IEC 60794-4-20:2018
(Main)Optical fibre cables - Part 4-20: Sectional specification - Aerial optical cables along electrical power lines - Family specification for ADSS (all dielectric self-supported) optical cables
Optical fibre cables - Part 4-20: Sectional specification - Aerial optical cables along electrical power lines - Family specification for ADSS (all dielectric self-supported) optical cables
IEC 60794-4-20:2018 covers optical telecommunication cables, commonly with single-mode fibres used primarily in overhead power lines applications. The cables can also be used in other overhead utility networks, such as for telephony or TV services. Requirements of the sectional specification IEC 60794-4 for aerial optical cables along electrical power lines are applicable to cables covered by this document. This document covers the construction, mechanical, electrical, and optical performance, installation guidelines, acceptance criteria, test requirements, environmental considerations, and accessories compatibility for an all dielectric, self-supporting fibre optic (ADSS) cable. This document provides construction and performance requirements that ensure, within the guidelines of this document, that the required mechanical integrity of the cable components as well as optical fibre mechanical reliability and transmission parameters are maintained. The ADSS cable consists of single mode optical fibres contained in one or more protective dielectric fibre optic units surrounded by or attached to suitable dielectric strength members and sheaths. The cable does not contain metallic components. An ADSS cable is designed to meet the optical and mechanical requirements under different installation, operating and environmental conditions and loadings, as described in Annex B. This document excludes any "lashed" or "wrapped" OPAC cables included in IEC 60794-4. Figure 8 aerial cables are also excluded; they are specified in IEC 60794-3-20. This second edition cancels and replaces the first edition published in 2012 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
- this document has been streamlined by cross-referencing IEC 60794-1-1,
- IEC 60794-4 (all parts) and IEC 60794-1-2;
- reference to the MICE table has been deleted;
- the example of test method for particular environment in Annex C has been deleted;
- creep test method has been updated in Annex E.
Keywords: optical telecommunication cables, single-mode fibres used primarily in overhead power lines
Câbles à fibres optiques - Partie 4-20: Spécification intermédiaire - Câbles optiques aériens le long des lignes électriques de puissance - Spécification de famille pour les câbles optiques autoporteurs entièrement diélectriques (ADSS)
.L'IEC 60794-4-20:2018 couvre les câbles optiques de télécommunication généralement équipés de fibres unimodales, utilisés principalement dans des applications le long des lignes aériennes à haute tension. Les câbles peuvent également être utilisés dans d'autres réseaux de services aériens, tels que des services de téléphonie ou de télévision. Les exigences de la spécification intermédiaire IEC 60794-4 pour des câbles optiques aériens le long de lignes électriques de puissance sont applicables aux câbles couverts par le présent document. Le présent document couvre la construction, les performances mécaniques, électriques et optiques, les lignes directrices relatives à l'installation, les critères d'acceptation, les exigences relatives aux essais, les considérations sur l'environnement et la compatibilité des accessoires pour câble fibronique autoporteur entièrement diélectrique (ADSS: all dielectric self-supporting). Le présent document fournit des exigences de performances et de construction qui garantissent, par les lignes directrices du présent document, que sont maintenus l'intégrité mécanique exigée des composants du câble ainsi que les paramètres de transmission et la fiabilité mécanique des fibres optiques. Le câble ADSS est constitué de fibres optiques unimodales contenues dans une ou plusieurs unités fibroniques diélectriques de protection entourées de, ou fixées à des gaines et des éléments de rigidité diélectrique appropriée. Le câble ne contient pas de composants métalliques. Un câble ADSS est conçu pour satisfaire aux exigences mécaniques et optiques dans différentes conditions d’installations, de fonctionnement et d'environnement et pour différentes charges, comme cela est décrit à l'Annexe B.AnchorAnchorAnchorAnchor Le présent document exclut les câbles OPAC "lacés" ou "enroulés" inclus dans l'IEC 60794-4. Les câbles aériens figure-8 sont également exclus; ils sont spécifiés dans l'IEC 60794‑3-20. Cette deuxième édition annule et remplace la première édition parue en 2012 dont elle constitue une révision technique. La présente édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
- le présent document a été simplifié par établissement de correspondances avec les normes IEC 60794-1-1, IEC 60794-4 (toutes les parties) et IEC 60794-1-2;
- la référence au tableau MICE a été supprimée;
- l'exemple de méthode d'essai pour un environnement particulier à l'Annexe C a été supprimé;
- la méthode d'essai de fluage a été mise à jour à l'Annexe E.
Mots-clés: câbles optiques de télécommunication, lignes aériennes à haute tension
General Information
- Status
- Published
- Publication Date
- 27-Aug-2018
- Technical Committee
- SC 86A - Fibres and cables
- Current Stage
- PPUB - Publication issued
- Start Date
- 28-Aug-2018
- Completion Date
- 03-Aug-2018
Relations
- Effective Date
- 05-Sep-2023
Overview
IEC 60794-4-20:2018 is the IEC sectional specification for ADSS (all dielectric self-supported) optical telecommunication cables intended primarily for installation on overhead power lines. It defines construction and performance requirements for cables containing single-mode fibres without metallic components. The standard covers mechanical, electrical and optical characteristics, installation guidance, acceptance criteria, test methods and environmental considerations to ensure long-term mechanical integrity and optical transmission reliability in overhead utility networks.
Key topics and technical requirements
- Scope and exclusions: Applies to ADSS cables (dielectric strength members and sheaths) used on power lines and other overhead utilities; excludes lashed/wrapped OPAC and Figure‑8 aerial cables (see IEC 60794-3-20).
- Cable construction: Requirements for optical units, dielectric strength members, sheaths and accessory compatibility to maintain fibre mechanical reliability and transmission parameters.
- Optical fibre parameters: Specifications for single-mode fibre attenuation, cut-off wavelength, PMD and other optical characteristics.
- Mechanical and electrical performance: Family and type test categories including tensile performance, sheave tests, repeated bending, impact, crush, torsion and kink resistance.
- Vibration and environmental testing: Aeolian vibration, low-frequency (galloping) tests, temperature cycling, water penetration, UV/weathering, tracking and erosion resistance.
- Creep and long-term behaviour: Updated creep test method (Annex E) to evaluate long-term mechanical performance under sustained loading.
- Testing and acceptance: Type, factory acceptance and routine tests, plus reporting of parameters and installation capability.
- Installation guidance and Annexes: Informative Annex B (installation considerations), Annex A (packaging/marking), Annex D (blank detail specification) and test-related annexes (C and E).
- 2018 revision highlights: Edition 2.0 streamlines cross-references to IEC 60794-1-1, IEC 60794-4 and IEC 60794-1-2, removes the MICE table and an example test in Annex C, and updates the creep test method.
Practical applications and users
Who uses IEC 60794-4-20:2018:
- Cable manufacturers developing ADSS products for power utilities
- Power companies and utility planners specifying fibre on transmission and distribution lines
- Telecom operators and system integrators deploying broadband, telephony or TV over power corridors
- Test laboratories and QC teams performing type and acceptance testing
- Procurement specialists and consultants writing technical specifications and tenders Practical value: ensures ADSS cables meet defined mechanical, optical and environmental benchmarks for safe, durable overhead installations, reducing risk of outages and ensuring regulatory and contractual compliance.
