1KV, 10KV, 20KV, 35KV heat-shrinkable power cable terminal head, intermediate joint series products, integrating waterproof, stress control and insulation. It has good electrical and mechanical properties and can be used for a long time under various harsh environmental conditions. It has the advantages of light weight and convenient installation. Widely used in power, petrochemical, metallurgy, railway ports and construction.
Heat-shrinkable cable accessories, commonly known as heat-shrinkable cable heads, are widely used in intermediate connections and terminals of cross-linked cables or oil-immersed cables of the following voltage grades for 35KV and heat-shrinkable cable accessories. Compared with traditional cable accessories, it has the characteristics of small size, light weight, safety and reliability, and convenient installation. The product meets the GB11033 standard, the long-term use temperature range is -55 ° C ~ 105 ° C, the aging life is up to 20 years, the radial shrinkage rate is ≥ 50%, the longitudinal shrinkage is < 5%, and the shrinkage temperature is 110 ° C ~ 140 ° C. < p="">
The materials used are generally composed of a blend of various material components such as polyethylene, ethylene-vinyl acetate (EVA) and ethylene propylene rubber.
This type of product mainly uses stress tubes to deal with the problem of electrical stress concentration. That is to say, the parameter control method is used to alleviate the electric field stress concentration.
The main advantages are light weight, easy installation and good performance. cheap price.
The stress tube is a heat shrinkable tube with a moderate electrical resistivity (1010-1012 Ω•cm) and a large dielectric constant (20--25). The electrical parameters are used to force the stress dissipation at the insulation of the cable insulation. A more uniform distribution along the stress tube. This technology can only be used in cable accessories up to 35kV. Because the voltage level is high, the stress tube will heat up and will not work.
The key technical problems in its use are: To ensure that the electrical parameters of the stress tube must meet the values specified in the above standards.
In addition, it is necessary to fill the air gap of the cable insulation semi-conductive layer with silicone grease to remove the gas, so as to reduce the partial discharge.
When the cross-linked cable is poorly treated due to internal stress, it will shrink greatly during operation. Therefore, when installing the accessory, pay attention to the stress tube and the insulation shield cover not less than 20mm to prevent the stress tube from being separated from the insulation shield during shrinkage.
Because of the low elasticity, the heat shrinkable attachment may cause an air gap at the interface during thermal expansion and contraction during operation. Therefore, the sealing technology is important to prevent moisture intrusion.
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