First of all, we understand the basic structure of electricity cable:
The basic structure of the electricity cable comprises a wire core (conductor), an insulating layer, a shielding layer and a protective layer is composed of four parts.
(1) the wire core
The wire core is a conductive part of the electricity cable, used to transport electricity, is the main part of electricity cable.
(2) insulation layer
The insulation layer is the core and the earth and the different phase of cable core in electrical isolated from each other, ensure power transmission, is an indispensable part in the structure of electricity cable.
(3) shielding layer
15KV and above electricity cable is generally a conductor shielding layer and an insulating shielding layer.
(4) protective layer
The role of protective layer is to protect the electricity cable from the intrusion of external impurities and moisture, and prevent external direct damage of electricity cable.
Secondly, we know about the classification of electricity cable:
According to the voltage level:
According to the voltage level can be divided into low and medium voltage electricity cable (35 thousand volts and below), high voltage cable (above 110 thousand volts), EHV cables (275 to 800 thousand volts) and ultra high voltage cable (1 million volts and above).
In addition, according to the current system can be divided into AC and DC cable cable.
According to the insulation material:
1, oil impregnated paper insulated electricity cable
In order to make oil paper insulated electricity cable. The application of the longest history. It is safe and reliable, long service life, low price. The main drawback is laying drop restrictions.
2, plastic insulated electricity cables
Insulation electricity cable for the extrusion of plastics. The commonly used plastic polyethylene crosslinked polyvinyl chloride, polyethylene. Plastic cable has the advantages of simple structure, convenient manufacture, light weight, convenient installation, can be laid without limit. It is widely used for medium voltage cables, and replace the sticky impregnated oil paper cable. The biggest drawback is the existence of tree breakdown phenomenon, which limits its use in higher voltage.
3, rubber insulated electricity cable
The insulation layer is a rubber with a variety of ingredients, after full mixing after extruded on the conductive line on the heart, after heating and curing.