IEC 61156-6:2007

INTERNATIONAL IEC
STANDARD 61156-6
Second edition
2007-06
Multicore and symmetrical pair/quad
cables for digital communications –
Part 6:
Symmetrical pair/quad cables with
transmission characteristics up to 1 000 MHz –
Work area wiring – Sectional specification

Reference number
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INTERNATIONAL IEC
STANDARD 61156-6
Second edition
2007-06
Multicore and symmetrical pair/quad
cables for digital communications –
Part 6:
Symmetrical pair/quad cables with
transmission characteristics up to 1 000 MHz –
Work area wiring – Sectional specification

PRICE CODE
Commission Electrotechnique Internationale R
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

– 2 – 61156-6 © IEC:2007(E)
CONTENTS
FOREWORD.4

1 Scope.6

2 Normative references .6

3 Terms and definitions .7

4 Installation considerations .7

4.1 General .7

4.2 Climatic conditions .7
5 Materials and cable construction .7
5.1 General remarks.7
5.2 Cable construction .7
5.2.1 Conductor.7
5.2.2 Insulation.7
5.2.3 Cable element .7
5.2.4 Cable make-up .8
5.2.5 Screening of the cable core .8
5.2.6 Sheath.8
5.2.7 Identification.8
5.2.8 Finished cable .8
6 Characteristics and requirements .8
6.1 General remarks.8
6.2 Electrical characteristics and tests .9
6.2.1 Conductor resistance.9
6.2.2 Resistance unbalance .9
6.2.3 Dielectric strength .9
6.2.4 Insulation resistance.9
6.2.5 Mutual capacitance.9
6.2.6 Capacitance unbalance .9
6.2.7 Transfer impedance.9
6.2.8 Coupling attenuation.10
6.2.9 Ampacity .10
6.3 Transmission characteristics .10
6.3.1 Velocity of propagation (phase velocity) .10

6.3.2 Phase delay and differential delay (delay skew) .10
6.3.3 Attenuation .11
6.3.4 Unbalance attenuation.11
6.3.5 Near-end crosstalk (NEXT).12
6.3.6 Far-end crosstalk (FEXT) .12
6.3.7 Alien (exogenous) near-end crosstalk.13
6.3.8 Alien (exogenous) far-end crosstalk.13
6.3.9 Alien (exogenous) crosstalk of bundled cables .14
6.3.10 Mean characteristic impedance .14
6.3.11 Return loss (RL) .14
6.4 Mechanical and dimensional characteristics and requirements .14
6.4.1 Dimensional requirements .14
6.4.2 Elongation at break of the conductors.14
6.4.3 Tensile strength of the insulation .14

61156-6 © IEC:2007(E) – 3 –
6.4.4 Elongation at break of the insulation.15

6.4.5 Adhesion of the insulation to the conductor .15

6.4.6 Elongation at break of the sheath .15

6.4.7 Tensile strength of the sheath .15

6.4.8 Crush test of the cable .15

6.4.9 Impact test of the cable .15

6.4.10 Bending under tension.15

6.4.11 Repeated bending of the cable .15

6.4.12 Tensile performance of the cable.15

6.4.13 Shock-test requirements of the cable.15

6.4.14 Bump-test requirements of the cable .15
6.4.15 Vibration-test requirements of a cable .15
6.5 Environmental characteristics.15
6.5.1 Shrinkage of insulation .15
6.5.2 Wrapping test of insulation after thermal ageing .16
6.5.3 Bending test of insulation at low temperature .16
6.5.4 Elongation at break of the sheath after ageing.16
6.5.5 Tensile strength of the sheath after ageing .16
6.5.6 Sheath pressure test at high temperature .16
6.5.7 Cold bend test of the cable .16
6.5.8 Heat shock test.16
6.5.9 Damp heat steady state.16
6.5.10 Solar radiation .16
6.5.11 Solvents and contaminating fluids.16
6.5.12 Salt mist and sulphur dioxide.16
6.5.13 Water immersion .16
6.5.14 Hygroscopicity.16
6.5.15 Wicking .16
6.5.16 Flame propagation characteristics of a single cable.17
6.5.17 Flame propagation characteristics of bunched cables .17
6.5.18 Halogen gas evolution .17
6.5.19 Smoke generation .17
6.5.20 Toxic gas emission .17
6.5.21 Integrated fire test .17
7 Introduction to the blank detail specification .17

Bibliography.18

Table 1 – Cable categories .6
Table 2 – Transfer impedance .10
Table 3 – Coupling attenuation .10
Table 4 – Attenuation, constant values .11
Table 5 – Near-end unbalance attenuation.12
Table 6 – Worst-pair PS NEXT values .12
Table 7 – Worst-pair PS EL FEXT .13
Table 8 – PS ANEXT .13
Table 9 – PS AELFEXT .14
Table 10 – Return loss.14

– 4 – 61156-6 © IEC:2007(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
MULTICORE AND SYMMETRICAL PAIR/QUAD CABLES

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

with transmission characteristics

up to 1 000 MHz – Work area wiring –

Sectional specification
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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Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
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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
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5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
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6) All users should ensure that they have the latest edition of this publication.
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Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61156-6 has been prepared by subcommittee 46C: Wires and
symmetric cables, of IEC technical committee 46: Cables, wires, waveguides, r.f. connectors,
r.f. and microwave passive components and accessories.
This second edition cancels and replaces the first edition published in 2002. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) new requirements for new cables Cat6 , Cat7 for 10 GBase-T applications;
A A
b) revised requirements and tests for the cables.

61156-6 © IEC:2007(E) – 5 –
The text of this standard is based on the first edition and on the following documents:

FDIS Report on voting
46C/818/FDIS 46C/826/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.

This standard shall be read in conjunction with IEC 61156-1.
The list of all the parts of the IEC 61156 series, under the general title Multicore and
symmetrical pair/quad cables for digital communications, can be found 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.

– 6 – 61156-6 © IEC:2007(E)
MULTICORE AND SYMMETRICAL PAIR/QUAD CABLES

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

with transmission characteristics

up to 1 000 MHz – Work area wiring –

Sectional specification
1 Scope
This part of IEC 61156 relates to IEC 61156-1. The cables described herein are intended for
work area wiring as defined in ISO/IEC 11801.
It covers individually screened, common screened and unscreened pairs or quads. The
transmission characteristics and the frequency range (see Table 1) of the cables are specified
at 20 °C.
Table 1 – Cable categories
Maximum reference
Cable designation frequency
MHz
Category 5e 100
Category 6 250
Category 6 500
A
Category 7 600
Category 7 1 000
A
These cables can be used for various communication channels 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 standard 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.
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 60304, Standard colours for insulation for low-frequency cables and wires
IEC 61156-1, Multicore and symmetrical pair/quad cables for digital communication
...