SIST EN 62305-2:2012
(Main)Protection against lightning - Part 2: Risk management
Protection against lightning - Part 2: Risk management
IEC 62305-2:2010(E) is applicable to risk assessment for 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 allows the selection of appropriate protection measures to be adopted to reduce the risk to or below the tolerable limit. This second edition cancels and replaces the first edition, published in 2006, and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: 1) Risk assessment for services connected to structures is excluded from the scope. 2) Injuries of living beings caused by electric shock inside the structure are considered. 3) Tolerable risk of loss of cultural heritage is lowered from 10-3 to 10-4. The value of tolerable risk of loss of economic value (RT = 10-3) is introduced, to be used when data for cost/benefit analysis are not available. 4) Extended damage to surroundings structures or to the environment is considered. 5) Improved equations are provided for evaluation of: - collection areas relevant to flashes nearby a structure, - collection areas relevant to flashes to and nearby a line, - probabilities that a flash can cause damage, - loss factors even in structures with risk of explosion, - risk relevant to a zone of a structure, - cost of loss. 6) Tables are provided to select the relative amount of loss in all cases. 7) Impulse withstand voltage level of equipments was extended down to 1 kV.
Blitzschutz - Teil 2: Risiko-Management
Protection contre la foudre - Partie 2: Evaluation des risques
La CEI 62305-2:2010 est applicable à l'évaluation des risques, dans une structure, en raison des coups de foudre au sol. Elle est destinée à proposer une procédure d'évaluation d'un tel risque. Une fois fixée la limite supérieure du risque tolérable, la procédure proposée permet de choisir les mesures de protection appropriées pour réduire le risque à une valeur inférieure ou égale à la valeur limite tolérable. Cette deuxième édition annule et remplace la première édition, publiée en 2006, et constitue une révision technique. Par rapport à la précédente, cette édition comprend les modifications techniques significatives suivantes:
1) L'évaluation des risques pour les services connectés aux structures est exclue du domaine d'application.
2) Les blessures aux êtres vivants dues au choc électrique à l'intérieur de la structure sont prises en compte.
3) Le risque tolérable de perte du patrimoine culturel est réduit de 10-3 à 10-4. La valeur du risque tolérable de perte de valeur économique (RT = 10-3) est introduite pour être utilisée lorsque les données applicables à l'analyse de rentabilité ne sont pas disponibles.
4) Les dommages étendus aux structures avoisinantes ou à l'environnement sont pris en compte.
5) Des équations améliorées sont fournies pour l'évaluation des éléments suivants:
- surfaces équivalentes d'exposition pour les coups de foudre à proximité d'une structure;
- surfaces équivalentes d'exposition pour les coups de foudre sur et à proximité d'un service;
- probabilités qu'un coup de foudre puisse provoquer des dommages;
- facteurs de pertes même dans des structures avec risque d'explosion;
- risque valable pour une zone d'une structure;
- coût des pertes.
6) Les tableaux sont fournis pour sélectionner le coût relatif des pertes dans tous les cas.
7) Le niveau de tension de tenue aux chocs des matériels a été porté jusqu'à 1 kV.
La présente version bilingue correspond à la version anglaise monolingue publiée en 2010-12.
Zaščita pred delovanjem strele - 2. del: Vodenje rizika (IEC 62305-2:2010, spremenjen)
Ta del standarda EN 62305 se uporablja za ocenjevanje rizika za zgradbo zaradi udara strele v zemljo. Njegov namen je določiti postopek za ocenjevanje takšnega tveganja. Ko je izbrana zgornja sprejemljiva meja za tveganje, ta postopek omogoča izbor ustreznih zaščitnih ukrepov za zmanjšanje tveganja na ali pod sprejemljivo mejo.
