CLC/TR 50174-99-2:2020
(Main)Information technology - Cabling installation - Part 99-2: Mitigation and protection from electrical interference
Information technology - Cabling installation - Part 99-2: Mitigation and protection from electrical interference
This document addresses the mitigation and protection of telecommunications cabling from electromagnetic interference by describing: a) coupling mechanisms and possible countermeasures; b) assessment of the electromagnetic environment; c) filtering, isolation and surge protections measures. Safety (electrical safety and protection, optical power, fire, etc.) and electromagnetic compatibility (EMC) requirements are outside the scope of this document and are covered by standards and regulations. However, information given in this document can be of assistance in meeting these standards and regulations.
Informationstechnik - Installation von Kommunikationsverkabelung - Teil 99-2: Abschwächung von und Schutz vor elektrischer Störung
Technologies de l’information - Installations de câblage - Partie 99-2: Atténuation des perturbations électriques et protection contre ces perturbations
Le présent document traite de l’atténuation des perturbations électromagnétiques et de la protection des câblages de télécommunications contre ces perturbations en décrivant: a) les mécanismes de couplage et les contre-mesures possibles; b) l’évaluation de l’environnement électromagnétique; c) les mesures de filtrage, d’isolation et de protection contre les surtensions. Les exigences relatives à la sécurité (sécurité et protection électriques, puissance optique, incendie, etc.) et à la compatibilité électromagnétique (CEM) ne relèvent pas du domaine d’application du présent document et sont couvertes par les normes et réglementations. Cependant, les informations données dans le présent document peuvent être utiles pour assurer la conformité à ces normes et réglementations.
Informacijska tehnologija - Kabelska inštalacija - 99-2. del: Zmanjševanje električnih motenj iin zaščita pred njimi
General Information
- Status
- Published
- Publication Date
- 19-Mar-2020
- Technical Committee
- CLC/TC 215 - Electrotechnical aspects of telecommunication equipment
- Drafting Committee
- CLC/TC 215 - Electrotechnical aspects of telecommunication equipment
- Current Stage
- 6060 - Document made available - Publishing
- Start Date
- 20-Mar-2020
- Due Date
- 04-Mar-2021
- Completion Date
- 20-Mar-2020
Overview
CLC/TR 50174-99-2:2020 - Information technology - Cabling installation - Part 99-2: Mitigation and protection from electrical interference - is a CENELEC technical report that explains how to protect telecommunications cabling from electromagnetic interference (EMI). Published in 2020, it complements the EN 50174 series by describing coupling mechanisms, how to assess the electromagnetic environment, and practical measures such as filtering, electrical isolation and surge protective devices. Safety and EMC regulatory requirements are outside its scope, but the guidance helps meet those requirements.
Key topics
- Coupling mechanisms: Describes how EMI is transferred to cabling - galvanic/common‑mode impedance, capacitive, inductive, radiative coupling and very low frequency fields.
- Countermeasures: Practical techniques including
- Symmetrical transmission on balanced cabling to improve common‑mode rejection;
- Screened cabling and continuous, low‑impedance screens bonded per EN 50174‑2 and EN 50310;
- Cable management systems (CMS) made from metallic/composite materials, bonded to the bonding network (BN) to form shielding and reduce loop area;
- Use of parallel earthing conductors (PECs), ferrites, filters and Faraday‑cage principles.
- Assessment of the electromagnetic environment: Checklist‑based approach (see Table 1/2) to identify risks - building type, power distribution topology, nearby disturbing sources (transformers, traction lines, welders, transmitters), CMS type and bonding topology.
- Filtering, isolation and surge protection: Guidance on selecting and installing filters, electrical isolation components and surge protective devices (SPDs) to reduce conducted interference and protect equipment.
- Bonding networks: Definitions and practical notes on Common Bonding Network (CBN) and Isolated Bonding Network (IBN) topologies and their role in minimizing common‑mode impedance.
Applications and who should use it
- Network designers and cabling installers specifying and installing structured cabling, especially in high‑EMI environments (industrial sites, rail corridors, near HV lines, hospitals).
- EMC engineers, facility managers and consultants assessing interference risks and defining mitigation strategies.
- Data center planners and building services engineers integrating bonding, screening and surge protection into building infrastructures.
- Anyone implementing EN 50174 series installations who needs detailed guidance on EMI mitigation and selection/installation of filters, isolators and SPDs.
Related standards
- EN 50174 (series) - Cabling installation planning and practices
- EN 50173 (series) - Generic cabling systems
- EN 50310:2016 - Telecommunications bonding networks for buildings and other structures
Using CLC/TR 50174-99-2:2020 helps reduce packet errors, increase link reliability and inform correct selection of screened cabling, CMS design and surge protection - essential for resilient cabling installations in electromagnetically challenging environments.
