IEC TR 60092-370:2009

IEC/TR 60092-370


®

Edition 1.0 2009-07



TECHNICAL



REPORT




Electrical installations in ships –
Part 370: Guidance on the selection of cables for telecommunication and data
transfer including radio-frequency cables



IEC/TR 60092-370:2009(E)

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IEC/TR 60092-370


®

Edition 1.0 2009-07



TECHNICAL



REPORT




Electrical installations in ships –
Part 370: Guidance on the selection of cables for telecommunication and data
transfer including radio-frequency cables



INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
R
ICS 29.060.20; 47.020.60 ISBN 978-2-88910-054-5
® Registered trademark of the International Electrotechnical Commission

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– 2 – TR 60092-370 © IEC:2009(E)



CONTENTS

FOREWORD.3


INTRODUCTION.5

1 Scope.6

2 Terms and definitions .6


3 Selection of cables .6

4 Fundamental considerations .6

5 Constructional considerations.7

5.1 Selection of conductor.7
5.2 Selection of insulation .7
5.3 Cable elements .7
5.4 Selection of screen, core screen or shield .7
5.5 Selection of outer protection.8
5.6 Selection of metallic sheath (covering), braid or armour .8
6 Marking .8
7 Guidance on the selection of appropriate tests .8
8 Guide to use.9
8.1 Introduction .9
8.2 General .9
8.3 Voltage rating.9
8.3.1 Data and telecommunication cables .9
8.3.2 High-frequency radio communications cables .10
8.4 Current ratings .10
8.5 Thermal considerations .10
8.6 Size of conductors.10
8.7 Radius of bend .10
8.8 Tensile stress.11
8.9 Compression .11
8.10 Mechanical damage .11
8.11 Electromagnetic interference .11
8.12 Terminations .12
8.13 Joints .12
9 Performance in a fire .12

Annex A (informative) Table of tests .14
Bibliography.17

Table 1 – Classification of cables by frequency range.9

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TR 60092-370 © IEC:2009(E) – 3 –


INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________



ELECTRICAL INSTALLATIONS IN SHIPS –



Part 370: Guidance on the selection of cables for telecommunication

and data transfer including radio-frequency cables





FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
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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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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
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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.
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC 60092-370, which is a technical report, has been prepared by subcommittee 18A: Electric
cables for ships and mobile and fixed offshore units, of IEC technical committee 18: Electrical
installations of ships and of mobile and fixed offshore units.

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– 4 – TR 60092-370 © IEC:2009(E)


The text of this technical report is based on the following documents:


Enquiry draft Report on voting

18A/289/DTR 18A/302/RVC




Full information on the voting for the approval of this technical report can be found in the

report on voting indicated in the above table.


This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all parts of the IEC 60092 series can be found, under the general title Electrical
installations in ships, on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result 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.

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TR 60092-370 © IEC:2009(E) – 5 –


INTRODUCTION


IEC 60092 series of International Standards concerns electrical installations in sea-going

ships, and fixed and mobile offshore units, incorporating good practice and co-ordinating as

far as possible existing rules.


These standards form a code of practical interpretation and amplification of the requirements

of the International Convention on Safety of Life at Sea, a guide for future regulations which

may be prepared and a statement of practice for use by shipowners, shipbuilders, mobile and

fixed offshore units owners and builders and appropriate organisations.


This IEC/TR 60092-370 has been prepared by the maintenance team MT2 of the IEC
subcommittee 18A.
Cables selected for installation onboard ships and on offshore installations are usually
installed and are expected to operate in much harsher environments than equivalent land
based types. The risk of mechanical abuse during installation, physical dislocation due to
tension and bending allied with extremes of temperature are examples of the conditions to
which these cables may be subject. If faults occur unlike onshore installations, trained
experienced technicians may not always be readily available to affect a repair or replacement.

