IEC 61156-7:2023

Multicore and symmetrical pair/quad cables for digital communications - Part 7: Symmetrical pair cables with transmission characteristics up to 1 200 MHz - Sectional specification for digital and analogue communication cables

IEC 61156-7:2023 specifies cables that can be used for various communication systems as well as for analogue systems, such as video, that exist or are under development and which may 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 as well as to enhance present systems. It covers a cable having four individually screened (S/FTP) pairs. The cable can be provided with a common screen over the cable core. This second edition cancels and replaces the first edition published in 2003 and Amendment 1:2012. This edition includes the following significant technical changes with respect to the previous edition:
a. align clauses with IEC 61156-1:2023;
b. remove the clause related to screening attenuation as it is no longer a test to be performed (replaced by coupling attenuation);
c. replace the IEC 62153-4-2 method (injection clamp) with IEC 61156-4-5 (absorbing clamp) for coupling attenuation measurement to be consistent with all other parts of the IEC 61156 series;
d. include IEC 62153-4-9 test method (triaxial) for coupling attenuation measurement to be consistent with all other parts of the IEC 61156 series;
e. incorporate the blank detail specification.

General Information

• Status: Published
• Publication Date: 09-Feb-2023
• ICS: 33.120.20 - Wires and symmetrical cables
• Technical Committee: SC 46C - Wires and symmetric cables
• Drafting Committee: WG 7 - TC 46/SC 46C/WG 7
• Current Stage: PPUB - Publication issued
• Start Date: 28-Feb-2023
• Completion Date: 10-Feb-2023

Relations

• Revises: IEC 61156-7:2003/COR1:2003 - Corrigendum 1 - Multicore and symmetrical pair/quad cables for digital communications - Part 7: Symmetrical pair cables with transmission characteristics up to 1 200 MHz - Sectional specification for digital and analog communication cables
• Effective Date: 05-Sep-2023
• Revises: IEC 61156-7:2003 - Multicore and symmetrical pair/quad cables for digital communications - Part 7: Symmetrical pair cables with transmission characteristics up to 1 200 MHz - Sectional specification for digital and analog communication cables
• Effective Date: 05-Sep-2023
• Revises: IEC 61156-7:2003/AMD1:2012 - Amendment 1 - Multicore and symmetrical pair/quad cables for digital communications - Part 7: Symmetrical pair cables with transmission characteristics up to 1 200 MHz - Sectional specification for digital and analog communication cables
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61156-7 ®
Edition 2.0 2023-02
INTERNATIONAL
STANDARD
Multicore and symmetrical pair/quad cables for digital communications –
Part 7: Symmetrical pair cables with transmission characteristics up to
1 200 MHz – Sectional specification for digital and analogue communication
cables
All rights reserved. Unless otherwise specified, 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
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Secretariat Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

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further assistance, please contact the Customer Service
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IEC 61156-7 ®
Edition 2.0 2023-02
INTERNATIONAL
STANDARD
Multicore and symmetrical pair/quad cables for digital communications –

Part 7: Symmetrical pair cables with transmission characteristics up to

1 200 MHz – Sectional specification for digital and analogue communication

cables
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.120.20 ISBN 978-2-8322-6374-7

– 2 – IEC 61156-7:2023 © IEC 2023
CONTENTS
FOREWORD . 5
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Installation consideration . 8
4.1 General remarks . 8
4.2 Bending radius of installed cable. 8
4.3 Climatic conditions . 8
5 Material and cable construction . 8
5.1 General remarks . 8
5.2 Cable construction . 8
5.2.1 General . 8
5.2.2 Conductor . 8
5.2.3 Insulation . 9
5.2.4 Cable element . 9
5.2.5 Cable make-up . 9
5.2.6 Screening of the cable core . 9
5.2.7 Sheath . 9
5.2.8 Identification . 10
5.2.9 Finished cable . 10
6 Characteristics and requirements . 10
6.1 General remarks . 10
6.2 Electrical characteristics and tests . 10
6.2.1 Conductor resistance . 10
6.2.2 Resistance unbalance within a pair . 10
6.2.3 Dielectric strength . 10
6.2.4 Insulation resistance . 11
6.2.5 Mutual capacitance . 11
6.2.6 Capacitance unbalance pair to ground . 11
6.2.7 Transfer impedance . 11
6.2.8 Coupling attenuation . 11
6.2.9 Current-carrying capacity . 12
6.2.10 Resistance of the screen . 12
6.3 Transmission characteristics . 12
6.3.1 General remark . 12
6.3.2 Velocity of propagation (phase velocity) . 12
6.3.3 Phase delay and differential phase delay (delay skew) . 12
6.3.4 Attenuation (α) . 13
6.3.5 Unbalance attenuation near-end (TCL, EL TCTL). 13
6.3.6 Near-end crosstalk (PS NEXT, NEXT) . 14
6.3.7 Far-end crosstalk (PS ACR-F, ACR-F) . 15
6.3.8 Alien (exogenous) near-end crosstalk . 16
6.3.9 Alien (exogenous) far-end crosstalk . 16
6.3.10 Alien (exogenous) crosstalk of bundled cables . 16
6.3.11 Impedance . 16
6.3.12 Return loss (RL) . 16