General Information
Relations
Buy Standard
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 62305-2:2012
01-julij-2012
1DGRPHãþD
SIST EN 62305-2:2006
=DãþLWDSUHGGHORYDQMHPVWUHOHGHO 9RGHQMHUL]LND ,(&
VSUHPHQMHQ
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 62305-2:2012
ICS:
91.120.40 =DãþLWDSUHGVWUHOR Lightning protection
SIST EN 62305-2:2012 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN 62305-2:2012
---------------------- Page: 2 ----------------------
SIST EN 62305-2:2012
EUROPEAN STANDARD
EN 62305-2
NORME EUROPÉENNE
May 2012
EUROPÄISCHE NORM
ICS 29.020; 91.120.40 Supersedes EN 62305-2:2006 + corr. Nov.2006
English version
Protection against lightning -
Part 2: Risk management
(IEC 62305-2:2010, modified)
Protection contre la foudre - Blitzschutz -
Partie 2: Evaluation des risques Teil 2: Risiko-Management
(CEI 62305-2:2010, modifiée) (IEC 62305-2:2010, modifiziert)
This European Standard was approved by CENELEC on 2012-03-19. 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, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland, Turkey and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Management Centre: Avenue Marnix 17, B - 1000 Brussels
© 2012 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62305-2:2012 E
---------------------- Page: 3 ----------------------
SIST EN 62305-2:2012
EN 62305-2:2012 – 2 –
Contents
For e wor d . 6
Introduction . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions, symbols and abbreviations . 8
3.1 Terms and definitions . 8
3.2 Symbols and abbreviations . 13
4 Explanation of terms . 16
4.1 Damage and loss . 16
4.2 Risk and risk components . 18
4.3 Composition of risk components . 20
5 Risk management . 21
5.1 Basic procedure . 21
5.2 Structure to be considered for risk assessment . 22
5.3 Tolerable risk R . 22
T
5.4 Specific procedure to evaluate the need of protection . 22
5.5 Procedure to evaluate the cost effectiveness of protection . 23
5.6 Protection measures . 26
5.7 Selection of protection measures . 26
6 Assessment of risk components . 26
6.1 Basic equation . 26
6.2 Assessment of risk components due to flashes to the structure (S1) . 27
6.3 Assessment of the risk component due to flashes near the structure (S2) . 27
6.4 Assessment of risk components due to flashes to a line connected to the structure
(S3) . 27
6.5 Assessment of risk component due to flashes near a line connected to the
structure (S4) . 28
6.6 Summary of risk components . 29
6.7 Partitioning of a structure in zones Z . 29
S
6.8 Partitioning of a line into sections S . 30
L
6.9 Assessment of risk components in a structure with zones Z . 30
S
6.10 Cost-benefit analysis for economic loss (L4) . 31
Annex A (informative) Assessment of annual number N of dangerous events . 32
A.1 General . 32
A.2 Assessment of the average annual number of dangerous events N due to flashes
D
to a structure and N to an adjacent structure . 32
DJ
A.3 Assessment of the average annual number of dangerous events N due to
M
flashes near a structure . 37
A.4 Assessment of the average annual number of dangerous events N due to flashes
L
to a line. 38
A.5 Assessment of average annual number of dangerous events N due to flashes
I
near a line. 39
Annex B (informative) Assessment of probability P of damage . 40
X
B.1 General . 40
B.2 Probability P that a flash to a structure will cause injury to living beings by
A
electric shock . 40
B.3 Probability P that a flash to a structure will cause physical damage . 41
B
---------------------- Page: 4 ----------------------
SIST EN 62305-2:2012
– 3 – EN 62305-2:2012
B.4 Probability P that a flash to a structure will cause failure of internal systems . 41
C
B.5 Probability P that a flash near a structure will cause failure of internal systems . 43
M
B.6 Probability P that a flash to a line will cause injury to living beings by electric
U
shock . 44
B.7 Probability P that a flash to a line will cause physical damage . 45
V
B.8 Probability P that a flash to a line will cause failure of internal systems . 46
W
B.9 Probability P that a lightning flash near an incoming line will cause failure of
Z
internal systems . 46
Annex C (informative) Assessment of amount of loss L . 48
X
C.1 General . 48
C.2 Mean relative amount of loss per dangerous event . 48
C.3 Loss of human life (L1) . 48
C.4 Unacceptable loss of service to the public (L2) . 51
C.5 Loss of irreplaceable cultural heritage (L3) . 52
C.6 Economic loss (L4) . 53
Annex D (informative) Evaluation of costs of loss . 56
Annex E (informative) Case study . 57
E.1 General . 57
E.2 Country house . 57
E.3 Office building . 62
E.4 Hospital . 69
E.5 Apartment block . 80
Bibliography . 85
Figures
Figure 1 – Procedure for deciding the need of protection and for selecting protection
measures . 24
Figure 2 – Procedure for evaluating the cost-effectiveness of protection measures . 25
Figure A.1 – Collection area A of an isolated structure . 33
D
Figure A.2 – Complex shaped structure . 34
Figure A.3 – Different methods to determine the collection area for the given structure . 35
Figure A.4 – Structure to be considered for evaluation of collection area A . 36
D
Figure A.5 – Collection areas (A , A , A , A ) . 39
D M I L
Figure E.1 – Country house . 57
Figure E.2 – Office building . 62
Figure E.3 – Hospital . 69
Figure E.4 – Apartment block . 81
Tables
Table 1 – Sources of damage, types of damage and types of loss according to the point of
strike . 18
Table 2 – Risk components to be considered for each type of loss in a structure . 20
Table 3 – Factors influencing the risk components . 21
Table 4 – Typical values of tolerable risk R . 22
T
Table 5 – Parameters relevant to the assessment of risk components . 28
Table 6 – Risk components for different types of damage and source of damage . 29
Table A.1 – Structure location factor C . 37
D
Table A.2 – Line installation factor C . 38
I
---------------------- Page: 5 ----------------------
SIST EN 62305-2:2012
EN 62305-2:2012 – 4 –
