The outer diameter of power cable is larger. It is difficult to transport and lay power cables.
The turning radius of power cable is also strict. In the construction of power cable, if the turning angle of power cable is too large, it may cause mechanical damage to the conductor, and the mechanical damage can not be seen because it is covered by the insulation layer of power cable. Even if the loop resistance is measured, it is difficult to find defects in the insulation and leakage test. During operation, the insulation strength of the cable will be reduced due to overheating at the damaged part, until the fault occurs.
Most of the reasons for the failure of power cable head are that the length of the three cable heads is the same when the cable head is made, the middle phase cable head is too long and becomes arch when it is connected with the equipment due to the limitation of terrain, and the root of the cable head is damaged and discharged. After that, measures are taken to shorten the connection length of the middle phase cable head according to the connection of different equipment, so that the three-phase cable head is free from external force. Practice has proved that the operation effect is good. It can be seen that in the process of power cable construction, the torsion of the cable should be reduced as much as possible. When the power cable turns and leaves the cable, the cable should be in natural bending, and the internal mechanical damage should be eliminated.