Related standards
- IEC 60794-4 (sectional specifications for aerial optical cables)
- IEC 60794-1-1 and IEC 60794-1-2 (general and testing cross-references)
- IEC 60794-3-20 (Figure‑8 aerial cables)
- Other IEC 60794 series documents governing optical telecommunication cables and test methods
Keywords: optical telecommunication cables, ADSS, all dielectric self-supported, single-mode fibres, overhead power lines, aerial optical cables, IEC 60794-4-20.
IEC 60794-4-20:2018 RLV - Optical fibre cables - Part 4-20: Sectional specification - Aerial optical cables along electrical power lines - Family specification for ADSS (all dielectric self-supported) optical cables Released:8/28/2018 Isbn:9782832260098
IEC 60794-4-20:2018 - Optical fibre cables - Part 4-20: Sectional specification - Aerial optical cables along electrical power lines - Family specification for ADSS (all dielectric self-supported) optical cables
Frequently Asked Questions
IEC 60794-4-20:2018 is a standard published by the International Electrotechnical Commission (IEC). Its full title is "Optical fibre cables - Part 4-20: Sectional specification - Aerial optical cables along electrical power lines - Family specification for ADSS (all dielectric self-supported) optical cables". This standard covers: IEC 60794-4-20:2018 covers optical telecommunication cables, commonly with single-mode fibres used primarily in overhead power lines applications. The cables can also be used in other overhead utility networks, such as for telephony or TV services. Requirements of the sectional specification IEC 60794-4 for aerial optical cables along electrical power lines are applicable to cables covered by this document. This document covers the construction, mechanical, electrical, and optical performance, installation guidelines, acceptance criteria, test requirements, environmental considerations, and accessories compatibility for an all dielectric, self-supporting fibre optic (ADSS) cable. This document provides construction and performance requirements that ensure, within the guidelines of this document, that the required mechanical integrity of the cable components as well as optical fibre mechanical reliability and transmission parameters are maintained. The ADSS cable consists of single mode optical fibres contained in one or more protective dielectric fibre optic units surrounded by or attached to suitable dielectric strength members and sheaths. The cable does not contain metallic components. An ADSS cable is designed to meet the optical and mechanical requirements under different installation, operating and environmental conditions and loadings, as described in Annex B. This document excludes any "lashed" or "wrapped" OPAC cables included in IEC 60794-4. Figure 8 aerial cables are also excluded; they are specified in IEC 60794-3-20. This second edition cancels and replaces the first edition published in 2012 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - this document has been streamlined by cross-referencing IEC 60794-1-1, - IEC 60794-4 (all parts) and IEC 60794-1-2; - reference to the MICE table has been deleted; - the example of test method for particular environment in Annex C has been deleted; - creep test method has been updated in Annex E. Keywords: optical telecommunication cables, single-mode fibres used primarily in overhead power lines
IEC 60794-4-20:2018 covers optical telecommunication cables, commonly with single-mode fibres used primarily in overhead power lines applications. The cables can also be used in other overhead utility networks, such as for telephony or TV services. Requirements of the sectional specification IEC 60794-4 for aerial optical cables along electrical power lines are applicable to cables covered by this document. This document covers the construction, mechanical, electrical, and optical performance, installation guidelines, acceptance criteria, test requirements, environmental considerations, and accessories compatibility for an all dielectric, self-supporting fibre optic (ADSS) cable. This document provides construction and performance requirements that ensure, within the guidelines of this document, that the required mechanical integrity of the cable components as well as optical fibre mechanical reliability and transmission parameters are maintained. The ADSS cable consists of single mode optical fibres contained in one or more protective dielectric fibre optic units surrounded by or attached to suitable dielectric strength members and sheaths. The cable does not contain metallic components. An ADSS cable is designed to meet the optical and mechanical requirements under different installation, operating and environmental conditions and loadings, as described in Annex B. This document excludes any "lashed" or "wrapped" OPAC cables included in IEC 60794-4. Figure 8 aerial cables are also excluded; they are specified in IEC 60794-3-20. This second edition cancels and replaces the first edition published in 2012 and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - this document has been streamlined by cross-referencing IEC 60794-1-1, - IEC 60794-4 (all parts) and IEC 60794-1-2; - reference to the MICE table has been deleted; - the example of test method for particular environment in Annex C has been deleted; - creep test method has been updated in Annex E. Keywords: optical telecommunication cables, single-mode fibres used primarily in overhead power lines
IEC 60794-4-20:2018 is classified under the following ICS (International Classification for Standards) categories: 33.180.10 - Fibres and cables. The ICS classification helps identify the subject area and facilitates finding related standards.
IEC 60794-4-20:2018 has the following relationships with other standards: It is inter standard links to IEC 60794-4-20:2012. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
IEC 60794-4-20:2018 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
IEC 60794-4-20 ®
Edition 2.0 2018-08
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Optical fibre cables –
Part 4-20: Sectional specification – Aerial optical cables along electrical power
lines – Family specification for ADSS (all dielectric self-supported) optical cables
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IEC 60794-4-20 ®
Edition 2.0 2018-08
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Optical fibre cables –
Part 4-20: Sectional specification – Aerial optical cables along electrical power
lines – Family specification for ADSS (all dielectric self-supported) optical cables
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.180.10 ISBN 978-2-8322-6009-8
– 2 – IEC 60794-4-20:2018 RLV © IEC 2018
CONTENTS
FOREWORD. 5
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 8
4 Optical fibres . 10
General .
Attenuation .
Attenuation coefficient .
Attenuation discontinuities .
Cut-off wavelength of cabled fibre .
Fibre colouring .
Polarisation mode dispersion (PMD) .
5 Cable elements . 11
6 Optical fibre cable constructions . 11
6.1 General . 11
Optical unit .
6.2 Cable protection elements . 11
7 Main requirements for installation and operating conditions . 12
8 Cable design considerations . 12
9 Cable tests . 13
9.1 General . 13
Classification of tests .
Type tests .
Factory acceptance tests .
Routine tests .
9.2 Tensile performance . 14
9.2.1 General . 14
9.2.2 Family requirement . 15
9.2.3 Test conditions . 15
9.3 Sheave test . 15
9.3.1 General . 15
9.3.2 Family requirement . 16
9.3.3 Test conditions . 16
Installation capability .
9.4 Repeated bending . 16
9.4.1 General . 16
9.4.2 Family requirements . 16
9.4.3 Test conditions . 16
9.5 Impact . 17
9.5.1 General . 17
9.5.2 Family requirements . 17
9.5.3 Test conditions . 17
9.6 Crush . 17
9.6.1 General . 17
9.6.2 Test requirements . 17
9.6.3 Test conditions . 17
Kink .
9.7 Torsion . 18
9.7.1 General . 18
9.7.2 Test requirements . 18
Vibration testing .
