EN IEC 62305-4:2024
(Main)Protection against lightning - Part 4: Electrical and electronic systems within structures
Protection against lightning - Part 4: Electrical and electronic systems within structures
IEC 62305-4:2024 provides requirements for the design, installation, inspection, maintenance, and testing of surge protection measures (SPM) for electrical and electronic systems to reduce the risk of permanent failures due to lightning electromagnetic impulse (LEMP) within a structure. 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) addition of new informative Annex E and Annex F on the determination of current sharing using modelling and current sharing in PV installations respectively; b) addition of a new informative Annex G on methods of testing of system level behaviour; c) addition of a new informative Annex H on induced voltages in SPD-protected installations.
Blitzschutz - Teil 4: Elektrische und elektronische Systeme in baulichen Anlagen
Protection contre la foudre - Partie 4: Réseaux de puissance et de communication dans les structures
L'IEC 62305-4:2024 fournit des exigences relatives à la conception, à l'installation, à l'inspection, à la maintenance et aux essais des mesures de protection contre les chocs (MPF) destinées aux réseaux de puissance et de communication, lesquelles visent à réduire le risque de défaillances permanentes dû aux impulsions électromagnétiques de foudre (IEMF) dans une structure. 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) ajout de nouvelles Annexe E et Annexe F informatives sur la détermination de la répartition du courant à l'aide d'une modélisation et dans les installations photovoltaïques, respectivement; b) ajout d'une nouvelle Annexe G informative sur les méthodes d'essai des comportements de niveau système; c) ajout d'une nouvelle Annexe H informative sur les tensions induites dans les installations protégées par des SPD.
Zaščita pred delovanjem strele - 4. del: Električni in elektronski sistemi v zgradbah
Standard IEC 62305-4:2024 določa zahteve za načrtovanje, namestitev, vzdrževanje in preskušanje ukrepov za zaščito pred prenapetostjo (SPM) za električne in elektronske sisteme, da se zmanjša tveganje trajnih okvar zaradi elektromagnetnega impulza strele (LEMP) v zgradbi.
Tretja izdaja razveljavlja in nadomešča drugo izdajo, objavljeno leta 2010. Ta izdaja je tehnično popravljena izdaja.
Ta izdaja v primerjavi s prejšnjo vključuje naslednje pomembne tehnične spremembe:
a) dodana sta bila nova informativna dodatka E in F o določanju delitve toka z modeliranjem oziroma deljenjem toka v fotonapetostnih (PV) napravah;
b) dodan je bil nov dodatek G o metodah za preskušanje delovanja na ravni sistema;
c) dodan je bil nov informativni dodatek H o induciranih napetostih v napravah z zaščito pred prenapetostjo.
General Information
Relations
Overview
EN IEC 62305-4:2024 - Protection against lightning: Part 4 specifies requirements for the design, installation, inspection, maintenance and testing of surge protection measures (SPM) for electrical and electronic systems inside structures. The standard focuses on reducing the risk of permanent failure caused by lightning electromagnetic impulse (LEMP) and constitutes the third edition (technical revision) superseding the 2010/2011 edition.
New informative annexes of this edition include:
- Annex E & F - determination of current sharing (modelling) and current sharing in PV installations;
- Annex G - methods for system-level testing;
- Annex H - induced voltages in SPD‑protected installations.
Key topics and technical requirements
The standard covers practical and technical aspects that form a coordinated SPM strategy:
- Design of SPM: selection and placement of surge protective devices (SPD), coordination and system-level behaviour.
- Lightning Protection Zones (LPZs): definition and measures for outer and inner LPZs to control electromagnetic environment.
- Earthing and bonding networks: earth-termination systems, bonding networks and bonding bars to limit potential differences.
- Magnetic shielding and line routing: spatial shielding, line routing and cable shielding to reduce induced voltages/currents from LEMP.
- Coordinated SPD system: compatibility and cascading of SPDs for power and signal lines.
- Isolating interfaces: protective interfaces to prevent propagation of surges between systems.
- SPM management: SPM management plan, inspection procedures, maintenance and documentation requirements.
- Testing & measurement: system-level testing methods (Annex G) and evaluation of induced voltages (Annex H).
Practical applications and who uses this standard
EN IEC 62305-4:2024 is essential for:
- Electrical and electronic design engineers specifying surge protection for commercial, industrial and residential buildings.
- Installers and contractors implementing earthing, bonding, SPDs and shielding measures.
- Facility managers and maintenance teams responsible for inspection, testing and lifecycle management of SPM.
- PV system designers and integrators (specific guidance via Annex F on PV current sharing).
