ส่วนประกอบหลักของเอสายไฟฟ้า consist of two basic parts: the conductor and the insulation layer. For cables/sheathed wires requiring higher protection, a sheath layer is added. Some wires for special applications may also include additional structures such as a shielding layer, filler layer, and armor layer. Each structure serves a specific function, ensuring the core requirements of conductivity, insulation, and protection.
Common materials: Copper (purple copper/oxygen-free copper, mainstream for household/industrial use, excellent conductivity and oxidation resistance), aluminum (low cost, lightweight, mostly used for outdoor overhead lines/large cross-section cables), and in a few special cases, copper-clad aluminum and copper alloys are used.