6.4 Mechanical and dimensional characteristics and requirements . 17
6.4.1 Dimensional requirements . 17
6.4.2 Elongation at break of the conductors . 17
6.4.3 Tensile strength of the insulation . 17
6.4.4 Elongation at break of the insulation . 17
6.4.5 Adhesion of the insulation to the conductor . 17
6.4.6 Elongation at break of the sheath . 17
6.4.7 Tensile strength of the sheath . 17
6.4.8 Crush test of the cable . 17
6.4.9 Impact test of the cable . 17
6.4.10 Bending under tension . 18
6.4.11 Repeated bending of the cable . 18
6.4.12 Tensile performance of the cable . 18
6.4.13 Shock-test requirements of the cable . 18
6.4.14 Bump-test requirements of the cable . 18
6.4.15 Vibration-test requirements of the cable . 18
6.5 Environmental characteristics . 18
6.5.1 Shrinkage of insulation . 18
6.5.2 Wrapping test of insulation after thermal ageing . 18
6.5.3 Bending test of insulation at low temperature . 18
6.5.4 Elongation at break of the sheath after ageing . 18
6.5.5 Tensile strength of the sheath after ageing . 18
6.5.6 Sheath pressure at high temperature . 18
6.5.7 Cold bend test of the cable . 19
6.5.8 Hot shock test. 19
6.5.9 Damp heat steady state . 19
6.5.10 Solar radiation (UV) . 19
6.5.11 Solvents and contaminating fluids . 19
6.5.12 Salt mist and sulphur dioxide . 19
6.5.13 Water immersion . 19
6.5.14 Hygroscopicity . 19
6.5.15 Wicking. 19
6.5.16 Flame propagation characteristics of a single cable . 19
6.5.17 Flame propagation characteristics of bunched cables . 19
6.5.18 Resistance to fire . 19
6.5.19 Halogen gas evolution . 19
6.5.20 Smoke generation . 20
6.5.21 Toxic gas emission . 20
6.5.22 Integrated fire test . 20
7 Introduction to the blank detail specification . 20
Annex A (informative) Blank detail specification . 21
Bibliography . 26

Table 1 – Transfer impedance . 11
Table 2 – Coupling attenuation . 11
Table 3 – Attenuation, constant values . 13
Table 4 – Attenuation values . 13
Table 5 – Near-end crosstalk, power-sum (PS NEXT). 15

– 4 – IEC 61156-7:2023 © IEC 2023
Table 6 – Far-end crosstalk (PS ACR-F) . 16
Table 7 – Return loss . 17
...

IEC 61156-7 ®
Edition 2.0 2023-02
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Multicore and symmetrical pair/quad cables for digital communications –
Part 7: Symmetrical pair cables with transmission characteristics up to
1 200 MHz – Sectional specification for digital and analogue communication
cables
All rights reserved. Unless otherwise specified, 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
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Secretariat Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC Products & Services Portal - products.iec.ch
The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the
variety of criteria (reference number, text, technical publications previews. With a subscription you will always have
committee, …). It also gives information on projects, replaced access to up to date content tailored to your needs.
and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 300 terminological entries in English
details all new publications released. Available online and once
and French, with equivalent terms in 19 additional languages.
a month by email.
Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc

If you wish to give us your feedback on this publication or need
further assistance, please contact the Customer Service
Centre: [e-mail].
IEC 61156-7 ®
Edition 2.0 2023-02
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Multicore and symmetrical pair/quad cables for digital communications –
Part 7: Symmetrical pair cables with transmission characteristics up to
1 200 MHz – Sectional specification for digital and analogue communication
cables
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 33.120.20 ISBN 978-2-8322-6487-4

