Current rating of single-core paper-insulated power cables

A method is given for calculating the current rating of single-core, paper-insulated power cables. Reference is made to some of the limiting conditions governing the permissible current rating of these cables and a reacutesumeacute of the literature is included. Correction factors for conductor resistance, skin and proximity effects, lead sheath losses and dielectric losses are derived. Notes are presented on the effects of installation conditions, including cables laid in air, in water and in ducts, with special attention to the thermal resistance. Tables giving British and U.S.A. current ratings are compared.