ClicksThe superiority of cold shrinkable cable accessories performance:
Cold-shrinkable cable accessories have the advantages of small size, convenient and fast operation, no special tools, wide application range and few product specifications. Compared with heat shrinkable cable accessories, it does not need to be heated by fire, and after installation, moving or bending will not cause the danger of disconnection between the internal layers of the accessories like heat shrinkable cable accessories (because cold shrinkable cable accessories rely on elastic compression Tightness).
However, no product is perfect, and cold-shrinkable cable accessories have their own limitations. This limitation is shown in:
The first point is that the specifications of cold-shrinkable cable accessories are restricted. It cannot be made too small, so that the application in low-voltage cable accessories is limited, especially for small square cross-sections.
The second point is that the cold shrinkage of oil-immersed cables is not applicable. It cannot block the oil, which limits the application of cold-shrinkable cable accessories to oil-immersed cables.
The third point is that its price is about 5-6 times that of heat-shrinkable cable accessories, and it will not be the first choice for some economical occasions.
Heat shrinkable cable accessories also have their irreplaceable special features:
Intermediate connections and terminals of voltage-grade cross-linked cables or oil-immersed cables. Compared with traditional cable accessories, it has the characteristics of small size, light weight, safety and reliability, and convenient installation. The product complies with 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 <5%, and the shrinkage temperature is 110℃～140℃.
The material used is generally a blend of polyethylene, ethylene-vinyl acetate (EVA), and ethylene-propylene rubber. This kind of product mainly uses stress tube to deal with the problem of electric stress concentration. That is, the parameter control method is used to relieve the electric field stress concentration. The main advantages are light weight, easy installation and good performance. cheap price.
Note:
The stress tube is a kind of heat-shrinkable tube with special electrical parameters with moderate volume resistivity (1010-1012Ω?cm) and large dielectric constant (20-25). The electrical parameters are used to force the stress evacuation at the fracture of the cable insulation shield. The components are more evenly distributed along the stress tube. This technology can only be used in cable accessories of 35kV and below. When the voltage level is high, the stress tube will heat up and cannot work.
From a technical perspective, the performance of cold-shrinkable cable accessories is mainly reflected in its partial discharge characteristics, and the comprehensive performance of heat-shrinkable cable accessories has certain advantages. In terms of installation, the installation time of cold-shrinkable cable accessories is shorter than that of heat-shrinkable cable accessories, and electricity can be sent after installation. Cold-shrinkable cable accessories have relatively advantages. To sum up, it is unlikely that cold-shrinkable cable accessories will completely replace heat-shrinkable cable accessories. Click to see the difference between cold-shrinkable cable accessories and heat-shrinkable cable accessories.
Here to remind users: choose the type of cable accessories according to their own industrial and mining conditions. Any product exists, has its reasons, and it is impossible to completely die. In fact, cable accessories such as cast-in type and wrap-around type have been used for nearly 50 years, but they are still in use.
