ITU-T Recommendations

This Recommendation deals with the protection for the structures in the neighborhood of telecommunication towers (including masts and poles) against damage and injury derived from direct lightning flashes to the tower. The assessment and protection measures just intend to reduce the possible risk derived from the erection of towers, but not to improve the overall lightning protection for every surrounding structure.

This Recommendation considers towers whose height is less than 100 m from ground level, which rarely meets the initiation condition of upward flashes, so that the presence of the tower does not significantly influence the incidence of lightning flashes.

Based on the analyses of sources of damage for an individual surrounding structure referring to [IEC62305-2], the risk components mostly includes the possible influence on the close vicinity of tower due to earth potential rise (EPR) and the transferred transients through common power feeds. For the former risk component, the hazard resulted from the occurrence of sparking and the injury to living beings are under consideration. For the latter, a series of exemption criteria and the corresponding protection (mitigation) measures are recommended. The requirements about the implementation of protection measures are also introduced.