– 2 – IEC 61156-7:2023 RLV © IEC 2023
CONTENTS
FOREWORD . 5
1 General .
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Installation consideration . 9
4.1 General remarks . 9
4.2 Bending radius of installed cable. 9
4.3 Climatic conditions . 9
5 Material and cable construction . 9
5.1 General remarks . 9
5.2 Cable construction . 10
5.2.1 General . 10
5.2.2 Conductor . 10
5.2.3 Insulation . 10
5.2.4 Cable element . 10
5.2.5 Cable make-up . 10
5.2.6 Screening of the cable core . 11
5.2.7 Sheath . 11
5.2.8 Identification . 11
5.2.9 Finished cable . 11
6 Characteristics and requirements . 12
6.1 General remarks . 12
6.2 Electrical characteristics and tests . 12
6.2.1 Conductor resistance . 12
6.2.2 Resistance unbalance within a pair . 12
6.2.3 Dielectric strength . 12
6.2.4 Insulation resistance . 12
6.2.5 Mutual capacitance . 12
6.2.6 Capacitance unbalance pair to ground . 12
6.2.7 Transfer impedance . 12
6.2.8 Coupling attenuation . 13
6.2.9 Current-carrying capacity . 13
6.2.10 Resistance of the screen . 13
6.3 Transmission characteristics . 13
6.3.1 General remark . 13
6.3.2 Velocity of propagation (phase velocity) . 14
6.3.3 Phase delay and differential phase delay (delay skew) . 14
6.3.4 Attenuation (α) . 14
6.3.5 Unbalance attenuation near-end (TCL, EL TCTL). 15
6.3.6 Near-end crosstalk (NEXT) (PS NEXT, NEXT) . 16
6.3.7 Far-end crosstalk (FEXT) (PS ACR-F, ACR-F) . 17
6.3.8 Alien (exogenous) near-end crosstalk . 17
6.3.9 Alien (exogenous) far-end crosstalk . 18
6.3.10 Alien (exogenous) crosstalk of bundled cables . 18
6.3.11 Characteristic Impedance . 18

6.3.12 Return loss (RL) . 17
3.3.8 Screening attenuation .
6.4 Mechanical and dimensional characteristics and requirements . 19
6.4.1 Dimensional requirements . 19
6.4.2 Elongation at break of the conductors . 19
6.4.3 Tensile strength of the insulation . 19
6.4.4 Elongation at break of the insulation . 19
6.4.5 Adhesion of the insulation to the conductor . 19
6.4.6 Elongation at break of the sheath . 19
6.4.7 Tensile strength of the sheath . 19
6.4.8 Crush test of the cable . 19
6.4.9 Impact test of the cable . 19
6.4.10 Bending under tension . 19
6.4.11 Repeated bending of the cable . 20
6.4.12 Tensile performance of the cable . 20
6.4.13 Shock-test requirements of the cable . 20
6.4.14 Bump-test requirements of the cable . 20
6.4.15 Vibration-test requirements of the cable . 20
6.5 Environmental characteristics . 20
6.5.1 Shrinkage of insulation . 20
6.5.2 Wrapping test of insulation after thermal ageing . 20
6.5.3 Bending test of insulation at low temperature . 20
6.5.4 Elongation at break of the sheath after ageing . 20
6.5.5 Tensile strength of the sheath after ageing . 20
6.5.6 Sheath pressure at high temperature . 20
6.5.7 Cold bend test of the cable . 21
6.5.8 Heat Hot shock test . 21
6.5.9 Damp heat steady state . 21
6.5.10 Solar radiation (UV) . 21
6.5.11 Solvents and contaminating fluids . 21
6.5.12 Salt mist and sulphur dioxide . 21
6.5.13 Water immersion . 21
6.5.14 Hygroscopicity . 21
6.5.15 Wicking. 21
6.5.16 Flame propagation characteristics of a single cable . 21
6.5.17 Flame propagation characteristics of bunched cables . 21
3.5.11 Acid gas evolution .
6.5.18 Resistance to fire . 21
6.5.19 Halogen gas evolution . 22
6.5.20 Smoke generation . 22
6.5.21 Toxic gas emission . 22
3.5.14 Combined flame and smoke test .
6.5.22 Integrated fire test . 22
7 Introduction to the blank detail specification . 21
Annex A (informative) Blank detail specification . 23
Bibliography . 28

Table 1 – Transfer impedance . 13

– 4 – IEC 61156-7:2023 RLV © IEC 2023
Table 2 – Coupling attenuation . 13
Table 3 – Attenuation, constant values . 15
Table 4 – Attenuation values . 15
Table 5 – Near-
...