Table A.3 – Line type factor C . 38
T
Table A.4 – Line environmental factor C . 38
E
Table B.1 – Values of probability P that a flash to a structure will cause shock to living
TA
beings due to dangerous touch and step voltages . 40
Table B.2 – Values of probability P depending on the protection measures to reduce
B
physical damage . 41
Table B.3 – Value of the probability P as a function of LPL for which SPDs are designed42
SPD
Table B.4 – Values of factors C and C depending on shielding, grounding and isolation
LD LI
c o n d i t i o n s . 42
Table B.5 – Value of factor K depending on internal wiring . 44
S3
Table B.6 – Values of probability P that a flash to an entering line will cause shock to
TU
living beings due to dangerous touch voltages . 45
Table B.7 – Value of the probability P as a function of LPL for which SPDs are designed 45
EB
Table B.8 – Values of the probability P depending on the resistance R of the cable
LD S
screen and the impulse withstand voltage U of the equipment . 45
W
Table B.9 – Values of the probability P depending on the line type and the impulse
LI
withstand voltage U of the equipment . 47
W
Table C.1 – Type of loss L1: Loss values for each zone . 49
Table C.2 – Type of loss L1: Typical mean values of L , L and L . 49
T F O
Table C.3 – Reduction factor r as a function of the type of surface of soil or floor . 50
t
Table C.4 – Reduction factor r as a function of provisions taken to reduce the
p
consequences of fire . 50
Table C.5 – Reduction factor r as a function of risk of fire or explosion of structure . 51
f
Table C.6 – Factor h increasing the relative amount of loss in presence of a special hazard51
z
Table C.7 – Type of loss L2: Loss values for each zone . 52
Table C.8 – Type of loss L2: Typical mean values of L and L . 52
F O
Table C.9 – Type of loss L3: Loss values for each zone . 52
Table C.10 – Type of loss L3: Typical mean value of L . 53
F
Table C.11 – Type of loss L4: Loss values for each zone . 53
Table C.12 – Type of loss L4: Typical mean values of L , L and L . 54
T F O
Table C.Z1 – Values to assess the total value c . 54
t
Table C.Z2 – Portions to assess the total values c , c , c , c . 55
a b c s
Table E.1 – Country house: Environment and structure characteristics . 58
Table E.2 – Country house: Power line . 58
Table E.3 – Country house: Telecom line (TLC) . 59
Table E.4 – Country house: Factors valid for zone Z (inside the building) . 60
2
Table E.5 – Country house: Collection areas of structure and lines . 60
Table E.6 – Country house: Expected annual number of dangerous events . 61
–5
Table E.7 – Country house: Risk R for the unprotected structure (values × 10 ) . 61
1
Table E.8 – Country house: Risk components relevant to risk R for protected structure . 62
1
Table E.9 – Office building: Environment and structure characteristics . 63
Table E.10 – Office building: Power line . 63
Table E.11 – Office building: Telecom line . 64
Table E.12 – Office building: Distribution of persons into zones . 64
Table E.13 – Office building: Factors valid for zone Z (entrance area outside) . 65
1
Table E.14 – Office building: Factors valid for zone Z (garden outside) . 65
2
---------------------- Page: 6 ----------------------
SIST EN 62305-2:2012
– 5 – EN 62305-2:2012
Table E.15 – Office building: Factors valid for zone Z (archive) . 66
3
Table E.16 – Office building: Factors valid for zone Z (offices) . 66
4
Table E.17 – Office building: Factors valid for zone Z (computer centre) . 67
5
Table E.18 – Office building: Collection areas of structure and lines . 67
Table E.19 – Office building: Expected annual number of dangerous events . 68
–5
Table E.20 – Office building: Risk R for the unprotected structure (values × 10 ) . 68
1
–5
Table E.21 – Office building: Risk R for the protected structure (values × 10 ) . 69
1
Table E.22 – Hospital: Environment and global structure characteristics . 70
Table E.23 – Hospital: Power line . 70
Table E.24 – Hospital: Telecom line . 71
Table E.25 – Hospital: Distribution of persons and of economic values into zones . 72
Table E.26 – Hospital: Factors valid for zone Z (outside the building) . 73
1
Table E.27 – Hospital: Factors valid for zone Z (rooms block) . 73
2
Table E.28 – Hospital: Factors valid for zone Z (operating block) . 74
3
Table E.29 – Hospital: Factors valid for zone Z (intensive care unit) . 75
4
Table E.30 – Hospital: Collection areas of structure and lines . 75
Table E.31 – Hospital: Expected annual number of dangerous events . 76
Table E.32 – Hospital: Risk R – Values of probability P for the unprotected structure . 76
1
–5
Table E.33 – Hospital: Risk R for the unprotected structure (values × 10 ) . 77
1
Table E.34 – Hospital: Risk R for the protected structure according to solution a)
1
-5
(values × 10 ) . 78
Table E.35 – Hospital: Risk R for the protected structure according to solution b)
1
-5
(values × 10 ) . 78
Table E.36 – Hospital: Risk R for the protected structure according to solution c)
1
-5
(values × 10 ) . 79
Table E.37 – Hospital: Cost of loss C (unprotected) and C (protected) . 79
L RL
Table E.38 – Hospital: Rates relevant to the protection measures . 80
Table E.39 – Hospital: Cost C and C of protection measures (values in $) . 80
P PM
Table E.40 – Hospital: Annual saving of money (values in $) . 80
Table E.41 – Apartment block: Environment and global structure characteristics . 81
Table E.42 – Apartment block: Power line . 82
Table E.43 – Apartment block: Telecom line . 82
Table E.44 – Apartment block: Factors valid for zone Z (inside the building). 83
2
Table E.45 – Apartment block: Risk R for the apartment block depending on protection
1
measures . 84
---------------------- Page: 7 ----------------------
SIST EN 62305-2:2012
EN 62305-2:2012 – 6 –
Foreword
This document (EN 62305-2:2012) consists of the text of IEC 62305-2:2010 prepared by IEC/TC 81,
"Lightning protection", together with the common modifications prepared by CLC/TC 81X, "Lightning
protection".
