Electric power industry
Cable lines (1 kV and above) are often laid in polymer pipes. In some countries, cable pipes are also referred to as ducts or conduits. These pipes/ducts/conduits allow to:✅Protect the cable from the mechanical damage.✅Protect the cable from the environment.✅Reduce the requirements for the quality of trench bottom preparation.✅Speed up cable pulling and its subsequent
If the outer sheath of the cable is damaged, water can penetrate into the cable, and this will lead to the defects in the XLPE insulation, followed by its breakdown (that is cable will get a short circuit). Therefore, it is important to monitor the condition of the outer sheath of the cable, preventing the
Cable lines are increasingly laid not in the open ground, but in pipes (ducts). This allows you to protect cables from mechanical influences and aggressive environment, ensure quick replacement of the cable with a new one, lay cables not only by the traditional method in trenches, but also by horizontal directional drilling HDD (this method
All over the world, more and more cable lines are laid not in the ground, but in ducts (conduits, pipes). Such ducts are made of various materials (PE, HDPE, PE-RT, PP, PVC), they can be single-layer or multi-layer. But all these ducts have one common problem – they have “infinite” impedance Rd of the side
Cable terminations are a weak element of the cable line, since:✅they have a complex structure;✅they are mounted manually (and the quality of installation depends on the qualification of the installer and his mood);✅they are subject to various external influences (sun, wind, rain, snow, ice etc). When a cable termination is damaged, it is not always
The photos show the exit point of the high voltage single-core cable from the ground near the cable ternination. Please note that the cable is placed in a black single-layer corrugated pipe. What’s wrong here? 1️⃣ Corrugated pipe is not a reliable mechanical protection for high-voltage cable. For example, pay attention to the deep cuts
When we were little boys and girls, many of us liked:1️⃣ Sit in the sandbox and dig the sand with a shovel.2️⃣ Shoot from an imaginary space weapon.3️⃣ Play hide-and-seek with each other. In the attached video, the team of cable specialists, despite their advanced age, was quite able to return to their childhood. Why
Let’s explain how, using the system of correction coefficients given in cable catalogs, the influence of pipes on the long-term permissible current should be taken into account. The error in such calculations is actually due not only to the fact that the catalogs have lost the relevance of the correction factor Kp = 0.9. To
Figure (A) shows the thermal scheme of a cable line laid in the ground. The following designations are used: Pc, Ps – loss of active power in the core and metallic screen of the cable; Tc, Ts, Tg – temperature of the core, screen, ground; Rins, Rosh, Rg – thermal resistances of insulation, outer sheath,
Laying cables in pipes is a common way of laying high-voltage cable lines. Usually, pipes are accounted for using a correction factor K=0.9, that is, it is assumed that laying cables in pipes reduces the permissible current by 10%. For example, if the cable line in the ground had a permissible current of 1000 A,