Electric power industry consulting
Cable couplings are one of the places where cable line damage often occurs. There are many different types of couplings, but most of them can be classified into one of two categories:✅ Cable terminations;✅ Cable joints. Cable terminations are placed above the ground and can be subjected to periodic inspection, which is a good thing.
Today we will not talk about alcohol (“bar”), but about a conductive element called:✅ equipotential bar (bar, bus);✅ earth continuity conductor (ECC). Questions arise:1️⃣ why do we need such a bar;2️⃣ how to provide equal distances from the bar to all phases A,B,C;3️⃣ how to calculate the optimal bar material and cross section (Fb). Unfortunately,
For cables there are many reasons for water penetration and growing of water trees inside the insulation. For example, it could be: 1️⃣ Production:👉 the raw materials used were not dried;👉 on the extrusion line (application of insulation or polymer sheath), when starting a new order or completing it, the water level in the cooling
Let us continue green posts. Today we’ll talk about how much the voltage on the equipment may differ from the voltage on the surge arrester (SA). To do this, consider a lighting wave coming from the overhead line (OHL) to switchgear. After passing the SA site, the wave decreases its magnitude to the level of
When designing cable lines, we use software to check ampacity, taking into account the key influencing factors:✅ cross-section of cable elements;✅ the mutual arrangement of phases and circuits;✅ screens’ bonding type;✅ laying conditions;✅ environmental parameters. It turns out that almost every software known in the cable industry calculates ampacity perfectly, and also helps with calculating
We all see here on the Internet (LinkedIn etc) the unspoken competition between different manufacturers of subsea cables. These companies build concrete towers in which the process of applying insulation to the cable core takes place. They always mention the height of the tower, and every new tower is more and more high. It looks
When XLPE was advertised to us, it was always said that dielectric constant of XLPE (2.4) is noticeable less than that of paper impregnated insulation (4.2). Hence, we had the impression that the capacitance of modern cables (XLPE) would less than that of the previous generation of cables (paper). Accordingly, this means that after switching
In medium voltage networks of 6-35 kV, at least the following methods of laying single-core cables in the ground are known:1️⃣ Directly in the ground;2️⃣ In the ground in a common pipe;3️⃣ In three different pipes arranged in a bundle. In 110-500 kV high voltage networks, option 2️⃣ is missing, and only options 1️⃣ and
Before putting the cable line into operation (and then periodically during operation), the integrity of the outer sheath of cables should be checked. The procedure consists of the following steps:1️⃣ Disconnect the line from the network (if it was in operation).2️⃣ Disconnect the SVLs from the link boxes.3️⃣ Unground cable screens at both sides of
Some companies like to talk about successful projects, and we know that there are really a lot of such projects, and this is very important for our industry. However, successful projects do not teach us much, and, in fact, it is much more interesting to study the mistakes that were made during the realization of