Thank you for your question regarding proper earthing at cellular stations, it is our pleasure to help.
Proper earthing at cellular stations is quite complex and detailed. There are many requirements for extensive bonding and a typical cellular station and getting into each of them would be far to much to cover in a simple blog. But needless to say, virtually every single piece of metal must be connected to a dedicated equipotential earthing system which is in turn bonded to an earthing system.
We recommend that you obtain a copy of Motorola’s R56 standard. It is by far and away the single best guide for the proper installation of a cellular station.
The earthing requirements for the typical cellular station generally require a buried counterpoise (ring) system around the stations equipment pads and fence, and should have a resistance-to-earth of less than 5-ohms.
The purpose of the earthing system at a cellular station is the same as at any transmitting antenna, to remove the energy that has been induced into the station by its own transmissions.
Transmitting antenna’s, including those found at cellular stations, will induce unwanted electrical energies into the base station. This energy will quickly build up causing electrical noise and harmonics that will compromise the signal quality and damage equipment. The above-grade bonding system will ensure that there are no differences in potential within the station and will allow the stray currents to move to the earthing system, which in turn provides a path to earth where the harmonics can pass harmlessly out of the system. The better the earthing is, the quicker and more effective the cellular station will be.
Achieving 5-ohms or less for your earthing system is all about understanding the make up of the soil at your site. The more resistive the soil is the more extensive the earthing system will need to be. Here is a link that discusses this topic more thoroughly:
We are of course more than happy to help you design an effective earthing system for your cellular station. All that is needed is a site plan and soil resistivity data, and we can provide you with a computer analyzed earthing design that meets your required 5-ohms specification, all via email. Please feel free to contact us again and we can make the arrangements, if you should need this service.
The Engineering Team at E&S Earthing Solutions
Photo credit: http://www.flickr.com/photos/fostercriff/4042237778/sizes/o/in/photostream/