The Reason Why Power Cables are Armored and Conductors are Stranded

Power cables play a very important role in infrastructure construction. 

Armored power cables refer to power cables that have a metal sheathed protective layer, such as N2XY cable, xlpe power cable, and medium voltage cable. 

In addition to enhancing the mechanical protection such as tensile strength and compressive strength to extend the service life.

It is also possible to improve the anti-interference performance of power cables through shielding protection.

The commonly used armored materials include steel belts, steel wires, aluminum tapes, and aluminum tubes. 

Among them, SWA and STA layers have high magnetic permeability and have good magnetic shielding effect. 

They can be used for anti-low frequency interference and can make it is practical to use power cables that are laid directly buried to avoid wearing pipes and are inexpensive.

Different sizes of copper wires are twisted together according to a certain arrangement order and twisting distance, and they become larger diameter conductors. 

Such twisted large-diameter stranded conductors are larger than the same diameter. 

The copper wire is more flexible, and the wire bending performance is good. 

It is not easy to break when the swing test is performed. 

It is easier to meet the requirements for some soft wire materials (such as medical grade wires).

According to the electrical performance, after the conductor is energized, heat is generated due to the electrical energy consumed by the resistor. 

As the temperature increases, the performance life of the insulating layer and the protective layer material will be affected. 

In order to make the power cable run efficiently, the cross section of the conductor should be increased, but a large section of single conductor is not easy to bend, and the flexibility is poor, which is not conducive to production and transportation and installation. 

From the mechanical properties, it is also required to have flexibility, reliability, and multiple single wires twisted and twisted to solve the contradiction.