The rated current of any power cable is severely affected by its capability to
dissipate lost power into its surroundings. The cable may be directly buried in soil. In this case it
may easily dissipate the heat into the soil. However, in some specific areas the cables are due to be
installed in pipes which deteriorates the heat transfer from the cable into the surroundings. Some
additional losses may also appear when metallic pipes are used. The aforementioned cases are
studied in this paper and an approach to the estimation of the permissible current of a cable in
each condition is proposed. Finally, the results are compared to that of an existing commercial
software provided by ETSA (Electric Trust of South Australia) and the possible reasons for the
minor disagreements in some cases as well as the validity of each method are discussed.Feyzi, Mohammad Reza; Parker, Anthon
