Heat-shrinkable plastics in high voltage applications

6 HEAT-SHRINKABLE PLASTICS IN HIGH-VOLTAGE (HV) APPLICATIONS 

Once early experience had built up in the weather-protected applications described above the technique was extended to outdoor, weather-exposed situations. This is a further example of a type of installation where the cast iron box and bitumen were to be replaced. The technique to be used was similar to that used in weather-protected situations except that provision now had to be made to prevent ingress of moisture in the outside environment. This meant the development of a sealant to go between the cable and the heat-shrinkable part. Table 26.3 shows the properties of a number of suitable sealants. 

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