Industry News

What Problems Should Be Paid Attention To In The Construction Of Power Cables?

Published by Author: Joey Wan August 13,2021

During the construction of power cables, there are many issues that need to be paid attention to, such as cable types, the choice of road,  the choice of laying method, and others. These problems are related to the safe operation of the cable, so the constructor must pay more attention to it. This article mainly discusses the problems that should be paid attention to in cable construction from four aspects, hoping to provide references for cable construction.

1) Eddy current problems are caused by high current power cables

In the construction of power cables, steel brackets are used, steel protection pipes are used, and cable clamps and overhead laying are used. Any steel (iron) closed circuit formed around the power cable can be used. Eddy currents can be formed, especially in high-current power cable systems, where eddy currents are greater. When applying I to the power cable, measures must be taken to prevent a steel (iron) closed-loop from being formed around the cable to prevent the cable from causing the vortex phenomenon to occur.

2) Mechanical damage caused by turning off power cables
Due to the large outer diameter of the power cable, it is difficult to transport and lay the power cable has stricter requirements on the turning radius. In the construction of power cables, if the turning angle is too large, it may cause the inner conductor. The part is mechanically damaged, and the mechanical damage is reduced by the insulation strength of the cable until the failure is found during the construction--the secondary cable head failure, when the cable head is made, the length of the three cable heads is the same as that of the equipment.
Due to the restriction of the terrain during connection, the medium-phase cable head is too long and the root of the arched cable head is damaged and discharged. Afterward, measures were taken to appropriately shorten the connection length of the middle-phase cable head in the connection of the equipment, so that the three-phase cable head was not subject to the external force. The practice has proved that the operation effect is good. It can be seen that in the process of cable construction, it is necessary to reduce the torsion of the cable as much as possible. When the cable is turned and the cable is left, the cable is naturally bent to prevent internal mechanical damage.

3) Moisture-proof problem of the power cable
Operating experience shows that most of the failures of medium and low-voltage power cables are cable intermediate joints and terminal head failures, while the intermediate joints and terminal head failures are mostly caused by poor sealing and moisture intrusion.
Insulation strength decreases, and medium and low-voltage power cable networks mostly adopt dendritic power supply. There are more cable terminals. Therefore, plugging and sealing the cable terminals and intermediate joints is one of the important measures to ensure the safe and reliable operation of cables.

4) Grounding problems of medium and low voltage power cables

In the public medium and low-voltage power cable network, because the three-phase load is not equal, if a cable with a metal sheath is used, the grounding problem of the metal sheath must be considered, and it should be ensured that the metal sheath is not grounded at any point. The normal induced voltage shall not be greater than 100V. We believe that in the medium and low-voltage cable network, all cable joints should be equipped with grounding electrodes (nets), and the metal sheath should be reliably grounded.

JZD wire & cable manufacturer always adheres to the core concept of manufacturing high-quality wires and cables and strives to provide customers with wires that customers need.

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