MV underground cables: effects of soil thermal resistivity on anomalous working temperatures
One of the parameters that has to be considered in designing underground cables is the thermal resistivity of the soil along their routes. In fact, the ampacity of the MV underground cables having different types of insulation is normally evaluated through the application of the IEC Standard 60287-x 'Electric cables - Calculation of the current rating'. This series of IEC Standard is formed of three parts as in the following: part 1: Formulae of ratings and power losses; part 2: Formulae for thermal resistance; part 3: Sections on operating conditions.