IEC 61643-12:2008

Low-voltage surge protective devices - Part 12: Surge protective devices connected to low-voltage power distribution systems - Selection and application principles

IEC 61643-12:2008 describes the principles for selection, operation, location and coordination of SPDs to be connected to 50 Hz to 60 Hz a.c. and to d.c. power circuits and equipment rated up to 1 000 V r.m.s. or 1 500 V d.c. Specific change with respect to the previous edition is the incorporation of Amendment 1, which was not published separately due to the number of changes and pages.

Parafoudres basse tension - Partie 12: Parafoudres connectés aux réseaux de distribution basse tension - Principes de choix et d'application

La CEI 61643-12:2008 décrit les principes relatifs au choix, à la mise en uvre, à l'emplacement et à la coordination des parafoudres à connecter sur des circuits de puissance 50 Hz à 60 Hz en courant alternatif et des circuits en courant continu, et des matériels de puissance allant jusqu'à 1 000 V en valeur efficace ou 1 500 V en courant continu. Le changement spécifique par rapport à l'édition précédente est l'intégration de l'Amendement 1, qui n'a pas été publié séparément en raison du nombre important de modifications et de pages.

General Information

• Status: Published
• Publication Date: 12-Nov-2008
• ICS: 29.240.10 - Substations. Surge arresters
• Technical Committee: SC 37A - Low-voltage surge protective devices
• Drafting Committee: WG 3 - TC 37/SC 37A/WG 3
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 07-May-2020

Relations

• Revised: IEC 61643-12:2020 - Low-voltage surge protective devices - Part 12: Surge protective devices connected to low-voltage power systems - Selection and application principles
• Effective Date: 05-Sep-2023
• Revises: IEC 61643-12:2002 - Low-voltage surge protective devices - Part 12: Surge protective devices connected to low-voltage power distribution systems - Selection and application principles
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61643-12
Edition 2.0 2008-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low-voltage surge protective devices –
Part 12: Surge protective devices connected to low-voltage power distribution
systems – Selection and application principles

Parafoudres basse tension –
Partie 12: Parafoudres connectés aux réseaux de distribution basse tension –
Principes de choix et d'application

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IEC 61643-12
Edition 2.0 2008-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Low-voltage surge protective devices –
Part 12: Surge protective devices connected to low-voltage power distribution
systems – Selection and application principles

Parafoudres basse tension –
Partie 12: Parafoudres connectés aux réseaux de distribution basse tension –
Principes de choix et d'application

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
XG
CODE PRIX
ICS 29.240; 29.240.10 ISBN 978-2-88910-550-2
– 2 – 61643-12 © IEC:2008
CONTENTS
FOREWORD.8

0 Introduction .11

0.1 General .11

0.2 Keys to understanding the structure of this standard .11

1 Scope.13

2 Normative references .13

3 Terms, definitions and abbreviated terms .14

3.1 Terms and definitions .14
3.2 List of abbreviations and acronyms used in this standard .25
4 Systems and equipment to be protected .26
4.1 Low-voltage power distribution systems.26
4.1.1 Lightning overvoltages and currents .27
4.1.2 Switching overvoltages .28
4.1.3 Temporary overvoltages U .28
TOV
4.2 Characteristics of the equipment to be protected .30
5 Surge protective devices .31
5.1 Basic functions of SPDs .31
5.2 Additional requirements.31
5.3 Classification of SPDs .31
5.3.1 SPD: classification.31
5.3.2 Typical design and topologies.32
5.4 Characteristics of SPDs.33
5.4.1 Service conditions described in IEC 61643-1 .33
5.4.2 List of parameters for SPD selection.34
5.5 Additional information on characteristics of SPDs.35
5.5.1 Information related to power-frequency voltages.35
5.5.2 Information related to surge currents .36
5.5.3 Information related to voltage protection level provided by SPDs.37
5.5.4 Information related to SPD failure modes .39
5.5.5 Information related to short-circuit withstand .40
5.5.6 Information related to load current I and to voltage drop (for two-
L
port SPDs or one-port SPDs with separate input and output
terminals) .40

5.5.7 Information related to change of characteristics of SPDs .40
6 Application of SPDs in low-voltage power distribution systems .40
6.1 Installation and its effect on the protection given by SPDs.40
6.1.1 Possible modes of protection and installation .41
6.1.2 Influence of the oscillation phenomena on the protective distance
(called separation distance in some countries) .43
6.1.3 Influence of the connecting lead length.44
6.1.4 Need for additional protection.45
6.1.5 Consideration regarding location of the SPD depending on the
classes of test .46
6.1.6 Protection zone concept .46
6.2 Selection of SPD .48
6.2.1 Selection of U , U , I , I , I and U of the SPD.49
c T n imp max oc
6.2.2 Protective distance .52

61643-12 © IEC:2008 – 3 –
6.2.3 Prospective life and failure mode.53

6.2.4 Interaction between SPDs and other devices.53

6.2.5 Choice of the voltage protection level U .54

p
6.2.6 Coordination between the chosen SPD and other SPDs .55

6.3 Characteristics of auxiliary devices.57

6.3.1 Disconnecting devices .57

6.3.2 Event counters .57

6.3.3 Status indicator .57

7 Risk analysis .57

Annex A (informative) Typical information given with inquiries and tenders and
explanation of testing procedures .59
A.1 Information given with inquiries .59
A.1.1 System data .59
A.1.2 SPD application considerations .59
A.1.3 Characteristics of SPD .59
A.1.4 Additional equipment and fittings.60
A.1.5 Any special abnormal conditions .60
A.2 Information given with tender.60
A.3 Explanation of testing procedures used in IEC 61643-1 .60
A.3.1 Determination of U for SPDs tested according to class I and class II tests.60
res
A.3.2 Impulse waveshape for assessment of U .61
res
A.3.3 Influence of a back filter on determination of U .61
res
A.3.4 Operating duty test for SPDs .61
A.3.5 TOV failure test .62
A.3.6 Differences in the testing conditions of Type 1 (test class I), 2 (test class II)
and 3 (test class III) SPDs.62
A.3.7 Short-circuit withstand capability test in conjunction with overcurrent
protection (if any) .63
Annex B (informative) Examples of relationship between U and the nominal voltage
c
used in some systems and example of relationship between U and U for ZnO
p c
varistor .64
B.1 Relationship between U and the nominal voltage of the system .64
c
B.2 Relationship between U and U for a ZnO varistor.64
p c
Annex C (informative) Environment – Surge voltages in LV systems .66
C.1 General .66

C.2 Lightning overvolta
...