What are the common profiles of heat shrinkable accessories?

Heat-shrinkable accessories are mainly based on the characteristics of the cable structure, which can not only restore the performance of the cable but also ensure the extension of the cable length and the connection of the terminal. The reliability of high-pressure heat shrinkable accessories can be judged from the aspects of electrical performance, sealing and moisture-proof performance, mechanical performance, and process performance. So what are the common profiles of heat shrinkable accessories? Let's take a look next.

This is the content list:

• Connection method

• Grouped equipment

• Key technical issues

Connection method

The connection method of heat shrinkable accessories is generally divided into terminal connection and intermediate connection. The terminal connection is divided into the indoor terminal and the outdoor terminal. Generally, outdoor terminal refers to outdoor cable joint, and indoor terminal refers to indoor connection cable and electrical equipment joint. The intermediate connection of heat shrinkable accessories is divided into two types: straight-through type and insulated type.

Grouped equipment

This set of quality assurance procedures for heat shrinkable accessories should at least include the following: When leaving the factory, factory tests on key components should be strictly carried out. Carefully check whether the test and measurement heat shrinkable accessories are reliable, whether the test method is effective, whether the test personnel is well-trained, and whether the test records are complete. Whether the installation and construction personnel dispatched by the manufacturer have received strict training and sufficient construction experience. Whether the coordination between the different departments of the manufacturing plant is good, and the past sales and operation records of heat shrinkable parts.

Key technical issues

The materials used for heat shrinkable accessories are generally a blend of polyethylene, ethylene-vinyl acetate (EVA), and ethylene-propylene rubber. Heat shrinkable parts mainly use stress tubes to deal with the problem of electric stress concentration. That is, the parameter control method is used to alleviate the electric field stress concentration. The main advantages are lightweight, easy installation, good performance, and low price. The stress tube is a kind of heat shrinkable tube with special electrical parameters with moderate volume resistivity (1010-1012Ωcm) and a large dielectric constant (20-25). The electrical parameters are used to force the stress at the cable insulation and shielding fracture to evacuate. The stress tubes are more evenly distributed. This technology is generally used in cable accessories of 35kV and below. Because the stress tube will heat up when the voltage level of the heat-shrinkable accessories is high and cannot work reliably. The key technical problem in its use is to ensure that the electrical parameters of the stress tube of the heat shrinkable accessories must reach the specified values of the above standards to work reliably. In addition, attention should be paid to filling the air gap of the cable insulation semi-conducting layer with silicone grease to eliminate the gas and achieve the purpose of reducing partial discharge. Cross-linked cables will shrink greatly during operation due to poor internal stress handling, so when installing heat shrinkable accessories, pay attention to the stress tube and insulation shielding cover not less than 20mm to prevent the stress tube and insulation shielding when the heat shrink fitting shrinks. Due to the small elasticity of heat shrinkable accessories, air gaps may occur at the interface during thermal expansion and contraction during operation. Therefore, sealing technology is very important to prevent moisture intrusion.

To produce more excellent heat shrinkable accessories, Haivo Electric Co., Ltd. has injected a lot of funds and scientific research strength in breaking through the technical problems of heat shrinkable accessories. If you are interested in heat shrinkable accessories, you can contact us. Our website is https ://www.haivofusecutout.com/.