【Summary】In recent years, the use of fire-resistant cables is increasing, mainly because the performance of this cable has been recognized by users, and the manufacturers of this cable are also increasing, whether the quality of fire-resistant cables is guaranteed and long-term stability, which is very important. In general, some companies when developing fire-resistant cable products
　　
In recent years, the use of fire-resistant cables has increased, mainly because the performance of this cable has been recognized, and the manufacturers of this cable are also increasing, whether the quality of fire-resistant cables is guaranteed and long-term stability, which is very important. Under normal circumstances, some companies in the development of fire-resistant cable products, are the first trial production of a section of products, sent to the relevant national detection agencies, after obtaining the detection report, batch production, a small number of cable manufacturers have created their own fire resistance test detection room, fire resistance test is for the production of cable process results of the inspection, the same process program, in different periods of the production of cable performance has a certain difference, for the production of fire-resistant cable enterprises if the fire resistant cable fire test pass rate of 99%, Then the fire-resistant cable has a 1% safety hazard risk, which is 100% danger for the user, in view of the above problems, the following on how to improve the fire resistance test of the fire-resistant cable pass rate, from the raw materials, conductor selection, production process control and other aspects of a description as follows:
　　
1. Copper conductor is adopted
　　
Some manufacturers use copper-clad aluminum conductors as cable conductor cores, but copper-clad aluminum conductors cannot be selected for the conductors of fire-resistant cables, and copper conductors are used.
　　
2. It is advisable to use a round pressing conductor
　　
For the circular core with axial symmetry, the mica tape is tight in all directions after wrapping, so the conductor structure of the fire-resistant cable should use a circular tight conductor.
　　
The reason is: some users propose that the conductor is a bundle twisted soft structure conductor, which requires the company to communicate with the user from the reliability of the use of the cable to change to a circular tight conductor, soft structure bundle line, complex twisting is easy to cause mica belt damage, as a fire-resistant cable conductor is not desirable, but some manufacturers think that the user needs what kind of fire-resistant cable, the manufacturer should meet the needs of the user, after all, the user is not very clear about the relevant details of the cable, the cable is closely related to human life, Therefore, cable manufacturers must clearly explain the relevant technical problems to users. Sector-shaped conductors should not be used, because the wrapping pressure of the mica tape of the sector-shaped conductor is unevenly distributed, easy to scratch and bruise, resulting in a decrease in electrical properties, in addition, from the cost point of view, the cross-sectional circumference of the sector conductor structure is greater than the circumference of the circular conductor section, which increases the precious material mica tape, although the outer diameter of the circular structure cable has increased. The amount of PVC sheath material has increased, but compared with the total cost of product materials, circular structure cables are still economical in terms of comprehensive cost. Based on the above description, from the technical and economic analysis, the conductor of the fire-resistant power cable is preferably with a circular structure.