Frequently Asked Questions
CLC/TR 50174-99-2:2020 is a technical report published by CLC. Its full title is "Information technology - Cabling installation - Part 99-2: Mitigation and protection from electrical interference". This standard covers: This document addresses the mitigation and protection of telecommunications cabling from electromagnetic interference by describing: a) coupling mechanisms and possible countermeasures; b) assessment of the electromagnetic environment; c) filtering, isolation and surge protections measures. Safety (electrical safety and protection, optical power, fire, etc.) and electromagnetic compatibility (EMC) requirements are outside the scope of this document and are covered by standards and regulations. However, information given in this document can be of assistance in meeting these standards and regulations.
This document addresses the mitigation and protection of telecommunications cabling from electromagnetic interference by describing: a) coupling mechanisms and possible countermeasures; b) assessment of the electromagnetic environment; c) filtering, isolation and surge protections measures. Safety (electrical safety and protection, optical power, fire, etc.) and electromagnetic compatibility (EMC) requirements are outside the scope of this document and are covered by standards and regulations. However, information given in this document can be of assistance in meeting these standards and regulations.
CLC/TR 50174-99-2:2020 is classified under the following ICS (International Classification for Standards) categories: 35.110 - Networking. The ICS classification helps identify the subject area and facilitates finding related standards.
You can purchase CLC/TR 50174-99-2:2020 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of CLC standards.
Standards Content (Sample)
SLOVENSKI STANDARD
01-maj-2020
Informacijska tehnologija - Polaganje kablov - 99-2. del: Zmanjševanje električnih
motenj iin zaščita pred njimi
Information technology - Cabling installation - Part 99-2: Mitigation and protection from
electrical interference
Informationstechnik - Installation von Kommunikationsverkabelung - Teil 99-2:
Abschwächung von und Schutz vor elektrischer Störung
Technologies de l'information - Installation de câblages - Partie 99-2:
Ta slovenski standard je istoveten z: CLC/TR 50174-99-2:2020
ICS:
33.040.50 Vodi, zveze in tokokrogi Lines, connections and
circuits
35.110 Omreževanje Networking
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
TECHNICAL REPORT CLC/TR 50174-99-2
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
March 2020
ICS 35.110
English Version
Information technology - Cabling installation - Part 99-2:
Mitigation and protection from electrical interference
Technologies de l'information - Installation de câblages - Informationstechnik - Installation von
Partie 99-2: Kommunikationsverkabelung - Teil 99-2: Abschwächung
von und Schutz vor elektrischer Störung
This Technical Report was approved by CENELEC on 2020-02-10.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. CLC/TR 50174-99-2:2020 E
Contents Page
European foreword .3
Introduction .4
1 Scope .5
2 Normative references .5
3 Definitions, abbreviations and symbology .5
3.1 Definitions .5
3.2 Abbreviations .6
4 Coupling mechanisms and countermeasures .6
4.1 General .6
4.2 Countermeasures against galvanic or common mode impedance coupling .6
4.3 Countermeasures against capacitive coupling .6
4.4 Countermeasures against inductive coupling .7
4.5 Countermeasures against radiative coupling.8
4.6 Protection against very low frequency fields.9
5 Assessment of the electromagnetic environment .9
6 Filtering and electrical isolation components and surge protective devices . 14
6.1 Filtering . 14
6.1.1 General . 14
6.1.2 Design . 15
6.1.3 Installation . 15
6.2 Electrical isolation components . 16
6.2.1 General . 16
6.2.2 Design . 16
6.2.3 Installation . 17
6.3 Surge protective devices. 19
6.3.1 General . 19
6.3.2 Design . 19
6.3.3 Installation . 19
Bibliography . 21
European foreword
This document (CLC/TR 50174-99-2:2020) was prepared by the Technical Committee CLC/TC 215,
“Electrotechnical aspects of telecommunication equipment”.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
A previous version of this document was published as informative Annex A in EN 50174-2:2009.
During the revision of EN 50174-2:2009, TC 215 decided to remove the Annex, revise and then
publish it as separate Technical Report.
Introduction
The EN 50174 series standards specify the specification, planning and practices applicable to
installation of telecommunications cabling.
This document supports the requirements and recommendations of the EN 50174 series in relation to
the mitigation and protection of telecommunications cabling from electromagnetic interference by
describing:
a) coupling mechanisms and possible countermeasures;
b) assessment of the electromagnetic environment;
c) filtering, isolation and surge protections measures.
1 Scope
This document addresses the mitigation and protection of telecommunications cabling from
electromagnetic interference by describing:
a) coupling mechanisms and possible countermeasures;
b) assessment of the electromagnetic environment;
c) filtering, isolation and surge protections measures.
