SIST EN IEC 60099-5:2018

SLOVENSKI STANDARD
01-maj-2018
1DGRPHãþD
SIST EN 60099-5:2013
3UHQDSHWRVWQLRGYRGQLNLGHO,]ELUDLQSULSRURþLOD]DXSRUDER
Surge arresters - Part 5: Selection and application recommendations
Überspannungsableiter - Teil 5: Anleitung für die Auswahl und die Anwendung
Parafoudres - Partie 5: Recommandations pour le choix et l'utilisation
Ta slovenski standard je istoveten z: EN IEC 60099-5:2018
ICS:
29.240.10 Transformatorske postaje. Substations. Surge arresters
Prenapetostni odvodniki
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60099-5

NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2018
ICS 29.120.50; 29.240.10 Supersedes EN 60099-5:2013
English Version
Surge arresters - Part 5: Selection and application
recommendations
(IEC 60099-5:2018)
Parafoudres - Partie 5: Recommandations pour le choix et Überspannungsableiter - Teil 5: Anleitung für die Auswahl
l'utilisation und die Anwendung
(IEC 60099-5:2018) (IEC 60099-5:2018)
This European Standard was approved by CENELEC on 2018-02-23. 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey 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
© 2018 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60099-5:2018 E

European foreword
The text of document 37/437/FDIS, future edition 3 of IEC 60099-5, prepared by IEC/TC 37 "Surge
arresters" 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 (dop) 2018-11-23
implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2021-02-23
• latest date by which the national
standards conflicting with the
document have to be withdrawn
This document supersedes EN 60099-5:2013.

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.

Endorsement notice
The text of the International Standard IEC 60099-5:2018 was approved by CENELEC as a European
Standard without any modification.
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.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60071-1 2006 Insulation co-ordination -- Part 1: EN 60071-1 2006
Definitions, principles and rules
+ A1 2010  + A1 2010
IEC 60071-2 1996 Insulation co-ordination -- Part 2: EN 60071-2 1997
Application guide
IEC 60099-4 2004  Surge arresters -- Part 4: Metal-oxide EN 60099-4 2004
surge arresters without gaps for a.c.
systems
+ A1 2006  + A1 2006
+ A2 2009  + A2 2009
IEC 60099-4 2014 Surge arresters - Part 4: Metal-oxide surge EN 60099-4 2014
arresters without gaps for a.c. systems
IEC 60099-6 2002 Surge arresters -- Part 6: Surge arresters - -
containing both series and parallel gapped
structures - Rated 52 kV and less
IEC 60099-8 2011 Surge arresters -- Part 8: Metal-oxide EN 60099-8 2011
surge arresters with external series gap
(EGLA) for overhead transmission and
distribution lines of a.c. systems above 1
kV
IEC 60507 -  Artificial pollution tests on high-voltage EN 60507 -
ceramic and glass insulators to be used on
a.c. systems
IEC 62271-200 -  High-voltage switchgear and controlgear -- EN 62271-200 -
Part 200: AC metal-enclosed switchgear
and controlgear for rated voltages above 1
kV and up to and including 52 kV
IEC 62271-203 -  High-voltage switchgear and controlgear -- EN 62271-203 -
Part 203: Gas-insulated metal-enclosed
switchgear for rated voltages above 52 kV
IEC/TR 60071-4 -  Insulation co-ordination -- Part 4: - -
Computational guide to insulation co-
ordination and modelling of electrical
networks
IEC/TS 60815-1 2008 Selection and dimensioning of high-voltage - -
insulators intended for use in polluted
conditions - Part 1: Definitions, information
and general principles
IEC 60099-5 ®
Edition 3.0 2018-01
INTERNATIONAL
STANDARD
colour
inside
Surge arresters –
Part 5: Selection and application recommendations

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.120.50; 29.240.10 ISBN 978-2-8322-5075-4

