What should be paid attention to in the construction of power cable?
Date: 2019-09-24 Source: Yaofeng
1. Eddy current problems caused by high-current power cables During the construction of power cables, steel supports are used, steel protection pipes are used, and cable cards and overhead installations are used. Steel (iron) is formed around the power cables. In the closed loop, it is possible to form eddy currents, especially in high current power cable systems, where eddy currents are larger. In the construction of power cables, measures must be taken to prevent the formation of steel (iron) closed loops around the cables to prevent eddy currents from occurring in the cables.
2. It is a mechanical damage caused by the turning of the power cable. Due to the large outer diameter of the power cable, transportation and laying are difficult, and the power cable has strict requirements on the turning radius. If the turning angle of the power cable is too large during construction, the inside of the conductor may be mechanically damaged, and the mechanical damage may be reduced due to the insulation strength of the cable until a fault occurs. A cable head fault is found during construction. When the cable head is manufactured, three cable heads are produced. The length is the same. When connected to the equipment, due to the terrain limitation, the middle phase cable head is long and becomes arched, and the root of the cable head is damaged and discharged. After taking measures, the connection length of the medium phase cable head is appropriately shortened in the connection of the equipment, so that the three-phase cable head is free from external force, and the operation effect is proved to be good. It can be seen that during the cable construction process, the torque received by the cable should be reduced as much as possible. When the cable turns and the cable is left, the cable is naturally bent to prevent internal mechanical damage.
3. The power cable moisture-proof problem operating experience shows that most of the medium and low-voltage power cable faults are cable intermediate joints and terminal head faults, while the middle joints and terminal head faults are mostly due to poor sealing, moisture intrusion and insulation strength decline However, the medium and low voltage power cable networks mostly adopt the dendritic power supply mode, and the number of cable terminals is large. Therefore, sealing the cable terminal and the intermediate connector to seal the gap is one of the important measures to ensure the safe and reliable operation of the cable.