EN 61643-351:2017

Components for low-voltage surge protective devices - Part 351: Performance requirements and test methods for telecommunications and signalling network surge isolation transformers (SIT)

IEC 61643-351:2016 defines test circuits and test methods for determining and verifying the SIT surge parameters. Preferred performance values for key parameters are given. Surge isolation transformers (SITs) are used for signal transformer applications with signal levels up to 400 V peak to peak. SITs are transformers, with or without an internal-winding screen, with a rated impulse withstand voltage greater than the peak voltage of the expected common-mode surge environment. SITs are applicable to components for surge protection against indirect and direct effects of lightning or other transient overvoltage. SITs are used to mitigate the onward propagation of common-mode voltage surges. This part of IEC 61643 does not cover SIT operation under differential-mode lightning surge conditions. Keywords: Surge isolation transformers (SITs)

Bauelemente für Überspannungsschutzgeräte für Niederspannung - Teil 351: Leistungsanforderungen sowie Prüfschaltungen und -verfahren für Überspannungstrenntransformatoren (SIT) in Telekommunikations- und signalverarbeitenden Netzen

Composants pour parafoudres basse tension - Partie 351: Exigences de performance et méthodes d'essai pour les transformateurs d'isolement contre les surtensions dans les réseaux de signalisation et de télécommunications

L'IEC 61643-351:2016 définit les circuits d'essai et les méthodes d'essai permettant de déterminer et de vérifier les paramètres d'onde de choc des SIT. Les valeurs préférentielles de performances sont indiquées pour les paramètres clés. Les transformateurs d'isolement contre les surtensions (SIT) sont utilisés pour les applications de transformateurs de signaux dont les niveaux de signal atteignent 400 V de crête à crête. Les SIT sont des transformateurs, dotés ou non d'un écran à enroulement interne, dont la tension assignée de tenue aux chocs est supérieure à la tension de crête de l'environnement de tension de choc de mode commun attendu. Ils sont applicables aux appareils de protection contre les effets indirects et directs de la foudre, et les autres types de surtensions transitoires. Ils sont utilisés pour atténuer la propagation de surtensions en mode commun. Mots clés: Les transformateurs d'isolement contre les surtensions (SIT)

Sestavni deli za nizkonapetostne naprave za zaščito pred prenapetostnimi udari - 351. del: Zahtevane lastnosti in metode preskušanja za izolacijske transformatorje (SIT) v telekomunikacijskih in signalnih omrežjih

Izolacijski transformatorji (SIT) se uporabljajo v signalnih transformatorjih pri ravneh signalov do 400 V od vršne vrednosti do vršne vrednosti. Izolacijski transformatorji so transformatorji z zaslonom notranjega navitja ali brez njega, z nazivno zdržno udarno napetostjo, ki je višja od temenske napetosti pričakovanega običajnega načina okolja prednapetostnega udara. Izolacijski transformatorji se uporabljajo kot komponente za zaščito pred prenapetostnimi udari v primeru posrednih in neposrednih učinkov strele ali drugih prehodnih prenapetosti. Izolacijski transformatorji se uporabljajo za širjenje običajnega načina napetostnih udarov. Ta del standarda IEC 61643 opredeljuje preskusne tokokroge in preskusne metode za ugotavljanje in preverjanje prednapetostnih parametrov izolacijskih transformatorjev. Podane so preferenčne vrednosti lastnosti za ključne parametre. Ta del standarda IEC 61643 ne zajema delovanja izolacijskih transformatorjev v pogojih diferencialnega načina napetostnega udara.

General Information

• Status: Published
• Publication Date: 09-Feb-2017
• Withdrawal Date: 01-Dec-2019
• ICS: 33.040.99 - Other equipment for telecommunication systems
• Technical Committee: CLC/SR 37B - Specific components for surge arresters and surge protective devices
• Drafting Committee: IEC/SC 37B - IEC_SC_37B
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 10-Feb-2017
• Completion Date: 10-Feb-2017
• Ref Project: SIST EN 61643-351:2017 - Components for lowvoltage surge protective devices - Part 351: Performance requirements and test methods for telecommunications and signalling network surge isolation transformers (SIT)

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2017
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Components for lowvoltage surge protective devices - Part 351: Performance
requirements and test methods for telecommunications and signalling network surge
isolation transformers (SIT)
Composants pour parafoudres basse tension - Partie 351: Exigences de performance et
méthodes d'essai pour les transformateurs d'isolement contre les surtensions dans les
réseaux de signalisation et de télécommunications
Ta slovenski standard je istoveten z: EN 61643-351:2017
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 61643-351

NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2017
ICS 33.040.99
English Version
Components for low-voltage surge protective devices -
Part 351: Performance requirements and test methods for
telecommunications and signalling network surge isolation
transformers (SIT)
(IEC 61643-351:2016)
Composants pour parafoudres basse tension -  Bauelemente für Überspannungsschutzgeräte für
Partie 351: Exigences de performance et méthodes d'essai Niederspannung - Teil 351: Leistungsanforderungen sowie
pour les transformateurs d'isolement contre les surtensions Prüfschaltungen und -verfahren für
dans les réseaux de signalisation et de télécommunications Blitzisoliertransformatoren in Telekommunikations- und
(IEC 61643-351:2016) signalverarbeitenden Netzen
(IEC 61643-351:2016)
This European Standard was approved by CENELEC on 2016-12-02. 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: Avenue Marnix 17, B-1000 Brussels
© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 61643-351:2017 E
European foreword
The text of document 37B/155/FDIS, future edition 1 of IEC 61643-351, prepared by SC 37B “Specific
components for surge arresters and surge protective devices” of IEC/TC 37 “Surge arresters" was
submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61643-351:2017.

