In electrical terms, the geologies found in the Nordic region can seem a tough nut to crack. It is no surprise that there are some unique difficulties with earthing power systems in this region.
Igneous rock types such as granite make the soil resistivity much higher than in other parts of Europe. As a result, large sums of money can be thrown into compliant earthing designs and now there is an additional string to the earthing armoury – chem-rods!
How and why of Chem-Rods?
Filled with naturally occurring electrolytes and minerals, which chemically saturate the interfacing cylinder and massively lower the ground impedance. Typically, just one Chem-rod can do the job of 10 conventional rod electrodes.
Due to the amazingly low impedance achieved by the chem-rod, it can have quite a dramatic effect on the Earth Potential Rise (EPR, or GPR). This rise can help control the spread of energy during fault conditions and contribute to the overall safety of an earthing design in geologically challenging situations.
High-Frequency Earthing for Lightning
Not only will chem-rods assist in power systems earthing but they also work as part of lightning protection systems. The chem-rod’s low impedance provides the optimised path for the transferring energy of a lightning strike. Again, helping to protect central communications, electronics and AC power systems.
The GreyMatters ‘integrated’ approach
Understanding the challenges of Nordic geology we use highly advanced geological testing equipment to know how the rock or soil will behave electrically. The surveying equipment used delivers up to one hundred times the signal strength of standard instrumentation, which means the material will reliably penetrate solid rock!!!
Once the electro-geological properties are understood, an armoury of tools such as CDEGS software, chem-rods and other low impedance solutions can be coordinated in the design to deliver a safety compliantly, optimised design.