Safety (electrical safety and protection, optical power, fire, etc.) and electromagnetic compatibility
(EMC) requirements are outside the scope of this document and are covered by standards and
regulations. However, information given in this document can be of assistance in meeting these
standards and regulations.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
EN 50173 (series), Information technology – Generic cabling systems
EN 50174 (series), Information technology - Cabling installation
EN 50174-2:2018, Information technology - Cabling installation - Part 2: Installation planning and
practices inside buildings
EN 50174-3, Information technology - Cabling installation - Part 3: Installation planning and practices
outside buildings
EN 50310:2016, Telecommunications bonding networks for buildings and other structures
3 Definitions, abbreviations and symbology
3.1 Definitions
For the purposes of this document, the terms and definitions given in the EN 50173 series and
EN 50174 series and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1.1
common bonding network
set of interconnected conductive structures that combine the functions of a protective bonding network
and a telecommunications bonding network
[SOURCE: EN 50310:2016, 3.1.6]
3.1.2
isolated bonding network
bonding network that has a single point of connection to either the common bonding network or
another isolated bonding network
Note 1 to entry: All IBNs considered here will have a connection to earth through the single point of connection.
3.2 Abbreviations
For the purposes of this technical report the following abbreviations apply in addition to those of the
EN 50173 series and EN 50174 series of standards.
BN Bonding Network
CBN Common Bonding Network
CMS cable management system
IBN Isolated Bonding Network
SRPP System Reference Potential Plane
4 Coupling mechanisms and countermeasures
4.1 General
Electromagnetic interference is transferred to installed telecommunications cabling by the following
coupling phenomena which can have adverse effects at different frequencies including:
— galvanic or common mode impedance coupling (see 4.2);
— capacitive coupling (see 4.3);
— inductive coupling (see 4.4);
— radiative coupling (see 4.5);
— low frequency fields (se 4.6).
4.2 Countermeasures against galvanic or common mode impedance coupling
Impedances in common mode current paths, if they cannot be avoided, should be kept as low as
possible.
The main countermeasures to minimize the effects of common mode impedance coupling are the
reduction of the:
a) common mode impedance;
b) amplitude of the disturbing currents.
4.3 Countermeasures against capacitive coupling
The main countermeasures to minimize the effects of capacitive coupling are:
a) Symmetrical transmission on balanced cabling
Conductors are exposed to the same electric field. Induced interfering voltages in both conductors
have the same polarity and amplitude; the wanted differential mode signal remains unaffected up
to a frequency dependent on the balance of the cabling. The interference appears as an
unwanted common mode signal. Depending on its common mode rejection ratio, the correct
operation of connected equipment is influenced by the presence of common mode voltages.
b) Screened cabling specially designed to mitigate electromagnetic interference if the cable screen
is:
— of low impedance;
— of large surface area;
— continuous along the cabling channel;
— bonded as detailed in EN 50174-2 and EN 50310.
NOTE At high frequencies the method of bonding of the screen at the ends of the cable is important. Even a
few centimetres of unscreened lead (pigtail) can compromise the screen effectiveness.
c) A cable management system (CMS) specially designed to mitigate electromagnetic interference if
it is:
— of low impedance;
— of large surface area;
— continuous along the cabling channel;
— bonded as detailed in EN 50174-2 and EN 50310.
NOTE Since the cable management system is fixed at earth potential via the bonding network, unwanted
electric charges cannot cause voltage rises.
4.4 Countermeasures against inductive coupling
The main countermeasures to minimize the effects of inductive couplings are:
a) Symmetrical transmission on balanced cabling
Conductors are twisted together making the surfaces of possible induction loops very small. Only
a few magnetic field lines penetrate these loops. Adjacent twists create induced voltages in phase
opposition which as a consequence cancel each other. The induced difference between the two
conductors approaches zero. However, a common mode disturbance is induced in the loop
formed with the (twisted) conductors and the bonding network. The influence on the equipment is
reduced by the common mode rejection of the connected port.
b) Screened cabling
The degree of protection against magnetic fields over a given frequency range provided by
screened cabling depends:
— upon the materials used in the screen;
— the bonding of the screen to the bonding network (BN) at the ends of the cable (see
EN 50174-2:2018, 4.7).
NOTE In general, no effective protection against magnetic fields is given if the screen of the cable is not
bonded in accordance with EN 50310. Exceptions to this rule exist e.g. when the unconnected cable screen
is placed on the surface of or near to a system reference potential plane (SRPP).
c) Metallic or composite CMS specially designed for to mitigate electromagnetic interference
The degree of protection against magnetic fields over a given frequency range provided depends
upon:
— the material used in the CMS and its thickness;
— the bonding of the elements of the CMS;
— the bonding of the CMS to the BN.
The disturbing magnetic field also induces a current in the loop built up by CMS and the BN. This
current creates an opposite magnetic field which compensates the initial one.
A limited degree of protection can be obtained with a parallel earthing conductor (PEC). The PEC
principle is explained in IEC/TR 61000-5-3.
Both capacitive and inductive coupling exist simultaneously, the countermeasure applied should take
the effect of each contributor into account (unless one can be neglected).
4.5 Countermeasures against radiative coupling
The main countermeasures to minimize the effects of radiative coupling are:
a) Reduction of the antenna effect of the disturbed cable
Mitigation of the interference from the electric field to the cable can be achieved by:
— reducing the cable height h in Figure 1;
— installing the cable in CMS specially designed to mitigate electromagnetic interference;
— the use of PECs, filters or ferrite beads etc.
