4.3 Buffer . 8
4.4 Tube . 9
4.5 Strength and anti-buckling members . 9
4.6 Sheath . 9
4.7 Sheath marking . 9
4.8 Examples of cable constructions . 9
5 Tests . 10
5.1 General . 10
5.2 Dimensions . 10
5.3 Mechanical requirements . 11
5.3.1 Tensile performance . 11
5.3.2 Crush . 11
5.3.3 Impact . 12
5.3.4 Repeated bending . 12
5.3.5 Bend . 12
5.3.6 Torsion . 13
5.3.7 Bend at low temperature . 13
5.3.8 Kink . 14
5.3.9 Sheath pull-off force . 14
5.3.10 Abrasion resistance of cable marking . 14
5.3.11 Buffered fibre movement under compression . 14
5.4 Environmental requirements . 15
5.4.1 Temperature cycling . 15
5.4.2 Sheath shrinkage . 15
6 Transmission requirements . 16
7 Fire performance . 16
Annex A (informative) Examples of cable constructions . 17
Annex B (informative) Guidance on the selection of tests applicable to optical fibre
cables for use in terminated cable assemblies . 20
Bibliography . 23
Figure A.1 – Simplex non-buffered cable . 17
Figure A.2 – Simplex cable . 17
Figure A.3 – Duplex non-buffered cable . 18
Figure A.4 – Duplex cable . 18
Figure A.5 – Duplex zip cord cable . 18
Figure A.6 – Duplex flat cable . 19
Figure A.7 – Duplex round cable (breakout cable) . 19
Table 1 – Outer dimensions of buffered fibres . 9
Table 2 – Preferred low and high temperatures . 15
Table B.1 – Cable test method summary . 20
Table B.2 – Blank detail specification for cable testing agreement . 22
– 4 – IEC 60794-2-50:2023 © IEC 2023
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRE CABLES –
Part 2-50: Indoor cables – Family specification for simplex
and duplex cables for use in terminated cable assemblies
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.
IEC 60794-2-50 has been prepared by subcommittee 86A: Fibres and cables, of IEC technical
committee 86: Fibre optics. It is an International Standard.
This third edition cancels and replaces the second edition published in 2020. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) added IEC 60793-1-46 and IEC 60794-1-211 to the normative references;
b) changed the load duration for the tensile test from 5 min to 10 min;
c) clarified the distance between the clamps for torsion test to 125 times cable diameter, but
not less than 0,3 m;
d) recommended the temperatures –10 °C and +60 °C for indoor simplex and duplex cables
HD HD
and included the low and high temperatures for category C, C , OP and OP according
to the operating service environments in IEC 61753-1 for temperature cycling and shrinkage
testing;
e) updated the shrinkage test standard to IEC 60794-1-211, F11A, and changed the
requirement to maximum 20 mm;
f) replaced the text for the fire performance with an improved description.
The text of this International Standard is based on the following documents:
Draft Report on voting
86A/2284/FDIS 86A/2316/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all the parts in the 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 document will remain unchanged until the
stability date indicated on the IEC website under 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 60794-2-50:2023 © IEC 2023
INTRODUCTION
This document includes test methods according to IEC 60794-1-21, IEC 60794-1-22 and
IEC 60794-1-23 that will be split into single documents and individually renumbered in the
IEC 60794-1-1xx series, IEC 60794-1-2xx series and IEC 60794-1-3xx series. Full cross-
reference details are given in IEC 60794-1-2.
OPTICAL FIBRE CABLES –
Part 2-50: Indoor cables – Family specification for simplex
and duplex cables for use in terminated cable assemblies
1 Scope
This part of IEC 60794 is a family specification that specifies requirements for simplex and
duplex optical fibre cables for use in terminated cable assemblies or as used for termination of
passive components.