– 2 – IEC 60099-5:2018 © IEC 2018
CONTENTS
FOREWORD . 9
1 Scope . 11
2 Normative references . 11
3 Terms and definitions . 12
4 General principles for the application of surge arresters . 21
5 Surge arrester fundamentals and applications issues . 22
5.1 Evolution of surge protection equipment . 22
5.2 Different types and designs and their electrical and mechanical
characteristics . 23
5.2.1 General . 23
5.2.2 Metal-oxide arresters without gaps according to IEC 60099-4 . 24
5.2.3 Metal-oxide surge arresters with internal series gaps according to
IEC 60099-6 . 34
5.2.4 Externally gapped line arresters (EGLA) according to IEC 60099-8. 36
5.2.5 Application considerations . 39
6 Insulation coordination and surge arrester applications. 52
6.1 General . 52
6.2 Insulation coordination overview . 52
6.2.1 General . 52
6.2.2 IEC insulation coordination procedure . 53
6.2.3 Overvoltages . 53
6.2.4 Line insulation coordination: Arrester Application Practices . 59
6.2.5 Substation insulation coordination: Arrester application practices . 64
6.2.6 Insulation coordination studies. 68
6.3 Selection of arresters . 70
6.3.1 General . 70
6.3.2 General procedure for the selection of surge arresters . 70
6.3.3 Selection of line surge arresters, LSA . 84
6.3.4 Selection of arresters for cable protection . 93
6.3.5 Selection of arresters for distribution systems – special attention . 95
6.3.6 Application and coordination of disconnectors . 96
6.3.7 Selection of UHV arresters . 98
6.4 Standard and special service conditions . 99
6.4.1 Standard service conditions . 99
6.4.2 Special service conditions . 99
7 Surge arresters for special applications . 103
7.1 Surge arresters for transformer neutrals . 103
7.1.1 General . 103
7.1.2 Surge arresters for fully insulated transformer neutrals . 103
7.1.3 Surge arresters for neutrals of transformers with non-uniform insulation . 103
7.2 Surge arresters between phases . 104
7.2.1 General . 104
7.2.2 6-arrester arrangement . 104
7.2.3 4-arrester (Neptune) arrangement . 104
7.3 Surge arresters for rotating machines . 105
7.4 Surge arresters in parallel . 106

IEC 60099-5:2018 © IEC 2018 – 3 –
7.4.1 General . 106
7.4.2 Combining different designs of arresters . 107
7.5 Surge arresters for capacitor switching . 107
7.6 Surge arresters for series capacitor banks . 109
8 Asset management of surge arresters . 110
8.1 General . 110
8.2 Managing surge arresters in a power grid . 110
8.2.1 Asset database . 110
8.2.2 Technical specifications . 110
8.2.3 Strategic spares . 110
8.2.4 Transportation and storage . 111
8.2.5 Commissioning . 111
8.3 Maintenance . 111
8.3.1 General . 111
8.3.2 Polluted arrester housing . 112
8.3.3 Coating of arrester housings . 112
8.3.4 Inspection of disconnectors on surge arresters . 112
8.3.5 Line surge arresters . 112
8.4 Performance and diagnostic tools . 112
8.5 End of life . 113
8.5.1 General . 113
8.5.2 GIS arresters . 113
8.6 Disposal and recycling . 113
Annex A (informative) Determination of temporary overvoltages due to earth faults . 114
Annex B (informative) Current practice . 118
Annex C (informative)  Arrester modelling techniques for studies involving insulation
coordination and energy requirements . 119
C.1 Arrester models for impulse simulations . 119
C.2 Application to insulation coordination studies . 120
C.3 Summary of proposed arrester models to be used for impulse applications . 120
Annex D (informative) Diagnostic indicators of metal-oxide surge arresters in service . 122
D.1 General . 122
D.1.1 Overview . 122
D.1.2 Fault indicators . 122
D.1.3 Disconnectors . 122
D.1.4 Surge counters . 122
D.1.5 Monitoring spark gaps . 123
D.1.6 Temperature measurements . 123
D.1.7 Leakage current measurements of gapless metal-oxide arresters . 123
D.2 Measurement of the total leakage current . 128
D.3 Measurement of the resistive leakage current or the power loss. 129
D.3.1 General . 129
D.3.2 Method A1 – Using the applied voltage signal as a reference . 129
D.3.3 Method A2 – Compensating the capacitive component using a voltage
signal . 130
D.3.4 Method A3 – Compensating the capacitive component without using a
voltage signal . 131
D.3.5 Method A4 – Capacitive compensation by combining the leakage
current of the three phases . 131

