I recently received a customer inquiry about the high-voltage cable. After the customer purchased the high-voltage cable from our company, the cable could not be used due to improper storage of water. What should we do? After the cable enters the water, it is very difficult to dry it (such as using hot nitrogen to pressurize it), and generally there is no corresponding equipment. In actual operation, if the dao cable is flooded, but only a few meters away from the front end, if the entire cable is flooded, it is undesirable. Therefore, the prevention of water ingress of cables should be based on prevention and the following measures should be adopted:
The cable head should be sealed. The sawed cable end should be sealed with plastic (using a special cable gland) to prevent moisture from penetrating, whether it is stacked or laid. After the wire is laid, the cable head should be made in time. When buying a cable, you must choose a manufacturer with excellent quality. Since impurities and pores in the insulation are the starting point of water treeing, the quality of the cable is very important to prevent water tree aging. Strengthen the management of the cable head manufacturing process. Once the cable enters water, the cable head is often the first to break down. Therefore, if the wire head is made well, the overall life of the cable can be prolonged. For example, when the cable is peeling off the semiconductor layer, make a few vertical strokes on the semiconductor layer, and then peel off the semiconductor like sugarcane peeling. However, when you use a knife to draw too deep, it will damage the insulating layer and give opportunities for water trees. In addition, when soldering, because the power source cannot be found, the torch will be used to melt the solder directly. At this time, the flame will damage the copper shielding layer and the insulation layer. Therefore, this phenomenon must be eliminated. The correct method can be configured to UPS, because the soldering The time required is generally only 10min, and the power is no more than 500W.
Use cold shrinkable cable head 3M’s cold shrinkable silicone rubber cable accessories, simple and convenient to manufacture, no blowtorch, no solder. In addition, the silicone rubber cable accessories are elastic and tightly attached to the cable, which overcomes the shortcomings of heat-shrinkable materials (the heat-shrinkable material is not elastic. During the process of thermal expansion and contraction of the cable, there will be a gap between the cable body Provides convenience for the development of water trees).
For long cables, several long cables are used in a cable branch box, each of which is about 3km in length. For such high-voltage cables, in addition to intermediate connectors, one or two cable branch boxes are also used. Once one of the cables enters water, it will not Spread to other sections of the high-voltage cable, and it is also convenient to find in sections when the high-voltage cable fails.