The so-called overhead line is relative to the cable, that is, the wire is set up by the pole tower at a certain height to transmit electrical energy. For the overhead line of the high-voltage transmission and distribution network, the ground insulation is generally based on air, and the previous distribution line (except 380V below 10kV) generally uses bare wires, but due to the complex distribution environment in the urban area, short circuit grounding and lightning strike lines often occur, resulting in reduced power supply reliability. Therefore, at present, the general overhead lines below 10kV are using insulated wires (that is, the outer layer of the wire is wrapped in the insulation layer), which is the so-called insulated overhead wires.

Overhead line has low voltage and high voltage points, the general model is divided into many kinds, such as street light overhead line, JKLYJ*10KVA*50*100, it shows the overhead line voltage, type, material, core cross-sectional area and length.