• Rohit Narayan - Director Global Telecom, nVent ERICO

The subject of bonding on telecommunications towers is not a new subject. However there has been a significant change in the type of feeders and equipment that are mounted on telecommunications towers in the last decade and this this gives cause to re-visit this subject. These changes include widespread application of remote radio units, use of d.c power to supply power to equipment on towers, use of ethernet and power of ethernet for communications to and from equipment mounted on towers. Furthermore, there are other changes in the industry that have caused a laxed approach to tower bonding in general around the globe. These changes include a rapid densification of equipment on existing and new towers, tower installation work carried out by multiple vendors and contractors and a lack of understanding on the need and methods for bonding on telecommunications. The ITU and other standards that do exist for tower bonding provide excellent guidance but inadequate detail on how to do this bonding. The author has recently come across several site failures and several instances of failures waiting to happen due to inadequate bonding on towers.

This paper will look at the reason and the need for bonding of equipment and feeders and practical methods of bonding on towers. We will look at the lightning attachment process to understand the effect on telecom tower that causes surges to be induced on feeders. We will look at experiment results from ITU K.56 and technical paper Current Distribution In A Telecommunication Towerstruck By Rocket-Triggered Lightning by C.F. Barbosa, F.E. Nallin S. Person, A. Zeddam. Bonding on tower reduced the effect of lightning on telecommunication feeder. Practical methods of bonding on telecommunication towers will be discussed.