IEC 61156-6:2002

INTERNATIONAL IEC
STANDARD
61156-6
First edition
2002-03
Multicore and symmetrical pair/quad cables
for digital communications –
Part 6:
Symmetrical pair/quad cables with transmission
characteristics up to 600 MHz–
Work area wiring – Sectional specification
Câbles multiconducteurs à paires symétriques et quartes
pour transmissions numériques –
Partie 6:
Câbles à paires symétriques et quartes avec caractéristiques
de transmission allant jusqu'à 600 MHz –
Raccordement de terminal – Spécification intermédiaire

Reference number
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60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.

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edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the base publication, the
base publication incorporating amendment 1 and the base publication incorporating
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INTERNATIONAL IEC
STANDARD
61156-6
First edition
2002-03
Multicore and symmetrical pair/quad cables
for digital communications –
Part 6:
Symmetrical pair/quad cables with transmission
characteristics up to 600 MHz–
Work area wiring – Sectional specification
Câbles multiconducteurs à paires symétriques et quartes
pour transmissions numériques –
Partie 6:
Câbles à paires symétriques et quartes avec caractéristiques
de transmission allant jusqu'à 600 MHz –
Raccordement de terminal – Spécification intermédiaire

 IEC 2002  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch  Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale
R
International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – 61156-6  IEC:2002(E)
CONTENTS
FOREWORD.4

1 General .5

1.1 Scope.5

1.2 Normative references .6

1.3 Installation considerations.6

1.4 Climatic conditions.6

2 Definitions, materials and cable construction.6
2.1 Definitions .6
2.2 Materials and cable construction.6
2.2.1 General remarks.6
2.2.2 Cable construction .6
2.2.3 Conductor.6
2.2.4 Insulation.7
2.2.5 Colour code of insulation.7
2.2.6 Cable element .7
2.2.7 Screening of cable element.7
2.2.8 Cable make-up .7
2.2.9 Screening of cable core .7
2.2.10 Sheath.7
2.2.11 Colour of sheath .8
2.2.12 Identification .8
2.2.13 Finished cable .8
3 Characteristics and requirements.8
3.1 General remarks.8
3.2 Electrical characteristics .8
3.2.1 Conductor resistance .8
3.2.2 Resistance unbalance.8
3.2.3 Dielectric strength.8
3.2.4 Insulation resistance .8
3.2.5 Mutual capacitance .9
3.2.6 Capacitance unbalance pair to ground.9
3.2.7 Transfer impedance.9

3.2.8 Resistance of the screen.9
3.3 Transmission characteristics.9
3.3.1 Velocity of propagation, delay and differential delay (delay skew) .9
3.3.2 Attenuation .10
3.3.3 Unbalance attenuation .11
3.3.4 Near-end crosstalk.12
3.3.5 Far-end crosstalk (FEXT).13
3.3.6 Characteristic impedance.14
3.3.7 Return loss (RL) .15
3.3.8 Screening attenuation .15
3.3.9 Coupling attenuation .15

61156-6  IEC:2002(E) – 3 –
3.4 Mechanical and dimensional characteristics and requirements .16

3.4.1 Dimensional requirements.16

3.4.2 Elongation at break of the conductor .16

3.4.3 Elongation at break of the insulation.16

3.4.4 Elongation at break of the sheath.16

3.4.5 Tensile strength of the sheath .16

3.4.6 Crush test of the cable.16

3.4.7 Impact test of the cable.16

3.4.8 Repeated bending of the cable.16

3.4.9 Tensile performance of the cable .16

3.5 Environmental characteristics .16
3.5.1 Shrinkage of insulation.16
3.5.2 Wrapping test of insulation after thermal ageing .16
3.5.3 Bending test of insulation at low temperature .16
3.5.4 Elongation at break of the sheath after ageing.17
3.5.5 Tensile strength of the sheath after ageing.17
3.5.6 Sheath pressure test at high temperature.17
3.5.7 Cold bend test of the cable .17
3.5.8 Heat shock test.17
3.5.9 Flame propagation characteristics of a single cable.17
3.5.10 Flame propagation characteristics of bunched cables.17
3.5.11 Acid gas evolution.17
3.5.12 Smoke generation.17
3.5.13 Toxic gas emission .17
3.5.14 Combined flame and smoke test .17
4 Introduction to the blank detail specification .17

