NYY and NYY-0/J series power cables are copper-core cables with high-performance insulating materials as their core advantage, designed specifically for medium and high-voltage power transmission scenarios. With a cross-sectional specification of 240mm² and a diversified structure of 1, 2, 3, 4, and 5 cores, they can meet the complex power supply needs in industrial, energy, construction, and other fields. This series of cables uses copper as the conductor material, combined with polyvinyl chloride (PVC) or cross-linked polyethylene (XLPE) insulation layers. While ensuring excellent conductivity, it has strong environmental adaptability and safety stability, making it an ideal choice in high-power power transmission systems.​ In terms of insulating materials, the series offers two high-performance options: the PVC insulation layer has excellent mechanical strength and chemical corrosion resistance, which can work stably in an environment of -15℃ to 60℃, and has high insulation resistance (not less than 100MΩ·km at room temperature), effectively preventing current leakage; the XLPE insulation layer forms a three-dimensional network structure through cross-linking technology, with better temperature resistance, which can adapt to a wide temperature range of -40℃ to 90℃, significantly improved anti-aging ability, low dielectric loss, and high insulation strength. It can withstand higher working voltages, especially suitable for high-voltage transmission lines. Both insulating materials have passed strict voltage resistance tests (no breakdown under 1kV and above power frequency voltage), ensuring safety during power transmission.​ The conductor is made of high-purity electrolytic copper (purity ≥99.9%) with high conductivity and low resistance. The 240mm² cross-sectional copper conductor can reach a current-carrying capacity of 480A (3-core structure) when laid in the air and 580A when laid underground, which can efficiently transmit high-power electricity and reduce energy loss. The diversity of core number design makes it suitable for different scenarios: 1-core cables are suitable for single-phase high-voltage transmission or grounding systems; 2-core cables are often used in single-phase power and lighting circuits; 3-core cables are widely used in three-phase AC power supply systems; 4-core and 5-core cables integrate neutral wires or grounding wires, suitable for complex systems that need to transmit power and ensure safe grounding at the same time, such as large industrial plants and substation outgoing lines.​ In terms of structural design, in addition to the core conductor and insulation layer, the cable also includes a shielding layer (for some models) and a polyvinyl chloride sheath. The shielding layer is braided with copper tape or copper wire, which can effectively reduce electromagnetic interference (EMI) and ensure the stability of signal transmission; the outer sheath enhances the wear resistance, impact resistance, and weather resistance of the cable, making it suitable for various laying methods such as underground, bridge, and pipeline, and can operate reliably for a long time even in humid, dusty, or mechanically vibrating environments.​ In terms of application fields, the high-power characteristics of NYY, NYY-0/J 240mm² cables make them play a core role in many key scenarios: in the industrial field, 3-core and 4-core cables provide power support for large motors and production lines; in the energy industry, 1-core and 3-core cables are used for grid-connected transmission in wind farms and photovoltaic power stations; in the construction field, 5-core cables serve as the main lines of high-rise buildings or commercial complexes to meet the centralized power supply needs of high-power equipment such as central air conditioners and elevators; in municipal engineering, this series of cables can be used in underground cable lines in urban power grid transformation to improve power supply reliability.​ In addition, this series of cables strictly complies with international standards such as DIN VDE, and has passed multiple tests including conductor resistance, insulation thickness, and flame retardancy to ensure no safety hazards such as short circuits and electric leakage during long-term use. Its diversified core number design, high-performance insulating materials, and stable conductivity make it a benchmark product with both practicality and safety in the medium and high-voltage power transmission field.