9.8 Aeolian vibration test . 18
9.8.1 General . 18
9.8.2 Family requirements . 18
9.8.3 Test conditions . 18
9.8.4 Parameters to be reported . 18
9.9 Low frequency vibration test (galloping test) . 19
9.9.1 General . 19
9.9.2 Family requirements . 19
9.9.3 Test conditions . 19
9.10 Temperature cycling . 20
9.10.1 General . 20
9.10.2 Family requirements . 20
9.10.3 Test conditions . 20
9.11 Water penetration . 20
9.12 Weathering resistance Cable UV resistance . 21
9.13 Tracking and erosion resistance test . 21
9.14 Creep behaviour . 21
9.15 Fitting compatibility . 22
Factory acceptance tests .
Routine tests .
10 Quality assurance . 23
Annex A (informative) Packaging and marking . 24
Annex B (informative) Installation considerations for ADSS cables . 25
Annex C (informative) Electrical test (tracking) . 27
C.1 General . 27
C.2 Option C1 C2 – Sheath material qualification . 27
C.2.1 Overview . 27
C.2.2 Test arrangements . 27
C.2.3 Test procedure . 28
C.2.4 Requirements . 28
Option C2 – Example of test for Sahara desert conditions .
C.3 Option C3 – Pollution level and tracking resistance . 31
C.3.1 Overview . 31
C.3.2 Test setup . 31
C.3.3 Test method . 33
C.3.4 Overview of pollution model and electrical test . 34
Annex D (informative) All dielectric self-supported (ADSS) cables to be used in
overhead power lines (blank detail specification) . 36
Bibliography . 38
Figure – Draft of test equipment .
Figure – Test chamber .
– 4 – IEC 60794-4-20:2018 RLV © IEC 2018
Figure B.1 – Example of different span lengths allowed for the same cable, depending
on sag variation . 26
Figure C.1 – Electric scheme for the test . 31
Figure C.2 – Foils of the electrodes . 32
Figure C.3 – Nozzle . 32
Figure C.4 – Details for the spraying . 33
Figure C.5 – Pollution model Distributed element model with dry band arc gap . 34
Figure C.6 – Basic circuit for arcing test Thevenin equivalent circuit . 35
Table 1 – Cable design characteristics . 13
Table 2 – Optional parameters (if required by customer) . 13
Table C.1 – R and C values for different pollution index values . 33
eq eq
Table D.1 – Blank detail specification . 36
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRE CABLES –
Part 4-20: Sectional specification – Aerial optical cables along
electrical power lines – Family specification for ADSS
(all dielectric self-supported) optical cables
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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– 6 – IEC 60794-4-20:2018 RLV © IEC 2018
International Standard IEC 60794-4-20 has been prepared by subcommittee 86A: Fibres and
cables, of IEC technical committee 86: Fibre optics.
This second edition cancels and replaces the first edition published in 2012 and constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) this document has been streamlined by cross-referencing IEC 60794-1-1,
IEC 60794-4 (all parts) and IEC 60794-1-2;
b) reference to the MICE table has been deleted;
c) the example of test method for particular environment in Annex C has been deleted;
The text of this International Standard is based on the following documents:
FDIS Report on voting
86A/1867/FDIS 86A/1876/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all 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 "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
OPTICAL FIBRE CABLES –
Part 4-20: Sectional specification – Aerial optical cables along
electrical power lines – Family specification for ADSS
(all dielectric self-supported) optical cables
1 Scope
This part of IEC 60794-4, which is a family specification, covers optical telecommunication
cables, commonly with single-mode fibres to be used primarily in overhead power lines
applications. The cables may can also be used in other overhead utility networks, such as for
telephony or TV services. Requirements of the sectional specification IEC 60794-4 for aerial
optical cables along electrical power lines are applicable to cables covered by this document.
This document covers the construction, mechanical, electrical, and optical performance,
installation guidelines, acceptance criteria, test requirements, environmental considerations,
and accessories compatibility for an all dielectric, self-supporting fibre optic (ADSS) cable.
This document provides construction and performance requirements that ensure, within the
guidelines of this document, that the required mechanical capabilities integrity of the cable
components and maintenance of optical fibre integrity and optical transmissions are proper as
well as optical fibre mechanical reliability and transmission parameters are maintained.
The ADSS cable consists of single mode optical fibres contained in one or more protective
dielectric fibre optic units surrounded by or attached to suitable dielectric strength members
and sheaths. The cable does not contain metallic components. An ADSS cable is designed to
meet the optical and mechanical requirements under different types of installation, operating
and environmental conditions and loadings, as described in Annex B.
This document excludes any "lashed" or "wrapped" OPAC cables included in IEC 60794-4.
Figure 8 aerial cables are also excluded; they are specified in IEC 60794-3-20.
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. These 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 discussion, see IEC/TR 62362.
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 60304, Standard colours for insulation for low-frequency cables and wires
IEC 60793-1-40, Optical fibres – Part 1-40: Measurement methods and test procedures –
Attenuation
___________
In some particular situations in the electrical industry, short overhead links can be also designed with
multimode fibres.
– 8 – IEC 60794-4-20:2018 RLV © IEC 2018
IEC 60793-1-44, Optical fibres – Part 1-44: Measurement methods and test procedures – Cut-
off wavelength
IEC 60793-1-48, Optical fibres – Part 1-48: Measurement methods and test procedures –
Polarization mode dispersion
IEC 60793-2, Optical fibres – Part 2: Product specifications – General
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: Generic specification – General
IEC 60794-1-2, Optical fibre cables – Part 1-2: Generic specification – Basic optical cable test
2 3
procedures ,
IEC 60794-1-21:2015, Optical fibre cables – Part 1-21: Generic specification – Basic optical
cable test procedures – Mechanical test methods
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 60794-4, Optical fibre cables – Part 4: Sectional Specification – Aerial optical cables
along electrical power lines
IEC 61395, Overhead electrical conductors – Creep test procedures for stranded conductors
ISO 9001, Quality management systems – Requirements
3 Terms, definitions and abbreviated terms
For the purposes of this document, the terms, definitions and abbreviated terms given in
IEC 60794-1-1 and IEC 60794-4, as well as 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
maximum allowable tension
MAT
maximum tensile load that may be applied to the cable without detriment to the performance
requirements (optical performance, fibre durability) due to fibre strain
___________
This document has been withdrawn, but can still be purchased, if necessary. Until IEC 60794-1-21 will be
available, the tests stated in Clause 9 have to be taken from IEC 60794-1-2.
This standard will be replaced by IEC 60794-1-21, Optical fibre cables – Part 1-21: Generic specification –
Basic optical cable test procedures – Mechanical test methods (see also Bibliography), as soon as it will be
available.
Note 1 to entry: Due to installation codes the MAT value is sometimes restricted to be less than 60 % of the
breaking tension of the cable.
3.2
maximum operation tension
MOT
tensile load that can be applied to the cable either permanently or for a long term without
producing any strain to the fibres
Note 1 to entry: This condition should correspond to the tension with no ice and no gale wind at average mean
temperatures throughout the year, assumed to be between 16 ºC and 20 ºC.
3.3
zero strain margin
tensile load that the cable can sustain without strain on fibres due to cable elongation
3.4
breaking tension
tensile load that will produce physical rupture of the cable
Note 1 to entry: There is no optical consideration related to this parameter.