– 4 – 61156-6  IEC:2002(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION

___________
MULTICORE AND SYMMETRICAL PAIR/QUAD CABLES

FOR DIGITAL COMMUNICATIONS –
Part 6: Symmetrical pair/quad cables

with transmission characteristics up to 600 MHz –

Work area wiring – Sectional specification

FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising all
national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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
National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form of
standards, technical specifications, technical reports or guides and they are accepted by the National Committees
in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International Standards
transparently to the maximum extent possible in their national and regional standards. Any divergence between the
IEC Standard and the corresponding national or regional standard shall be clearly indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61156-6 has been prepared by subcommittee 46C: Wires and
symmetric cables, of IEC technical committee 46: Cables, wires, waveguides, RF connectors and
accessories for communication and signalling.
The text of this standard is based on the following documents:
FDIS Report on voting
46C/512/FDIS 46C/518/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 standard should be read in conjunction with IEC 61156-1.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until 2004.
At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
61156-6  IEC:2002(E) – 5 –
MULTICORE AND SYMMETRICAL PAIR/QUAD CABLES

FOR DIGITAL COMMUNICATIONS –
Part 6: Symmetrical pair/quad cables

with transmission characteristics up to 600 MHz –

Work area wiring – Sectional specification

1 General
1.1 Scope
This sectional specification relates to IEC 61156-1: Multicore and symmetrical pair/quad cables
for digital communications – Part 1: Generic specification. The cables described herein are
specifically intended to construct patch, equipment, and work area cords for class D, E and F
channels, as defined in IEC 11801:2000, Information technology – Generic cabling for customer
premises (see Table 1).
It covers individually screened (STP), common screened (FTP) and unscreened (UTP) pairs or
quads having a pair count of four pairs or less. The transmission characteristics of the cables are
specified at 20 °C. See Annex A of IEC 61156-5 for a discussion of cable performance at
temperatures higher than 20 °C.
The designation "Category 5e" is used herein to describe an enhanced Category 5 cable and is
used in the same context as "Category 5" in ISO/IEC 11801. This enhanced cable is designated
Category 5e to differentiate it from the Category 5 cables described in IEC 61156-2, 61156-3, and
61156-4. Although both Category 5 and 5e cables are characterized to 100 MHz and can in used
for Class D channels, Category 5e has additional requirements, as compared to Category 5, which
make it preferred for use in systems utilizing four pairs transmitting simultaneously in both
directions.
Table 1 – Cable categories
Maximum reference
Cable designation Channel designation
frequency
MHz
a
Category 5e 100 D
Category 6 250 E
Category 7 600 F
a
Some characteristics are measured up to 125 MHz in order to comply with IEEE’s
request to specify the electrical performances up to a frequency 25 % higher than the
referenced frequency.
These cables are intended for various new communication systems that are under development
and which use as many as four pairs simultaneously. In this sense, this sectional specification
provides the cable characteristics required by system developers to evaluate new systems.
The cables covered by this sectional specification are intended to operate with voltages and
currents normally encountered in communication systems. These cables are not intended to be
used in conjunction with low impedance sources, for example, the electric power supplies of public
utility mains.
Though the recommended temperature range during installation is 0 °C +50 °C, the actual
temperature range during installation should be indicated in the detail specification.