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 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 60793-1-32, Optical fibres – Part 1-32: Measurement methods and test procedures –
Coating strippability
IEC 60793-1-40, Optical fibres – Part 1-40: Attenuation measurement methods
IEC 60793-1-46, Optical fibres – Part 1-46: Measurement methods and test procedures –
Monitoring of changes in optical transmittance
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 – General guidance
IEC 60794-1-211, Optical fibre cables – Part 1-211: Generic specification – Basic optical cable
test procedures – Environmental test methods – Sheath shrinkage, method F11
IEC 60794-1-21, Optical fibre cables – Part 1-21: Generic specification – Basic optical cable
test procedures – Mechanical tests methods
IEC 60794-1-22, Optical fibre cables – Part 1-22: Generic specification – Basic optical cable
test procedures – Environmental tests methods
– 8 – IEC 60794-2-50:2023 © IEC 2023
IEC 60794-1-23, Optical fibre cables – Part 1-23: Generic specification – Basic optical cable
test procedures – Cable element test methods
IEC 60794-2, Optical fibre cables – Part 2: Indoor cables – Sectional specification
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
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60794-1-1 and the
following 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
3.1
terminated cable assembly
cable terminated with connectors
Note 1 to entry: Examples from the ISO/IEC 11801 series are optical fibre cords used to establish connections on
patch panels, equipment and at work areas or to connect outlets to the terminal equipment.
Note 2 to entry: A so called patch cord or jumper is one type of a terminated cable assembly.
4 Construction
4.1 General
In addition to the constructional requirements in IEC 60794-2, the following considerations
apply to simplex and duplex indoor cables for use in terminated cable assemblies.
It is not the intention of this document to specify the finished terminated cable assembly
complete with terminations.
There shall be no fibre splice in a delivery length. It shall be possible to identify each individual
fibre throughout the length of the cable.
4.2 Optical fibres and primary coating
Multimode or single-mode optical fibres meeting the requirements of IEC 60793-2-10
sub-categories A1-OM1 or A1-OM2 to A1-OM5 or IEC 60793-2-50 class B shall be used.
4.3 Buffer
If a tight or semi-tight (loosely applied) buffer is required, it shall consist of one or more layers
of inert material. Unless otherwise specified, the tight buffer shall be removed in one operation
together with fibre coating over the specified length. Semi-tight tubes may be filled. For
semi-tight and loose buffer, the buffer material is removed for a specified length leaving the
primary coating of the fibre intact.
Specified buffer strippability minimum lengths:
– tight: 15 mm;
– semi tight: 300 mm;
– loose: 1,0 m.
Strip force shall comply to the values stated in the relevant specification and the evaluation
shall be carried out according to IEC 60793-1-32.
Buffer dimensions are shown in Table 1.
Table 1 – Outer dimensions of buffered fibres
Nominal outer diameter Tolerance
mm mm
0,3 to 0,9 ±0,05
Lower tolerance levels can be a requirement for buffered fibres having a low nominal diameter
within the specified range. In such cases, tolerance values shall be agreed between supplier
and customer.
4.4 Tube
One or two primary coated or buffered fibres are packaged in a tube construction which may be
filled. A tube is a cable element that is not covered in 4.3 and typically has a larger outer
diameter than what is specified in 4.3. The tube may be reinforced with a composite wall.
If required, the suitability of the tube shall be determined by an evaluation of its kink resistance
in accordance with IEC 60794-1-23, method G7.
4.5 Strength and anti-buckling members
The cable shall be designed with sufficient strength members to meet the requirements of this
document.
The strength and/or anti-buckling member 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.
4.6 Sheath
The cable shall have a uniform overall protective sheath. The cable diameter shall be specified
in the relevant specification. Sheath removal is an important feature of these cables. Sheath
pull-off force shall be determined in accordance with IEC 60794-1-21, method E21.
4.7 Sheath marking
If required, the cable shall be marked as agreed between the customer and supplier.
4.8 Examples of cable constructions
Examples of cable constructions are shown in Annex A.
Other configurations are not excluded if they meet the mechanical, environmental, transmission
and termination requirements given in this document.
