Field monitoring of parameters and testing of EP and TR-XLPE distribution cables

Five commercial ethylene-propylene rubber (EP) and one tree-retardant cross-linked polyethylene (TR-XLPE) 15 kV cables are being aged in the laboratory, and in field service on a utility distribution system. The cables were obtained from six different manufacturers. This study subjects commercially available, widely used EP cables, and one TR-XLPE cable to similar conditions at three different sites. Two test sites are located at Orange and Rockland Utilities' (OR the second is a normal 35 kV service site, with the cable aging under accelerated voltage conditions. Line voltage, voltage surges, load current, earth, duct and cable temperatures on the systems are being field monitored. Cable Technology Laboratories (CTL) has provided an accelerated aging set-up for the third site. This paper describes the methodology, characterization testing and some preliminary results from this project.