- Safety auditors and compliance officers ensuring alignment with lightning protection risk management.
Typical applications include protection of power distribution, telecoms, control systems, IT equipment, security/automation systems and photovoltaic (PV) installations within structures.
Related standards (selection)
EN IEC 62305-4:2024 is part of the IEC 62305 series and references related standards for coordinated implementation:
- IEC 62305-1, -2, -3 (general principles, risk management, physical damage & life hazard)
- IEC 61643 series (low-voltage surge protective devices)
- IEC 62561 series (LPSC components)
- EMC test standards (IEC 61000‑4‑5 etc.)
Using this standard ensures a systematic, documented approach to minimizing LEMP-related failures through design, installation and ongoing SPM management.
Frequently Asked Questions
EN IEC 62305-4:2024 is a standard published by CLC. Its full title is "Protection against lightning - Part 4: Electrical and electronic systems within structures". This standard covers: IEC 62305-4:2024 provides requirements for the design, installation, inspection, maintenance, and testing of surge protection measures (SPM) for electrical and electronic systems to reduce the risk of permanent failures due to lightning electromagnetic impulse (LEMP) within a structure. 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) addition of new informative Annex E and Annex F on the determination of current sharing using modelling and current sharing in PV installations respectively; b) addition of a new informative Annex G on methods of testing of system level behaviour; c) addition of a new informative Annex H on induced voltages in SPD-protected installations.
IEC 62305-4:2024 provides requirements for the design, installation, inspection, maintenance, and testing of surge protection measures (SPM) for electrical and electronic systems to reduce the risk of permanent failures due to lightning electromagnetic impulse (LEMP) within a structure. 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) addition of new informative Annex E and Annex F on the determination of current sharing using modelling and current sharing in PV installations respectively; b) addition of a new informative Annex G on methods of testing of system level behaviour; c) addition of a new informative Annex H on induced voltages in SPD-protected installations.
EN IEC 62305-4:2024 is classified under the following ICS (International Classification for Standards) categories: 29.020 - Electrical engineering in general; 91.120.40 - Lightning protection. The ICS classification helps identify the subject area and facilitates finding related standards.
EN IEC 62305-4:2024 has the following relationships with other standards: It is inter standard links to EN 62305-4:2011, EN 62305-4:2011/AC:2016-11. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
You can purchase EN IEC 62305-4:2024 directly from iTeh Standards. The document is available in PDF format and is delivered instantly after payment. Add the standard to your cart and complete the secure checkout process. iTeh Standards is an authorized distributor of CLC standards.
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2024
Nadomešča:
SIST EN 62305-4:2011
SIST EN 62305-4:2011/AC:2016
Zaščita pred delovanjem strele - 4. del: Električni in elektronski sistemi v zgradbah
Protection against lightning - Part 4: Electrical and electronic systems within structures
Blitzschutz --Teil 4: Elektrische und elektronische Systeme in baulichen Anlagen
Protection contre la foudre - Partie 4: Réseaux de puissance et de communication dans
les structures
Ta slovenski standard je istoveten z: EN IEC 62305-4:2024
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 62305-4
NORME EUROPÉENNE
EUROPÄISCHE NORM October 2024
ICS 29.020; 91.120.40 Supersedes EN 62305-4:2011; EN 62305-
4:2011/AC:2016-11
English Version
Protection against lightning - Part 4: Electrical and electronic
systems within structures
(IEC 62305-4:2024)
Protection contre la foudre - Partie 4: Réseaux de Blitzschutz - Teil 4: Elektrische und elektronische Systeme
puissance et de communication dans les structures in baulichen Anlagen
(IEC 62305-4:2024) (IEC 62305-4:2024)
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 62305-4:2024 E
European foreword
The text of document 81/733/FDIS, future edition 3 of IEC 62305-4, 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 62305-4:2011 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 62305-4:2024 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 60364-4-43 NOTE Approved as HD 60364-4-43
