Thank you for your question regarding using a SCADA system and monitoring copper earth wires for theft, it is our pleasure to help.
SCADA is an acronym that stands for “Supervisory Control and Data Acquisition” and generally refers to industrial control systems which are computer systems that monitor and control industrial, infrastructure, or facility-based processes. SCADA systems that are related to electrical power utilities, utilize Remote Terminal Units (RTU) to connect vital power control systems, typically at substations, back to a central Supervisory Control Station. The RTU’s allow the Supervisory Control Station to remotely throw switches, change transformers, regulate voltages, monitor kilowatts used, etc. Most utility companies have either recently completed upgrading to SCADA systems, or are in the process of installing these vital systems.
While these SCADA systems have the ability to monitor virtually any sensor system one would care to plug into it and program accordingly, we have never heard of it being used to monitor the earth systems for theft, or in fact to monitor the earth system at all. We are not saying that it isn’t possible, or that there are not important engineering factors related to the earth systems that shouldn’t be monitored, we are simply not aware of it being done.
That said, it would be a challenge to monitor the earth system for theft. The typical substation has dozens, if not hundreds of connections to the earth grid. Ground fault detectors may not trip unless every single earth wire is removed, even a single connection to the grid may be enough to make a earth fault sensor believe it has a good earth. There are resistance meters that could be permanently installed on the earth grid that may be able to detect changes in the grids integrity, but that would have to be researched and developed. Another choice may be a high-frequency pulse that is sent through the system at some regular interval, with the return on the opposite end of the system. The resulting return signal may be able to detect changes in the grid, however environmental conditions such as frost and rain may change the signal even more than the theft of a few conductors. You would probably be better off installing security barricades, cameras, or even a guard dog.
That said, one of our engineers found this piece of equipment that you may want to review. We have never seen it in operation, so we cannot tell you if it is a valid tool or not, but it is certainly what you were looking for. Let us know if you install this and how it works!
The Engineering Team at E&S Earthing Solutions
Photo credit: http://www.flickr.com/photos/kafreddy/4219421534/sizes/l/in/photostream/