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– 6 – TR 60092-370 © IEC:2009(E)


ELECTRICAL INSTALLATIONS IN SHIPS –



Part 370: Guidance on the selection of cables for telecommunication

and data transfer including radio-frequency cables








1 Scope


This Technical Report gives guidance and lays down the basic recommendations for the
selection and installation of shipboard and offshore unit cables intended for electrical systems
used in both essential and non-essential analogue or digital signal communication,
transmission and control networks, including types suitable for high-frequency signals (i.e.
5
signals with a frequency of more than 10 Hz). These cables are not suitable for direct
connection to low impedance supplies. Where such cables are required, attention is drawn to
IEC 60092-353.
Cables intended to have limited circuit integrity (fire resistance) when affected by fire are not
covered by this technical report.
Fibre optical cables are not included.
Sub-sea or umbilical cables are not included.
2 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60092-350 apply.
3 Selection of cables
Cables with physical and electrical characteristics in accordance with the IEC 60092 series of
international standards are recommended for use in the marine environment.
Cables constructed in accordance with the following standards are acceptable provided that
due consideration has been given to their use in a marine environment: IEC 60189-1,
IEC 60189-2, IEC 60189-3, and IEC 60096-0-1.
4 Fundamental considerations

The choice of materials and cable construction should be suitable for the intended application
and installation of the cable.
The high level of electrical performance associated with many modern cables is only achieved
by the accurate, consistent positioning of the various components within the cable. Careless
or excess tension, compression or bending can alter this relationship. This may then have
significant detrimental effects upon the fundamental performance of the cable at high data
rates.
Similarly these high levels of electrical performance can usually only be achieved by the use
of polymers and insulation systems that may not have the same reaction to fire characteristics
as the more traditional materials used in other marine cables. In recognition of this, careful
consideration should be given to the method of installation to select that most appropriate to
the particular application (see also Clause 8).

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TR 60092-370 © IEC:2009(E) – 7 –


5 Constructional considerations


5.1 Selection of conductor


Only circular copper conductors, either plain or metal coated, or copper covered steel are

recommended for use in a marine environment. Stranded conductors are recommended for

general use. Where the applicable product standard specifies solid conductors, consideration

should be given to the possible effects of vibration (due to the movement of the ship or

installation) or movement (due to motion of the ship or installation).


The properties of copper conductors should be in accordance with IEC 60228. Joints in solid

conductors or complete stranded conductors are not permitted, however joints in individual
strands are allowed.
NOTE When cables are subject to continuous flexing the advice of the manufacture should be sought.
5.2 Selection of insulation
The range of materials for use as conductor insulation should, where possible, be selected
from those listed in the IEC 60092-351 or as given in IEC 60096-0-1 and IEC 61156-5-1. For
cables operating at the higher frequencies the insulation may be solid, cellular or a foam skin
composite. The rated operating temperature of the insulating material should be at least 10 °C
higher than the maximum ambient temperature likely to exist, or to be produced, in the space
where the cable is installed.
The insulation should be continuous having a thickness as uniform as possible. The insulation
should be applied to fit closely to the conductor.
NOTE The user should carefully select the insulation material regarding its electrical characteristics and intended
use in the marine environment.
5.3 Cable elements
The cores within each pair, triple, or quad should be clearly identified by colour or number as
given in the applicable cable standard. The identification used should be durable and legible.
The choice of the maximum average length of lay in the finished cable should be selected with
respect to the specified crosstalk requirements, handling performance and the pair or quad
integrity.
5.4 Selection of screen, core screen or shield
If a screen is required, it may consist of the following:

a) a metallic laminated tape bonded to polyester and a drain wire in direct contact with
the metallic side of the tape,
b) plain or metal coated copper braid,
c) a metallic laminated tape bonded to polyester and a drain wire in direct contact with
the metallic side of the tape with a plain or metal coated copper braid.
The construction of the screen, core screen or shield should be as listed in IEC 60092-350 or
the applicable cable standard. Care should be taken when putting dissimilar metals in contact
with each other. Coatings or other methods of protection may be necessary to prevent
galvanic interaction often encountered in the saliferous marine environment.
NOTE The type of screening should be carefully selected by the user in respect of not only the type of
disturbance, electrostatic or electro-magnetic, but also the mechanical hazards, and potential for corrosion,
encountered in the marine environment.