– 4 – IEC 60099-5:2018 © IEC 2018
D.3.6 Method B1 – Third order harmonic analysis . 132
D.3.7 Method B2 – Third order harmonic analysis with compensation for
harmonics in the voltage . 133
D.3.8 Method B3 – First order harmonic analysis . 133
D.3.9 Method C – Direct determination of the power losses . 133
D.4 Leakage current information from the arrester manufacturer . 133
D.5 Summary of diagnostic methods . 135
Annex E (informative) Typical data needed from arrester manufacturers for proper
selection of surge arresters . 136
Annex F (informative) Typical maximum residual voltages for metal-oxide arresters
without gaps according to IEC 60099-4 . 137
Annex G (informative) Steepness reduction of incoming surge with additional line
terminal surge capacitance . 138
G.1 General . 138
G.2 Steepness reduction factor . 138
G.3 Equivalent capacitance associated with incoming surge fronts . 140
G.3.1 General . 140
G.3.2 Examples of incoming surge steepness change, f , using typical 550 kV
s
& 245 kV circuit parameters . 141
G.3.3 Change in coordination withstand voltage, U , with steepness
cw
reduction, f : . 142
s
G.4 EMTP & capacitor charging models for steepness change comparisons at
line open terminal . 142
G.5 Typical steepness (S = 1000 kV/µs), change comparisons with C & C . 143
0 0 s
G.6 Faster steepness (2000 kV/µs), change comparisons with C & C . 145
o s
Annex H (informative) Comparison of the former energy classification system based
on line discharge classes and the present classification system based on thermal
energy ratings for operating duty tests and repetitive charge transfer ratings for
repetitive single event energies. 147
H.1 General . 147
H.2 Examples . 150
Annex I (informative) Estimation of arrester cumulative charges and energies during
line switching . 155
I.1 Simplified method of estimating arrester line switching energies . 155
I.1.1 Introduction . 155
I.1.2 Simplified method calculation steps . 156
I.1.3 Typical line surge impedances with bundled conductors . 158
I.1.4 Prospective switching surge overvoltages . 158
I.1.5 Use of IEC 60099-4:2009 to obtain values for surge impedance and
prospective surge voltages . 159
I.2 Example of charge and energy calculated using line discharge parameters. 160
I.3 Arrester line switching energy examples . 164
I.3.1 General . 164
I.3.2 Case 1 – 145 kV . 167
I.3.3 Case 2 – 242 kV . 167
I.3.4 Case 3 – 362 kV . 167
I.3.5 Case 4 – 420 kV . 168
I.3.6 Case 5 – 550 kV . 168
Annex J (informative) End of life and replacement of old gapped SiC-arresters . 180
J.1 Overview. 180
J.2 Design and operation of SiC-arresters . 180

IEC 60099-5:2018 © IEC 2018 – 5 –
J.3 Failure causes and aging phenomena . 180
J.3.1 General . 180
J.3.2 Sealing problems . 180
J.3.3 Equalization of internal and external pressure and atmosphere . 181
J.3.4 Gap electrode erosion . 181
J.3.5 Ageing of grading components . 182
J.3.6 Changed system conditions . 182
J.3.7 Increased pollution levels . 182
J.4 Possibility to check the status of the arresters . 182
J.5 Advantages of planning replacements ahead . 182
J.5.1 General . 182
J.5.2 Improved reliability . 183
J.5.3 Cost advantages . 183
J.5.4 Increased safety requirements . 183
J.6 Replacement issues . 183
J.6.1 General . 183
J.6.2 Establishing replacement priority . 183
J.6.3 Selection of MO arresters for replacement installations . 184
Bibliography . 185