Note 2 to entry: The breaking tension should be calculated. The design model shall be validated; the cables do not
need to be tested.
3.5
maximum installation tension
MIT
maximum load that should be applied during the installation procedure
Note 1 to entry: The maximum installation tension refers mainly to the final adjust of sag (also called sagging
load), and the same tension limit can be used for the deployment of the cable (also called stringing load).
Note 2 to entry: This is a recommended value aimed at avoiding tension values higher than MAT during
operational life due to wind, ice or temperature changes.
3.6
ADSS
all dielectric self supported cable
dielectric cable that is capable of enduring aerial installation and providing long term service,
without any external tensile support
3.7
OPAC
optical attached cable
dielectric, not self-supported, optical attached cable
Note 1 to entry: OPACs can be used with one of the following attachment methods:
• wrapped, known as an all-dielectric (wrap): using special machinery, a lightweight flexible non-metallic cable is
wrapped helically around either the earth wire or the phase conductor;
• lashed: non-metallic cables are installed longitudinally alongside the earth wire, the phase conductor or on a
separate support cable (on a pole route) and are held in position with a binder or adhesive cord;
• spiral attached: similar to the lashed cables except that the method of attachment involves the use of special
preformed spiral attachment clips.
Note 2 to entry: OPAC cable designs are not covered by this specification.
– 10 – IEC 60794-4-20:2018 RLV © IEC 2018
3.8
cable fittings and dampers
3.8.1
suspension cable fitting
device to hold up the cable in intermediate support points along an aerial line, where the
cable is under tension at both sides of the fitting
3.8.2
dead end cable fitting
device designed to terminate an installation run, isolate a splice location or maintenance coil,
provide slack span locations, or provide for extreme angle turns, where the cable is under
tensional load on one side of the fitting and tension free on the other
3.8.2
damper
device attached to a cable in order to suppress or minimize vibrations due to wind
4 Optical fibres
4.1 General
Single mode optical fibres shall be used that meet the requirements of IEC 60793-2-50. In this
clause only the main characteristics are mentioned. Other types of fibre can be agreed upon
between the customer and the supplier; such fibre shall conform to IEC 60793-2. The cabled
fibre shall conform to IEC 60794-4.
Fibres other than those specified above can be used, if mutually agreed between the
customer and supplier. In this case, fibre characteristics and attenuation criteria for
mechanical tests shall be specified in the detail specification.
4.2 Attenuation
4.2.1 Attenuation coefficient
The requirements for the uncabled fibres shall be according to IEC 60793-2-50.
Unless other values are agreed between supplier and customer, the maximum attenuation
coefficient of the cabled fibres shall be 0,35 dB/km when measured at 1 310 nm and/or
0,25 dB/km at 1 550 nm.
Different values from those stated above can be agreed between customer and supplier.
The attenuation coefficient shall be measured in accordance with IEC 60793-1-40.
4.2.2 Attenuation discontinuities
The local attenuation shall not have point discontinuities in excess of 0,10 dB.
The test method used to verify the functional requirements shall be in accordance with
IEC 60793-1-40.
4.3 Cut-off wavelength of cabled fibre
The cabled fibre cut-off wavelength λ shall be lower than the operational wavelength when
CC
measured in accordance with IEC 60793-1-44.
4.4 Fibre colouring
The primary coated fibres shall be coloured for identification. The coloured coating shall be
readily identifiable throughout the lifetime of the cable and shall be at a reasonable match to
the requirements stated on IEC 60304. If required, the colouring shall permit sufficient light to
be transmitted through the primary coating to allow local light injection and detection.
4.5 Polarisation mode dispersion (PMD)
PMD shall meet the values indicated in IEC 60793-2-50. The measurement procedure shall be
in accordance with IEC 60793-1-48.
5 Cable elements
Refer to the relevant parts of the sectional specification IEC 60794-4; the following
requirements apply specifically to ADSS cables.
The material(s) used for a cable element shall be selected to be compatible with the other
elements in contact with it.
Optical elements (cable elements containing optical fibres) and each fibre within a cable
element shall be uniquely identified, for example, by colours, by a positional scheme, by
markings or as agreed between customer and manufacturer.
For loose tube construction, one or more primary coated fibres or optical elements are
packaged, loosely in a tube construction, with a suitable water-blocking system. The plastic
tube may be reinforced with a composite wall.
If required by the customer, the suitability of the tube shall be determined by an evaluation of
its kink resistance in accordance with IEC 60794-1-23, Method G7.
When used, optical fibre ribbons should comply with the requirements stated in IEC 60794-3.
6 Optical fibre cable constructions
6.1 General
The construction and characteristics of cable elements shall conform to IEC 60794-4. The
cable shall not contain any metallic material.
6.2 Optical unit
Optical unit elements as described in Clause 5 may be laid up as follows:
Single optical unit in the cable centre, which may contain one or more optical elements:
a) number of loose tubes using helical or SZ stranding configurations around a central
element of reinforced plastic, epoxy-glass, or other dielectric material. Ribbon elements
may be laid up by stacking two or more elements inside the loose tubes;
b) configuration based on a channelled dielectric rod, containing units such as ribbons or
plastic tubes, which may contain one or more optical elements.
6.2 Cable protection elements
In addition to the optical unit, the cable construction may consist of the following.
a) The outer sheath shall be a weather-resistant type material. In certain conditions, it shall
be necessary to consider the use of a tracking-resistant sheath.
– 12 – IEC 60794-4-20:2018 RLV © IEC 2018
b) An ADSS cable shall contain self-supported systems that are integral to the cable. The
purpose of the support system is to ensure that the cable meets the optical requirements
under specified installation conditions, temperatures, and environmental loading for its
whole operating design life. This standard excludes any “lashed” or “wrapped” OPAC
cables.
c) The basic annular construction may have strength yarns (e.g. aramid yarns) or other
dielectric strands or a channelled dielectric rods as a support structure. In addition, other
cable elements, such as central members, may be load bearing. A single central dielectric
shaft, channelled to accommodate the optical elements, is also accepted.
d) Fibre strain allowance.
ed) The cable shall be designed such that fibre strain does not exceed the limit allowed by the
cable manufacturer under design tension limits of the cable (MAT). Maximum allowable
fibre strain under MAT condition will generally be a function of the proof test level and
strength and fatigue parameters of the optical fibre, 0,33 % is specified for fibre proof
tested to 1 % shall be ≤ 0,2 % for 0,69 GPa proof-tested fibres.
f) A water blocking material shall be used to prevent water penetration to the optical units
and to the cable core. The material shall be easily removed without the use of materials
considered to be hazardous or dangerous. Water swell able blocking materials can also be
used.
When used in the cable construction, the filling compound shall not flow at temperatures
lower than the maximum specified operation temperature of cable.
NOTE In some countries, a special requirement of shotgun resistance can be specified for aerial cables.
ADSS covered by this standard are not designed for this condition.
Cables with reinforced textile protection, could still meet the dielectric condition, but the
increase in diameter and weight would require a significant enhancement of the tensile
performance of the cable.