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– 8 – TR 60092-370 © IEC:2009(E)


5.5 Selection of outer protection


The range of materials for use as protective sheath should, where possible, be selected from

those listed in IEC 60092-359 which have been proven by experience to be suitable for use in

the marine environment. Materials listed in IEC 60096-0-1 and IEC 61156-1 may also be

considered, the material chosen should meet the requirements of this technical report.


The material selected should be compatible with the cable components with which it is in

contact and compatible with the intended environment and operating temperature of the cable.


In instances where the construction of a cable does not conform with a standard from the

IEC 60092 series, it should be ensured that the material used as the protective sheath has
adequate mechanical strength in respect of the mechanical hazards to which it may be
subjected during installation and service. The potential for corrosion, of underlying layers,
encountered in the marine environment should also be considered. Attention is drawn to the
list of permitted protective coverings given in IEC 60092-350.
Due consideration should be given to fluid resistance for cables installed where water
condensation or harmful vapours (including oil vapour) may be present. In this instance, the
cables should meet the appropriate fluid resistance requirements of Annex D of IEC 61892-4.
NOTE Not all materials in IEC 60092-359 meet the fluid resistance requirement.
Also consideration should be given to the fire performance characteristics given in Clause 9.
The minimum thickness of sheath considered as being acceptable for cables for installation
onboard a ship or offshore installation is 0,7 mm.
5.6 Selection of metallic sheath (covering), braid or armour
The construction of the metal braid armour should be in accordance with IEC 60092-350. The
type of metal braid armour should be carefully selected by the user in respect of not only the
mechanical hazards but also and potential for corrosion encountered in the marine
environment. Care should be taken when putting dissimilar metals in contact with each other.
Coatings or other methods of protection may be necessary to prevent galvanic interaction
often encountered in the saliferous marine environment.
6 Marking
Cables should be provided with a continuous indication of origin (manufacturers name or
trade mark), by one of the following methods:

a) printing, indenting or embossing on the outer sheath,
b) a printed tape within the cable,
c) the inclusion of identification threads within the cable,
d) printing on the insulation of at least one core.
The marking should be durable and legible.
The spacings and dimensions of the indication of origin should be as given in the applicable
product standard.
7 Guidance on the selection of appropriate tests
Unless otherwise specified in the applicable product standard, tests should be made at an
ambient temperature of (20 ± 15) °C.

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TR 60092-370 © IEC:2009(E) – 9 –


This technical report defines, by the frequency range in the intended application, seven

classes of cable (Table 1) and in Annex A gives guidance in the selection of the appropriate

tests to be applied, related to each class.


Table 1 – Classification of cables by frequency range




Cable type Frequency range

1 f max <100 kHz

2 100 kHz 1 MHz


3
1 MHz 16 MHz
4
16 MHz 125 MHz
5 125 MHz 250 MHz
6
250 MHz 600 MHz
7
250 Hz 1 000 MHz
NOTE All cables are backwards compatible.
8 Guide to use
8.1 Introduction
The aim of this section is to inform users of characteristics and limitations of electric cables
and thereby to minimise misuse.
It is assumed that the design of installation and the specification, purchase and installation of
cables in accordance with this technical report is entrusted to suitable skilled and competent
people.
In case of doubt as to the suitability of cables covered by this technical report for a particular
use, further specific information should be obtained from the manufacturer.
8.2 General
All cables should be stored in a suitable place until required. Consideration should be given to
security and environmental conditions.
Any protective packaging should not be removed until the cable is to be installed.
The ends of cables should always remain sealed during storage and installation to prevent the

ingress of water and other contaminants.
8.3 Voltage rating
8.3.1 Data and telecommunication cables
All cables covered by this technical report should be subject to electrical tests applicable to
their maximum rated voltage. Recommended maximum rated voltages for data and
instrumentation cables are:
• 60 V a.c.
• 250 V a.c.
The rated voltage of any cable should not be lower than the nominal voltage of the circuit for
which it is used.
NOTE These cables are not intended to be used for power supply.

