CONTENTS

�1���� Scope
�2���� References
�3���� Definitions
�4���� Reference configuration
�5���� Expected risk of damages
������� 5.1���� General
������� 5.2���� Frequency of damages for cables
������� 5.3���� Frequency of damages for structures that the cable enters
������� 5.4���� Parameters for the evaluation of the frequency of damages
����������������� 5.4.1���� Lightning ground flash density (N_g)
����������������� 5.4.2���� Current probability factor (p(i))
����������������� 5.4.3���� Environmental factor (K_e)
����������������� 5.4.4���� Striking distance (D)
����������������� 5.4.5���� Damage correction factor (K_d)
�6���� Determination of failure current (I_a)
������� 6.1���� Lightning discharges to cables
������� 6.2���� Lightning discharges to structures where the cable enters
�7���� Protection procedures
������� 7.1���� Selection of the environment
������� 7.2���� Choice of the cable
����������������� 7.2.1���� Dielectric optical fibre cable
����������������� 7.2.2���� Cable with high sheath breakdown current
����������������� 7.2.3���� Cable with high sheath breakdown voltage
������� 7.3���� Buried or aerial installation
������� 7.4���� Use of surge protective devices (SPD)
������� 7.5���� Shielding
������� 7.6���� Route redundancy
Annex A-Evaluation of the sheath breakdown current
������� A.1���� Buried cable
������� A.2���� Aerial cable
Appendix I - Tests for the evaluation of surge resistibility of cables
������� I.1���� Breakdown voltage (U_b)
������� I.2���� Test current (I_t) for buried cable
������� I.3���� Test current (I_t) for aerial cable
Appendix II - Expected loss per damage (d)