The following dates are fixed:
(dop) 2013-03-19
• latest date by which this document has to be
implemented
at national level by publication of an identical
national standard or by endorsement
(dow) 2014-01-13
• latest date by which the national standards conflicting
with this document have to be withdrawn
This document supersedes EN 62305-2:2006 + corrigendum November 2006.
EN 62305-2:2012 includes the following significant technical changes with respect to
EN 62305-2:2006:
1) risk assessment for services connected to structures is excluded from the scope;
2) injuries of living beings caused by electric shock inside the structure are considered;
-3 -4
3) tolerable risk of loss of cultural heritage is lowered from 10 to 10 ;
4) extended damage to surroundings structures or to the environment is considered;
5) improved formulas are provided for evaluation of
– collection areas relevant to flashes nearby a structure,
– collection areas relevant to flashes to and nearby a line,
– probabilities that a flash can cause damage,
– loss factors even in structures with risk of explosion,
– risk relevant to a zone of a structure,
– cost of loss.
6) tables are provided to select the relative amount of loss in all cases;
7) impulse withstand voltage level of equipments was extended down to 1 kV.
Notes and tables, which are additional to those in IEC 62305-2:2010 are prefixed “Z”.
In this document, the common modifications to IEC 62305-2:2010 are indicated by a vertical line in
the left margin of the text.
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.
---------------------- Page: 8 ----------------------
SIST EN 62305-2:2012
– 7 – EN 62305-2:2012
Introduction
Lightning flashes to earth may be hazardous to structures and to lines.
The hazard to a structure can result in
– damage to the structure and to its contents,
– failure of associated electrical and electronic systems,
– injury to living beings in or close to the structure.
Consequential effects of the damage and failures may be extended to the surroundings of the
structure or may involve its environment.
To reduce the loss due to lightning, protection measures may be required. Whether they are
needed, and to what extent, should be determined by risk assessment.
The risk, defined in this part of EN 62305 as the probable average annual loss in a structure due to
lightning flashes, depends on
– the annual number of lightning flashes influencing the structure,
– the probability of damage by one of the influencing lightning flashes,
– the mean amount of consequential loss.
Lightning flashes influencing the structure may be divided into
– flashes terminating on the structure,
– flashes terminating near the structure, direct to connected lines (power, telecommunication
lines,) or near the lines.
Flashes to the structure or a connected line may cause physical damage and life hazards. Flashes
near the structure or line as well as flashes to the structure or line may cause failure of electrical
and electronic systems due to overvoltages resulting from resistive and inductive coupling of these
systems with the lightning current.
Moreover, failures caused by lightning overvoltages in users’ installations and in power supply lines
may also generate switching type overvoltages in the installations.
NOTE Malfunctioning of electrical and electronic systems is not covered by the EN 62305 series. Reference should be
[2] )
1
made to EN 61000-4-5 .
The number of lightning flashes influencing the structure depends on the dimensions and the
characteristics of the structure and of the connected lines, on the environmental characteristics of
the structure and the lines, as well as on lightning ground flash density in the region where the
structure and the lines are located.
The probability of lightning damage depends on the structure, the connected lines, and the lightning
current characteristics, as well as on the type and efficiency of applied protection measures.
The annual mean amount of the consequential loss depends on the extent of damage and the
consequential effects which may occur as result of a lightning flash.
The effect of protection measures results from the features of each protection measure and may
reduce the damage probabilities or the amount of consequential loss.
The decision to provide lightning protection may be taken regardless of the outcome of risk
assessment where there is a desire that there be no avoidable risk.
___________
1) Figures in square brackets refer to the bibliography.
---------------------- Page: 9 ----------------------
SIST EN 62305-2:2012
EN 62305-2:2012 – 8 –
1 Scope
This part of EN 62305 is applicable to risk assessment for 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 allows the selection of appropriate protection
measures to be adopted to reduce the risk to or below the tolerable limit.
2 Normative references
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.
EN 62305-1:2011, Protection against lightning – Part 1: General principles (IEC 62305-1:2010,
mod.)