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– 10 – TR 60092-370 © IEC:2009(E)


8.3.2 High-frequency radio communications cables


The voltage rating of the cable should not be lower than the nominal voltage of the radio

communication system in which it will be used.


8.4 Current ratings

The cables covered by this technical report are only recommended for use in circuits carrying
analogue and digital signals.



Where high power co-axial feeder cables are to be used, advice from the cable manufacturer
should be sought.

NOTE These cables are not intended to be used for power supply.
8.5 Thermal considerations
It is recommended that the rated operating temperature of the cable selected shall be at least
10 °C higher than the maximum ambient temperature likely to exist, or to be produced, in the
space where the cable is installed.
These cables should not normally be run in groups or bundles containing power cables
operating at or near their maximum operating temperature. Where this is unavoidable then the
operating temperature should be based upon the lowest maximum operating temperature of
any cable in the group or bundle.
All insulation and sheathing materials used for cables become progressively stiffer as their
temperature is lowered below the normal ambient temperature to the point where they
become brittle. This should be carefully considered when comparing the minimum operating
temperature of the cable with the intended environment and application.
The cable should be acclimatised at the recommended environmental conditions before
installation.
8.6 Size of conductors
The selection of the size of each conductor should not be based upon the attenuation or the
electrical characteristics of the circuit alone. Account should be taken of the mechanical
strength, the method, as well as the route, upon which the cable is to be installed. The cable
should be of sufficient size as to mitigate mechanical damage, and impairment of its electrical
integrity and characteristics, during installation and subsequent operation in the conditions
encountered in the marine environment.

8.7 Radius of bend
The internal radius of bend for the installation of all cables should be chosen according to the
type of cable as recommended by the manufacturer such that the electrical integrity and
characteristics of the cable are not impaired due to disassociation of components within the
cable.
The minimum bending radius used should never be less than what is recommended by the
manufacturer.
Particular care should be taken when dressing cable, inserting cable into conduit, bending
around corners in conduit or at the transition from vertical to horizontal tray to ensure that the
cable is never bent below the recommended minimum bending radius.
NOTE Cable runs should be selected to keep the number of bends to a minimum.
Cables with class 5 conductors are not intended for flexible applications.

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TR 60092-370 © IEC:2009(E) – 11 –


8.8 Tensile stress


In assessing the risk of mechanical damage to cables, account should be taken of any

mechanical strains likely to be imposed during the normal process of installation of cables.


Cables should be so installed that the tensile stress applied to them either by reason of their

own weight or for any other reason, is minimised. Excessive tension can cause disassociation

of components within the cable resulting in the impairment of the electrical integrity and

characteristics of the cable. These precautions are particularly important for cables of small
cross-section and for cables on vertical runs or in vertical conduit or ducting.



The distances between supports should be as recommended by the cable manufacturer and
chosen to avoid excessive tension due to sagging in the cable. Careful consideration should
be given to cable runs along weather decks, when the cable run is arranged so that the
cables can be subjected to forces by water washing over the deck.
The mechanical strength of conductors should be sufficient for the method of installation and
working conditions.
8.9 Compression
Fixings and supports used should have a surface area sufficiently large and be shaped that
the cables remain tight without their coverings being damaged. Care should be exercised to
ensure that the forces applied by these fixings do not cause impairment of the electrical
integrity and characteristics of the cable due to disassociation of components within the cable.
Installations should be such that tensions in cables and cinching of bundles shall be
minimized. The cable sheath should not be deformed.
Where individual stuffing glands or boxes containing several
...