Industry experts on how to improve the fire experiment of cable pass rates


"Cable network" as fire-resistant cables are now more and more widely used, so many manufacturers are producing, but often the quality is not guaranteed. So in general situation Xia, enterprise in development refractory cable products Shi, are is first trial a products, sends related national detection institutions, made detection report Hou, on bulk for production, has minority cable production manufacturers established has himself of refractory test detection room, everyone know, refractory test is for by production cable process results of test, also of process programme, and in different of period by production cable performance exists must of differences sex, for production refractory cable of enterprise, if refractory cable of refractory experiment through rate for 99 %, Then the danger of fire-resistant cable there are 1% security risks, it is 100% dangerous to users, to solve these problems, industry experts on how to improve fire-resistant cables fire resistance test pass rates, from raw material, conductor selection, production process control, explains:


1. with three mica, synthetic mica, phlogopite, Muscovite, their quality is the best synthetic mica, Muscovite worst for small cable you must select the synthetic MICA tape for wrapping, MICA tape layer cannot be used, MICA tape for long-term storage easy to absorb moisture, so must be considered in Mica tape storage temperature and humidity of the surrounding environment.


2. use mica tape winding device, stability should be used, wrap angle best wrapped in 300--400, MICA tape wrapped even closer, all the guide rollers and rods must be smooth contact with the device, cable tidy, tension-not too big, reel tool wheel side plate and a cylinder smooth.


3. for round conductors with axial symmetry after its MICA tape wrapped tightly in all directions, so for the fire-resistant structure suitable for round cable conductor compacted conductor. The reason for this is as follows:


① some user proposed conductor for beam twisted soft structure conductor, this on need enterprise from cable using of reliability aspects and user communication to round tight pressure conductor, soft structure beam line, and complex twisted easy caused MICA with injury, as refractory cable conductor not desirable, but some manufacturers think user need what Yao sample of refractory cable, manufacturing manufacturers on should meet user needs, I think user after all on cable of related details sex problem does not is understand, cable is and people of life is closely related to of, Cable manufacturers technical problems and user must be clear.


II sector conductors should not be used, MICA tape for fan-shaped conductor wrapped pressure is uneven, as shown in the figure, from fan Bao Yunmu around core can be seen in the figure is the largest of the three fan point of pressure, since the mica is flaky silicate polymer, molecular attraction between its far better than S1-0 the key weak covalent bonding within the Crystal. Layer between easy sliding, by Silicon bonded, but bonded strength also low, in forces scraping mill, and extrusion Shi very easy off, and split, especially used fan structure Shi, around package Hou of line core through wheel, and points line rod and row line to tooling round side Board edge, and Hou road process squeeze package insulation into die core Shi, are easy scraping injury and the touch injury to led to electric performance declined.


In addition, the structure from a cost perspective sector conductors cross-section circumference greater than circular conductor cross section perimeter, thus increasing the precious materials, MICA tape, cable diameter circular structure has been enlarged. PVC sheath material consumption increased, but compared with the total cost of materials, a comprehensive cost circular structure cable is still saving. Based on the description above, from a technical and economic analysis, fire-resistant conductor power cable with circular structure is the best.