EN IEC 61643-352:2018

SLOVENSKI STANDARD
01-maj-2018
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Components for low-voltage surge protection - Part 352: Selection and application
principles for telecommunications and signalling network surge isolation transformers
(SIT)
Ta slovenski standard je istoveten z: EN IEC 61643-352:2018
ICS:
29.240.10 Transformatorske postaje. Substations. Surge arresters
Prenapetostni odvodniki
33.040.99 Druga oprema za Other equipment for
telekomunikacijske sisteme telecommunication systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 61643-352

NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2018
ICS 33.040.99
English Version
Components for low-voltage surge protection - Part 352:
Selection and application principles for telecommunications and
signalling network surge isolation transformers (SITs)
(IEC 61643-352:2018)
Composants pour protection par parafoudres basse tension Bauelemente für Überspannungsschutzgeräte für
- Partie 352: Principes de choix et d'application pour les Niederspannung - Teil 352: Auswahl- und
transformateurs d'isolement contre les surtensions (SIT) Anwendungsprinzipien für
dans les réseaux de signalisation et de télécommunications Überspannungstrenntransformatoren (SIT) für den Einsatz
(IEC 61643-352:2018) in Telekommunikations- und signalverarbeitenden
Netzwerken
(IEC 61643-352:2018)
This European Standard was approved by CENELEC on 2018-02-14. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, 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
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61643-352:2018 E

European foreword
The text of document 37B/161/FDIS, future edition 1 of IEC 61643-352, prepared by IEC/SC 37B,
"Components for low-voltage surge protection" of IEC/TC 37 "Surge arresters" was submitted to the
IEC-CENELEC parallel vote and approved by CENELEC as EN IEC 61643-352:2018.

The following dates are fixed:
• latest date by which the document has to be (dop) 2018-11-14
implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2021-02-14
• latest date by which the national
standards conflicting with the
document have to be withdrawn
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.

Endorsement notice
The text of the International Standard IEC 61643-352:2018 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:

IEC 60065:2001 NOTE Harmonized as EN 60065:2002 (modified).
IEC 60068-2-1:2007 NOTE Harmonized as EN 60068-2-1:2007 (not modified).
IEC 60068-2-2:2007 NOTE Harmonized as EN 60068-2-2:2007 (not modified).
IEC 60076-1:2011 NOTE Harmonized as EN 60076-1:2011 (not modified).
IEC 60064-1 NOTE Harmonized as EN 60064-1.
IEC 60721-3-9:1993 NOTE Harmonized as EN 60721-3-9:1993 (not modified).
IEC 61340-4-8:2014 NOTE Harmonized as EN 61340-4-8:2015 (not modified).
IEC 61558-1 NOTE Harmonized as EN 61558-1.
IEC 61558-2-4:2009 NOTE Harmonized as EN 61558-2-4:2009 (not modified).
IEC 61558-2-6:2009 NOTE Harmonized as EN 61558-2-6:2009 (not modified).
IEC 61643-21 NOTE Harmonized as EN 61643-21.

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 61643-351 -  Components for low-voltage surge EN 61643-351 -
protective devices - Part 351: Performance
requirements and test methods for
telecommunications and signalling network
surge isolation transformers (SIT)

IEC 61643-352 ®
Edition 1.0 2018-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Components for low-voltage surge protection –

Part 352: Selection and application principles for telecommunications and

signalling network surge isolation transformers (SITs)

Composants pour protection par parafoudres basse tension –

Partie 352: Principes de choix et d'application pour les transformateurs

d'isolement contre les surtensions (SIT) dans les réseaux de signalisation et de

télécommunications
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.040.99 ISBN 978-2-8322-5225-3

– 2 – IEC 61643-352:2018 © IEC 2018
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions, symbols and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Symbols . 8
3.3 Abbreviated terms . 9
4 Service conditions . 10
4.1 Temperature range . 10
4.2 Humidity . 10
4.3 Altitude . 10
4.4 Microclimate . 10
5 SIT surge conditions . 11
5.1 SIT surge mitigation . 11
5.2 Common-mode surges . 12
5.3 Differential-mode surges . 13
5.3.1 General . 13
5.3.2 Ethernet transformer differential surge action . 13
6 Selection . 13
6.1 General . 13
6.2 Impulse withstand voltage . 13
6.3 Rated values of SIT . 14
7 Applications . 14
7.1 General . 14
7.2 Example of surge protection using SITs with ES for control and terminal
equipment installed in two different buildings respectively . 14
7.3 Example of surge protection using SITs for telecommunication equipment in
substation . 14
7.4 Example of surge protection using SITs for transmission and switching
equipment installed in different floors in a communication building . 16
7.5 Example of surge protection using SITs for computer network equipment in a
data centre . 17
7.6 Example of surge protection using SITs for a Power over Ethernet (PoE)
system . 17
7.7 Example of surge protection using SITs for LAN . 18
Annex A (informative) Lightning overvoltages of telecommunication line . 19
Bibliography . 20

Figure 1 – Symbol for a two-winding SIT . 8
Figure 2 – Symbol for a two-winding SIT with polarity indication . 9
Figure 3 – Symbol for a two-winding SIT with electric screen . 9
Figure 4 – SIT with centre tapped windings . 9
Figure 5 – Common-mode surge conditions for SIT . 11
Figure 6 – Common-mode surge conditions for SIT with an electric screen . 12
Figure 7 – Transformer differential surge truncation . 13

IEC 61643-352:2018 © IEC 2018 – 3 –
Figure 8 – Example of surge protection using SITs in order to isolate two different
buildings . 14
Figure 9 – Example of surge protection using SITs in substation . 15
Figure 10 – Example of surge protection using SITs in a communication building . 16
Figure 11 – Example of surge protection using SITs in a data centre . 17
Figure 12 – Example of surge protection using SITs for a Power over Ethernet (PoE)
system . 17
Figure 13 – Example of surge protection using SITs for LAN . 18
Figure A.1 – Lightning overvoltages of telecommunication line. 19

Table 1 – List of abbreviated terms used in this document . 10
Table 2 – Classification of microclimate condition . 10

– 4 – IEC 61643-352:2018 © IEC 2018
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
COMPONENTS FOR LOW-VOLTAGE SURGE PROTECTION –

Part 352: Selection and application principles for telecommunications and
signalling network surge isolation transformers (SITs)

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization compri
...