IEC 60099-5:2018

FOREWORD
1 Scope
2 Normative references
3 Terms and definitions
4 General principles for the application of surge arresters
5 Surge arrester fundamentals and applications issues
6 Insulation coordination and surge arrester applications
7 Surge arresters for special applications
8 Asset management of surge arresters
Annex A (informative) - Determination of temporary
        overvoltages due to earth faults
Annex B (informative) - Current practice
Annex C (informative) - Arrester modelling techniques for
        studies involving insulation coordination and energy
        requirements
Annex D (informative) - Diagnostic indicators of metal-oxide
        surge arresters in service
Annex E (informative) - Typical data needed from arrester
        manufacturers for proper selection of surge arresters
Annex F (informative) - Typical maximum residual voltages
        for metal-oxide arresters without gaps according to
        IEC 60099-4
Annex G (informative) - Steepness reduction of incoming
        surge with additional line terminal surge capacitance
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
Annex I (informative) - Estimation of arrester cumulative
        charges and energies during line switching
Annex J (informative) - End of life and replacement of
        old gapped SiC-arresters
Bibliography

IEC 60099-5:2018 provides information, guidance, and recommendations for the selection and application of surge arresters to be used in three-phase systems with nominal voltages above 1 kV. It applies to gapless metal-oxide surge arresters as defined in IEC 60099-4, to surge arresters containing both series and parallel gapped structure – rated 52 kV and less as defined in IEC 60099-6 and metal-oxide surge arresters with external series gap for overhead transmission and distribution lines (EGLA) as defined in IEC 60099-8. In Annex J, some aspects regarding the old type of SiC gapped arresters are discussed. Surge arrester residual voltage is a major parameter to which most users have paid a lot of attention to when selecting the type and rating. Typical maximum residual voltages are given in Annex F. It is likely, however, that for some systems, or in some countries, the requirements on system reliability and design are sufficiently uniform, so that the recommendations of the present standard may lead to the definition of narrow ranges of arresters. The user of surge arresters will, in that case, not be required to apply the whole process introduced here to any new installation and the selection of characteristics resulting from prior practice may be continued. Annexes H and I present comparisons and calculations between old line discharge classification and new charge classification. This third edition cancels and replaces the second edition published in 2013. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition regarding the new surge arrester classification introduced in IEC 60099-4:2014:
a) Expanded discussion of comparison between the old and new classification and how to calculate or estimate the corresponding charge for different stresses.
b) New annexes dealing with:
- Comparison between line discharge classes and charge classification
- Estimation of arrester cumulative charges and energies during line switching
Keywords: selection and application of surge arrestors, nominal voltages above 1 kV