NOTE In some countries, a special requirement of shotgun resistance can be specified for aerial cables. ADSS
cables covered by this document are not designed for such a condition. Cables with reinforced textile protection
could still meet the dielectric condition, but the increase in diameter and weight would make necessary a significant
enhancement of the tensile performance of the cable.
7 Main requirements for installation and operating conditions
Operating conditions are particularly important for ADSS cables.
Installation and operating conditions shall be agreed between the customer and the supplier.
For the ADSS cable, a detailed study of the field conditions and an important amount a certain
level of technical support by the supplier or third-party expert should precede the agreement.
Annex B provides a general view of such considerations.
The type of fittings and hardware used to attach the ADSS to the structures shall be approved
between the customer and the supplier. Their compatibility has to be checked according to
9.11 and the supplier or the customer fittings' specification shall be verified in accordance
with 9.15 and the fittings product specification.
8 Cable design considerations
Table 1 is a summary of cable characteristics which may be of importance as specifications to
both the customer and the supplier. Table 2 includes optional engineering parameters
relevant for the design and installation of the overhead line with an ADSS cable. Other
characteristics may be mutually agreed upon by both the customer and the supplier. A
complete blank specification is shown in Annex D.
Table 1 – Cable design characteristics
Ref. Characteristics Units
4 Number and type of fibres NA
- Modularity of cable core (fibres per tube) NA
6 Detailed description of cable design construction NA
- Overall cable diameter mm
Cable weight kg/km
9.2 MAT (maximum allowable tension) kN
9-10 Allowable temperature for storage, installation and operation °C
9.3 Minimum bending diameter during installation mm
9.4 Minimum bending radius diameter installed mm
Table 2 – Optional parameters (if required by customer)
Ref. Characteristics Units
9.13 MIT, maximum installation (or sagging) load kN
- Modulus of elasticity MPa
-6
- Coefficient of thermal expansion 10 /°C
9.2 Fibre strain at MAT load %
Annex B Zero strain margin kN
9.9 Creep behaviour mm
Maximum Sag at MOT and MAT m
Environmental loading conditions – Reference to local or regional installation NA
code
Recommended span and sag under MAT limit m/%
C.3 Maximum ADSS cable space potential exposure (generally specified for a low- kV
pollution environment unless specified otherwise by the customer)
9 Cable tests
9.1 General
The parameters specified in this standard may be affected by measurement uncertainty
arising either from measurement errors or calibration errors due to the lack of suitable
standards. Acceptance criteria shall be interpreted with respect to this consideration. For
some of the parameters specified in this standard, the objective is no change in attenuation.
These parameters may be affected by measurement uncertainty arising either from
measurement errors or calibration errors due to a lack of suitable standards. Acceptance
criteria shall be interpreted with respect to this consideration. The total uncertainty of
measurement for this standard shall be ≤0,05 dB for attenuation or 0,05 dB/km for attenuation
coefficient.
Any measured value within this range, either positive or negative, shall be considered as “no
change in attenuation”. By agreement between customer and supplier, minor deviation from
this limit may be accepted at some low frequency, e.g. less than 10 % of the fibres. However,
for mechanical tests no deviation in excess of 0,15 dB shall be accepted.
In mechanical tests, the general optical criteria is no change in attenuation, as described in
IEC 60794-1-1 and IEC 60794-4.
– 14 – IEC 60794-4-20:2018 RLV © IEC 2018
In some environmental and installation tests, some increase is accepted. These are the
sheave test, the aeolian vibration test and the galloping test.
The number of fibres tested shall be representative of the cable design according to fibre
sampling indicated IEC 60794-1-1. Different sampling can be agreed between the customer
and the supplier.
The tests applicable for aerial cables are listed below. The minimum acceptance criteria for
the different designs of cables shall be indicated in the product specification.
The specimens for the tests shall be taken from the supplier in advance to the tests.
9.2 Classification of tests
9.2.1 Type tests
Tests required to be carried out before supplying a cable covered by this standard on a
general commercial basis in order to demonstrate satisfactory performance characteristics to
meet the intended application. These tests shall be carried out on a cable length which meets
the requirements of the relevant routine tests. These tests are of such a nature that, after they
have been made, they need not to be repeated unless significant changes are made in the
cable material, design or type of manufacturing process which might change the performance
characteristics.
A full type verification of a cable design includes all tests and characteristics specified in this
standard. Tests to be repeated shall be agreed between the customer and the supplier.
9.2.2 Factory acceptance tests
Tests made on samples of completed cable, or components taken from a completed cable to
verify that the finished product meets the design specifications. Scope and incidence of
sample tests, if required, shall be agreed between the customer and the supplier.
Failure of a test specimen to comply with any one of the requirements of this standard shall
constitute grounds for rejection of the lot represented by the specimen. If any lot is so
rejected, the supplier shall have the right to test, only once, all individual drums of cables in
the lot and submit those which meet the requirements for acceptance.
9.2.3 Routine tests
Tests made on all production cable lengths to demonstrate their integrity.
Failure of a test specimen to comply with any one of the requirements of this standard shall
constitute grounds for rejection of the lot represented by the specimen. If any lot is so
rejected, the supplier shall have the right to test, only once, all individual drums of cables in
the lot and submit those which meet the requirements for acceptance.
9.2 Tensile performance
9.2.1 General
The tensile performance of the cable is verified with the test methods in 9.2.1 and 9.2.2. The
cable manufacturer shall specify the MOT and the MAT for the ADSS design. Both tests shall
be evaluated on the same cable sample, subjecting in a first step, the sample to the MOT test,
releasing the load to zero tension and then applying the MAT test.
9.3.2 Maximum allowed tension (MAT)
The cable shall be terminated with suitable dead end
...
