IEC 60728-11:2010

Cable networks for television signals, sound signals and interactive services - Part 11: Safety

IEC 60728-11:2010(E) deals with the safety requirements applicable to fixed sited systems and equipment. As far as applicable, it is also valid for mobile and temporarily installed systems, for example, caravans. Additional requirements may be applied. It is intended to provide specifically for the safety of the system, personnel working on it, subscribers and subscriber equipment. It deals only with safety aspects and is not intended to define a standard for the protection of the equipment used in the system. This third edition cancels and replaces the second edition published in 2005. This edition constitutes a technical revision and includes the following significant technical changes with respect to the previous edition: The list of "differences in some countries" was transferred from the "Foreword" to informative Annex D. Some new terms and definitions were added. All Figures were reworked among other things concerning equipotential bonding and earthing details and were incorporated in the text at the appropriate places. Clause 11 "Protection against atmospheric overvoltages and elimination of potential differences" was completely reworked and re-structured taking into account among other things the provisions and requirements of the IEC 62305 series on "Lightning protection". New informative Annex A on "Earth loop impedance" was added. New informative Annex C on "Examples of calculation of risk due to lightning" was added. Former Annex B on "Special conditions using IT power line networks" was re-worded and incorporated in Annex D as "Difference in Norway".

General Information

• Status: Published
• Publication Date: 28-Jun-2010
• ICS: 33.060.40 - Cabled distribution systems
• Technical Committee: TC 100 - Audio, video and multimedia systems and equipment
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 24-Mar-2016

Relations

• Revised: IEC 60728-11:2016 - Cable networks for television signals, sound signals and interactive services - Part 11: Safety
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60728-11
®
Edition 3.0 2010-06
INTERNATIONAL
STANDARD

colour
inside

Cable networks for television signals, sound signals and interactive services –
Part 11: Safety



IEC 60728-11:2010(E)

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IEC 60728-11
®
Edition 3.0 2010-06
INTERNATIONAL
STANDARD

colour
inside

Cable networks for television signals, sound signals and interactive services –
Part 11: Safety


INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XB
ICS 33.060.40 ISBN 978-2-88910-993-7
® Registered trademark of the International Electrotechnical Commission

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– 2 – 60728-11 © IEC:2010(E)
CONTENTS
FOREWORD.5
INTRODUCTION.7
1 Scope.8
2 Normative references.8
3 Terms, definitions, symbols and abbreviations .9
3.1 Terms and definitions .9
3.2 Symbols .15
3.3 Abbreviations.15
4 Fundamental requirements .16
4.1 General .16
4.2 Mechanical requirements .16
4.3 Accessible parts .16
4.4 Laser radiation.16
5 Protection against environmental influences.16
6 Equipotential bonding and earthing .17
6.1 General requirements .17
6.2 Equipotential bonding mechanisms .17
6.3 Equipotential bonding in meshed systems .26
6.3.1 References to other standards .26
6.3.2 General on AC mains.26
6.3.3 AC power distribution and connection of the protective conductor .26
6.3.4 Dangers and malfunction .27
6.3.5 Measures.27
7 Mains-supplied equipment .27
8 Remote power feeding in cable networks .28
8.1 Remote power feeding.28
8.1.1 Maximum allowed voltages .28
8.1.2 General requirements for equipment .28
8.1.3 Current-carrying capacity and dielectric strength of the components .28
8.2 Remote powering from subscriber premises.29
9 Protection against contact and proximity to electric power distribution systems.29
9.1 General .29
9.2 Overhead lines .29
9.2.1 Overhead lines up to 1 000 V .29
9.2.2 Overhead lines above 1 000 V .30
9.3 House installations up to 1 000 V .30
10 System outlets and transfer points .30
10.1 General .30
10.2 System outlet.31
10.2.1 Types of system outlets .31
10.2.2 Fully isolated system outlet .31
10.2.3 Semi-isolated system outlet .31
10.2.4 Non-isolated system outlet with protective element.31
10.2.5 Non-isolated system outlet without protective element .31
10.3 Transfer point .32
11 Protection against atmospheric overvoltages and elimination of potential differences.32

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60728-11 © IEC:2010(E) – 3 –
11.1 General .32
11.2 Protection of the antenna system .33
11.2.1 Selection of appropriate methods for protection of antenna systems .33
11.2.2 Building equipped with a lightning protection system (LPS).34
11.2.3 Building not equipped with an LPS .40
11.3 Earthing and bonding of the antenna system .44
11.3.1 Internal protection system .44
11.3.2 Earthing conductors .44
11.3.3 Earth termination system .47
11.4 Overvoltage protection.49
12 Mechanical stability.50
12.1 General requirements .50
12.2 Bending moment.50
12.3 Wind-pressure values .52
12.4 Mast construction .52
12.5 Data to be published.53
Annex A (informative) Earth loop impedance .54
Annex B (informative) Use of shield wires to protect installations with coaxial cables .57
Annex C (informative) Examples of calculation of risk due to lightning .60
Annex D (informative) The following differences exist in some countries .63
Bibliography .74