– 10 – IEC 60794-2-50:2023 © IEC 2023
5 Tests
5.1 General
Compliance with the specification requirements shall be verified by carrying out tests selected
from Clause 5. It is not intended that all tests be carried out in all cases, and Annex B provides
guidance on the selection of applicable tests. The tests to be applied and the frequency of
testing need to be agreed between the customer and supplier.
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 making it possible to detect permanent changes in
attenuation. As a general requirement for the tests specified in this document, the goal is to
keep "no change in attenuation" criteria at the end of each evaluation, although the parameters
specified in this document may be affected by measurement uncertainty arising either from
measurement errors or calibration errors. The optical total uncertainty of measurement for this
document shall be ±0,05 dB for single-mode fibres and ±0,2 dB for multimode fibres. Any
measured value within this range shall be considered as "no change in attenuation".
Single-mode fibre cables are measured at 1 550 nm or 1 625 nm and the measuring wavelength
shall be agreed between the customer and supplier. Multimode fibre cables are measured at
850 nm or 1 300 nm and the measuring wavelength shall be agreed between the customer and
supplier. Measurements of attenuation shall be carried out according to IEC 60793-1-40.
Change in attenuation measurements shall be carried out according to IEC 60793-1-46.
NOTE The optimized wavelength for multimode fibres A1-OM3 and A1-OM4 is 850 nm and for A1-OM5 fibre, the
targeted operational wavelength range is in the vicinity of 850 nm to 950 nm.
If loops are used within a test to fix the ends of a cable, the loop diameter shall be equal or
greater than the specified minimum cable bend diameter to avoid cable damage and excessive
mode filtering in multimode fibre.
Unless otherwise specified, all tests shall be carried out at expanded test conditions as
specified in IEC 60794-1-2.
5.2 Dimensions
The fibre dimensions and tolerances shall be checked in accordance with test method
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 60811-202
and IEC 60811-203.
The nominal outer cable diameter is abbreviated as "d" in this document. "d" for the different
cable constructions is defined as follows:
– for simplex cable, "d" is the outer diameter;
– for zip cord cable, "d" is the outer diameter of the simplex cable which is used to be combined
with another simplex cable to form a zip cord;
– for duplex flat cable, "d" is the outer diameter of the inner cables which include the optical
fibre, the buffer, the strength members and the sheath;
– for duplex round cable, "d" is the outer diameter of the inner cables which include the optical
fibre, the buffer, the strength members and the sheath.
The cable diameter tolerance shall be ±0,2 mm.
The deviation of the average sheath thickness shall be within the tolerance of ±0,1 mm for
100 % of the cable length.
5.3 Mechanical requirements
5.3.1 Tensile performance
Method: IEC 60794-1-21, E1
Diameter of chuck drums and transfer devices: not less than the minimum loaded bending
diameter specified for the cable, at least 250 mm diameter.
Load for 10 min:
– simplex cables d < 1,2 mm at 50 N; simplex cables 1,2 mm ≤ d ≤ 2,0 mm at 70 N; simplex
cables d > 2,0 mm at 100 N;
– duplex round cables at 100 N;
– zipcord and duplex flat cables d ≤ 2,0 mm at 140 N; zipcord and duplex flat cables d
> 2,0 mm at 200 N.
Length of sample: sufficient to achieve the desired accuracy of measurement of attenuation
change shall be agreed between the customer and supplier.
Requirements:
– in all cases, fibre strain shall not exceed 60 % of the proof strain (equals to absolute 0,6 %
strain for 1 % proof-tested fibres);
– the maximum allowable increase in attenuation during the test shall be specified in the
relevant specification;
– there shall be no change in attenuation after the test.
5.3.2 Crush
Method: IEC 60794-1-21, E3A
Force short-term:
– 300 N for simplex/duplex cables with d ≤ 2,0 mm;
– 500 N for simplex/duplex cables with d > 2,0 mm.
Duration short-term: 1 min
Number of crushes short-term: 1
Force long-term:
– 100 N for simplex/duplex cables with d ≤ 2,0 mm;
– 200 N for simplex/duplex cables with d > 2,0 mm.
