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: Évaluation 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: Vodenje rizika
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN IEC 62305-2:2023
01-oktober-2023
Zaščita pred delovanjem strele - 2. del: Vodenje rizika
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: prEN IEC 62305-2:2023
ICS:
91.120.40 Zaščita pred strelo Lightning protection
oSIST prEN IEC 62305-2:2023 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
oSIST prEN IEC 62305-2:2023
oSIST prEN IEC 62305-2:2023
81/731/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 62305-2 ED3
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2023-07-21 2023-10-13
SUPERSEDES DOCUMENTS:
81/687/CDV, 81/712A/RVC
IEC TC 81 : LIGHTNING PROTECTION
SECRETARIAT: SECRETARY:
Italy Mrs Marina Bernardi
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:
SC 37A,TC 64,TC 88
Other TC/SCs are requested to indicate their interest, if
any, in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft
for Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
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which they are aware and to provide supporting documentation.
Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some
Countries” clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is
the final stage for submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).
TITLE:
Protection against lightning - Part 2: Risk management
PROPOSED STABILITY DATE: 2028
NOTE FROM TC/SC OFFICERS:
download this electronic file, to make a copy and to print out the content for the sole purpose of preparing National
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oSIST prEN IEC 62305-2:2023
IEC CDV 62305-2 © IEC 2023 2 81/731/CDV
1 CONTENTS
3 FOREWORD. 7
4 INTRODUCTION . 9
5 1 Scope . 11
6 2 Normative references . 11
7 3 Terms and definitions . 11
8 4 Symbol and abbreviations . 19
9 5 Damage and loss . 23
10 5.1 Source of damage . 23
11 5.2 Cause of damage . 23
12 5.3 Type of loss . 23
13 6 Risk and risk components . 24
14 6.1 Risk . 24
15 6.2 Risk components . 25
16 6.2.1 Risk components for a structure due to source S1 . 25
17 6.2.2 Risk component for a structure due to source S2 . 25
18 6.2.3 Risk components for a structure due to source S3 . 25
19 6.2.4 Risk component for a structure due to source S4 . 25
20 6.2.5 Factors affecting risk components for a structure . 25
21 6.3 Composition of risk components . 26
22 6.3.1 Composition of risk components according to source of damage . 26
23 6.3.2 Composition of risk components according to type of loss . 27
24 7 Risk assessment . 28
25 7.1 Basic procedure . 28
26 7.2 Structure to be considered for risk assessment . 28
27 7.3 Procedure to evaluate the need of protection for risk R . 28
28 8 Assessment of risk components . 31
29 8.1 Basic equation . 31
30 8.2 Assessment of risk components due to different sources of damage . 31
31 8.3 Partitioning of a structure in risk zones ZS . 33
32 8.4 Partitioning of a line into sections SL . 34
33 8.5 Assessment of risk components in a zone of a structure with risk zones ZS . 34
34 8.5.1 General criteria . 34
35 8.5.2 Single-zoned structure . 34
36 8.5.3 Multi-zoned structure . 35
37 9 Frequency of damage and its components . 35
38 9.1 Frequency of damage . 35
39 9.2 Assessment of partial frequency of damage . 35
40 9.3 Procedure to evaluate the need of protection for frequency of damage F . 36
41 9.4 Assessment of partial frequency of damage . 39
42 9.4.1 General criteria . 39
43 9.4.2 Single-zoned structure . 39
44 9.4.3 Multi-zoned structure . 39
45 Annex A (informative) Assessment of annual number N of dangerous events . 40
46 A.1 General . 40
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47 A.2 Assessment of the average annual number of dangerous events ND due to
48 flashes to a structure and NDJ to an adjacent structure . 41
49 A.2.1 Determination of the collection area AD . 41
50 A.2.2 Structure as a part of a building . 43
51 A.2.3 Relative location of the structure . 44
52 A.2.4 Number of dangerous events ND for the structure . 45
53 A.2.5 Number of dangerous events NDJ for an adjacent structure . 45
54 A.3 Assessment of the average annual number of dangerous events NM due to
55 flashes near a structure . 45
56 A.4 Assessment of the average annual number of dangerous events NL due to
57 flashes to a line . 46
58 A.5 Assessment of average annual number of dangerous events NI due to
59 flashes near a line . 47
60 A.6 Representation of the equivalent collection areas . 48
61 Annex B (informative) Assessment of probability PX of damage . 49
62 B.1 General . 49
63 B.2 Probability PAT that a flash to a structure will cause dangerous touch and
64 step voltage . 50
65 B.3 Probability PAD that a flash will cause damage to an exposed person on the
66 structure. . 51
67 B.4 Probability PB that a flash to a structure will cause physical damage by fire
68 or explosion . 52
69 B.5 Probability PC that a flash to a structure will cause failure of internal
70 systems . 54
71 B.6 Probability PM that a flash near a structure will cause failure of internal
72 systems . 59
73 B.7 Probability PU that a flash to a line will cause damage due to touch voltage . 61
74 B.8 Probability PV that a flash to a line will cause physical damage by fire or
75 explosion . 63
76 B.9 Probability PW that a flash to a line will cause failure of internal systems . 64
77 B.10 Probability PZ that a lightning flash near an incoming line will cause failure
78 of internal systems . 65
79 B.11 Probability PP that a person will be in a dangerous place . 65
80 B.12 Probability Pe that an equipment will be exposed to a damaging event . 65
81 Annex C (informative) Assessment of loss LX . 66
82 C.1 General . 66
83 C.2 Mean relative loss per dangerous event . 66
84 Annex D (informative) PSPD Evaluation . 69
85 D.1 Introduction . 69
86 D.2 PQ values . 69
87 D.2.1 Probability values of both the negative and positive first strokes . 69
88 D.2.2 Source of damage S1 . 70
89 D.2.3 Source of damage S3 . 70
90 D.2.4 Sources of damage S2 and S4 . 71
91 D.3 SPD protection level . 71
92 D.3.1 Source of damage S1 . 71
93 D.3.2 Source of damage S3 . 75
94 D.3.3 Energy coordinated SPDs: One voltage switching SPD and one voltage
95 limiting SPD downstream . 80
96 D.4 Source of damage S4 . 83
97 D.4.1 One voltage limiting SPD . 83
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98 D.4.2 One voltage switching SPD . 83
99 D.5 Source of damage S2 . 84
100 Annex E (informative) Detailed investigation of additional losses LE related to
101 surroundings . 85
102 E.1 General . 85
103 E.2 Calculation of risk components . 85
104 Annex F (informative) Case study . 89
105 F.1 General . 89
106 F.2 House . 89
107 F.2.1 Relevant data and characterist
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