The power cable market is a crucial transmission cable for underground power grids, power station outgoing lines, internal power supplies for industrial and mining enterprises, and underwater transmission lines crossing rivers and seas. As power cables are often laid in harsh environments, they require sheathing to protect them from external damage.
1. For AC system single-core power cables, when mechanical and electrical installation projects require enhanced cable resistance to external forces, non-magnetic metal armor should be used. Steel armor that has not been effectively treated for non-magnetism should not be used.
2. For cables used in humid, chemically corrosive environments, or those susceptible to water immersion, the metal layer, reinforcement layer, and armor should have a polyethylene outer sheath. Thick steel wire armor for submerged cables should have an extruded outer sheath.
3. For crowded public facilities and locations requiring low-toxicity flame retardancy and fire protection, halogen-free outer sheaths such as polyethylene or ethylene propylene rubber can be used. When low-toxicity fire protection is required, polyvinyl chloride outer sheaths are not suitable. 4. Polyethylene is preferred for extruded outer sheaths in low-temperature environments below -15°C, locations exposed to pharmaceutical chemical liquids, and locations requiring low toxicity and flame retardancy. Polyvinyl chloride outer sheaths may be used for other cable applications.
5. Cross-linked polyethylene cables (XLPE) above 35kV, used in critical circuits of 6-35kV, or in locations exposed to water or chemical liquids, must have radial waterproofing structures such as a metal-plastic composite water-blocking layer and a metal sheath that meet the requirements.
