Firstly, the guide, ground material requirements:

Requirements for Conductor Material: Function and Condition of Conductor - Transmission of electrical energy, energization, and mechanical loading. The basic requirements of its materials: has good electrical conductivity and sufficient mechanical strength, and has a certain degree of corrosion resistance, high temperature and processability, and light weight, stable performance, wear resistance, low price and so on. Materials that can meet the above requirements are mainly aluminum and steel, the former has good electrical conductivity but poor mechanical strength; the latter has poor electrical conductivity and good mechanical properties. Therefore, most of the current combination of these two kinds of materials produced wire, such as ACSR.

Some Basic Requirements for Overhead Cables

1 The requirements of the ground wire material: the role of overhead ground wire.

Lead into the ground, reducing the chance of tripping the line of lightning strikes, raising the level of lightning-resistant lines to ensure the safety of power transmission lines. 

2 Overhead ground line categories: 

Common overhead ground line - not insulated with the tower, only from the role of the role of lead into the ground.

Insulated overhead ground line - with the tower insulation, played the role of lead into the ground, but also for carrier communication channel, Ground ice itself, overhaul the electric power supply and low-power users of the power supply to common overhead ground wire material: only requires a higher mechanical properties and good corrosion resistance, the general use of strand. 

3 Insulation ground wire material: 

High mechanical properties, good fatigue resistance, corrosion resistance and good electrical conductivity. 

Generally used ACSR, aluminum-magnesium alloy strands and aluminum clad copper wire. 

To reduce communication attenuation, improve communication quality.