Electricity flowing in a conductor generates heat. Any resistance to heat flow between the cable and the ambient environment causes the cable temperature to rise. When cables are buried, soil forms part of the thermal resistance, and thus soil thermal properties become an important part of cable design.
Even in a well-designed system, the soil may account for half of the total thermal resistance. Engineers need to treat soil thermal resistivity with as much respect as they do the cables and ducts.
In the Australian environment, the water content of the vadose zone is constantly changing, unlike in parts of Europe.
It is critical to understand the impact of water content on thermal properties of the soil and hence the measurement of thermal properties. This is set out on page 16 “Critical Water Content” section of the document.
It is for this reason that the ICT International MPKit is purchased/hired with each KD2PRO that is purchased/hired.
Water Content and Thermal Resistivities of a Silt Loam at Different Temperatures