SIST EN IEC 62305-2:2024
(Main)Protection against lightning - Part 2: Risk management
Protection against lightning - Part 2: Risk management
IEC 62305-2:2024 is applicable to the risk management of a structure due to lightning flashes to earth.
Its purpose is to provide a procedure for the evaluation of such a risk. Once an upper tolerable limit for the risk has been selected, this procedure provides a means for the selection of appropriate protection measures to be adopted to reduce the risk to or below the tolerable limit.
This third edition cancels and replaces the second edition, published in 2010. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) The concept of a single risk, to combine loss of human life and loss due to fire, has been introduced.
b) The concept of frequency of damage that can impair the availability of the internal systems within the structure has been introduced.
c) The lightning ground strike-point density NSG has been introduced replacing the lightning flash density NG in the evaluation of expected average annual number of dangerous events.
d) Reduction of a few risk components can be achieved by the use of preventive temporary measures activated by means of a thunderstorm warning system (TWS) compliant with IEC 62793. The risk of direct strike to people in open areas has been introduced, considering the reduction of that risk using a TWS.
Blitzschutz - Teil 2: Risiko-Management
Protection contre la foudre - Partie 2: Evaluation des risques
L'IEC 62305-2:2024 s'applique à l'évaluation des risques auxquels une structure est exposée en raison des coups de foudre à la terre.
Elle est destinée à proposer une procédure d'évaluation d'un tel risque. Lorsque la limite supérieure du risque tolérable est fixée, la procédure permet de choisir les mesures de protection appropriées pour réduire le risque à une valeur inférieure ou égale à la valeur limite tolérable.
Cette troisième édition annule et remplace la deuxième édition parue en 2010. Cette édition constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) adoption du concept de risque unique, afin de combiner les pertes de vies humaines et les pertes dues à un incendie;
b) adoption du concept de fréquence des dommages qui peuvent influencer la disponibilité des réseaux internes à la structure;
c) adoption de la densité de points d'impact au sol de la foudre NSG en remplacement de la densité des coups de foudre NG dans l'évaluation du nombre moyen annuel d'événements dangereux prévisibles;
d) la réduction de quelques composantes de risque peut être obtenue par l'utilisation de mesures préventives temporaires activées par un système d'alerte aux orages (TWS) conforme à l'IEC 62793. Le risque que des personnes soient directement frappées par la foudre dans des espaces ouverts a été décrit, en tenant compte de la réduction de ce risque au moyen d'un TWS.
Zaščita pred delovanjem strele - 2. del: Obvladovanje tveganja
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2024
Nadomešča:
SIST EN 62305-2:2012
Zaščita pred delovanjem strele - 2. del: Obvladovanje tveganja
Protection against lightning - Part 2: Risk management
Blitzschutz - Teil 2: Risiko-Management
Protection contre la foudre - Partie 2: Evaluation des risques
Ta slovenski standard je istoveten z: EN IEC 62305-2:2024
ICS:
91.120.40 Zaščita pred strelo Lightning protection
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD EN IEC 62305-2
NORME EUROPÉENNE
EUROPÄISCHE NORM October 2024
ICS 29.020; 91.120.40 Supersedes EN 62305-2:2012
English Version
Protection against lightning - Part 2: Risk management
(IEC 62305-2:2024)
Protection contre la foudre - Partie 2: Évaluation des Blitzschutz - Teil 2: Risiko-Management
risques (IEC 62305-2:2024)
(IEC 62305-2:2024)
This European Standard was approved by CENELEC on 2024-10-17. 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, 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,
Türkiye 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
© 2024 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 62305-2:2024 E
European foreword
The text of document 81/769/FDIS, future edition 3 of IEC 62305-2, prepared by TC 81 "Lightning
protection" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2025-10-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2027-10-31
document have to be withdrawn
This document supersedes EN 62305-2:2012 and all of its amendments and corrigenda (if any).
