1 Scope
2 References
3 Definitions
3.1 Terms defined elsewhere
3.2 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Conventions
6 Need for protection
7 Earthing network for transformer and RBS
7.1 Basic principles
7.2 Common earthing network
7.3 Separated earthing network
8 Direct lightning protection
9 Transformer insulation level
10 MV/LV arresters requirements
11 MV/LV arresters installation
11.1 Protection schemes
11.2 Bonding of the transformer
12 Protection of ancillary facilities
12.1 Power meters
12.2 Power conductors
Annex A – Calculation for lightning risk factors
A.1 Lightning risk analysis
A.2 Calculation examples
Appendix I – Analysis on the reasons of lightning damage
I.1 Analysis of the processes that may lead to damage
I.2 Reasons for transformer damage
I.3 Forward transformation overvoltage (FTO)
I.4 Inverse transformation overvoltage (ITO)
Appendix II – Selection and installation of MV/LV arresters
II.1 Solidly earthed power distribution systems
II.2 Non-solidly earthed power distribution systems
II.3 Installation of MV/LV arresters and drop-out fuse
Bibliography