Cable lines - various topics / 19.07.2025

Cable sheath thickness

It has always been obvious to me that in terms of thickness, there are two types of outer sheath of high voltage (HV) and extra-high voltage (EHV) cables:✅ Ordinary sheath – it has a thickness of about 5 mm.✅ Reinforced sheath – it has a thickness of about 6-7 mm.However, when I started trying to

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Cable lines - various topics / 29.05.2025

Cable outer sheath strength

To design the cable line, we need to pass the following stages:✅ Evaluate the electrical strength of the cable outer sheath (jacket) and agree on what is the permissible voltage on the screen.✅ Select the grounding/bonding scheme of the screens (number of sections, cycles, etc.)✅ Perform the thermal calculation of the cable line and select

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Cable lines - various topics / 12.05.2025

Reserve cable phase

There are projects where reserve cables or reserve pipes/ducts are provided (empty or with a cable in them). Of course, this complicates the project and makes it more expensive, but maybe it’s worth it? It looks like we are talking about “insuring” a cable line in case of trouble, but the problem is that even

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Cable lines - various topics / 10.04.2025

Long HVAC cable line

We all know that to build an extended cable line, we have to replace HVAC technology with HVDC technology. However, where does one get the value of the length of the line, after which the transition to HVDC can no longer be avoided? It turns out that this length can be determined by calculation, and

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Cable lines - various topics / 12.03.2025

Cable installation errors

Cable is like a child – it’s not enough to give birth to him at the “factory”, but he must also be given to the right “school” with good “teachers”. Let’s take a closer look at the “graduation” of our cable. The photo shows the set of 110 kV cables and their terminations, and I’m

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Cable lines - various topics / 06.03.2025

Induced currents of zero sequence

Single-core cables of 6-35 kV usually have a two-side grounding of the screens (“solid bonding”). This leads to the fact that in normal operation, the magnetic field of the core induces 50 Hz currents in the screens. At a given current in the core, the induced currents in the screens depend on:✅the cross-section of the

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Cable lines - various topics / 03.03.2025

Cable preheating

Last week in LinkedIn, I came across a post where the cable was “preheated” with an open fire before laying. Workers “heated up” beautiful cable with open fire and at the same time cheerfully said, “How good that we have a cable with a non-flammable outer sheath”. I couldn’t get past such a terrible attitude

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Cable lines - various topics / 21.02.2025

Multifaceted transition pole

There are cable lines, there are overhead lines. However, there are also mixed lines consisting of both cable and overhead sections. On such mixed lines, the question arises as to how best to equip a transition point. There are a lot of issues there:➡️ where to place the set of cable terminations and of which

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Cable lines - various topics / 29.01.2025

Cable protection

When laying cable lines in the ground, there are several different ways to provide mechanical protection for cables. The following options are known:1️⃣ Covering the cable with bricks on top.2️⃣ Covering the cable with polymer tiles/covers.3️⃣ Laying cable in pipe/duct/conduit.4️⃣ Laying cable in tray/trough.5️⃣ Laying cable in concrete tunnel.Another way of protection is to lay

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Cable lines - screen bonding / 24.01.2025

Universal cable line

We often think that 6-35 kV medium-voltage (MV) networks are simpler than 110-500 kV high-voltage (HV) networks. Of course, this is not the case, and it is in MV networks that many serious problems are concentrated – among them, for example, the selection of the optimal method of neutral grounding as well as the selection

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