EN 62305-3:2011, Protection against lightning – Part 3: Physical damage to structures and life
hazard (IEC 62305-3:2010, mod.)
EN 62305-4:2011, Protection against lightning – Part 4: Electrical and electronic systems within
structures (IEC 62305-4:2010, mod.)
3 Terms, definitions, symbols and abbreviations
For the purposes of this document, the following terms, definitions, symbols and abbreviations,
some of which have already been cited in Part 1 but are repeated here for ease of reading, as well
as those given in other parts of EN 62305, apply.
3.1 Terms and definitions
3.1.1
structure to be protected
structure for which protection is required against the effects of lightning in accordance with this
standard
Note 1 to entry: A structure to be protected may be part of a larger structure.
3.1.2
structures with risk of explosion
structures containing solid explosives materials or hazardous zones as determined in accordance
[3] [4]
with EN 60079-10-1 and EN 60079-10-2
3.1.3
structures dangerous to the environment
structures which may cause biological, chemical or radioactive emission as a consequence of
lightning (such as chemical, petrochemical, nuclear plants, etc.)
3.1.4
urban environment
area with a high density of buildings or densely populated communiti
...
SLOVENSKI STANDARD
oSIST FprEN 62305-2:2009
01-december-2009
=DãþLWDSUHGGHORYDQMHPVWUHOHGHO 9RGHQMHUL]LND
Protection against lightning -- Part 2: Risk management
Ta slovenski standard je istoveten z: FprEN 62305-2:2009
ICS:
29.020 Elektrotehnika na splošno Electrical engineering in
general
91.120.40 =DãþLWDSUHGVWUHOR Lightning protection
oSIST FprEN 62305-2:2009 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST FprEN 62305-2:2009
---------------------- Page: 2 ----------------------
oSIST FprEN 62305-2:2009
81/336/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
®
PROJET DE COMITÉ POUR VOTE (CDV)
Project number IEC 62305-2 Ed.2
Numéro de projet
IEC/TC or SC: Secretariat / Secrétariat
81
Italy
CEI/CE ou SC:
Date of circulation Closing date for voting (Voting
Submitted for parallel voting in
Date de diffusion mandatory for P-members)
CENELEC
Date de clôture du vote (Vote
2009-09-18
obligatoire pour les membres (P))
Soumis au vote parallèle au
CENELEC
2010-02-19
Also of interest to the following committees Supersedes document
Intéresse également les comités suivants Remplace le document
SC 37A,TC 64,TC 77 81/296/CD – 81/303/CC
Proposed horizontal standard
Norme horizontale suggérée
Other TC/SCs are requested to indicate their interest, if any, in this CDV to the TC/SC secretary
Les autres CE/SC sont requis d’indiquer leur intérêt, si nécessaire, dans ce CDV à l’intention du secrétaire du CE/SC
Functions concerned
Fonctions concernées
Safety EMC Environment Quality assurance
Sécurité
CEM Environnement Assurance qualité
CE DOCUMENT EST TOUJOURS À L'ÉTUDE ET SUSCEPTIBLE DE THIS DOCUMENT IS STILL UNDER STUDY AND SUBJECT TO CHANGE. IT
MODIFICATION. IL NE PEUT SERVIR DE RÉFÉRENCE. SHOULD NOT BE USED FOR REFERENCE PURPOSES.
LES RÉCIPIENDAIRES DU PRÉSENT DOCUMENT SONT INVITÉS À RECIPIENTS OF THIS DOCUMENT ARE INVITED TO SUBMIT, WITH THEIR
PRÉSENTER, AVEC LEURS OBSERVATIONS, LA NOTIFICATION DES COMMENTS, NOTIFICATION OF ANY RELEVANT PATENT RIGHTS OF
DROITS DE PROPRIÉTÉ DONT ILS AURAIENT ÉVENTUELLEMENT WHICH THEY ARE AWARE AND TO PROVIDE SUPPORTING
CONNAISSANCE ET À FOURNIR UNE DOCUMENTATION EXPLICATIVE. DOCUMENTATION.
Titre : Protection contre la foudre - Partie 2: Title : Protection against lightning - Part 2: Risk
Evaluation des risques management
Note d'introduction Introductory note
This CDV is circulated in English only in the absence
of a French version from the French national
committee within two months from date of request.
ATTENTION ATTENTION
VOTE PARALLÈLE IEC – CENELEC
CEI – CENELEC PARALLEL VOTING
L’attention des Comités nationaux de la CEI, membres du The attention of IEC National Committees, members of
CENELEC, est attirée sur le fait que ce projet de comité CENELEC, is drawn to the fact that this Committee Draft for
pour vote (CDV) de Norme internationale est soumis au Vote (CDV) for an International Standard is submitted for
vote parallèle. parallel voting.
Les membres du CENELEC sont invités à voter via le The CENELEC members are invited to vote through the
système de vote en ligne du CENELEC. CENELEC online voting system.
