Determination of Cable Temperatures by Means of Reduced-Scale Models

A method, using reduced-scale model installations, is developed for the laboratory determination of cable temperatures obtaining in the field. The theory of the method is given, followed by the description of three sets of experiments conducted to show the feasibility of the method. One set of experiments is concerned with a single-conductor cable buried directly in the soil of the model setup, and temperatures obtained are compared with computed values. Another set is concerned with a single-conductor cable in a model duct bank, and sheath and duct temperatures obtained are compared with those of field determinations in an actual field installation. The third set is concerned with a model three-conductor cable in a duct bank, and conductor-sheath temperature differentials are compared with field data. All tests show that the accuracy of the method is sufficient for practical purposes.