IEC 60794-4-20 ®
Edition 2.0 2018-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibre cables –
Part 4-20: Sectional specification – Aerial optical cables along electrical power
lines – Family specification for ADSS (all dielectric self-supported) optical cables
Câbles à fibres optiques –
Partie 4-20: Spécification intermédiaire – Câbles optiques aériens le long des
lignes électriques de puissance – Spécification de famille pour les câbles
optiques autoporteurs entièrement diélectriques (ADSS)
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IEC 60794-4-20 ®
Edition 2.0 2018-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Optical fibre cables –
Part 4-20: Sectional specification – Aerial optical cables along electrical power
lines – Family specification for ADSS (all dielectric self-supported) optical cables
Câbles à fibres optiques –
Partie 4-20: Spécification intermédiaire – Câbles optiques aériens le long des
lignes électriques de puissance – Spécification de famille pour les câbles
optiques autoporteurs entièrement diélectriques (ADSS)
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.180.10 ISBN 978-2-8322-5907-8
– 2 – IEC 60794-4-20:2018 © IEC 2018
CONTENTS
FOREWORD. 4
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviated terms . 7
4 Optical fibres . 7
5 Cable elements . 7
6 Optical fibre cable constructions . 7
6.1 General . 7
6.2 Cable protection elements . 7
7 Main requirements for installation and operating conditions . 8
8 Cable design considerations . 8
9 Cable tests . 9
9.1 General . 9
9.2 Tensile performance . 9
9.2.1 General . 9
9.2.2 Family requirement . 9
9.2.3 Test conditions . 9
9.3 Sheave test . 9
9.3.1 General . 9
9.3.2 Family requirement . 9
9.3.3 Test conditions . 9
9.4 Repeated bending . 10
9.4.1 General . 10
9.4.2 Family requirements . 10
9.4.3 Test conditions . 10
9.5 Impact . 10
9.5.1 General . 10
9.5.2 Family requirements . 10
9.5.3 Test conditions . 10
9.6 Crush . 10
9.6.1 General . 10
9.6.2 Test requirements . 11
9.6.3 Test conditions . 11
9.7 Torsion . 11
9.7.1 General . 11
9.7.2 Test requirements . 11
9.8 Aeolian vibration test . 11
9.8.1 General . 11
9.8.2 Family requirements . 11
9.8.3 Test conditions . 11
9.8.4 Parameters to be reported . 11
9.9 Low frequency vibration test (galloping test) . 12
9.9.1 General . 12
9.9.2 Family requirements . 12
9.9.3 Test conditions . 12
9.10 Temperature cycling . 12
9.10.1 General . 12
9.10.2 Family requirements . 12
9.10.3 Test conditions . 12
9.11 Water penetration . 13
9.12 Cable UV resistance . 13
9.13 Tracking and erosion resistance test . 13
9.14 Creep . 13
9.15 Fitting compatibility . 14
10 Quality assurance . 14
Annex A (informative) Packaging and marking . 15
Annex B (informative) Installation considerations for ADSS cables . 16
Annex C (informative) Electrical test (tracking) . 18
C.1 General . 18
C.2 Option C2 – Sheath material qualification . 18
C.2.1 Overview . 18
C.2.2 Test arrangements . 18
C.2.3 Test procedure . 19
C.2.4 Requirements . 19
C.3 Option C3 – Pollution level and tracking resistance . 19
C.3.1 Overview . 19
C.3.2 Test setup . 20
C.3.3 Test method . 22
C.3.4 Overview of pollution model and electrical test . 22
Annex D (informative) All dielectric self-supported (ADSS) cables to be used in
overhead power lines (blank detail specification) . 24
Bibliography . 26
Figure B.1 – Example of different span lengths allowed for the same cable, depending
on sag variation . 17
Figure C.1 – Electric scheme for the test . 20
Figure C.2 – Foils of the electrodes . 20
Figure C.3 – Nozzle . 21
Figure C.4 – Details for the spraying . 21
Figure C.5 – Distributed element model with dry band arc gap . 23
Figure C.6 – Thevenin equivalent circuit . 23
Table 1 – Cable design characteristics . 8
Table 2 – Optional parameters (if required by customer) . 8
Table C.1 – R and C values for different pollution index values . 22
eq eq
Table D.1 – Blank detail specification . 24
– 4 – IEC 60794-4-20:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
OPTICAL FIBRE CABLES –
Part 4-20: Sectional specification – Aerial optical cables along
electrical power lines – Family specification for ADSS
(all dielectric self-supported) 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,
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in the subject dealt with may participate in this preparatory work. International, governmental and
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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
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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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
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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 60794-4-20 has been prepared by subcommittee 86A: Fibres and
cables, of IEC technical committee 86: Fibre optics.
This second edition cancels and replaces the first edition published in 2012 and constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) this document has been streamlined by cross-referencing IEC 60794-1-1,
IEC 60794-4 (all parts) and IEC 60794-1-2;
b) reference to the MICE table has been deleted;
c) the example of test method for particular environment in Annex C has been deleted;
The text of this International Standard is based on the following documents:
FDIS Report on voting
86A/1867/FDIS 86A/1876/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all 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 "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – IEC 60794-4-20:2018 © IEC 2018
OPTICAL FIBRE CABLES –
Part 4-20: Sectional specification – Aerial optical cables along
electrical power lines – Family specification for ADSS
(all dielectric self-supported) optical cables
1 Scope
This part of IEC 60794-4, which is a family specification, covers optical telecommunication
cables, commonly with single-mode fibres used primarily in overhead power lines
applications. The cables can also be used in other overhead utility networks, such as for
telephony or TV services. Requirements of the sectional specification IEC 60794-4 for aerial
optical cables along electrical power lines are applicable to cables covered by this document.
This document covers the construction, mechanical, electrical, and optical performance,
installation guidelines, acceptance criteria, test requirements, environmental considerations,
and accessories compatibility for an all dielectric, self-supporting fibre optic (ADSS) cable.
This document provides construction and performance requirements that ensure, within the
guidelines of this document, that the required mechanical integrity of the cable components as
well as optical fibre mechanical reliability and transmission parameters are maintained.
The ADSS cable consists of single mode optical fibres contained in one or more protective
dielectric fibre optic units surrounded by or attached to suitable dielectric strength members
and sheaths. The cable does not contain metallic components. An ADSS cable is designed to
meet the optical and mechanical requirements under different installation, operating and
environmental conditions and loadings, as described in Annex B.
This document excludes any "lashed" or "wrapped" OPAC cables included in IEC 60794-4.
Figure 8 aerial cables are also excluded; they are specified in IEC 60794-3-20.
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 60793-2, Optical fibres – Part 2: Product specifications – General
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: Generic specification – General
IEC 60794-1-21:2015, Optical fibre cables – Part 1-21: Generic specification – Basic optical
cable test procedures – Mechanical test methods
IEC 60794-1-22, Optical fibre cables – Part 1-22: Generic specification – Basic optical cable
test procedures – Environmental test methods
___________
In some particular situations in the electrical industry, short overhead links can be also designed with
multimode fibres.
IEC 60794-4, Optical fibre cables – Part 4: Sectional specification – Aerial optical cables
along electrical power lines
ISO 9001, Quality management systems – Requirements
3 Terms, definitions and abbreviated terms
For the purposes of this document, the terms, definitions and abbreviated terms given in
IEC 60794-1-1 and IEC 60794-4 apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
4 Optical fibres
Single-mode optical fibres shall be used that meet the requirements of IEC 60793-2-50. Other
types of fibre can be agreed upon between the customer and the supplier; such fibre shall
conform to IEC 60793-2. The cabled fibre shall conform to IEC 60794-4.
5 Cable elements
Refer to the relevant parts of the sectional specification IEC 60794-4.
6 Optical fibre cable constructions
6.1 General
The construction and characteristics of cable elements shall conform to IEC 60794-4. The
cable shall not contain any metallic material.
6.2 Cable protection elements
In addition to the optical unit, the cable construction may consist of the following.
a) The outer sheath shall be a weather-resistant type material. In certain conditions, it shall
be necessary to consider the use of a tracking-resistant sheath.
b) An ADSS cable shall contain self-supported systems that are integral to the cable. The
purpose of the support system is to ensure that the cable meets the optical requirements
under specified installation conditions, temperatures, and environmental loading for its
whole operating design life.
c) The basic annular construction may have strength yarns (e.g. aramid yarns) or other
dielectric strands or dielectric rods as a support structure. A single central dielectric shaft,
channelled to accommodate the optical elements, is also accepted.
d) The cable shall be designed such that fibre strain does not exceed the limit allowed by the
cable manufacturer under design tension limits of the cable (MAT). Maximum allowable
fibre strain under MAT condition shall be ≤ 0,2 % for 0,69 GPa proof-tested fibres.
