The 16mm² and 25mm² green-yellow copper earth cables are core components of electrical safety systems, specifically designed for grounding protection. They use high-purity electrolytic copper as conductors, coated with weather-resistant PVC insulation, and adopt internationally recognized green-yellow dual-color marking. Widely applied in grounding circuits of construction, industry, and power sectors, they provide reliable leakage protection for equipment and personnel.​ In terms of specifications, the key differences between the two earth cables lie in conductor cross-section and current-carrying capacity. The 16mm² earth cable’s conductor is stranded by multiple fine copper wires, with a total cross-sectional area precisely controlled at 16±0.8mm². At room temperature (20℃), the conductor’s DC resistance is ≤1.15Ω/km, and the short-time withstand current can reach 1500A (for 1 second). It is suitable for small and medium-sized power distribution systems, main grounding terminals in civil buildings, and grounding of industrial equipment with power ≤50kW. The 25mm² earth cable has a conductor cross-sectional area of 25±1.2mm², DC resistance ≤0.74Ω/km, and short-time withstand current of 2500A (for 1 second), adapting to large factories, substation grounding grids, and safety grounding of high-power equipment (above 50kW).​ In terms of materials, the conductor is made of electrolytic copper with purity ≥99.95%, formed through multi-strand stranding technology, which combines excellent conductivity and flexibility. The stranded structure allows the earth cable to be bent and laid in narrow spaces (minimum bending radius is 6 times the outer diameter), while high-purity copper ensures that leakage current can be quickly conducted into the ground, reducing the risk of electric shock. The insulation layer is PVC material resistant to temperatures from -20℃ to 70℃, with insulation resistance ≥100MΩ. It has acid and alkali resistance, UV resistance, and mechanical wear resistance, maintaining stable performance even in humid and dusty industrial environments. The green-yellow two-color insulation strictly complies with IEC 60446 standards, intuitively identifying the grounding function to avoid confusion with phase lines and neutral lines, reducing wiring errors.​ In application scenarios, 16mm² earth cables are often used for safety grounding of residential distribution box grounding bars, air conditioner outdoor units, water heaters and other household appliances, as well as floor grounding trunks in commercial buildings. 25mm² earth cables are mainly used for grounding of large motors and transformer enclosures in factory workshops, main lines of substation grounding grids, and grounding systems of new energy charging piles. Both earth cables have passed the inspection of GB 50169 "Code for Construction and Acceptance of Grounding Devices" and need to be reliably connected to grounding bodies (such as galvanized angle steel, copper rods) to form a low-impedance grounding loop (grounding resistance ≤4Ω). With a service life of over 20 years, they can effectively cope with long-term current impact and environmental erosion, serving as the "lifeline" to ensure the safe operation of electrical systems.