Duration long-term: 10 min
Number of crushes long-term: 1, separated at least 500 mm to any other loaded position.
Requirements:
– the maximum increase in attenuation during the test with a long-term force shall be specified
in the relevant specification;
– there shall be no change in attenuation after the test with short-term and long-term force;
– there shall be no damage to the cable elements; any flattening of cable elements is not
considered as damage.
– 12 – IEC 60794-2-50:2023 © IEC 2023
For cables having a non-circular cross section, the force shall be applied in the direction of the
minor axis (perpendicular to the major axis), as shown in Figure A.6 as an example.
5.3.3 Impact
Method: IEC 60794-1-21, E4
– impact energy: 0,5 J for simplex/duplex cables with d ≤ 2,0 mm; 1,0 J for simplex/duplex
cables with d > 2,0 mm;
– number of impacts: 3, each separated at least 500 mm.
Requirements:
– there shall be no change in attenuation after the test;
– there shall be no damage to the cable elements; any flattening of cable elements is not
considered as damage.
For cables having a non-circular cross section, the force shall be applied in the direction of the
minor axis (perpendicular to the major axis), as shown in Figure A.5 and Figure A.6.
5.3.4 Repeated bending
Method: IEC 60794-1-21, E6
Bending diameter:
– 60 mm for simplex and non-circular duplex cables (consider the cable diameter is the minor
dimension);
– 40 times cable diameter for round duplex cables but not less than 60 mm.
Number of cycles: 200
Mass of weights: sufficient to contour the apparatus, for example 1 kg to 2 kg.
Requirements:
– the maximum increase in attenuation during the test shall be specified in the relevant
specification;
– there shall be no change in attenuation after the test;
– there shall be no damage to the cable elements; any flattening of cable elements is not
considered as damage.
NOTE For cables having a non-circular cross section, the bend requirements are determined using the minor axis
as the cable diameter with bending in the direction of the preferential bend, as shown in Figure A.5 and Figure A.6.
5.3.5 Bend
Method: IEC 60794-1-21, E11A
Bending diameter: 20 times cable diameter, but not less than 60 mm (for non-circular cables
see note below).
NOTE A cable with smaller bend diameter than specified above can be required for an application. Such a cable
can contain bending loss insensitive (enhanced macrobend loss) fibre(s). A smaller bending diameter can be agreed
between customer and supplier.
Number of turns: 6
Number of cycles: 3
Length of sample: sufficient to carry out the test.
Prior to bending: at both ends of the sample, all the cable components shall be fixed together,
for example by clamps or glue.
Requirements:
– the maximum increase in attenuation during the test shall be specified in the relevant
specification;
– there shall be no change in attenuation after the test;
– there shall be no damage to the cable elements; any flattening of cable elements is not
considered as damage.
NOTE For cables having a non-circular cross section, the bend requirements are determined using the minor axis
as the cable diameter with bending in the direction of the preferential bend, as shown in Figure A.5 and Figure A.6.
5.3.6 Torsion
Method: IEC 60794-1-21, E7
Number of cycles: 10
Distance between fixed and rotating clamps: 125 times cable diameter (for non-circular cables,
the cable diameter is the minor dimension) but not less than 0,3 m.
Length of sample: sufficient to carry out the test.
Unless otherwise specified in the relevant specification, sample sag or bend may be minimized
by applying tension sufficient to keep the sample straight.
Requirements:
– the maximum increase in attenuation during the test shall be specified in the relevant
specification;
– there shall be no change in attenuation after the test;
– there shall be no damage to the cable elements.
5.3.7 Bend at low temperature
Method: IEC 60794-1-21, E11A
Bending diameter: 20 times cable diameter (for non-circular cables, the cable diameter is the
minor dimension) but not less than 60 mm.
NOTE A cable with smaller bend diameter than specified above can be required for an application. Such a cable
can contain bending loss insensitive (enhanced macrobend loss) fibre(s). A smaller bending diameter can be agreed
between customer and supplier.