NOTE In some countries, a special requirement of shotgun resistance can be specified for aerial cables. ADSS
cables covered by this document are not designed for such a condition. Cables with reinforced textile protection
could still meet the dielectric condition, but the increase in diameter and weight would make necessary a significant
enhancement of the tensile performance of the cable.
– 8 – IEC 60794-4-20:2018 © IEC 2018
7 Main requirements for installation and operating conditions
Operating conditions are particularly important for ADSS cables.
Installation and operating conditions shall be agreed between the customer and the supplier.
For the ADSS cable, a detailed study of the field conditions and a certain level of technical
support by the supplier or third-party expert should precede the agreement. Annex B provides
a general view of such considerations.
The type of fittings and hardware used to attach the ADSS to the structures shall be approved
between the customer and the supplier. Their compatibility shall be verified in accordance
with 9.15 and the fittings product specification.
8 Cable design considerations
Table 1 is a summary of cable characteristics which may be of importance as specifications to
both the customer and the supplier. Table 2 includes optional engineering parameters
relevant for the design and installation of the overhead line with an ADSS cable. Other
characteristics may be mutually agreed upon by both the customer and the supplier. A
complete blank specification is shown in Annex D.
Table 1 – Cable design characteristics
Ref. Characteristics Units
4 Number and type of fibres NA
- Modularity of cable core NA
6 Detailed description of cable construction NA
- Overall cable diameter mm
Cable weight kg/km
9.2 MAT (maximum allowable tension) kN
9-10 Allowable temperature for storage, installation and operation °C
9.3 Minimum bending diameter during installation mm
9.4 Minimum bending diameter installed mm
Table 2 – Optional parameters (if required by customer)
Ref. Characteristics Units
9.13 MIT, maximum installation (or sagging) load kN
- Modulus of elasticity MPa
-6
- Coefficient of thermal expansion 10 /°C
9.2 Fibre strain at MAT load %
Annex B Zero strain margin kN
Environmental loading conditions – Reference to local or regional installation NA
code
Recommended span and sag under MAT limit m/%
C.3 Maximum ADSS cable space potential exposure (generally specified for a low- kV
pollution environment unless specified otherwise by the customer)
9 Cable tests
9.1 General
In mechanical tests, the general optical criteria is no change in attenuation, as described in
IEC 60794-1-1 and IEC 60794-4.
In some environmental and installation tests, some increase is accepted. These are the
sheave test, the aeolian vibration test and the galloping test.
The number of fibres tested shall be representative of the cable design according to fibre
sampling indicated IEC 60794-1-1. Different sampling can be agreed between the customer
and the supplier.
The tests applicable for aerial cables are listed below. The minimum acceptance criteria for
the different designs of cables shall be indicated in the product specification.
9.2 Tensile performance
9.2.1 General
The cable should be tested in accordance with IEC 60794-1-21, method E1. Under this test,
the cables shall meet the specified MAT value.
9.2.2 Family requirement
Loaded with MAT, no change in attenuation at 1 550 nm shall be measured, and the strain in
the fibre shall be ≤ 0.2 % for 0,69 GPa proof-tested fibres. Other values can be agreed
between the customer and the supplier.
NOTE Strain limit values for fibres with different proof test values are under study.
9.2.3 Test conditions
• Test set in a straight path in accordance with Figure 1 of IEC 60794-1-21:2015 (no drums
or pulleys allowed).
• The cable shall be terminated with adequate dead-end fittings.
• Sample length of 25 m minimum.
• MAT is sustained for 1 h.
• The fibres shall be loop-back spliced so that a minimum of 100 m of fibre are under test.
9.3 Sheave test
9.3.1 General
The cable shall be tested in accordance with method E18B of IEC 60794-1-21.
9.3.2 Family requirement
Maximum permanent increase in attenuation: 0,10 dB at 1 550 nm.
No physical damage in cable elements.
9.3.3 Test conditions
• Method E18B of IEC 60794-1-21, procedure 1 or 2.
• Tension level applied during test: maximum stringing load (or MIT).
• Length of the cable: 9 m minimum. Length bent under tension: 2 m.
– 10 – IEC 60794-4-20:2018 © IEC 2018
• The cable should be terminated with the recommended dead-end fittings.
• The fibres shall be loop-back spliced so that a minimum of 100 m of fibre are under test.
• Diameter (D) of roller/cylinders ≥ manufacturer’s minimum bend diameter (approximately
≥ 40 times cable outside diameter is recommended).
• Bending angle: 45° ±15°.
• Moving speed: 1 m/s ≤ speed ≤ 10 m/s.
• Number of complete moving cycles: 20.
9.4 Repeated bending
9.4.1 General
The cable shall be tested in accordance with the method specified in IEC 60794-1-21,
method E6.
9.4.2 Family requirements
Under visual examination without magnification, there shall be no damage to the sheath or
cable elements. There shall be no change in attenuation at 1 550 nm after the completion of
the test.
9.4.3 Test conditions
• Bending radius: 20 d.
• Number of cycles: 25.
Particular conditions may be agreed between the customer and the supplier.
9.5 Impact
9.5.1 General
The cable construction shall be tested in accordance with the method specified in
IEC 60794-1-21, method E4.
9.5.2 Family requirements
Under visual examination without magnification, there shall be no damage to the sheath or to
the cable elements. The imprint of the striking surface on the sheath is not considered
mechanical damage.
There shall be no change in attenuation at 1 550 nm.
9.5.3 Test conditions
• Striking surface radius: 300 mm.
• Impact energy: 10 J.
• Number of impacts: three, each in a different place spaced not less than 500 mm apart.
NOTE these values are for general purpose use. Particular requirement could be included in product
specification.
9.6 Crush
9.6.1 General
The cable shall be tested in accordance with IEC 60794-1-21, method E3, without physical
damage or change in attenuation.
9.6.2 Test requirements
Under visual examination, there shall be no damage to the sheath or to the cable elements.
The imprint of the plate or mandrel on the sheath is not considered mechanical damage.
Long term ≥ 10 min. No change in attenuation (prior to release of load).
Short term ≥ 1 min. No change in attenuation (after test).
9.6.3 Test conditions
• Load (plate/plate): 2,2 kN for short-term load, 1,1 kN for long-term load.
• Duration of load: 1 min of short-term load, followed by 10 min of long-term load.
• Number of tests: 3.
• Spacing between test places: 500 mm.
NOTE These values are for general purpose use. Particular requirements can be included in a product
specification.
9.7 Torsion
9.7.1 General
The cable shall be tested in accordance with IEC 60794-1-21, method E7.
9.7.2 Test requirements
Under visual examination without magnification, there shall be no damage to the sheath or to
the cable elements.
No change on attenuation after the test at 1 550 nm.
9.8 Aeolian vibration test
9.8.1 General
The resistance of the cable to aeolian vibration shall be tested in accordance with
method E19 of IEC 60794-1-21.
