Trends in underground residential distribution cable systems

Some observed trends in cable designs being installed are discussed, the performance of cable accessories is reviewed, and the accessory application issues concerning alternate cable designs are highlighted. It is noted that, despite their excellent intrinsic electrical properties (100% insulation thickness, unjacketed concentric neutral) polyethylene insulated cables have not supplied the expected service life of 30 to 40 years in underground residential distribution systems. Use of other insulation materials has increased service life but is still below expectations. Users are installing cables with alternate designs in order to improve service life. Cable accessory standards have lagged behind the cable standards in required performance testing. Some users believe that accessories are the weak link in the cable distribution system. Recent changes to the joint standard have upgraded the required design proof testing. Installation of jacketed cable requires evaluation of cable accessories to insure that all application issues are addressed