IEC 60364-4-44:2007 NOTE Approved as HD 60364-4-444:2010
IEC 60364-4-44:2007/A1:2015 NOTE Approved as HD 60364-4-443:2016
IEC 61000 series NOTE Approved as EN IEC 61000 series
IEC 62475 NOTE Approved as EN 62475
IEC 60060 series NOTE Approved as EN 60060 series
IEC 62793 NOTE Approved as EN IEC 62793
IEC 60038 NOTE Approved as EN 60038
IEC 61643-351 NOTE Approved as EN 61643-351
IEC 61643-352 NOTE Approved as EN IEC 61643-352
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 60364-5-53 2019 Low-voltage electrical installations -- Part - -
5-53: Selection and erection of electrical
equipment - Protection, isolation,
switching, control and monitoring
IEC 60664-1 - Insulation coordination for equipment EN IEC 60664-1 -
within low-voltage supply systems - Part 1:
Principles, requirements and tests
IEC 61000-4-5 - Electromagnetic compatibility (EMC) - Part EN 61000-4-5 -
4-5: Testing and measurement techniques
- Surge immunity test
IEC 61000-4-9 - Electromagnetic compatibility (EMC) – Part EN 61000-4-9 -
4-9: Testing and measurement techniques
– Impulse magnetic field immunity test
IEC 61000-4-10 - Electromagnetic compatibility (EMC) – Part EN 61000-4-10 -
4-10: Testing and measurement
techniques – Damped oscillatory magnetic
field immunity test
IEC 61643-11 (mod) 2011 Low-voltage surge protective devices - Part EN 61643-11 2012
11: Surge protective devices connected to
low-voltage power systems - Requirements
and test methods
- - + A11 2018
IEC 61643-12 2020 Low-voltage surge protective devices - Part - -
12: Surge protective devices connected to
low-voltage power systems - Selection and
application principles
IEC 61643-21 - Low voltage surge protective devices - Part EN 61643-21 -
21: Surge protective devices connected to
telecommunications and signalling
networks - Performance requirements and
testing methods
Publication Year Title EN/HD Year
IEC 61643-22 - Low-voltage surge protective devices - Part CLC/TS 61643-22 -
22: Surge protective devices connected to
telecommunications and signalling
networks - Selection and application
principles
IEC 61643-31 - Low-voltage surge protective devices – EN 61643-31 -
Part 31: Requirements and test methods
for SPDs for photovoltaic installations
IEC 61643-32 2017 Low-voltage surge protective devices – - -
Part 32: Surge protective devices
connected to the d.c. side of photovoltaic
installations – Selection and application
principles
IEC 62305-1 2024 Protection against lightning - Part 1: EN IEC 62305-1 2024
General principles
IEC 62305-2 2024 Protection against lightning - Part 2: Risk EN IEC 62305-2 2024
management
IEC 62305-3 2024 Protection against lightning - Part 3: EN IEC 62305-3 2024
Physical damage to structures and life
hazard
IEC 62561 series Lightning protection system components EN IEC 62561 series
(LPSC) - Part 1: Requirements for
connection components
IEC 62305-4 ®
Edition 3.0 2024-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Protection against lightning –
Part 4: Electrical and electronic systems within structures
Protection contre la foudre –
Partie 4: Réseaux de puissance et de communication dans les structures
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.020, 91.120.40 ISBN 978-2-8322-7933-5
– 2 – IEC 62305-4:2024 © IEC 2024
CONTENTS
FOREWORD . 8
INTRODUCTION . 10
1 Scope . 11
2 Normative references . 11
3 Terms and definitions . 12
4 Design and installation of SPM . 16
4.1 General . 16
4.2 Design of SPM . 20
4.3 Lightning protection zones (LPZs) . 20
4.3.1 General . 20
4.3.2 Outer zones . 20
4.3.3 Inner zones . 21
4.4 Basic SPM . 23
5 Earthing and bonding networks . 24
5.1 General . 24
5.2 Earth-termination system . 25
5.3 Bonding network . 26
5.4 Bonding bars . 31
5.5 Bonding at the boundary of an LPZ . 32
5.6 Material and dimensions of bonding components . 32
6 Magnetic shielding and line routing . 33
6.1 General . 33
6.2 Spatial shielding . 33
6.3 Shielding of internal lines . 33
6.4 Routing of internal lines . 34
6.5 Shielding of external lines . 34
6.6 Material and dimensions of magnetic shields . 34
7 Coordinated SPD system . 34
8 Isolating interfaces . 35
9 SPM management . 35
9.1 General . 35
9.2 SPM management plan . 36
9.3 Inspection of SPM . 38
9.3.1 General . 38
9.3.2 Inspection procedure . 38
9.3.3 Inspection documentation . 39
9.4 Maintenance . 39
Annex A (informative) Basis of electromagnetic environment evaluation in an LPZ . 40
A.1 General . 40
A.2 Damaging effects on electrical and electronic systems due to lightning . 40
A.2.1 Sources of damage . 40
A.2.2 Object of damage . 40
A.2.3 Withstand of equipment signal ports . 40
A.2.4 Withstand of equipment power ports . 41