Figure 1 — Radiative coupling from the electric field
b) Reduction of the disturbed loop area
Mitigation of the interference from the field to the loop can be achieved by:
— reducing the cable height h in Figure 2;
— reducing the cable length l in Figure 2;
— installing the cable in CMS specially designed to mitigate electromagnetic interference;
— the use of PECs, filters or ferrite beads etc.
Figure 2 — Radiative coupling from the magnetic field
c) The use of the Faraday cage principle:
A screened cable connected at both ends with the screening of the equipment is a possible
solution.
The equipment does not require to be bonded in order to prevent interference from high
frequencies. If the equipment is bonded, current loops should be avoided or at least minimized.
4.6 Protection against very low frequency fields
See EN 50174-2.
5 Assessment of the electromagnetic environment
The questions of Table 1 should be completed to provide a determination of the electromagnetic
environment. Table 2 should be used to complete the assessment based on the answers to the
questions of Table 1.
Table 1 — Assessment checklist
No. ASPECTS TO BE CONSIDERED YES NO COMMENT
1 Building
1a) Existing building? Δ Ο
1b) New building projected? Δ Ο
1c) New building existing? Δ Ο
1d) New and existing building mixed? Δ Ο
1e) Hospital? Δ Ο
No. ASPECTS TO BE CONSIDERED YES NO COMMENT
2 Power distribution system
2a) TN-S? Ο Ο Best solution
2b) TN-C-S? Δ Ο
2c) TN-C? Δ Ο
2d) TT? Δ Ο
2e) IT? Δ Ο
3 Disturbing sources
3a) Transformer station? Δ Ο
3b) Proximity to electrical traction (e.g. railways)? Δ Ο
3c) Proximity to high voltage power lines? Δ Ο
3d) Arc welders? Δ Ο
3e) Frequency induction heaters? Δ Ο
3f) Transmitting equipment (radio, television, wireless telephone and Δ Ο
radar)?
3g) a Ο Δ
Does the installed equipment comply with relevant EMC
Standards?
3h) Power supply cables screened? Δ Ο
3i) Proximity to coaxial or unbalanced cabling? Δ Ο
4 Additional customer requirements
4a) Very sensitive application(s)? Δ Ο
4b) Hospital environment? Δ Ο
5 Structure of the existing and/or future bonding network
5a) Mesh topology, CBN or meshed BN? Ο
5b) Star topology, IBN or meshed IBN? Δ
5c) More than one answer a), b), c)? Δ
6 CMS
6a) Telecommunications cabling parallel to power supply cables? Δ Ο
6b) Plastic or metallic CMS (see EN 50174-2:2018, Clause 6) Δ Ο Plastic
Δ Ο Metallic
6c) Plastic or metallic separation between telecommunications Δ Δ Plastic
cabling and power supply cables? (see EN 50174-2:2018, Ο Δ Metallic
Clause 6)
6d) Are the metallic or composite CMS, specially designed for Ο Δ
electromagnetic screening, bonded repeatedly or at least at both
ends?
6e) Is the cabling between buildings carried out with metallic cables? Δ Ο
Key: Ο = No action required, Δ = See Table 2
a
This refers not only to the connected equipment but also to other equipment in the environment (e.g. copiers, fluorescent
and LED lighting).
Table 2 — Actions resulting from the answers of Table 1
No. Subject
1 Building
1a) Existing building?
Yes Old buildings have the highest probability of critical electricity distribution systems and the
earthing and bonding system is based on very old concepts. In addition, some of the older
buildings are protected by special laws which do not allow all actions to be performed in the
building. For example: Drilling of holes is not
...