Number of cycles: 2
Number of turns: 4
Test temperature: 0 °C
– 14 – IEC 60794-2-50:2023 © IEC 2023
Requirements:
– the maximum increase in attenuation during the test shall be specified in the relevant
specification;
– there shall be no change in attenuation after the test;
– there shall be no damage to the cable elements; any flattening of cable elements is not
considered as damage.
5.3.8 Kink
Method: IEC 60794-1-21, E10
Inner loop diameter (for non-circular cables, the cable diameter is the minor dimension):
– for cables with outer diameter ≤ 3,0 mm, to be 15 mm;
– for cables with outer diameter > 3,0 mm, to be 5 times the cable outer diameter.
NOTE This is not an operational parameter; this is to address short-term installation/handling performance.
Requirement: no kink on cable shall occur when submitted to the specified loop diameter.
5.3.9 Sheath pull-off force
Method: IEC 60794-1-21, E21
Rate of separation: ≤ 200 mm/min
Strip length: 50 mm
Requirement: the force to strip the sheath shall not be greater than 15 N.
5.3.10 Abrasion resistance of cable marking
Method: IEC 60794-1-21, E2B, method 2
Number of cycles: 50
Requirement: the marking shall be legible on completion of the test, after the number of
specified cycles.
5.3.11 Buffered fibre movement under compression
Method: IEC 60794-1-21, E22
Compression distance: 1 mm
Number of movements: 5
Requirements:
– the maximum increase in attenuation during the test shall be specified in the relevant
specification;
– the reaction force shall be less than 1 N at 0,4 mm.
5.4 Environmental requirements
5.4.1 Temperature cycling
Method: IEC 60794-1-22, method F12
Length of device under test (DUT): 10 m
NOTE The length of the DUT is the length between the fixing points of all components of the cable. The cable
sample length is longer to allow for connection to the optical measurement device outside the temperature chamber.
At both ends of the length of the DUT, all components of the cable shall be fixed together, for
example with clamps or glue.
For indoor simplex and duplex cables, –10 °C and +60 °C are the recommended low and high
temperatures. Specific operating temperatures can be agreed between customer and supplier.
Table 2 gives the preferred operating temperatures.
Table 2 – Preferred low and high temperatures
Low High Sources of temperatures (informative) Remark
temperature temperature
Performance categories Environmental
T T
of connectors, classification
A B
components and of customer
a
premises
protective housings
°C °C b
cabling
–10 +60 C M I C E Recommended
x x 1 x
HD
–10 +70 -
C
–25 +70 OP M I C E
x x 2 x
HD
–25 +85 -
OP
A suitable operating service environment (performance category) or environmental classification should be
selected according to the application. A complete list of operating service environments can be found in
IEC 60794-1-1.
a
Included in IEC 61753-1. The abbreviations represent:
C: indoor controlled environment;
OP: outdoor protected environment;
HD
: indicates an extended upper temperature necessary due to additional dissipation by active electronics.
b
Included in ISO/IEC 11801-1. For an introduction to the MICE environmental classification system, use
ISO/IEC TR 29106. The abbreviation MICE represents: mechanical, ingress, climatic, electromagnetic.
Soak time t : 1 h
Number of cycles: 5
Requirements:
– the maximum change in attenuation during the test shall be specified in the relevant
specification;
– there shall be no change in attenuation after the test.
5.4.2 Sheath shrinkage
Method: IEC 60794-1-211, F11A
Low and high temperature: One pair should be selected in Table 2 according to the application.
– 16 – IEC 60794-2-50:2023 © IEC 2023
Nominal length of samples: 1 m
Soak time t : 1 h
Number of cycles: 5
Requirement: The maximum sheath shrinkage shall be equal or less than 20 mm.
NOTE IEC TR 62959 provides information on cable shrinkage characterisation of optical fibre cables that consist
of standard glass optical fibres for telecommunication applications. The characterisation is directed to the effects of
cable shrinkage or cable element shrinkage on the termination of cables.
6 Transmission requirements
The transmission requirements shall be 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 IEC 60794-1-1.