A.2.5 Relationship between the object of damage and the source of damage . 42
A.3 Spatial shielding, line routing and line shielding . 42
IEC 62305-4:2024 © IEC 2024 – 3 –
A.3.1 General . 42
A.3.2 Grid-like spatial shields . 45
A.3.3 Line routing and line shielding . 47
A.4 Magnetic field inside LPZ . 51
A.4.1 Approximation for the magnetic field inside LPZ . 51
A.4.2 Numerical magnetic field calculation in case of direct lightning strikes . 57
A.4.3 Experimental evaluation of the magnetic field due to a direct lightning
strike . 61
A.5 Calculation of induced voltages and currents . 62
A.5.1 General . 62
A.5.2 Situation inside LPZ 1 in the case of a direct lightning strike . 62
A.5.3 Situation inside LPZ 1 in the case of a nearby lightning strike . 65
A.5.4 Situation inside LPZ 2 and higher . 66
Annex B (informative) Implementation of SPM for an existing structure . 67
B.1 General . 67
B.2 Checklists . 67
B.3 Design of SPM for an existing structure . 68
B.4 Design of basic protection measures for LPZs . 70
B.4.1 Design of basic protection measures for LPZ 1 . 70
B.4.2 Design of basic protection measures for LPZ 2 . 70
B.4.3 Design of basic protection measures for LPZ 3 . 71
B.5 Improvement of an existing LPS using spatial shielding of LPZ 1 . 71
B.6 Establishment of LPZs for electrical and electronic systems . 71
B.7 Protection using a bonding network . 74
B.8 Protection by surge protective devices . 74
B.9 Protection by isolating interfaces . 75
B.10 Protection measures by line routing and shielding . 75
B.11 Protection measures for externally installed equipment . 77
B.11.1 General . 77
B.11.2 Protection of external equipment . 77
B.11.3 Protection by maintaining electrical insulation to the LPS . 79
B.11.4 Reduction of overvoltages in cables . 80
B.12 Improving interconnections between structures . 81
B.12.1 General . 81
B.12.2 Isolating lines . 81
B.12.3 Metallic lines . 81
B.13 Integration of new internal systems into existing structures . 81
B.14 Overview of possible protection measures . 82
B.14.1 Power supply . 82
B.14.2 Surge protective devices . 83
B.14.3 Isolating interfaces . 83
B.14.4 Line routing and shielding . 83
B.14.5 Spatial shielding . 83
B.14.6 Bonding . 83
B.15 Upgrading a power supply and cable installation inside the structure . 83
Annex C (informative) Selection and installation of a coordinated SPD system . 84
C.1 General . 84
C.2 Selection of SPDs . 85
C.2.1 Location of SPDs according to source of damage . 85
– 4 – IEC 62305-4:2024 © IEC 2024
C.2.2 Selection with regard to lightning current I . 86
C.2.3 Selection with regard to voltage protection level U . 87
p
C.2.4 SPD arrangements . 92
C.2.5 Equipment protection by two SPDs . 92
C.2.6 Equipment connected to two different services . 93
C.2.7 Selection with regard to location and discharge current . 93
C.2.8 Coordination of the SPD with back-up overcurrent protective device
(OCPD) . 96
C.3 Installation of a coordinated SPD system . 97
C.3.1 General . 97
C.3.2 Installation location of SPDs . 97
C.3.3 Connecting conductors . 98
C.3.4 Coordination of SPDs . 98
C.3.5 Procedure for installation of a coordinated SPD system . 98
Annex D (informative) Factors to be considered in the selection of SPDs . 99
D.1 General . 99
D.2 Factors determining the stress experienced by an SPD . 99
D.3 Quantifying the statistical threat level to an SPD . 101
D.3.1 General . 101
D.3.2 Installation factors effecting current distribution . 101
D.3.3 Considerations in the selection of SPD ratings: I , [I ], I , U . 102
imp max n OC
Annex E (informative) Lightning current sharing using simulation modelling . 104
E.1 General . 104
E.1.1 Overview . 104
E.1.2 Methods to determine the lightning current distribution . 104
E.2 Lightning current parameters for SPDs . 105
E.2.1 Lightning current parameters in accordance with IEC 62305-1 . 105
E.2.2 Conclusion on lightning current sharing from numerical modelling . 105
E.3 Distribution of lightning currents in power supply systems . 106
E.3.1 Influencing factors . 106
E.3.2 Considerations in lightning current sharing using numerical modelling . 108
E.4 Current distribution in structures . 111
E.4.1 General . 111
E.4.2 Structures with externally installed equipment and non-isolated LPS . 112
E.4.3 Tall buildings . 113
E.4.4 Transformer located inside a structure . 114
Annex F (informative) Lightning current sharing in photovoltaic installations . 115
F.1 General . 115
F.2 Structures with roof-mounted PV systems . 117
F.2.1 Description and assumptions . 117
F.2.2 Simplified calculation for the lightning current flowing in DC conductors . 117
F.3 Outside free-field power plant with a non-isolated LPS. 119