SLOVENSKI STANDARD
01-maj-2020
Informacijska tehnologija - Kabelska inštalacija - 99-2. del: Zmanjševanje
električnih motenj iin zaščita pred njimi
Information technology - Cabling installation - Part 99-2: Mitigation and protection from
electrical interference
Informationstechnik - Installation von Kommunikationsverkabelung - Teil 99-2:
Abschwächung von und Schutz vor elektrischer Störung
Technologies de l'information - Installation de câblages - Partie 99-2:
Ta slovenski standard je istoveten z: CLC/TR 50174-99-2:2020
ICS:
33.040.50 Vodi, zveze in tokokrogi Lines, connections and
circuits
35.110 Omreževanje Networking
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
TECHNICAL REPORT CLC/TR 50174-99-2
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
March 2020
ICS 35.110
English Version
Information technology - Cabling installation - Part 99-2:
Mitigation and protection from electrical interference
Technologies de l'information - Installation de câblages - Informationstechnik - Installation von
Partie 99-2: Kommunikationsverkabelung - Teil 99-2: Abschwächung
von und Schutz vor elektrischer Störung
This Technical Report was approved by CENELEC on 2020-02-10.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. CLC/TR 50174-99-2:2020 E
Contents Page
European foreword .3
Introduction .4
1 Scope .5
2 Normative references .5
3 Definitions, abbreviations and symbology .5
3.1 Definitions .5
3.2 Abbreviations .6
4 Coupling mechanisms and countermeasures .6
4.1 General .6
4.2 Countermeasures against galvanic or common mode impedance coupling .6
4.3 Countermeasures against capacitive coupling .6
4.4 Countermeasures against inductive coupling .7
4.5 Countermeasures against radiative coupling.8
4.6 Protection against very low frequency fields.9
5 Assessment of the electromagnetic environment .9
6 Filtering and electrical isolation components and surge protective devices . 14
6.1 Filtering . 14
6.1.1 General . 14
6.1.2 Design . 15
6.1.3 Installation . 15
6.2 Electrical isolation components . 16
6.2.1 General . 16
6.2.2 Design . 16
6.2.3 Installation . 17
6.3 Surge protective devices. 19
6.3.1 General . 19
6.3.2 Design . 19
6.3.3 Installation . 19
Bibliography . 21
European foreword
This document (CLC/TR 50174-99-2:2020) was prepared by the Technical Committee CLC/TC 215,
“Electrotechnical aspects of telecommunication equipment”.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
A previous version of this document was published as informative Annex A in EN 50174-2:2009.
During the revision of EN 50174-2:2009, TC 215 decided to remove the Annex, revise and then
publish it as separate Technical Report.
Introduction
The EN 50174 series standards specify the specification, planning and practices applicable to
installation of telecommunications cabling.
This document supports the requirements and recommendations of the EN 50174 series in relation to
the mitigation and protection of telecommunications cabling from electromagnetic interference by
describing:
a) coupling mechanisms and possible countermeasures;
b) assessment of the electromagnetic environment;
c) filtering, isolation and surge protections measures.
1 Scope
This document addresses the mitigation and protection of telecommunications cabling from
electromagnetic interference by describing:
a) coupling mechanisms and possible countermeasures;
b) assessment of the electromagnetic environment;
c) filtering, isolation and surge protections measures.
Safety (electrical safety and protection, optical power, fire, etc.) and electromagnetic compatibility
(EMC) requirements are outside the scope of this document and are covered by standards and
regulations. However, information given in this document can be of assistance in meeting these
standards and regulations.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
EN 50173 (series), Information technology – Generic cabling systems
EN 50174 (series), Information technology - Cabling installation
EN 50174-2:2018, Information technology - Cabling installation - Part 2: Installation planning and
practices inside buildings
EN 50174-3, Information technology - Cabling installation - Part 3: Installation planning and practices
outside buildings
EN 50310:2016, Telecommunications bonding networks for buildings and other structures
3 Definitions, abbreviations and symbology
3.1 Definitions
For the purposes of this document, the terms and definitions given in the EN 50173 series and
EN 50174 series and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1.1
common bonding network
set of interconnected conductive structures that combine the functions of a protective bonding network
and a telecommunications bonding network
[SOURCE: EN 50310:2016, 3.1.6]
3.1.2
isolated bonding network
bonding network that has a single point of connection to either the common bonding network or
another isolated bonding network
Note 1 to entry: All IBNs considered here will have a connection to earth through the single point of connection.
3.2 Abbreviations
For the purposes of this technical report the following abbreviations apply in addition to those of the
EN 50173 series and EN 50174 series of standards.
BN Bonding Network
CBN Common Bonding Network
CMS cable management system
IBN Isolated Bonding Network
SRPP System Reference Potential Plane
4 Coupling mechanisms and countermeasures
4.1 General
Electromagnetic interference is transferred to installed telecommunications cabling by the following
coupling phenomena which can have adverse effects at different frequencies including:
— galvanic or common mode impedance coupling (see 4.2);
— capacitive coupling (see 4.3);
— inductive coupling (see 4.4);
— radiative coupling (see 4.5);
— low frequency fields (se 4.6).
4.2 Countermeasures against galvanic or common mode impedance coupling
Impedances in common mode current paths, if they cannot be avoided, should be kept as low as
possible.
The main countermeasures to minimize the effects of common mode impedance coupling are the
reduction of the:
a) common mode impedance;
b) amplitude of the disturbing currents.
4.3 Countermeasures against capacitive coupling
The main countermeasures to minimize the effects of capacitive coupling are:
a) Symmetrical transmission on balanced cabling
Conductors are exposed to the same electric field. Induced interfering voltages in both conductors
have the same polarity and amplitude; the wanted differential mode signal remains unaffected up
to a frequency dependent on the balance of the cabling. The interference appears as an
unwanted common mode signal. Depending on its common mode rejection ratio, the correct
operation of connected equipment is influenced by the presence of common mode voltages.
b) Screened cabling specially designed to mitigate electromagnetic interference if the cable screen
is:
— of low impedance;
— of large surface area;
— continuous along the cabling channel;
— bonded as detailed in EN 50174-2 and EN 50310.