9.8.2 Family requirements
Under visual examination without magnification, there shall be no damage to the sheath or to
the cable elements. The variation on attenuation after the test shall be no greater than
0,10 dB at 1 550 nm.
9.8.3 Test conditions
The cable should be terminated with the recommended dead-end and suspension fittings.
9.8.4 Parameters to be reported
• Length of spans.
• Length of cable and fibres tested.
• Vibration mode/characteristics maintained during the test.
• Characteristics of measuring equipment.
• Ambient temperature and humidity during the test.
• Mass/unit length and diameter of the cable.
– 12 – IEC 60794-4-20:2018 © IEC 2018
9.9 Low frequency vibration test (galloping test)
9.9.1 General
The resistance of the cable to low frequency vibration shall be tested in accordance with
IEC 60794-1-21, method E26. This test applies for ADSS cables to be installed in areas
where ice build-up and/or strong winds are envisaged.
9.9.2 Family requirements
Permanent or temporary increase in attenuation at 1 550 nm shall be ≤ 0,10 dB.
The sheath shall have no cracks or splits.
9.9.3 Test conditions
The final optical measurement shall be taken at least 2 h after the completion of the vibration
test. A section of cable from the location of the hardware support shall be loaded to the MAT,
and the attenuation shall comply with 9.2.1.
9.10 Temperature cycling
9.10.1 General
The cable shall be tested in accordance with the method specified in IEC 60794-1-22,
method F1, one-cycle procedure with the temperature limits, in accordance with operation
limits in the product specification, or combined test procedure if different storage limits are
specified.
9.10.2 Family requirements
For T and T (T and T in combined test), there shall be no change in attenuation from the
A B A1 B1
reference room temperature measurement when measured in the 1 550 nm region or at the
operational wavelength when specified by the user. T and T temperature levels are only
A1 B1
required during the last cycle.
For T and T , the change in attenuation coefficient shall be ≤ 0,15 dB/km during the last
A2 B2
cycle from the reference room temperature measurement.
On completion of the test, there shall be no change in attenuation. The measurement shall be
made in the 1 550 nm region.
9.10.3 Test conditions
• Sample length: finished cable length of at least 500 m.
• High temperature, T for one-cycle procedure (T for combined test): +60 °C.
B B1
• High temperature, T : +70 °C (only for combined test).
B2
• Low temperature, T for one-cycle procedure (T for combined test): −20 °C.
A A1
• Low temperature, T : −40 °C (only for combined test).
A2
• Rate of heating: sufficiently slow so that the effect of changing the temperature does not
cause temperature shock or 40 °C/h if not specified.
• t : enough time to get temperature stability in the sample.
• Number of cycles: 2. Additional cycles may be required depending on user requirements.
• Temperature values may vary depending on user requirements.
9.11 Water penetration
The cable shall be tested in accordance with IEC 60794-1-22, method F5B for jelly filled
cables or F5C for all-dry cables.
No water shall be detected at the unsealed end of the sample during and at the end of the
test.
9.12 Cable UV resistance
The outer sheath shall be made of UV-stabilized weather-resistant material in accordance
with IEC 60794-1-22, method F14.
Further requirements are under consideration.
9.13 Tracking and erosion resistance test
Dielectric cables installed on power lines are exposed to electrical fields. The magnitude of
this field space potential exposure depends on the line voltage, tower design, conductor
configuration, and installation location for the ADSS. Together with specific environmental
conditions, especially desert or highly polluted areas close to the sea, this can lead to
electrical degradation (e.g. dry-band arcing), which can cause severe damage to the outer
cable sheath and finally can cause a total cable failure. The sensitivity to electrical
degradation depends on a combination of the space potential, the cable, environment, and
sheath material used. In areas with higher space potentials or poor environmental conditions,
track resistant sheath materials may be essential to alleviate the risk to product life.
Experience has shown that the formerly used > 12 kV space potential transition point for
using track resistant sheath materials may be too high depending on the environmental
conditions. Under certain environmental conditions as mentioned above, tracking-resistant
sheaths may be needed with space potentials down to 4 kV. Even with tracking-resistant
sheath materials, special consideration about the feasibility of ADSS applications is required
for levels higher than 20 kV.
Tracking-resistant sheath materials shall be used in the following field conditions:
a) power lines with an operation voltage of 150 kV or higher;
b) power lines producing space potential of 4 kV or higher in salty or polluted areas.
If the ADSS cable is to be used in telecommunication poles or low-voltage distribution lines,
track-resistant requirements can be waived.
Two current options for evaluating the quality of track-resistant sheath materials are given in
Annex C:
1) salt fog method: evaluates cable in a wet condition (continuous salt water spray);
2) alternating wet dry cycles with different current levels to reflect different degrees of
resistivity resulting from varying degrees of regional environmental conditions.
Other test conditions may be needed to evaluate ADSS tracking resistance for specific
environments.
9.14 Creep
There is no pass/fail criterion for creep. This parameter is an engineering guidance to the
behaviour of the cable during its working life. The cable creep behaviour should be
determined using a test method agreed between the customer and the supplier. Suitable tests
are IEC 60794-1-21, method E32 or found in IEC 61395.
– 14 – IEC 60794-4-20:2018 © IEC 2018
9.15 Fitting compatibility
The type of fittings shall be approved between the customer and the supplier, and their
compatibility shall be verified as follows.
• Dead-end fittings shall be used during the MAT test (9.2), with a maximum of 3 mm of
displacement between the fitting and the cable during and after the test. There should be
no change in attenuation.
• A cable sample with dead-end fittings shall stand 24 h at a temperature of 60 °C ± 2 °C
and controlled RH of 85 % ± 5%, under MIT load, with a maximum displacement of 3 mm
between each fitting and cable. There should be no change in attenuation.
• Suspension fitting shall be used during vibration tests (9.8 and 9.9) with no damage to the
cable during the test. There should be no change in attenuation. Vibration dampers can
also be qualified during this test.
• Following the completed testing, the hardware fittings shall be removed and the cable's
outer sheath inspected. There shall be no splits or tears in the outer sheath.
Sample for verification of the temperature and humidity condition shall be long enough to
accept a dead-end fixture and a connection length at both ends; at least 10 m is
recommended. The complete setup should be exposed at the indicated temperature and
humidity
NOTE The use of vibration dampers is not compulsory but is an installation option.
10 Quality assurance
It is the responsibility of the manufacturer to establish quality assurance by quality control
procedures which ensure that the product meets the requirements of this document. When the
purchaser wishes to specify acceptance tests to other quality procedures, it is essential that
an agreement is reached between the customer and the supplier at the time of ordering.
The supplier shall establish, introduce and maintain a quality management system in
accordance with ISO 9001 or equivalent.
Annex A provides recommendations for packaging and marking.
Annex A
(informative)
Packaging and marking
The cable should be tightly and uniformly wound onto reel(s) in layers. Reel lengths may be
either standard length or specified length. Standard lengths are reel lengths normally provided
by a supplier. This length will be defined by the supplier. Specified lengths are reel lengths
that are specified by the customer. A tolerance of ±2,0 % should be maintained for specified
lengths and standard lengths.
Reels may be either wooden non-returnable or steel returnable type. Unless specified
othe
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