Electric wires are conductors used to transmit electrical energy; based on their structure, they are classified into three categories: bare wires, magnet wires, and insulated wires. Bare wires lack an insulating layer and are used for outdoor overhead lines; magnet wires are coated with a thin insulating layer and are utilized in motors and transformer equipment; insulated wires consist of a conductor, an insulating layer, and a protective layer. Some high-voltage wires and cables also incorporate a shielding layer to mitigate electromagnetic interference-a feature of particular importance for high-voltage lines-while insulated wires are also widely used in low-voltage electrical equipment. Wires and cables generally comprise four main components: the conductor, the insulating layer, the shielding layer, and the protective layer.
Conductor
The conductor is the conductive element of a wire or cable; it serves to transmit electrical energy and constitutes the primary component of the assembly.
Insulating Layer
The insulating layer functions to electrically isolate the conductor from the ground, as well as from conductors of different phases, thereby ensuring the safe transmission of electrical energy; it is an indispensable component within the structure of a wire or cable.
Shielding Layer
Wires and cables rated at 15 kV and above typically feature both a conductor shielding layer and an insulation shielding layer.
Protective Layer
The purpose of the protective layer is to safeguard the wire or cable against the ingress of external contaminants and moisture, as well as to prevent direct mechanical damage to the power cable caused by external forces.