NOTE At high frequencies the method of bonding of the screen at the ends of the cable is important. Even a
few centimetres of unscreened lead (pigtail) can compromise the screen effectiveness.
c) A cable management system (CMS) specially designed to mitigate electromagnetic interference if
it is:
— of low impedance;
— of large surface area;
— continuous along the cabling channel;
— bonded as detailed in EN 50174-2 and EN 50310.
NOTE Since the cable management system is fixed at earth potential via the bonding network, unwanted
electric charges cannot cause voltage rises.
4.4 Countermeasures against inductive coupling
The main countermeasures to minimize the effects of inductive couplings are:
a) Symmetrical transmission on balanced cabling
Conductors are twisted together making the surfaces of possible induction loops very small. Only
a few magnetic field lines penetrate these loops. Adjacent twists create induced voltages in phase
opposition which as a consequence cancel each other. The induced difference between the two
conductors approaches zero. However, a common mode disturbance is induced in the loop
formed with the (twisted) conductors and the bonding network. The influence on the equipment is
reduced by the common mode rejection of the connected port.
b) Screened cabling
The degree of protection against magnetic fields over a given frequency range provided by
screened cabling depends:
— upon the materials used in the screen;
— the bonding of the screen to the bonding network (BN) at the ends of the cable (see
EN 50174-2:2018, 4.7).
NOTE In general, no effective protection against magnetic fields is given if the screen of the cable is not
bonded in accordance with EN 50310. Exceptions to this rule exist e.g. when the unconnected cable screen
is placed on the surface of or near to a system reference potential plane (SRPP).
c) Metallic or composite CMS specially designed for to mitigate electromagnetic interference
The degree of protection against magnetic fields over a given frequency range provided depends
upon:
— the material used in the CMS and its thickness;
— the bonding of the elements of the CMS;
— the bonding of the CMS to the BN.
The disturbing magnetic field also induces a current in the loop built up by CMS and the BN. This
current creates an opposite magnetic field which compensates the initial one.
A limited degree of protection can be obtained with a parallel earthing conductor (PEC). The PEC
principle is explained in IEC/TR 61000-5-3.
Both capacitive and inductive coupling exist simultaneously, the countermeasure applied should take
the effect of each contributor into account (unless one can be neglected).
4.5 Countermeasures against radiative coupling
The main countermeasures to minimize the effects of radiative coupling are:
a) Reduction of the antenna effect of the disturbed cable
Mitigation of the interference from the electric field to the cable can be achieved by:
— reducing the cable height h in Figure 1;
— installing the cable in CMS specially designed to mitigate electromagnetic interference;
— the use of PECs, filters or ferrite beads etc.
Figure 1 — Radiative coupling from the electric field
b) Reduction of the disturbed loop area
Mitigation of the interference from the field to the loop can be achieved by:
— reducing the cable height h in Figure 2;
— reducing the cable length l in Figure 2;
— installing the cable in CMS specially designed to mitigate electromagnetic interference;
— the use of PECs, filters or ferrite beads etc.
Figure 2 — Radiative coupling from the magnetic field
c) The use of the Faraday cage principle:
A screened cable connected at both ends with the screening of the equipment is a possible
solution.
The equipment does not require to be bonded in order to prevent interference from high
frequencies. If the equipment is bonded, current loops should be avoided or at least minimized.
4.6 Protection against very low frequency fields
See EN 50174-2.
5 Assessment of the electromagnetic environment
The questions of Table 1 should be completed to provide a determination of the electromagnetic
environment. Table 2 should be used to complete the assessment based on the answers to the
questions of Table 1.
Table 1 — Assessment checklist
No. ASPECTS TO BE CONSIDERED YES NO COMMENT
1 Building
1a) Existing building? Δ Ο
1b) New building projected? Δ Ο
1c) New building existing? Δ Ο
1d) New and existing building mixed? Δ Ο
1e) Hospital? Δ Ο
No. ASPECTS TO BE CONSIDERED YES NO COMMENT
2 Power distribution system
2a) TN-S? Ο Ο Best solution
2b) TN-C-S? Δ Ο
2c) TN-C? Δ Ο
2d) TT? Δ Ο
2e) IT? Δ Ο
3 Disturbing sources
3a) Transformer station? Δ Ο
3b) Proximity to electrical traction (e.g. railways)? Δ Ο
3c) Proximity to high voltage power lines? Δ Ο
3d) Arc welders? Δ Ο
3e) Frequency induction heaters? Δ Ο
3f) Transmitting equipment (radio, television, wireless telephone and Δ Ο
radar)?
3g) a Ο Δ
Does the installed equipment comply with relevant EMC
Standards?
