Are you having problems with your electrical cables failing? Do you find that cables buried in your land have a shorter lifespan than you would expect? Have you just had a catastrophic electrical failure caused by overheating cables? If any of these situations describe what you are experiencing, then there could be a problem with thermal conductivity. Soil has much more of effect on your cables than you might think.
How the soil type impacts your electrical cables
Soil thermal resistivity probably isn't something you spend much time thinking about, but it really does pay to consider the type of soil in which you will be laying your cables.
When you lay your cables in the open air then the heat that is generated while the cable is in use will be dissipated through the air, when the same cable is buried in the ground then the cable is reliant upon the soil to dissipate the heat and when it comes to thermal conductivity soil types are not all equally efficient. Without adequate heat dissipation, the performance of your cable will be significantly impacted and the life of the cable shortened.
Identifying your soil thermal resistivity
To identify your prevailing thermal conductivity, soil samples should be taken from your proposed cable alignment. Find a company that offers soil thermal resistivity testing and arrange from them to analyse your soil. They will dry your soil samples and then check them for resistivity under a range of moisture conditions. Once a representative selection of soil samples have been analysed, you will be able to forecast how well your cable will perform throughout the changing seasons.
What is the solution to thermal conductivity problems?
Knowing that you have a thermal conductivity problem is a good start but what can you do about it? In some cases, the easiest solution to thermal resistivity issues is to simply find an alternative route for your cable. If there is a route that you could take which offers better soil conductivity, then that is often the most logical option. If you can't change the route of the cable, then the most practical solution is to change the soil through which the cable runs.
If you do need to change your soil, then your resistivity testing company should be able to suggest a soil with better properties. Just scoop out your existing soil along the route of the cable and for better thermal conductivity soil with a more conductive nature should replace it.
Don't risk damaging your cables by letting them get too hot, arrange for testing of the soil before you lay your cables.