Figure 1 – Example of GIS arresters of three mechanical/one electrical column
(middle) and one column (left) design and current path of the three mechanical/one
electrical column design (right) . 29
Figure 2 – Typical deadfront arrester . 30
Figure 3 – Internally gapped metal-oxide surge arrester designs . 35
Figure 4 – Components of an EGLA acc. to IEC 60099-8 . 36
Figure 5 – Typical arrangement of a 420 kV arrester . 41
Figure 6 – Examples of UHV and HV arresters with grading and corona rings . 42
Figure 7 – Same type of arrester mounted on a pedestal (left), suspended from an
earthed steel structure (middle) or suspended from a line conductor (right . 43
Figure 8 – Installations without earth-mat (distribution systems) . 44
Figure 9 – Installations with earth-mat (high-voltage substations) . 45
Figure 10 – Definition of mechanical loads according to IEC 60099-4:2014 . 47
Figure 11 – Distribution arrester with disconnector and insulating bracket. 48
Figure 12 – Examples of good and poor connection principles for distribution arresters . 50
Figure 13 – Typical voltages and duration example for differently earthed systems . 54
Figure 14 – Typical phase-to-earth overvoltages encountered in power systems . 55
Figure 15 – Arrester voltage-current characteristics . 56
Figure 16 – Direct strike to a phase conductor with LSA . 61
Figure 17 – Strike to a shield wire or tower with LSA . 62
Figure 18 – Typical procedure for a surge arrester insulation coordination study . 69
Figure 19 – Flow diagrams for standard selection of surge arrester . 73
Figure 20 – Examples of arrester TOV capability . 74
Figure 21 – Flow diagram for the selection of NGLA . 87
Figure 22 – Flow diagram for the selection of EGLA . 91
Figure 23 – Common neutral configurations . 96

– 6 – IEC 60099-5:2018 © IEC 2018
Figure 24 – Typical configurations for arresters connected phase-to-phase and phase-
to-ground . 105
Figure A.1 – Earth fault factor k on a base of X /X , for R /X = R = 0 . 114
0 1 1 1 1
Figure A.2 – Relationship between R /X and X /X for constant values of earth fault
0 1 0 1
factor k where R = 0 . 115
Figure A.3 – Relationship between R0/X1 and X0/X1 for constant values of earth fault
factor k where R = 0,5 X . 115
1 1
Figure A.4 – Relationship between R /X and X /X for constant values of earth fault
0 1 0 1
factor k where R = X . 116
1 1
Figure A.5 – Relationship between R /X and X /X for constant values of earth fault
0 1 0 1
factor k where R = 2X . 116
1 1
Figure C.1 – Schematic sketch of a typical arrester installation . 119
Figure C.2 – Increase in residual voltage as function of virtual current front time . 120
Figure C.3 – Arrester model for insulation coordination studies – fast- front
overvoltages and preliminary calculation (Option 1) . 121
Figure C.4 – Arrester model for insulation coordination studies – fast- front
overvoltages and preliminary calculation (Option 2) . 121
Figure C.5 – Arrester model for insulation coordination studies – slow-front
overvoltages . 121
Figure D.1 – Typical leakage current of a non-linear metal-oxide resistor in laboratory
conditions . 124
Figure D.2 – Typical leakage currents of arresters in service conditions . 125
Figure D.3 – Typical voltage-current characteristics for non-linear metal-oxide resistors . 126
Figure D.4 – Typical normalized voltage dependence at +20 °C . 126
Figure D.5 – Typical normalized temperature dependence at U . 127
c
Figure D.6 – Influence on total leakage current by increase in resistive leakage current . 128
Figure D.7 – Measured voltage and leakage current and calculated resistive and
capacitive currents (V = 6,3 kV r.m.s) . 130
Figure D.8 – Remaining current after compensation by capacitive current at U . 131
c
Figure D.9 – Error in the evaluation of the leakage current third harmonic for different
phase angles of system voltage third harmonic, considering various capacitances and
voltage-current characteristics of non-linear metal-oxide resistors . 132
Figure D.10 – Typical information for conversion to "standard" operating voltage
conditions . 134
Figure D.11 – Typical information for conversion to "standard" ambient temperature
conditions . 134
Figure G.1 – Surge voltage waveforms at various distances from strike location
(0,0 km) due to corona . 139
Figure G.2 – Case 1: EMTP Model: Thevenin equivalent source, line (Z,c) & substation
bus (Z,c) & Cap(C ). 142
s
Figure G.3 – Case 2: Capacitor Voltage charge via line Z: u(t) = 2×U × (1 – exp[-
surge
t/(Z×C]) . 143
Figure G.4 – EMTP model . 143
Figure G.5 – Simulated surge voltages at the line-substation bus interface . 144
Figure G.6 – Simulated Surge Voltages at the Transformer . 145
Figure G.7 – EMTP model . 145
Figure G.8 – Simulated surge voltages at the line-substation bus interface . 146
Figure G.9 – Simulated surge voltages at the transformer . 146