Copyright © 2009 International Electrotechnical Commission, IEC. All rights reserved. It is
permitted to download this electronic file, to make a copy and to print out the content for the sole
purpose of preparing National Committee positions. You may not copy or "mirror" the file or printed
version of the document, or any part of it, for any other purpose without permission in writing from
IEC.
FORM CDV (IEC)
® Registered trademark of the International Electrotechnical Commission
2009-01-09
---------------------- Page: 3 ----------------------
oSIST FprEN 62305-2:2009
62305-2, Ed. 2 © IEC:2009 – 2 – 81/336/CDV
IEC 62305-2, Ed.2: Protection against lightning –
Part 2: Risk Management
---------------------- Page: 4 ----------------------
oSIST FprEN 62305-2:2009
62305-2, Ed. 2 © IEC:2009 – 3 – 81/336/CDV
CONTENTS
1 Scope .11
2 Normative references.11
3 Terms, definitions, symbols and abbreviations .11
3.1 Terms and definitions.12
3.2 Symbols and abbreviations.17
4 Explanation of terms .20
4.1 Damage and loss.20
4.1.1 Source of damage .20
4.1.2 Types of damage.20
4.1.3 Types of loss.20
4.2 Risk and risk components .21
4.2.1 Risk.21
4.2.2 Risk components for a structure due to flashes to the structure.22
4.2.4 Risk components for a structure due to flashes to a line connected to
the structure.22
4.2.5 Risk component for a structure due to flashes near a line connected
to the structure.22
4.3 Composition of risk components related to a structure .23
5 Risk management.24
5.1 Basic procedure.24
5.2 Structure to be considered for risk assessment .24
Protection does not include connected lines outside of the structure.25
5.3 Tolerable risk R .25
T
5.4 Specific procedure to evaluate the need of protection .25
5.5 Procedure to evaluate the cost effectiveness of protection .26
5.6 Protection measures .29
5.7 Selection of protection measures.29
6 Assessment of risk components for a structure.29
6.1 Basic equation.29
6.2 Assessment of risk components due to flashes to the structure (S1).29
6.3 Assessment of the risk component due to flashes near the structure (S2) .30
6.4 Assessment of risk components due to flashes to a line connected to the
structure (S3) .30
6.5 Assessment of risk component due to flashes near a line connected to the
structure (S4) .31
6.6 Summary of risk components in a structure .32
6.7 Partitioning of a structure in zones Z .32
S
6.8 Partitioning of a line into sections S .33
S
6.9 Assessment of risk components in a structure with zones Z .33
S
6.9.1 Single zone structure.33
6.9.2 Multi-zone structure.33
6.10 Cost-benefit analysis for economic loss (L4) .34
ANNEX A (informative) Assessment of annual number N of dangerous events .35
A.1 General .35
A.2 Assessment of the average annual number of dangerous events N due to
D
flashes to a structure and N to a structure connected at “a” end of a line .35
Da
A.2.1 Determination of the collection area A .35
d
---------------------- Page: 5 ----------------------
oSIST FprEN 62305-2:2009
62305-2, Ed. 2 © IEC:2009 – 4 – 81/336/CDV
A.2.2 Structure as a part of a building.38
A.2.3 Relative location of the structure .39
A.2.4 Number of dangerous events N for a structure (“b” end of a line).40
D
A.2.5 Number of dangerous events N for an adjacent structure (“a” end of a
Da
line) .40
A.4 Assessment of the average annual number of dangerous events N due to
L
flashes to a line .41
A.5 Assessment of average annual number of dangerous events N due to
I
flashes near a line .42
ANNEX B (informative) Assessment of probability P of damage for a structure.44
X
B.1 Probability P that a flash to a structure will cause injury to living beings by
A
electric shock .44
B.2 Probability P that a flash to a structure will cause physical damage .45
B
B.3 Probability P that a flash to a structure will cause failure of internal systems .45
C
B.4 Probability P that a flash near a structure will cause failure of internal
M
systems.47
B.5 Probability P that a flash to a line will cause injury to living beings .48
U
B.6 Probability P that a flash to a line will cause physical damage.50
V
B.7 Probability P that a flash to a line will cause failure of internal systems.50
W
B.8 Probability P that a lightning flash near an incoming line will cause failure of
Z
internal systems .51
ANNEX C (informative) Assessment of amount of loss L in a structure .52
X
C.1 Mean relative amount of loss per year.52
C.2 Loss of human life (L1).52
C.3 Unacceptable loss of service to the public (L2).55
C.4 Loss of irreplaceable cultural heritage (L3).56
C.5 Economic loss (L4) .57
ANNEX D (informative) Evaluation of costs of loss .59
ANNEX E (informative) Case study for structures . Error! Bookmark not defined.