7 Fire performance
All cables according to this document shall pass fire performance specifications. The
requirements may differ in different regions (e.g. North America, EU). But they also can differ
from country to country.
NOTE 1 IEC TR 62222 provides guidance and recommendations for the requirements and test methods for the fire
performance of communication cables when installed in buildings. The recommendations relate to typical applications
and installation practices, and an assessment of the fire hazards presented. Account is also taken of applicable
legislation and regulation.
IEC TR 62222 references several IEC fire performance test methods and also other test methods that can be required
by local or national legislation and regulation. It is important that the tests to be applied fulfil the national legislation
and regulation and the specific requirements by its intended use.
Products placed on the EU or UK market should determine whether harmonised EN 50575 is
applicable after checking with local regulations.
Annex A
(informative)
Examples of cable constructions
Figure A.1 to Figure A.7 shows examples of cable constructions. The main dimensions depend
on agreement between customer and supplier.
Figure A.1 – Simplex non-buffered cable
Figure A.2 – Simplex cable
– 18 – IEC 60794-2-50:2023 © IEC 2023
Figure A.3 – Duplex non-buffered cable
Figure A.4 – Duplex cable
Figure A.5 – Duplex zip cord cable
Figure A.6 – Duplex flat cable
Figure A.7 – Duplex round cable (breakout cable)
Connectors for indoor use are usually not terminated to a duplex flat cable shown in Figure A.6
and not to a duplex round cable (breakout cable) shown in Figure A.7 directly, but terminated
to each sub-unit that contains an optical fibre (simplex cable).
– 20 – IEC 60794-2-50:2023 © IEC 2023
Annex B
(informative)
Guidance on the selection of tests applicable to
optical fibre cables for use in terminated cable assemblies
Annex B provides guidance on the selection of the tests to be applied according to the
description in Clause 5.
Table B.1 summarizes all cable test methods used for terminated cable assemblies and
provides information on the purpose of the various test methods.
Table B.1 – Cable test method summary
Clause/ Test method Purpose
Subclause
5.2 Dimensions
The check of fibre dimensions and tolerances ensures that the cable mates
with other patchcord components (e.g. connectors) to support processing and
installation.
5.3 Mechanical requirements
5.3.1 Tensile Determines the optical transmission and mechanical changes that typically
performance occur due to tensile loading, primarily as a result of installation or re-patching
related forces.
Cables used in patchcord applications are not likely to see high tensile forces
due to the relatively short lengths employed. The tensile capability of
connectorized cable is addressed in the performance specifications for finished
cable assemblies.
5.3.2 Crush Determines the optical transmission and mechanical changes that may occur
in cable subjected to compressive loading perpendicular to the axis of the
cable. This test evaluates the ability of the cable construction to isolate the
optical fibres from external compressive forces (e.g. induced by a person
standing on the cable).
5.3.3 Impact Determines the optical transmission and mechanical changes that may occur
when the cable is subjected to an impact perpendicular to its jacket surface. It
is used to evaluate the ability of the cable to survive impact forces as may be
encountered during installation efforts, during shipping or handling, or post
installation.
5.3.4 Repeated Determines the ability of a cable to withstand flexure through a 180° arc for a
bending prescribed number of cycles. It is used to evaluate the ability of the cable to
survive repeated bending as may be encountered during installation or
repositioning of the installed patchcord.
5.3.5 Bend The bend test determines the ability of an optical fibre cable to withstand
repeated wrapping around a mandrel to replicate forces that might be
encountered during installation or repositioning of installed patchcords.
5.3.6 Torsion Determines the optical transmission and mechanical changes that may occur
in a cable due to twisting along the longitudinal axis. Cables used in patchcord
applications are not likely to see excessive twisting due to the relatively short
lengths employed.
5.3.7 Bend at low Determines the ability of a cable to withstand bending at low temperatures as
temperature might be encountered during initial installation in a specific environment.
Cables used in indoor patchcord applications are not likely to see installation
at low temperatures due to the environment in which they are employed.
5.3.8 Kink Determines the minimum
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.
Loading comments...