IEC 60099-5:2018 © IEC 2018 – 7 –
Figure H.1 – Specific energy in kJ per kV rating dependant on the ratio of switching
impulse residual voltage (U ) to the r.m.s. value of the rated voltage U of the arrester . 148
a r
Figure I.1 – Simple network used for Arrester Line Discharge Calculation and Testing
according to IEC 60099-4:2009 . 155
Figure I.2 – Linearized arrester equation in the typical line switching current range
(voltage values shown are for a 372 kV rated arrester used on a 420 kV system) . 156
Figure I.3 – Graphical illustration of linearized line switching condition and arrester
characteristic . 157
Figure I.4 – Range of 2 % slow-front overvoltages at the receiving end due to line
energization and re-energization . 159
Figure I.5 – Arrester class 2 & 3 voltages calculated by EMTP calculations: U and
ps2
U (V × 10 ) . 162
ps3
Figure I.6 – Class 2 & 3 arrester currents calculated by EMTP studies: I and I
ps2 ps3
(A) . 162
Figure I.7 – Arrester Class 2 & 3 cumulative charges calculated by EMTP simulation:
Q and Q (C) . 163
rs2 rs3
Figure I.8 – Arrester Class 2 & 3 cumulative absorbed energies calculated by EMTP
simulation: W and W (kJ/kV U ) . 163
s2 s3 r
Figure I.9 – Typical Line Reclosing Computer Simulation Network . 164
Figure I.10 – Typical 550 kV Reclose Switching Overvoltage Profile along 480 km Line . 165
Figure I.11 – IEC LD based charge transfer, Q with varying arrester protective ratios . 166
rs
Figure I.12 – IEC LD based switching energy, W with varying arrester protective
th
ratios . 166
Figure I.13 – U for 145 kV system simulation (V x 10 ) . 170
ps
Figure I.14 – I for 145 kV system simulation (A) . 170
ps
Figure I.15 – 1 Cumulative charge (Q ) for 145 kV system simulation (C) . 171
rs
Figure I.16 – Cumulative energy (W ) for 145 kV system simulation (kJ/kV U ) . 171
th r
Figure I.17 – U for 245 kV system simulation (V x 10 ) . 172
ps
Figure I.18 – I for 245 kV system simulation (A) . 172
ps
Figure I.19 – Cumulative charge (Q ) for 245 kV system simulation (C) . 173
rs
Figure I.20 – Cumulative energy (W ) for 245 kV system simulation (kJ/kV U ) . 173
th r
Figure I.21 – U for 362 kV system simulation (V x 10 ) . 174
ps
Figure I.22 – I for 362 kV system simulation (A) . 174
ps
Figure I.23 – Cumulative charge (Q ) for 362 kV system simulation (C) . 175
rs
Figure I.24 – Cumulative energy (W ) for 362 kV system simulation (kJ/kV U ) . 175
th r
Figure I.25 – U for 420 kV system simulation (V x 10 ) . 176
ps
Figure I.26 – I for 420 kV system simulation (A) . 176
ps
Figure I.27 – Cumulative charge (Q ) for 420 kV system simulation (C) . 177
rs
Figure I.28 – Cumulative energy (W ) for 420 kV system simulation (kJ/kV U ) . 177
th r
Figure I.29 – U for 550 kV system simulation (V x 10 ) . 178
ps
Figure I.30 – I for 550 kV system simulation (A) . 178
ps
Figure I.31 – Cumulative charge (Q ) for 550 kV system simulation (C) . 179
rs
Figure I.32 – Cumulative energy (W ) for 550 kV system simulation (kJ/kV U ) . 179
th r
Figure J.1 – Internal SiC-arrester stack . 181

