ITU-T K.56:2021

Summary
History
FOREWORD
Table of Contents
1 Scope and purpose
2 References
3 Definitions
3.1 Terms defined elsewhere
3.2 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Conventions
6 Need of protection
7 External area
7.1 Lightning protection system (LPS)
7.1.1 Metallic tower
7.1.2 Non-metallic tower
7.1.3 Building
7.2 Bonding in the tower
7.2.1 Feeder cables
7.2.2 Cable supplying power to the tower lights
7.2.2.1 Metallic duct
7.2.2.2 Shielded cable
7.2.2.3 Unshielded cable
7.2.3 Feeder tray
7.3 Earthing
7.3.1 Earthing configuration
7.3.2 Surface covering
7.3.3 Fences
7.4 Power meter station
8 Equipment building
8.1 Feeder and lighting cables
8.1.1 Bonding at the feed-through window
8.1.2 Use of SPDs
8.2 Power conductors
8.2.1 Electric board
8.2.2 Installation of SPD in the electric board
8.2.3 Selection of SPDs
8.3 Telecommunication conductors
8.3.1 Distribution frame
8.3.2 Installation of SPDs in the distribution frame
8.4 Earthing and bonding of metallic elements
9 Protection of RBS equipment
9.1 Inductive voltage drop across the SPD connecting leads
9.2 Voltage induced in the internal cabling
Annex A Shielding factor (β) of cable trays
Annex B Shielding factor (η) of building walls
Annex C Example of earthing and bonding configuration inside an RBS
Appendix I Results of tests with rocket-triggered lightning on a radio base station
I.1 Introduction
I.2 Description of the test site
I.3 Recordings of the lightning current
I.4 Shielding factor of tower and feeder tray
I.5 Bonding the feeder to the tower at ground level
I.6 Current flowing through service conductors
I.7 Inductive voltage drop in the SPD connecting leads
Bibliography

Recommendation ITU-T K.56 presents the techniques applied to a telecommunication radio base station in order to protect it against lightning discharges.

This Recommendation addresses radio base stations (RBSs) made of a shelter or small building to house the equipment and a nearby tower to hold the antennas.