3h) Power supply cables screened? Δ Ο
3i) Proximity to coaxial or unbalanced cabling? Δ Ο
4 Additional customer requirements
4a) Very sensitive application(s)? Δ Ο
4b) Hospital environment? Δ Ο
5 Structure of the existing and/or future bonding network
5a) Mesh topology, CBN or meshed BN? Ο
5b) Star topology, IBN or meshed IBN? Δ
5c) More than one answer a), b), c)? Δ
6 CMS
6a) Telecommunications cabling parallel to power supply cables? Δ Ο
6b) Plastic or metallic CMS (see EN 50174-2:2018, Clause 6) Δ Ο Plastic
Δ Ο Metallic
6c) Plastic or metallic separation between telecommunications Δ Δ Plastic
cabling and power supply cables? (see EN 50174-2:2018, Ο Δ Metallic
Clause 6)
6d) Are the metallic or composite CMS, specially designed for Ο Δ
electromagnetic screening, bonded repeatedly or at least at both
ends?
6e) Is the cabling between buildings carried out with metallic cables? Δ Ο
Key: Ο = No action required, Δ = See Table 2
a
This refers not only to the connected equipment but also to other equipment in the environment (e.g. copiers, fluorescent
and LED lighting).
Table 2 — Actions resulting from the answers of Table 1
No. Subject
1 Building
1a) Existing building?
Yes Old buildings have the highest probability of critical electricity distribution systems and the
earthing and bonding system is based on very old concepts. In addition, some of the older
buildings are protected by special laws which do not allow all actions to be performed in the
building. For example: Drilling of holes is no
...
Le document SIST-TP CLC/TR 50174-99-2:2020 se concentre sur la problématique de l'atténuation et de la protection des câblages de télécommunications contre les interférences électromagnétiques. Il aborde des mécanismes de couplage ainsi que des contre-mesures qui permettent de garantir une installation de câblage de qualité. L'une des forces majeures de cette norme est sa capacité à évaluer l'environnement électromagnétique. Cela permet aux professionnels du secteur de mieux comprendre les risques associés et de prendre des décisions éclairées concernant les installations de câblage. De plus, le document présente des mesures de filtrage, d'isolation et de protection contre les surtensions, qui sont essentielles pour assurer la pérennité et la fiabilité des infrastructures de télécommunications. Bien que des exigences de sécurité électrique, de protection optique et de compatibilité électromagnétique (EMC) soient exclues du champ d'application, le contenu de ce document s'avère pertinent pour assister les entreprises dans leur conformité à ces normes et réglementations. En résumant les meilleures pratiques et en offrant des conseils pratiques, cette norme permet aux professionnels d'optimiser les installations en réduisant les impacts des interférences électromagnétiques. En conclusion, la norme SIST-TP CLC/TR 50174-99-2:2020 se révèle être un outil crucial pour les techniciens et les ingénieurs impliqués dans l'installation de câblages de communication, garantissant ainsi la performance et la durabilité des systèmes téléphoniques et de données.
CLC/TR 50174-99-2:2020は、情報技術における通信ケーブルの設置に関する重要な標準であり、特に電磁干渉からの軽減および保護に焦点を当てています。このドキュメントは、通信ケーブルが直面する可能性のある電磁干渉を軽減するための方法を包括的に解説しています。 まず、カバリングメカニズムとそれに対する対策について詳述されており、専門家が実際の現場で導入可能な具体的な対策を提供しています。さらに、電磁環境の評価についても明確な指針を示しており、設置プロセスにおいて必要な考慮事項を体系的に整理しています。 また、フィルタリングや隔離、サージ保護の手法に関する情報が豊富に含まれており、電磁干渉に対抗するための実践的なアプローチを提供します。これにより、通信ネットワークの安定性と信頼性を確保するための重要なツールとなります。 ただし、安全性や電磁適合性（EMC）に関する要求事項はこのドキュメントの範囲外であり、別の標準や規制に基づいていますが、本標準が提供する情報は、それらの基準や規制を満たすために役立つことが強調されています。このように、CLC/TR 50174-99-2:2020は通信ケーブルの設置における電磁干渉の対策を詳細に示すことで、業界における標準化の重要な一翼を担っています。
CLC/TR 50174-99-2:2020 표준 문서에 대한 리뷰는 다음과 같습니다. 이 문서는 전기 간섭으로부터 통신 케이블의 완화 및 보호에 대한 내용을 다룹니다. 주요 내용은 전자기 간섭의 전이 메커니즘과 가능한 대응책, 전자기 환경의 평가, 필터링, 격리 및 서지 보호 조치 등으로 구성되어 있습니다. 이 표준의 강점은 전자기 간섭을 효과적으로 낮추기 위한 구체적인 방법론을 제시함으로써 통신 인프라의 성능과 신뢰성을 높이는 데 기여하는 것입니다. 특히, 각종 통신 네트워크에서 발생할 수 있는 전자기 간섭을 이해하고 이를 최소화하기 위한 명확한 지침을 제공하는 점에서 매우 중요한 역할을 합니다. 또한, 이 문서는 안전 요구사항(전기 안전 및 보호, 광학 전원, 화재 등) 및 전자기 호환성(EMC) 기준은 다른 규정 및 표준에서 다루고 있지만, 이 표준에서 제공되는 정보는 이러한 기준을 충족하는 데 유용하게 활용될 수 있음을 명확히 하고 있습니다. 결과적으로, CLC/TR 50174-99-2:2020 표준은 통신 케이블 설치와 관련하여 전자기 간섭으로부터의 보호 및 완화 방안을 체계적으로 다루며, 기술적 요구를 충족하는 데 핵심적인 자료로 자리잡고 있습니다. 이 표준은 통신업계를 포함한 다양한 산업에서 전자기 간섭 문제를 사전에 예방하고 최소화하는 데 필수적인 참고 자료로 활용될 수 있습니다.