---------------------- Page: 6 ----------------------
oSIST FprEN 62305-2:2009
62305-2, Ed. 2 © IEC:2009 – 5 – 81/336/CDV
LIST OF FIGURES
Figure 1 - Procedure for deciding the need of protection and for selecting protection
measures in structures.26
Figure 2 – Procedure for evaluating the cost-effectiveness of protection measures .28
Figure A.1 – Collection area A of an isolated structure .36
d
Figure A.2 – Complex-shaped structure .37
Figure A.3 – Different methods to determine the collection area for the given structure .38
Figure A.4 – Structure to be considered for evaluation of collection area A .39
d
Figure A.5 – Collection areas (A , A , A , A ) .43
d m i l
---------------------- Page: 7 ----------------------
oSIST FprEN 62305-2:2009
62305-2, Ed. 2 © IEC:2009 – 6 – 81/336/CDV
LIST OF TABLES
Table 1 – Sources of damage, types of damage and types of loss according to the
point of strike .21
Table 2 – Risk components to be considered for each type of loss in a structure.23
Table 3 – Factors influencing the risk components in a structure .24
Table 4 – Typical values of tolerable risk R .25
T
Table 5 – Parameters relevant to the assessment of risk components for a structure .31
Table 6 – Risk components for different types of damage and source of this.32
Table A.1 – Location factor C .40
d
Table A.2 – Installation factor C .41
i
Table A.3 – Line type factor C .41
t
Table A.4 – Environmental factor C .42
e
Table B.2 – Values of P depending on the protection measures to reduce physical
B
damage.45
Table B.3 – Value of the probability P as a function of LPL for which SPDs are
SPD
designed .46
Table B.4 – Values of factors C and C depending on shielding, grounding and
LD LI
isolation conditions . Error! Bookmark not defined.
Table B.5 – Value of factor K depending on internal wiring.48
S3
Table B.6 – Values of probability P that a flash to an entering line will cause shock
TU
to living beings due to dangerous touch voltages.49
Table B.7 – Value of the probability P as a function of LPL for which SPDs are
EB
designed .49
Table B.8 – Values of the probability P depending on the resistance R of the cable
LD S
screen and the impulse withstand voltage U of the equipment .49
w
Table B.9 – Values of the probability P depending on the line type and the impulse
LI
withstand voltage U of the equipment .51
w
Table C.1 – Type of loss L1: Typical mean values of L , L and L .53
t f o
Table C.2 – Reduction factors r as a function of the type of surface of soil or floor .54
t
Table C.3 – Reduction factor r as a function of provisions taken to reduce the
p
consequences of fire.54
Table C.4 – Reduction factor r as a function of risk of fire or explosion of structure .54
f
Table C.5 – Factor h increasing the relative amount of loss in presence of a special
z
hazard .55
Table C.6 – Type of loss L2: Typical mean values of L and L .55
f o
Table C.7 – Type of loss L3: Typical mean values of L .56
f
Table C.8 – Type of loss L4: Typical mean values of L , L and L .57
t f o
---------------------- Page: 8 ----------------------
oSIST FprEN 62305-2:2009
62305-2, Ed. 2 © IEC:2009 – 7 – 81/336/CDV
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
PROTECTION AGAINST LIGHTNING –
Part 2: Risk management
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to the IEC or its directors, employees, servants or agents including individual experts
and members of its technical committees and IEC National Committees for any personal injury, property
damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees)
and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62305-2 has been prepared by IEC technical committee 81:
Lightning protection.
The text of this second edition of IEC 62305-2 is compiled from and replaces IEC 62305-2,
first edition (2006).
The text of this standard is based on the following documents:
FDIS Report on voting
81/xxx/FDIS 81/xxx/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted, as closely as possible, in accordance with the ISO/IEC
Directives, Part 2.
---------------------- Page: 9 ----------------------
oSIST FprEN 62305-2:2009
62305-2, Ed. 2 © IEC:2009 – 8 – 81/336/CDV
IEC 62305 consists of the following parts, under the general title Protection against lightning:
Part 1: General principles
Part 2: Risk management
Part 3: Physical damage to structures and life hazard
Part 4: Electrical and electronic systems within structures
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
---------------------- Page: 10 ----------------------
oSIST FprEN 62305-2:2009
62305-2, Ed. 2 © IEC:2009 – 9 – 81/336/CDV
INTRODUCTION
Lightning flashes to earth may be hazardous to structures and to lines.
The hazard to a structure can result in
– damage to the structure and to its contents,
– failure of associated electrical and electronic systems,
– injury to living beings in or close to the structure.
Consequential effects of the damage and failures may be extended to the surroundings of the
structure or may involve its environment.
To reduce the loss due to lightning, protection measures may be required. Whether they are
needed, and to what extent, should be determined by risk assessment.
The risk, defined in this standard as the probable average annual loss in a structure due to
lightning flashes, depends on:
– the annual number of lightning flashes influencing the structure;
– the probability of damage by one of the influencing lightning flashes;
– the mean amount of consequential loss.
Lightning flashes influencing the structure may be divided into
– flashes terminating on the structure,
– flashes terminating near the structure, direct to connected lines (power, telecom-
munication lines,) or near the lines.
Flashes to the structure or a connected line may cause physical damage and life hazards.
Flashes near the structure or line as well as flashes to the structure or line may cause failure
of electrical and electronic systems due to overvoltages resulting from resistive and inductive
coupling of these systems with the lightning current.