F.3.1 General . 119
F.3.2 Finding the lightning current flowing through the DC conductor via the
SPD . 120
F.3.3 Results . 120
Annex G (informative) Testing system level behaviour under lightning discharge
conditions . 122
G.1 General . 122
IEC 62305-4:2024 © IEC 2024 – 5 –
G.2 SPD discharge current test under normal service conditions . 122
G.3 Induction test due to lightning currents . 122
G.4 Recommended test classification of system level immunity (IEC 61000-4-5) . 122
Annex H (informative) Induced voltage in the circuits protected by an SPD . 124
H.1 General . 124
H.2 Direct flashes to the structure (Figure H.1) . 124
H.3 Flashes near the structure (Figure H.2) . 125
H.4 Flashes to the service . 126
Annex I (informative) Isolation interfaces using surge isolation transformers (SITs) . 128
I.1 SIT for low-voltage power distribution system . 128
I.2 SIT for communication systems . 128
I.3 SIT surge mitigation performance (low-voltage power distribution systems) . 128
Bibliography . 130
Figure 1 – General principle for the division into different LPZs . 17
Figure 2 – Examples of possible SPM (LEMP protection measures) . 19
Figure 3 – Examples of interconnected LPZs . 22
Figure 4 – Examples of extended lightning protection zones . 23
Figure 5 – Example of a three-dimensional earthing system consisting of the bonding
network interconnected with the earth-termination system . 25
Figure 6 – Meshed earth-termination system of a plant . 26
Figure 7 – Utilization of reinforcing rods of a structure as a protection measure against
LEMP and for equipotential bonding. 28
Figure 8 – Equipotential bonding in a structure with steel reinforcement . 29
Figure 9 – Integration of conductive parts of internal systems into the bonding network . 30
Figure 10 – Combinations of integration methods of conductive parts of internal
systems into the bonding network . 31
Figure A.1 – LEMP situation due to lightning strike to the structure . 42
Figure A.2 – Simulation of the rise of the field of the subsequent stroke (0,25/100 µs)
by damped 1 MHz oscillations (multiple impulses 0,2/0,5 µs) . 45
Figure A.3 – Large volume shield built by metal reinforcement and metal frames . 46
Figure A.4 – Volume for electrical and electronic systems inside an inner LPZ n . 47
Figure A.5 – Reducing induction effects by line routing and shielding measures . 48
Figure A.6 – Example of SPM for an office building . 50
Figure A.7 – Evaluation of the magnetic field values in case of a direct lightning strike . 51
Figure A.8 – Evaluation of the magnetic field values in case of a nearby lightning strike . 53
Figure A.9 – Distance s depending on rolling sphere radius and structure dimensions. 56
a
Figure A.10 – Types of structure geometries with different volume shields . 58
Figure A.11 – Magnetic field strength H inside a grid-like shield for the cubic
1/MAX
structure shown in Figure A.10 [14] . 59
Figure A.12 – Magnetic field strength H inside a grid-like shield for the cubic
1/MAX
structure according to mesh width . 60
Figure A.13 – Low-level test to evaluate the magnetic field inside a shielded structure . 61
Figure A.14 – Voltages and currents induced into a loop formed by lines . 62
Figure B.1 – SPM design steps for an existing structure . 70
Figure B.2 – Methods of establishing LPZs in existing structures . 73
– 6 – IEC 62305-4:2024 © IEC 2024
Figure B.3 – Reduction of loop area using shielded cables close to a metal plate . 76
Figure B.4 – Example of a metal plate for additional shielding . 76
Figure B.5 – Protection of aerials and other external equipment . 78
Figure B.6 – Separation distance maintained or not maintained . 79
Figure B.7 – Inherent shielding provided by bonded ladders and pipes . 80
Figure B.8 – Ideal positions for lines on a mast (cross-section of steel lattice mast) . 80
Figure B.9 – Upgrading of the SPM in existing structures . 82
Figure C.1 – Selection of SPDs by source of damage . 86
Figure C.2 – Example of installation of an SPD to reduce the effect of SPD lead length . 88
Figure C.3 – Surge voltage between live conductor and bonding bar . 91
Figure C.4 – Equipment with two ports and SPDs on both services bonded to two
different earthing points of a non-equipotential earthing system . 93
Figure D.1 – Installation example of SPD test class I, class II and class III in a TN
system . 100
Figure D.2 – Basic example of different sources of damage to a structure and lightning
current distribution within a system . 101
Figure D.3 – Example of the simplified current distribution in a TN power distribution
system . 102
Figure E.1 – Approach to computer simulation used to analyse lightning current