The following dates are fixed:
(dop) 2017-09-02
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2019-12-02
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 [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
Endorsement notice
The text of the International Standard IEC 61643-351:2016 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 60060-1:2010 NOTE Harmonized as EN 60060-1:2010 (not 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 NOTE Harmonized as EN 60076-1.
IEC 60721-3-9:1993 NOTE Harmonized as EN 60721-3-9:1993 (not modified).
IEC 61340-4-8 NOTE Harmonized as EN 61340-4-8.
IEC 61558-1 NOTE Harmonized as EN 61558-1.
IEC 61558-2-4 NOTE Harmonized as EN 61558-2-4.
IEC 61558-2-6 NOTE Harmonized as EN 61558-2-6.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.

NOTE 1 When 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 60721-3-3 -  Classification of environmental conditions - EN 60721-3-3 -
- Part 3: Classification of groups of
environmental parameters and their
severities -
Section 3: Stationary use at
weatherprotected locations
IEC/TR 60664-2-1 2011 Insulation coordination for equipment - -
within low-voltage systems -
Part 2-1: Application guide - Explanation of
the application of the IEC 60664 series,
dimensioning examples and dielectric
testing
IEC 61643-351 ®
Edition 1.0 2016-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Components for low-voltage surge protective devices –

Part 351: Performance requirements and test methods for telecommunications

and signalling network surge isolation transformers (SIT)

Composants pour parafoudres basse tension –

Partie 351: Exigences de performance et méthodes d'essai pour les

transformateurs d'isolement contre les surtensions dans les réseaux de

signalisation et de télécommunications

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.040.99 ISBN 978-2-8322-3717-5

– 2 – IEC 61643-351:2016 © IEC 2016
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions, symbols, abbreviations and acronyms . 7
3.1 Terms and definitions . 7
3.2 Symbols . 10
3.3 Abbreviations and acronyms . 12
4 Service conditions . 12
4.1 Temperature range . 12
4.2 Humidity . 12
4.3 Altitude . 12
4.4 Microclimate . 12
5 SIT surge conditions . 13
5.1 SIT surge mitigation . 13
5.2 Common-mode surges . 14
5.3 Differential-mode surges . 14
6 Characteristics . 15
6.1 Characteristic measurement . 15
6.2 Input winding to output winding capacitance . 15
6.3 Insulation resistance (IR) . 16
6.4 Signal SIT voltage-time product . 18
7 Ratings . 19
7.1 Rated impulse withstand voltage . 19
7.2 Signal SIT rated winding direct current . 22
8 Identification . 24
8.1 General . 24
8.2 Datasheet . 24
8.3 Marking . 24
Annex A (informative)  1,2/50 impulse . 25
Bibliography . 26

Figure 1 – Symbol for two-winding SIT . 10
Figure 2 – Symbol for a two-winding SIT with polarity indication . 11
Figure 3 – Symbol for a two-winding SIT with electric screen . 11
Figure 4 – SIT with centre tapped windings . 11
Figure 5 – Common-mode surge conditions for SIT . 13
Figure 6 – Common-mode surge conditions for SIT with an electric screen . 14
Figure 7 – Test circuit to measure SIT internal-winding capacitance . 15
Figure 8 – Test circuit to measure the internal-winding capacitance of SIT with an
electric screen . 16
Figure 9 – Test circuit to measure the insulation resistance of SIT . 17
Figure 10 – Test circuit to measure the insulation resistance of SIT with an electric
screen . 17
Figure 11 – Test circuit to measure SIT voltage-time product . 18

IEC 61643-351:2016 © IEC 2016 – 3 –
Figure 12 – Generator and SIT secondary voltage waveforms . 18
Figure 13 – SIT rated impulse voltage test circuit . 19
Figure 14 – Rated impulse voltage test circuit for SIT with an electric screen . 20
Figure 15 – Construction of pass/fail template from the 1,2/50 open-circuit waveform . 20
Figure 16 – Pass/fail template and test waveforms . 21
Figure 17 – Winding conductor temperature rise test circuit . 23
Figure A.1 – 1,2/50 time periods and voltage amplitudes . 25

Table 1 – Classification of microclimate condition . 12
Table 2 – Impulse withstand test voltage for rated impulse voltage . 22
Table A.1 – 1,2/50 voltage impulse generator parameters . 25

– 4 – IEC 61643-351:2016 © IEC 2016
INTERNATIONAL ELECTROTECHNICAL COMMISSION
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COMPONENTS FOR LOW-VOLTAGE SURGE PROTECTIVE DEVICES –

Part 351: Performance requirements and test m
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