Laminate sheaths as moisture barriers for medium voltage cables

An immense amount of data and information on moisture barrier cable has emerged. In spite of this body of knowledge on the effectiveness of moisture barriers against treeing and the commercialization of moisture barrier cable, the treeing phenomena is still being researched and studied. Well over a thousand papers have been presented on treeing related research. Great energy is still being expended to understand the mechanism and the material constraints. Yet the three things that cause or accelerate treeing are well known. They are electrical stress, the presence of water and the presence of ionic species. The evidence is indisputable that if moisture and ions are kept out of the insulation, then cable service life is benefited. To this end, radial and longitudinal moisture barriers have been developed to the degree that practical, cost efficient cable designs are available. In point of fact, there has been a proliferation of moisture barrier or impervious cable designs in recent years. Field data on performance is starting to emerge and it is excellent.<>