– 6 – 61156-6  IEC:2002(E)
1.2 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 61156-5, Multicore and symmetrical pair/quad cables for digital communications – Part 5:

Symmetrical pair/quad cables with transmission characteristics up up to 600 MHz – Horizontal floor

wiring – Sectional specification

ISO/IEC 11801:2000, Information technology – Generic cabling for customer premises

Publications listed in IEC 61156-1 also apply.
1.3 Installation considerations
Installation considerations will be addressed in a future revision of 1.3 of IEC 61156-1.
1.4 Climatic conditions
Under static conditions, the cables shall operate in the temperature range from –40 °C to +60 °C.
The temperature dependence of the cables is specified for screened and unscreened cables, and
should be taken into account for the design of an actual cabling system. Patch cables are
susceptible to moisture pick-up. This in turn impacts also on the attenuation. Therefore the
maximum increase in attenuation due to long term exposure to humidity is specified.
2 Definitions, materials and cable construction
2.1 Definitions
See 2.1 of IEC 61156-1.
2.2 Materials and cable construction
2.2.1 General remarks
The choice of materials and cable construction shall be suitable for the intended application and
installation of the cable. Particular care shall be taken to meet any special requirements for fire
performance (such as burning properties, smoke generation, evolution of halogen gas, etc.).
2.2.2 Cable construction
The cable construction shall be in accordance with the details and dimensions given in the relevant
detail specification.
2.2.3 Conductor
The conductor shall be solid or stranded annealed copper conductor, in accordance with 2.2.3 of
IEC 61156-1 and shall have a nominal diameter between 0,4 mm to 0,65 mm. The stranded
conductor should have preferably seven strands. Conductor diameter up to 0,8 mm may be used
if compatible with the connecting hardware.
The conductor shall be plain or tinned.
The conductor may consist of one or more elements of thin copper or copper alloy tape, which
shall be applied helically over a fibrous thread (tinsel cord). In this case, joints in the complete
element shall not be permitted.

61156-6  IEC:2002(E) – 7 –
2.2.4 Insulation
The conductor shall be insulated with a suitable thermoplastic material. Examples of suitable

materials are
– polyolefin;
– fluoropolymer;
– low-smoke zero-halogen thermoplastic material.

The insulation may be solid or cellular with or without a solid dielectric skin. The insulation shall

be continuous and shall have a thickness such that the completed cable meets the specified

requirements. The nominal thickness of the insulation shall be compatible with the method of
conductor termination.
2.2.5 Colour code of insulation
The colour code is not specified but shall be indicated in the relevant detail specification. The
colours shall be readily identifiable and shall correspond reasonably with the standard colours
shown in IEC 60304.
NOTE It is acceptable to mark or stripe the "a" wire with the colour of the "b" wire to facilitate pair identification.
2.2.6 Cable element
The cable element shall be a pair or quad adequately twisted.
2.2.7 Screening of cable element
When required, the screen for the cable element shall be in accordance with 2.2.7 of IEC 61156-1.
2.2.8 Cable make-up
A cross web or any other spacer may be used to separate the cable elements. The cable elements,
including cross webs or spacers, shall be assembled to form the cable core.
The core of the cable may be wrapped with a protective layer of non-hygroscopic material.
2.2.9 Screening of cable core
When required by the relevant detail specification, a screen for the cable core shall be provided.
The screen shall be in accordance with 2.2.9 of IEC 61156-1.

2.2.10 Sheath
The sheath material shall consist of a suitable thermoplastic material.
Examples of suitable materials are
– polyolefin;
– PVC;
– fluoropolymer;
– low-smoke zero-halogen thermoplastic material.
The sheath shall be continuous, having a thickness as uniform as possible. A non-metallic ripcord
may be provided. When provided, the ripcord shall be non-hygroscopic.

– 8 – 61156-6  IEC:2002(E)
2.2.11 Colour of sheath
The colour of the sheath is not specified, but it should be stated in the relevant detail specification.

2.2.12 Identification
Each length of cable shall be identified as to the manufacturer, and when required, the year of

manufacture, using one of the following methods:

a) appropriately coloure
...