Basic knowledge of Cable Accessories

Cable accessories refer to the straight through joint connection and termination connection of various cables in the cable line, which together with the cable constitute the power transmission network. With the continuous development of cable manufacturing technology, cable accessories have experienced several stages, such as pouring cable accessories, wrapping cable accessories, heat shrinkable cable accessories, prefabricated cable accessories and cold shrinkable cable accessories. At present, the most widely used are heat shrinkable cable accessories, prefabricated cable accessories and cold shrinkable cable accessories.

Wrapping type: Cable accessories made of rubber strip (self-adhesive) are called wrapping type cable accessories, which are easy to loose, poor fire resistance and short life.

Watering type: with thermosetting resin as the main material in the field of watering, the selected materials are epoxy resin, polyurethane, acrylic, etc., the fatal drawback of this kind of accessories is easy to produce bubbles when curing.

Molded type: It is mainly used for middle connection of cable, adding die and heating on site, and integrated with cable. The production process of this accessory is complicated and takes a long time, and it is not suitable for terminal joint.

Cold shrinkable type: with silicone rubber, ethylene propylene diene rubber and other elastomers in the factory pre-expansion and add plastic support strip and forming. In the field construction, the support strip is extracted to make the pipe shrink on the cable under the inherent elastic effect of rubber, and the cable accessories are made. The accessories are most suitable for the construction places that cannot be heated by open fire, such as mines, petrochemical industry, etc.

Heat shrinkable type: accessories made of rubber and plastic alloy made of different component products with shape memory effect and heated on the cable in the field. The accessory has the characteristics of light weight, simple and convenient construction, reliable operation and low price.

Prefabricated type: accessories made of silicone rubber injected into different components, once vulcanized, only retaining the contact interface and inserting cables during field construction. The construction process can reduce the unmeasurable adverse factors in the environment to a minimum degree, so the accessories have great potential use value, is the development direction of crosslinked cable accessories, but the manufacturing technology is difficult, involving a variety of disciplines and industries. The installation materials of the prefabricated accessories below the three branches of the cable and the shield mouth are still made of heat-shrinkable materials, so it is actually a combination of prefabricated and heat-shrinkable.

Now the most commonly used and the most convenient installation and use is the heat shrinkable and cold shrinkable type:

Heat shrinkable cable accessories, as the name implies, are cable accessories that need to be shrunk by high temperature heating. Generally, the suitable place is the place that can be used for fire heating, which has certain safety risks, so the range of use is limited. The advantage is that the price is cheaper than the cold shrinkage.

Cold shrinkable cable accessories are generally made of elastic silicone rubber and ethylene-propylene rubber, which are injected and vulcanized, then expanded and lined with plastic spiral supports. It has the advantages of small size, convenient operation, rapid, no special tools, wide range of application. Compared with the heat shrinkable cable accessories, there is no need to use fire heating, and after installation, moving or bending will not be as dangerous as the heat shrinkable cable accessories between the internal layers of the accessories.