sharing . 105
Figure E.2 – MEN earthing system . 108
Figure E.3 – Parallel connected structures . 109
Figure E.4 – Influence of lightning current flow in parallel connected structures . 109
Figure E.5 – Influence of lightning current flow in star connected structures . 110
Figure E.6 – Influence of other metallic conductive services on lightning current
sharing . 110
Figure E.7 – Influence of lightning current flow from S3 events . 111
Figure E.8 – Structures with externally installed equipment and non-isolated LPS . 112
Figure E.9 – Protection of internally located sub-station transformers . 114
Figure F.1 – Current sharing between LPS down conductors and the internal cabling of
a PV system in which the separation distance s has not been maintained . 116
Figure F.2 – Protection of a roof-mounted PV system . 117
Figure F.3 – Free-field PV power plant with multiple earthing and meshed earthing
system . 120
Figure G.1 – Example circuit of an SPD discharge current test under service conditions . 123
Figure G.2 – Example circuit of an induction test due to lightning currents . 123
Figure H.1 – Induced loop by a lightning current on the structure . 125
Figure H.2 – Induced loop by a lightning current near the structure . 125
Figure I.1 – Use of SPDs to protect windings of SIT . 129
Table 1 – Minimum cross-sections for bonding components . 33
Table 2 – SPM management plan for new buildings and for extensive changes in
construction or use of existing buildings . 37
Table A.1 – Rated impulse voltage of equipment per IEC 60364-4-44:2007, Clause 443
and IEC 60364-4-44:2007/AMD1:2015, Clause 443 . 41
Table A.2 – Parameters relevant to source of harm and equipment . 43
IEC 62305-4:2024 © IEC 2024 – 7 –
Table A.3 – Examples for I = 100 kA and w = 2 m . 53
0/MAX m
Table A.4 – Attenuation of the magnetic field of grid-like spatial shields for a plane
wave . 54
Table A.5 – Rolling sphere radius corresponding to maximum lightning current . 56
Table A.6 – Examples for I = 100 kA and w = 2 m corresponding to
0/MAX m
SF = 12,6 dB . 57
Table B.1 – Structural characteristics and surroundings . 67
Table B.2 – Installation characteristics . 68
Table B.3 – Equipment characteristics . 68
Table B.4 – Other questions to be considered for the protection concept . 68
Table B.5 – Type of LPS . 68
Table C.1 – Required rated impulse voltage of equipment. 87
Table C.2 – Connection of the SPD dependent on supply system . 94
Table C.3 – Selection of impulse discharge current (I ) where the building is
imp
protected against direct lightning strike (S1) based on simplified rules . 95
Table C.4 – Nominal discharge current (I ) in kA depending on supply system and
n
connection type . 95
Table C.5 – Selection of impulse discharge current (I ) where the building is
imp
protected from direct strikes to the line (S3) . 96
Table D.1 – Preferred values of I . 99
imp
Table E.1 – General trends associated with protection installations for different power
distribution systems . 107
Table F.1 – Simplified calculated values of I (I ) and I (I ) for voltage-
imp 10/350 n 8/20
limiting SPDs on the DC side of a PV installation mounted on the roof of a building with
an external LPS if the separation distance is not maintained (see Figure F.1) . 118
Table F.2 – Simplified calculated values of I (I ) for voltage switching SPDs
imp 10/350
on the DC side of a PV installation mounted on the roof of a building with an external
LPS if the separation distance is not maintained (see Figure F.1) . 119
Table F.3 – Simplified calculated values of I and I for SPDs intended to be
10/350 8/20
used in free-field PV power plants with multiple earthing and a meshed earthing
system based on Figure F.3 . 121
Table H.1 – Flashes near the structure: induced voltage per square metre q as a
function of LPL. 126
Table H.2 – Values of k . 127
c
Table H.3 – Values of k and k for some copper shields . 127
S1 S2
– 8 – IEC 62305-4:2024 © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PROTECTION AGAINST LIGHTNING –
Part 4: Electrical and electronic systems within structures
FOREWORD
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IEC 62305-4 has been prepared by IEC technical committee 81: Lightning protection. It is an
International Standard.
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) addition of new informative Annex E and Annex F on the determination of current sharing
using modelling and current sharing in PV installations respectively;
b) addition of a new informative Annex G on methods of testing of system level behaviour;
c) addition of a new informative Annex H on induced voltages in SPD-protected installations.
