Field test program and results to verify HPFF cable rating

Steps taken by one utility to obtain substantial increases in power transfer capability for an existing 115 kV pipe-type cable circuit are summarized, and tests and analyses that were done to verify that the cable could achieve the new ampacity are described. Novel approaches are developed to monitor cable and earth temperatures using versatile, inexpensive monitors, to transfer data to a PC-based analysis system, and to properly account for actual hourly loading on the circuits. Tests and analysis showed that the modifications to the cable circuit did permit a significant ampacity increase. Approaches in both uprating and verification of ampacity will be applicable to many cable-using utilities