Figure 1 – Example of equipotential bonding and earthing of a metal enclosure .18
Figure 2 – Example of equipotential bonding .19
Figure 3 – Example of equipotential bonding and indirect earthing of the amplifier and
the cables via a voltage-dependent protective device.20
Figure 4 – Example of equipotential bonding and earthing of a building installation
(underground connection) .21
Figure 5 – Example of equipotential bonding and earthing of a building installation
(above ground connection) .22
Figure 6 – Example of equipotential bonding with a galvanic isolated cable entering a
building (underground connection).23
Figure 7 – Example of maintaining equipotential bonding whilst a unit is removed .25
Figure 8 – Areas of antenna-outdoor-mounting on buildings, where earthing is not
mandatory.33
Figure 9 – Flow chart for selection of the appropriate method for protecting the antenna
system against atmospheric overvoltages.35
Figure 10 – Example of equipotential bonded headends and antennas in a protected
volume of the building LPS.36
Figure 11 – Example of equipotential bonded headends and antennas in a protected

volume of the building LPS.37
Figure 12 – Example of equipotential bonded headends and antennas in a protected
volume of an external isolated ATS .38
Figure 13 – Example of equipotential bonded antennas (not installed in a protected
volume) and headend with direct connection to building LPS.39
Figure 14 – Example of equipotential bonded headend and earthed antennas (building
without LPS) .42
Figure 15 – Example of bonding for antennas and headend (building without LPS and
lightning risk lower than or equal to the tolerable risk).43

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– 4 – 60728-11 © IEC:2010(E)
Figure 16 – Example of protecting an antenna system (not installed in a protected
volume) by additional discharge conductors (R > R ) .46
T
Figure 17 – Examples of earthing mechanisms (minimum dimensions) .48
Figure 18 – Example of an overvoltage protective device for single dwelling unit.49
Figure 19 – Example of application of a coaxial overvoltage protective device for
multiple dwelling unit .50
Figure 20 – Example of bending moment of an antenna mast .51
Figure A.1 – Systematic of earth loop resistance .55
Figure B.1 – Principle of single shield wire.59
Figure B.2 – Principle of two shield wires.59
Figure C.1 – Template for calculation of the risk due to lightning (Example No. 1).60
Figure C.2 – Template for calculation of the risk due to lightning (Example No. 2).62
Figure D.1 – IT power distribution system in Norway.64
Figure D.2 – Example of installations located farther than 20 m away from a
transforming station .65
Figure D.3 – Example of installations located closer than 20m from a transforming
station.65
Figure D.4 – Example of cabinets for cable network with locally fed equipment and
mains placed less than 2 m apart .66
Figure D.5 – Example of cabinets for cable network with remotely fed equipment and
mains placed less than 2 m apart .66
Figure D.6 – Example of cabinets for cable network with locally fed equipment and
mains placed more than 2 m apart.67
Figure D.7 – Example of cabinets for cable network with remotely fed equipment and
mains placed more than 2m apart.67
Figure D.8 – Example of an installation placing the amplifier in front of the galvanic
isolator.68
Figure D.9 – Example of protection using a voltage depending device on network
installations on poles.69
Figure D.10 – Example of the installation of a safety terminal in Japan .71
Figure D.11 – Examples of installation of a lightning protection system in Japan .72

Table 1 – Maximum allowed operation voltages and maximum allowed currents for
coaxial cables in different cable network applications .29
Table 2 – Solutions for protection of antenna systems against atmospheric
overvoltages .34
Table B.1 – Conductivity of different types of soil.57
Table B.2 – Protection factors (K ) of protection measures against direct lightning
p
strokes for buried cables .58

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60728-11 © IEC:2010(E) – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________

CABLE NETWORKS FOR TELEVISION SIGNALS,
SOUND SIGNALS AND INTERACTIVE SERVICES –

Part 11: Safety


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
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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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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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 60728-11 has been prepared by technical area 5: Cable networks
for television signals, sound signals and interactive services, of IEC technical committee 100:
Audio, video and multimedia systems and equipment.
This third edition cancels and replaces the second edition published in 2005. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition.
• The list of "differences in some countries" was transferred from the "Foreword" to
informative Annex D.
• Some new terms and definitions were added.
• All Figures were reworked among other things concerning equipotential bonding and
earthing details and were incorporated in the text at the appropriate places.

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– 6 – 60728-11 © IEC:2010(E)
• Clause 11 "Protection against atmospheric overvoltages and elimination of potential
differences" was completely reworked and re-structured taking into account among other
things the provisions and requirements of the IEC 62305 series on "Lightning protection".
• New informative Annex A on "Earth loop impedance" was added.
• New informative Annex C on "Examples of calculation of risk due to lightning" was added.
• Former Annex B on "Special conditions using IT power line networks" was re-worded and
incorporated in Annex D as "Difference in Norway".
The text of this standard is based on the following documents:
FDIS Report on voting
100/1679/FDIS 100/1708/RVD

Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The list of all the parts of the IEC 60728 series, under the general title Cable networks for
television signals, sound signals and interactive services, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

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.