Die Norm CLC/TR 50174-99-2:2020 widmet sich der wichtigen Thematik der Kabelführung in der Informationstechnologie, insbesondere der Minderung und dem Schutz von Telekommunikationskabeln vor elektromagnetischer Störung. Der umfassende Ansatz, der in diesem Dokument beschrieben wird, befasst sich mit verschiedenen Aspekten der elektromagnetischen Interferenz (EMI), was für die Planung und Installation von Telekommunikationsinfrastrukturen von entscheidender Bedeutung ist. Zu den Stärken dieser Norm gehört die detaillierte Beschreibung der Kopplungsmechanismen, die es ermöglichen, die Ursachen für elektromagnetische Störungen zu verstehen. Diese Information ist besonders wertvoll für Installateure und Planer, da sie gezielte Gegenmaßnahmen ergreifen können, um die Auswirkungen von EMI zu minimieren. Darüber hinaus bietet das Dokument eine umfassende Bewertung der elektromagnetischen Umgebung, was dazu beiträgt, potenzielle Risiken frühzeitig zu identifizieren und geeignete Lösungen zu entwickeln. Ein weiterer wichtiger Aspekt dieser Norm ist die Integration von Maßnahmen zur Filterung, Isolation und Überspannungsschutz. Diese Schutzmaßnahmen sind essenziell, um die Integrität der Telekommunikationskabel zu gewährleisten und die Verfügbarkeit der Kommunikationsdienste in Umgebungen mit potenzieller elektromagnetischer Störung sicherzustellen. Die praktische Anwendbarkeit der bereitgestellten Informationen ermöglicht es Fachleuten, die Qualität und Zuverlässigkeit von Kommunikationssystemen erheblich zu verbessern. Die Relevanz der CLC/TR 50174-99-2:2020 Norm wird durch die zunehmend elektronisierte Welt unterstrichen, in der elektrische Störungen alltäglich sind und schwerwiegende Auswirkungen auf die Leistungsfähigkeit von Netzwerken haben können. Obwohl sicherheitstechnische Aspekte und Anforderungen an die elektromagnetische Verträglichkeit (EMC) nicht Teil des Dokuments sind, bietet der Inhalt wertvolle Hinweise und Empfehlungen, die bei der Einhaltung anderer relevanter Standards und Vorschriften hilfreich sein können. Insgesamt stellt die CLC/TR 50174-99-2:2020 einen äußerst wertvollen Leitfaden dar, der es Fachleuten im Bereich der Informationstechnologie ermöglicht, Kabelführungssysteme effektiv gegen elektromagnetische Interferenzen zu schützen und die Betriebssicherheit von Kommunikationsinfrastrukturen zu erhöhen.
The CLC/TR 50174-99-2:2020 standard provides a comprehensive framework for the mitigation and protection of telecommunications cabling against electrical interference. Its scope is explicitly defined, focusing on several key areas critical for effective cabling installation in environments susceptible to electromagnetic interference. One of the notable strengths of this standard is its detailed examination of coupling mechanisms that can lead to interference, allowing users to understand the underlying issues at play. By elucidating possible countermeasures, the standard equips installers with actionable strategies to safeguard cabling from interference, significantly enhancing the reliability and performance of telecommunications systems. Additionally, the document provides guidance on assessing the electromagnetic environment, an essential component for determining the potential risks and challenges faced during installation. This assessment capability is crucial for engineers and technicians tasked with planning and deploying cabling systems in various settings, ensuring they can strategize effectively against external threats. The standard also emphasizes the importance of filtering, isolation, and surge protection measures. These protective strategies are vital for preserving the integrity of data transmission and minimizing downtime caused by electrical interference. Its well-structured approach aids professionals in implementing best practices, thereby reinforcing the standard's relevance in the field of information technology. While the CLC/TR 50174-99-2:2020 does not cover safety requirements related to electrical safety, optical power, fire, or electromagnetic compatibility (EMC), it acknowledges these elements and indicates that the information provided can assist in complying with existing standards and regulations in these areas. This intersection provides added value, enabling adherence to broader regulatory frameworks without compromising on the specifics of cabling installation. In summary, the CLC/TR 50174-99-2:2020 standard stands out for its targeted approach to mitigating electromagnetic interference in telecommunications cabling, presenting practical guidelines that are both relevant and essential for ensuring effective installation and maintenance of cabling systems.
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