Table 1 – Minimum mechanical requirements (for porcelain-housed arresters) . 46

– 8 – IEC 60099-5:2018 © IEC 2018
Table 2 – Arrester classification . 78
Table 3 – Definition of factor A in formulas (14 and 15) for various overhead lines . 82
Table 4 – Examples for protective zones calculated by formula (16) for open-air
substations . 83
Table 5 – Example of the condition for calculating lightning current duty of EGLA in
77 kV transmission lines . 90
Table 6 – Probability of insulator flashover in Formula (18) . 93
Table D.1 – Summary of diagnostic methods . 135
Table D.2 – Properties of on-site leakage current measurement methods . 135
Table E.1 – Arrester data needed for the selection of surge arresters . 136
Table F.1 – Residual voltages for 20 000 A and 10 000 A arresters in per unit of rated
voltage . 137
Table F.2 – Residual voltages for 5 000 A, and 2 500 A arresters in per unit of rated
voltage . 137
Table G.1 – C impact on steepness ratio f and steepness S . 141
s s n
Table G.2 – Change in coordination withstand voltage, U . 142
cw
Table H.1 – Peak currents for switching impulse residual voltage test . 147
Table H.2 – Parameters for the line discharge test on 20 000 A and 10 000 A arresters. 148
Table H.3 – Comparison of the classification system according to IEC 60099-4:2009

and to IEC 6099-4 2014 . 149
Table I.1 – Typical Arrester Switching (U vs I ) Characteristics . 156
ps ps
Table I.2 – Typical line surge impedances (Z ) with single and bundled conductors . 158
s
Table I.3 – Line Parameters Prescribed by IEC 60099-4:2009 Line Discharge Class
Tests . 159
Table I.4 – Line surge impedances and prospective surge voltages derived from line
discharge tests parameters of IEC 60099-4:2009 for different system voltages and
arrester ratings . 160
Table I.5 – Comparison of energy and charge calculated by simplified method with
values calculated by EMTP simulation – Base parameters from Table I.4, used for
simplified method and for EMTP simulation . 161
Table I.6 – Comparison of energy and charge calculated by simplified method with

values calculated by EMTP simulation – Calculations using simplified method . 161
Table I.7 – Comparison of energy and charge calculated by simplified method with
values calculated by EMTP simulation – I.5.(c) Results from EMTP studies . 161
Table I.8 – Results of calculations using the ndifferent methods described for different
system voltages and arrester selection . 169

IEC 60099-5:2018 © IEC 2018 – 9 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
SURGE ARRESTERS –
Part 5: Selection and application recommendations

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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...