Today we will talk about the cold and heat shrinkable cable accessories.
The first point of cold and heat shrinkable cable accessories: excellent electrical performance of materials. The material used for the cold shrinkable cable accessories is silicone rubber, which has high elasticity, good insulation performance, hydrophobicity, weather resistance and UV aging resistance. The material used for the heat shrinkable cable accessories is rubber plastic composite material. The material itself has no elasticity, only the "elastic memory" function.
The second point of cold and heat shrinkable cable accessories: electrical stress control unit performance. The electric stress control unit of the cold shrinkable cable accessory is geometric type: stress cone, which depends on the geometric curve to improve the electric field distortion. Its shape has been well formed in the company, so the performance of the electric stress control unit is stable. The electric stress control unit of the heat shrinkable cable accessory is of parameter type, that is, the electric stress control unit is formed by using the material with high dielectric constant and volume resistivity between the insulating material and the semi conducting material. The special parameters of this material are difficult to control and easy to change in the forming and construction process, resulting in the unstable performance of the electric stress control unit.
The third point of cold and heat shrinkable cable accessories: the structure is more ideal. The stress cone and insulation part of the cold shrinkable cable accessories are prefabricated into a whole in the factory through the high temperature and high pressure forming process. During the installation, the accessories only need to be packaged on the processed cable. The product quality can be controlled in the factory, and the field installation workload is small. The structure of the heat shrinkable cable accessories is: stress tube, internal and external insulation tube, and semi conducting tube, which are overlapped. It is inevitable that there is a small air gap between various pipes.
The fourth point of cold and heat shrinkable cable accessories: more convenient installation. Due to the limitation of the structure form of cold shrinkable cable accessories, there is no need for hot work during installation, so the hot shrinkable cable accessories are not applicable in some fire-resistant situations; however, the cold shrinkable cable accessories are not subject to this limitation, and only the support strip in the main body needs to be pulled out during installation.
Fifth point of cold and heat shrinkable cable accessories: sealing performance. The material of the cold shrinkable cable accessories is high elastic silicone rubber. After installation, the accessories and the cable are integrated. When the temperature of the cable causes the phenomenon of thermal expansion and cold shrinkage, the accessories will also be thermal expansion and cold shrinkage, always tight on the cable, with excellent sealing performance. The sealing of heat shrinkable cable accessories is mainly realized by hot-melt adhesive and shrinkage compression stress. After the installation of heat shrinkable accessories, when the temperature drops, the cable shrinks, and the shrinkable parts with good shrinkage are stable in structure and no longer elastic, so the elastic compression force of the cable is lost and the sealing performance is not reliable.
Sixth point of cold and heat shrinkable cable accessories: materials and production cost. The material price of domestic cold shrinkable cable accessories is 4-5 times of that of heat shrinkable cable accessories. Therefore, the manufacturing cost of cold shrink cable accessories is slightly higher than that of heat shrink cable accessories.