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60728-11 © IEC:2010(E) – 7 –
INTRODUCTION
Standards of the IEC 60728 series deal with cable networks including equipment and
associated methods of measurement for headend reception, processing and distribution of
television signals, sound signals and their associated data signals and for processing,
interfacing and transmitting all kinds of signals for interactive services using all applicable
transmission media.
This includes

• CATV networks,
• MATV networks and SMATV networks,
• individual receiving networks
and all kinds of equipment, systems and installations installed in such networks.
NOTE CATV encompasses the Hybrid Fibre Coaxial (HFC) networks used nowadays to provide
telecommunications services, voice, data, audio and video both broadcast and narrowcast.
The extent of this standardization work is from the antennas, special signal source inputs to the
headend or other interface points to the network up to the terminal input.
The standardization of any user terminals (i.e. tuners, receivers, decoders, terminals, etc.) as
well as of any coaxial and optical cables and accessories thereof is excluded.

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CABLE NETWORKS FOR TELEVISION SIGNALS,
SOUND SIGNALS AND INTERACTIVE SERVICES –

Part 11: Safety



1 Scope
This part of IEC 60728 deals with the safety requirements applicable to fixed sited systems and
equipment. As far as applicable, it is also valid for mobile and temporarily installed systems, for
example, caravans.
Additional requirements may be applied, for example, referring to
• electrical installations of buildings and overhead lines,
• other telecommunication services distribution systems,
• water distribution systems,
• gas distribution systems,
• lightning systems.
This standard is intended to provide specifically for the safety of the system, personnel working
on it, subscribers and subscriber equipment. It deals only with safety aspects and is not
intended to define a standard for the protection of the equipment used in the system.
2 Normative references
The following referenced documents are indispensable for the application of this document. For
dated references, only the edition cited applies. For undated references, the latest edition of
the referenced document (including any amendments) applies.
IEC 60065:2001, Audio, video and similar electronic apparatus – Safety requirements
IEC 60364 (all parts), Low-voltage electrical installations
IEC 60364-1, Low-voltage electrical installations – Part 1: Fundamental principles, assessment
of general characteristics, definitions
IEC 60364-5-52, Electrical installations of buildings – Part 5-52: Selection and erection of
electrical equipment – Wiring systems
IEC 60364-5-54, Electrical installations of buildings – Part 5-54: Selection and erection of
electrical equipment – Earthing arrangements, protective conductors and protective bonding
conductors
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 60617, Graphical symbols for diagrams
IEC 60825-1, Safety of laser products – Part 1: Equipment classification and requirements
IEC 60825-2, Safety of laser products – Part 2: Safety of optical fibre communication systems
(OFCS)

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60728-11 © IEC:2010(E) – 9 –
IEC 60950-1:2005, Information technology equipment – Safety – Part 1: General requirements
IEC 60990, Methods of measurement of touch current and protective conductor current
IEC 61140:2001, Protection against electric shock – Common aspects for installation and
equipment
IEC 62305 (all parts), Protection against lightning
IEC 62305-2:2006 Protection against lightning – Part 2: Risk management
IEC 62305-3:2006, Protection against lightning – Part 3: Physical damage to structures and life
hazard
IEC 62305-4, Protection against lightning – Part 4: Electrical and electronic systems within
structures
ISO 3864-1:2002, Graphical symbols – Safety colours and safety signs – Part 1: Design
principles for safety signs in workplaces and public areas
EN 50117 (all parts), Coaxial cables
EN 50164-1, Lightning Protection Components (LPC) – Part 1: Requirements for connection
components
EN 50164-2, Lightning Protection Components (LPC) – Part 2: Requirements for conductors
and earth electrodes
EN 50174-2, Information technology – Cabling installation – Part 2: Installation planning and
practices inside buildings
EN 50310, Application of equipotential bonding and earthing in buildings with information
technology equipment
CENELEC R 064-004, Electrical installations of buildings – Protection against electromagnetic
interference (EMI) in installations of buildings
3 Terms, definitions, symbols and abbreviations
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
NOTE Some terms have been taken from IEC 60050-195, IEC 60050-826 and IEC 60050-851, with the IEV
numbering in square brackets, and from other IEC standards, also referenced to in square brackets.
3.1.1
air termination system
part of an external LPS using metallic elements such as rods, mesh conductors or catenary
wires intended to intercept lightning flashes
[IEC 62305-3:2006, 3.6]
3.1.2
amplifier
device to compensate for attenuation

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3.1.3
attenuation
decibel ratio of the input power to the output power
3.1.4
cable networks (for television signals, sound signals and interactive services)
general overall term used to define CATV-networks, MATV-networks, SMATV-networks and
individual receiving networks; these networks can be used in downstream and upstream
directions
3.1.5
CATV network or community antenna television network
networ
...