Moreover, failures caused by lightning overvoltages in users′ installations and in power supply
lines may also generate switching type overvoltages in the installations.
NOTE 1 Malfunctioning of electrical and electronic systems is not covered by the IEC 62305 series. Reference
1
should be made to IEC 61000-4-5 [1] .
The number of lightning flashes influencing the structure depends on the dimensions and the
characteristics of the structure and of the connected lines, on the environmental
characteristics of the structure and the lines, as well as on lightning ground flash density in
the region where the structure and the lines are located.
The probability of lightning damage depends on the structure, the connected lines, and the
lightning current characteristics, as well as on the type and efficiency of applied protection
measures.
The annual mean amount of the consequential loss depends on the extent of damage and the
consequential effects which may occur as result of a lightning flash.
The effect of protection measures results from the features of each protection measure and
may reduce the damage probabilities or the amount of consequential loss.
___________
1
Figures in square brackets refer to the bibliography.
---------------------- Page: 11 ----------------------
oSIST FprEN 62305-2:2009
62305-2, Ed. 2 © IEC:2009 – 10 – 81/336/CDV
The decision to provide lightning protection may be taken regardless of the outcome of risk
assessment where there is a desire that there be no avoidable risk.
---------------------- Page: 12 ----------------------
oSIST FprEN 62305-2:2009
62305-2, Ed. 2 © IEC:2009 – 11 – 81/336/CDV
PROTECTION AGAINST LIGHTNING
Part 2: Risk management
1 Scope
This part of IEC 62305 is applicable to risk assessment for 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 allows the selection of
appropriate protection measures to be adopted to reduce the risk to or below the tolerable
limit.
2 Normative references
The following referenced documents are indispensable for the application 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.
IEC 60079-10:2002, Electrical apparatus for explosive gas atmosphere – Part 10:
Classification of hazardous areas
IEC 61241-10:2004, Electrical apparatus for use in the presence of combustible dust – Part
10: Classification of areas where combustible dusts are or may be present
IEC 62305-1, Protection against lightning – Part 1: General principles
IEC 62305-3, Protection against lightning – Part 3: Physical damage to structures and life
hazard
IEC 62305-4, Protection against lightning – Part 4: Electrical and electronic systems within
structures
3 Terms, definitions, symbols and abbreviations
For the purposes of this Standard, the following terms, definitions, symbols and abbreviations,
some of which have already been cited in Part 1 but are repeated here for ease of reading, as
well as those given in other parts of IEC 62305, apply.
---------------------- Page: 13 ----------------------
oSIST FprEN 62305-2:2009
62305-2, Ed. 2 © IEC:2009 – 12 – 81/336/CDV
3.1 Terms and definitions
3.1.1
structure to be protected
structure for which protection is required against the effects of lightning in accordance with
this standard
NOTE A structure to be protected may be a part of a larger structure.
3.1.2
structures with risk of explosion
structures containing solid explosives materials or hazardous zones as determined in
accordance with IEC 60079-10 and IEC 61241-10
3.1.3
structures dangerous to the environment
structures which may cause biological, chemical or radioactive emission as a consequence of
lightning (such as chemical, petrochemical, nuclear plants, etc).
3.1.4
urban environment
area with a high density of buildings or densely populated communities with tall buildings
NOTE ’Town centre’ is an example of an urban environment.
3.1.5
suburban environment
area with a medium density of buildings
NOTE ‘Town outskirts’ is an example of a suburban environment.
3.1.6
rural environment
area with a low density of buildings.
NOTE ’Countryside’ is an example of a rural environment.
3.1.7
rated impulse withstand voltage level
U
w
impulse withstand voltage assigned by the manufacturer to the equipment or to a part of it,
characterizing the specified withstand capability of its insulation against overvoltages
NOTE For the purposes of this standard, only the withstand voltage between live conductors and earth is
considered.
3.1.8
electrical system
system incorporating low voltage power supply components
3.1.9
electronic system
system incorporating sensitive electronic components such as telecommunication equipment,
computer, control and instrumentation systems, radio systems, power electronic installations
3.1.10
internal systems
electrical and electronic systems within a structure
3.1.11
line
power line or telecommunication line connected to the structure to be protected
---------------------- Page: 14 ----------------------
oSIST FprEN 62305-2:2009
62305-2, Ed. 2 © IEC:2009 – 13 – 81/336/CDV
3.1.12
telecommunication lines
lines intended for communication between equipment that may be located in separate
structures, such as phone lines and data lines
3.1.13
power lines
distribution lines feeding electrical energy into a structure to power electrical and electronic
equipment located there, such as low voltage (LV) or high voltage (HV) electric mains
3.1.14
dangerous event
lightning flash to or near the structure to be protected, or to or near a line connected to the
structure to be protected
3.1.15
lightning flash to a structure
lightning flash striking a structure to be protected
3.1.16
lightning flash near a structure
lightning flash striking close enough to a structure to be protected that it may cause
dangerous ov
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.