Specifying Quality Cables
Vitaliy Yaroslavskiy, VP, Technology, Cable Technology Labs
Initial deployment of medium voltage cables with polymeric insulations (XLPE and EPR) in 1960-70th had disappointing results, with epidemic failures after only 7-8 years in service (somewhat better with EPR, much worse with XLPE). Faced with extremely high failure rate, the industry was forced to radically improved cable performance in materials, design, and manufacturing processes delivering cables with life expectancy exceeding 40 years. Critical quality issues remain, which require a laser focused effort throughout all quality assurance programs.
A brief overview of the industry standards and guides related to cable specifications will be followed by illustration of typical imperfections in medium voltage cables, discussion of performance of modern cables (based on results of laboratory qualification tests), most significant and frequent issues with cable quality, and experience with different level quality assurance programs.