IEC 62305-4:2024 © IEC 2024 – 9 –
The text of this International Standard is based on the following documents:
Draft Report on voting
81/733/FDIS 81/752/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International St
...
SIST EN IEC 62305-4:2024は、構造物内の電気および電子システムに対する雷保護についての要求事項を定めた重要な文書です。この標準は、雷の電磁インパルス（LEMP）による永久的な故障のリスクを低減するためのサージ保護措置（SPM）の設計、設置、点検、維持管理、およびテストに関する具体的な指針を提供します。 この標準の強みは、技術的な進展を反映した最新の知見を基にしている点です。特に、第3版では2010年に発行された第2版を廃止し、技術的な改訂が行われています。新たに追加された情報的附属書EおよびFでは、モデリングを用いた電流の分配の決定方法と、PV設備における電流の分配に関する情報が提供されています。また、附属書Gではシステムレベルの挙動のテスト方法が紹介されており、附属書HではSPD保護された設備における誘導電圧に関する情報が追加されています。 これらの技術的変更は、雷からの保護を必要とするすべての電気および電子システムの安全性を向上させるための重要な要素となっており、特に近年の技術革新に対する適応がなされています。そのため、SIST EN IEC 62305-4:2024は、設計からメンテナンスまで、雷保護における実務者にとって非常に relevante な標準として位置づけられます。
The EN IEC 62305-4:2024 standard is pivotal for enhancing protection against lightning within structures, particularly focusing on the safety of electrical and electronic systems. Its comprehensive scope addresses the essential requirements for the effective design, installation, inspection, maintenance, and testing of surge protection measures (SPM), thus significantly reducing the risk of permanent failures caused by lightning electromagnetic impulse (LEMP). One of the primary strengths of the EN IEC 62305-4:2024 standard is its incorporation of advanced technical updates that reflect ongoing developments in the field. The introduction of new informative Annexes, such as Annex E, which discusses the determination of current sharing using modeling, is particularly valuable for engineers designing modern systems. Furthermore, Annex F focuses on current sharing in photovoltaic (PV) installations, acknowledging the growing integration of renewable energy systems and their specific surge protection needs. Another notable aspect of this standard is the new Annex G, which details methods for testing system-level behavior, allowing for a structured approach to evaluate the efficacy of surge protection mechanisms. This addition reinforces the importance of thorough testing in ensuring the reliability of protection measures. Annex H, which addresses induced voltages in SPD-protected installations, also enhances the standard’s relevance by providing insights into minimizing potential hazards associated with surge protectors. The technical revisions in this edition, as it replaces the previous 2010 edition, ensure that the recommendations are not only up-to-date but also aligned with current best practices in electrical safety. The systematic approach to surge protection measures articulated in the EN IEC 62305-4:2024 standard is crucial for professionals involved in the design and maintenance of electrical systems, ensuring they adhere to recognized safety protocols in an increasingly electrified environment. Overall, this standard is an essential resource for ensuring the protection of electrical and electronic systems within structures against lightning, emphasizing the importance of robust surge protection measures and advancing the collective knowledge on lightning safety. Its relevance is unmistakable, given the rising importance of protecting sensitive electronic equipment in both residential and commercial buildings. The EN IEC 62305-4:2024 standard not only sets a benchmark for safety but also promotes ongoing education and innovation in lightning protection technologies.
SIST EN IEC 62305-4:2024 문서는 구조 내 전기 및 전자 시스템을 위한 낙뢰 보호에 대한 요구 사항을 제공합니다. 이 표준의 주요 목적은 전기 및 전자 시스템의 서지 보호 조치(Surge Protection Measures, SPM)를 설계, 설치, 검사, 유지 관리 및 테스트하여 낙뢰 전자기 임펄스(LEMP)로 인한 영구적인 실패의 위험을 줄이는 것입니다. 이 세 번째 판은 2010년에 발표된 두 번째 판을 취소하고 대체하며, 기술적인 개정을 포함하고 있습니다. 특히 이전 판과 비교하여 다음과 같은 중요한 기술적 변경 사항이 포함되어 있습니다. 첫째, 새로운 정보성 부록 E와 F가 추가되어 각각 모델링을 통한 전류 공유 결정 방법 및 태양광 PV 설치에서의 전류 공유에 관한 내용을 다루고 있습니다. 둘째, 시스템 수준 행동 테스트 방법에 대한 새로운 정보성 부록 G가 추가되었습니다. 셋째, SPD 보호 설치에서 유도 전압에 대한 새로운 정보성 부록 H가 추가되어, 보다 포괄적인 보호 기준을 제공합니다. 이 표준은 전기 및 전자 시스템의 안전성을 높이기 위한 요구 사항을 체계적으로 제시하여, 모든 관련 분야의 전문가와 엔지니어들이 낙뢰로 인한 위험을 효율적으로 관리할 수 있도록 돕는 非정규적 문서입니다. 낙뢰 보호와 관련된 요소들이 종합적으로 검토되고 반영되어 있어, 현업에서 실질적인 적용이 가능한 매우 유용한 기준이 됩니다.