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.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 62305-2:2024 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 standard indicated:
IEC 60364-4-44 NOTE Approved as HD 60364-4-444
IEC 61000-4-5:2014 NOTE Approved as EN 61000-4-5:2014 (not modified)
IEC 60079-10-1 NOTE Approved as EN IEC 60079-10-1
IEC 60079-10-2 NOTE Approved as EN 60079-10-2
IEC 60664-1:2020 NOTE Approved as EN IEC 60664-1:2020 (not modified)
IEC 61643-11:2011 NOTE Approved as EN 61643-11:2012 +A11:2018
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.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 61643 series Low-voltage surge protective devices -- EN IEC 61643 series
Part 1: Surge protective devices connected
to low-voltage power distribution systems -
Requirements and tests
IEC 62305-1 2024 Protection against lightning - Part 1: EN IEC 62305-1 2024
General principles
IEC 62305-3 2024 Protection against lightning - Part 3: EN IEC 62305-3 2024
Physical damage to structures and life
hazard
IEC 62305-4 2024 Protection against lightning - Part 4: EN IEC 62305-4 2024
Electrical and electronic systems within
structures
IEC 62793 - Thunderstorm warning systems - EN IEC 62793 -
Protection against lightning
IEC 62858 - Lightning density based on lightning EN IEC 62858 -
location systems (LLS) - General principles
IEC 62305-2 ®
Edition 3.0 2024-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Protection against lightning –
Part 2: Risk management
Protection contre la foudre –
Partie 2: Évaluation des risques
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.020, 91.120.40 ISBN 978-2-8322-9549-6
– 2 – IEC 62305-2:2024 © IEC 2024
CONTENTS
FOREWORD . 8
INTRODUCTION . 11
1 Scope . 13
2 Normative references . 13
3 Terms and definitions . 13
4 Symbols and abbreviated terms . 21
5 Damage and loss . 25
5.1 Source of damage . 25
5.2 Cause of damage . 25
5.3 Type of loss . 25
6 Risk and risk components . 26
6.1 Risk . 26
6.2 Risk components . 27
6.2.1 Risk components for a structure due to source S1 . 27
6.2.2 Risk component for a structure due to source S2 . 28
6.2.3 Risk components for a structure due to source S3 . 28
6.2.4 Risk component for a structure due to source S4 . 28
6.2.5 Factors affecting risk components for a structure . 28
6.3 Composition of risk components . 29
6.3.1 Composition of risk components according to source of damage . 29
6.3.2 Composition of risk components according to type of loss . 30
7 Risk assessment . 31
7.1 Basic procedure . 31
7.2 Structure to be considered for risk assessment . 31
7.3 Procedure to evaluate the need of protection for risk R . 31
8 Assessment of risk components . 33
8.1 Basic equation . 33
8.2 Assessment of risk components due to different sources of damage . 34
8.3 Partitioning of a structure in risk zones Z . 36
S
8.4 Partitioning of a line into sections S . 37
L
8.5 Assessment of risk components in a zone of a structure with risk zones Z . 38
S
8.5.1 General criteria . 38
8.5.2 Single-zoned structure . 38
8.5.3 Multi-zoned structure . 38
9 Frequency of damage and its components . 39
9.1 Frequency of damage . 39
9.2 Assessment of partial frequency of damage . 39
9.3 Procedure to evaluate the need of protection for frequency of damage F . 40
9.4 Assessment of partial frequency of damage in zones . 42
9.4.1 General criteria . 42
9.4.2 Single-zoned structure . 42
9.4.3 Multi-zoned structure . 42
Annex A (informative) Assessment of annual number N of dangerous events . 43
A.1 General . 43
IEC 62305-2:2024 © IEC 2024 – 3 –
A.2 Assessment of the average annual number of dangerous events N due to
D
flashes to a structure and N to an adjacent structure . 44
DJ
A.2.1 Determination of the collection area A . 44
D
A.2.2 Structure as a part of a building . 46
A.2.3 Relative location of the structure . 48
A.2.4 Number of dangerous events N for the structure . 48
D
A.2.5 Number of dangerous events N for an adjacent structure . 49
DJ
A.3 Assessment of the average annual number of dangerous events N due to
M
flashes near a structure . 49
A.4 Assessment of the average annual number of dangerous events N due to
L
flashes to a line . 50
A.5 Assessment of average annual number of dangerous events N due to
I
flashes near a line . 51
A.6 Representation of the equivalent collection areas . 52
Annex B (informative) Assessment of probability P of damage . 53
X
B.1 General . 53
B.2 Probability P that a flash to a structure will cause dangerous touch and
AT
step voltages . 54
B.3 Probability P that a flash will cause damage to an exposed person on the
AD
structure . 55
B.4 Probability P that a flash to a structure will cause physical damage by fire
B
or explosion . 57
B.5 Probability P that a flash to a structure will cause failure of internal
C
systems . 59
B.6 Probability P that a flash near a structure will cause failure of internal
M
systems .
...
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