Heat Transfer Measurements On Unequally Loaded Underground Power Cables With Constant And Cyclic Currents

A test site was constructed with underground power cables in a typical distribution-type duct bank arrangement. The site can be used to obtain temperatures throughout the duct bank and surrounding soil medium for known cable currents. A personal computer with an analog to digital converter system is used to independently set the currents in each cable to any load so that steady, cyclic, and transient experiments can be performed. Results of a number of constant and cyclic current experiments show good agreement between experimental temperature data and the calculated temperatures from an ampacity computer program.