Die Norm EN IEC 62305-4:2024 bietet ein umfassendes Regelwerk zur Ausstattung von Gebäuden mit Schutzmaßnahmen gegen Blitzeinschläge, insbesondere für elektrische und elektronische Systeme. Mit einem klaren Fokus auf die Anforderungen an Planung, Installation, Inspektion, Wartung und Prüfung von Überspannungsschutzmaßnahmen (SPM), zielt die Norm darauf ab, das Risiko dauerhafter Fehlfunktionen aufgrund von Blitz-Elektromagnetischen Impulsen (LEMP) innerhalb von Strukturen erheblich zu verringern. Eine der herausragenden Stärken dieser aktuellen dritten Ausgabe ist die technische Überarbeitung im Vergleich zur vorhergehenden, im Jahr 2010 veröffentlichten, Version. Die Einführung von neuen informativen Anhängen, insbesondere Anhänge E und F, ist besonders bedeutsam: Sie behandeln die Bestimmung des Stromverhaltens durch Modellierung sowie die spezifischen Aspekte des Stromverhaltens in Photovoltaikanlagen. Dies zeigt, dass die Norm den neuesten technologischen Entwicklungen Rechnung trägt und die Anwendung moderner Schutzmaßnahmen in verschiedenen Kontexten berücksichtigt. Darüber hinaus wurden informative Anhänge G und H hinzugefügt, die sich mit den Testmethoden für das Systemverhalten auf Systemebene sowie mit den induzierten Spannungen in durch Überspannungsschutzgeräte (SPD) geschützten Installationen befassen. Diese Ergänzungen sind entscheidend, da sie Fachleuten helfen, die Effektivität von Schutzmaßnahmen besser zu bewerten und sicherzustellen, dass Systemsicherheit und Zuverlässigkeit in verschiedenen Anwendungsszenarien gewährleistet sind. Die Relevanz der Norm EN IEC 62305-4:2024 kann nicht hoch genug eingeschätzt werden, insbesondere in einer Zeit, in der die Anzahl elektrischer und elektronischer Systeme in modernen Gebäuden ständig steigt. Die Norm bietet eine wichtige Grundlage für die Sicherstellung der Langlebigkeit und Funktionsfähigkeit solcher Systeme unter extremen Wetterbedingungen und leistet somit einen wesentlichen Beitrag zur Gesamtsicherheit von Infrastrukturen.
La norme EN IEC 62305-4:2024 se positionne comme un élément fondamental dans la protection contre la foudre, en particulier pour les systèmes électriques et électroniques au sein des structures. Son champ d'application est clairement défini, englobant les exigences relatives à la conception, l'installation, l'inspection, la maintenance et les tests des mesures de protection contre les surtensions (SPM). Cela est crucial pour atténuer le risque de pannes permanentes dues à l'impulsion électromagnétique de la foudre (LEMP). Parmi les points forts de cette norme, on note l'introduction d'annexes informatives enrichissantes. L'ajout de l'Annexe E, qui traite de la détermination du partage de courant à l'aide de modélisations, ainsi que l'Annexe F sur le partage de courant dans les installations photovoltaïques, montre une mise à jour significative et pertinente par rapport à l'édition précédente. L'Annexe G, qui aborde les méthodes de test du comportement à l'échelle du système, est également une avancée importante, apportant des perspectives pratiques et des méthodes fiables pour évaluer la performance des systèmes protégés. Enfin, la nouvelle Annexe H, qui traite des tensions induites dans les installations protégées par des dispositifs de protection contre les surtensions (SPD), complète la norme en fournissant des informations essentielles sur la sécurité électrique. La révision technique de cette troisième édition, qui annule et remplace la seconde édition de 2010, témoigne de l'engagement continu à adapter les normes aux évolutions technologiques et aux exigences actuelles du secteur. La norme EN IEC 62305-4:2024 s'avère donc être un document incontournable pour les professionnels, en leur fournissant des directives claires et précises sur la protection des systèmes électroniques et électriques dans un contexte de sécurité et de fiabilité renforcées. Sa pertinence ne peut être sous-estimée dans la prévention des impacts négatifs liés aux événements d'électromagnétisme causés par la foudre.
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