NSY/WSY/JSY 6/10KV 1-3 core 25-500mm² outdoor and indoor high voltage cross-linked cable heat shrinkable terminal and intermediate joint

Heat-shrinkable power cable terminal head and intermediate joint series products integrate 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 electric power, petrochemical, metallurgy, railway port and construction fields.
Heat-shrinkable cable accessories, commonly known as heat-shrinkable cable heads, are widely used in the intermediate connections and terminals of cross-linked cables or oil-immersed cables with voltage levels below 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 conforms to the GB11033 standard, the long-term use temperature range is -55℃～105℃, the aging life is up to 20 years, the radial shrinkage rate is ≥50%, the longitudinal shrinkage rate is less than 5%, and the shrinkage temperature is 110℃～140℃.
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 tube to deal with the problem of electrical stress concentration. That is, the parameter control method is used to relieve the stress concentration of the electric field.
The main advantages are light weight, easy installation and good performance. cheap price.
The stress tube is a heat shrinkable tube with special electrical parameters with moderate volume resistivity (1010-1012Ω•cm) and high dielectric constant (20--25). The electrical parameters are used to force the stress evacuation at the fracture of the cable insulation and shielding. into a more uniform distribution along the stress tube. This technology can only be used in 35kV and below cable accessories. Because the stress tube will heat up and cannot work when the voltage level is high.
The key technical problems in its use are: To ensure that the electrical parameters of the stress tube must meet the specified values ​​of the above-mentioned standards, it can work.
In addition, attention should be paid to filling the air gap at the fracture of the insulating semiconducting layer of the cable with silicone grease to remove gas and reduce partial discharge.
The cross-linked cable will shrink greatly during operation due to poor internal stress treatment. Therefore, when installing accessories, pay attention to the overlap between the stress tube and the insulating shield of not less than 20mm to prevent the stress tube and the insulating shield from detaching during shrinkage.
Due to the low elasticity of heat shrinkable accessories, air gaps may be created at the interface during thermal expansion and contraction during operation, so sealing technology is important to prevent moisture intrusion.