The 450/750V 120mm², 150mm², and 240mm² green/yellow earth cables are a series of dedicated grounding cables that comply with international standards. They all adopt high-quality stranded copper conductors and polyvinyl chloride (PVC) insulation layers, designed for safe grounding in low-voltage electrical systems of different scales. Their core function is consistent: in the event of electric leakage, short circuits, or equipment failures in the circuit, they quickly conduct fault currents to the ground, preventing electric shock to personnel and damage to equipment, and serving as core components to ensure the safe operation of power systems.​ In terms of specifications, the main difference between these three cables lies in the conductor cross-sectional area, which are 120mm², 150mm², and 240mm² respectively, to meet the grounding needs of different current loads. All three use stranded copper conductors (usually Class 2 or Class 5 structures, in accordance with IEC 60228 standards), which are made by stranding multiple copper wires, combining flexibility and mechanical strength. The 120mm² cable is suitable for grounding of medium-sized industrial equipment and commercial buildings; the 150mm² is applicable to large industrial machinery and high-voltage distribution systems; the 240mm² is aimed at scenarios that need to carry huge fault currents, such as super-high-power equipment and large substations. The conductor material is high-purity electrolytic copper (purity ≥99.95%), with excellent conductivity, which can effectively reduce grounding resistance and ensure the rapid dissipation of fault currents.​ The insulation layers are all made of polyvinyl chloride (PVC) material, which has good electrical insulation performance and can withstand the rated voltage of 450/750V (450V is phase-to-earth voltage, 750V is phase-to-phase voltage). The PVC insulation layer also has excellent wear resistance, chemical corrosion resistance, and moisture resistance, which can resist erosion from environmental factors such as oil stains, dust, and moisture. The insulation layers of the three cables all adopt the internationally 通用 green-yellow color identification, and the color distribution complies with IEC 60446 standards (each color accounts for 30%-70%). The eye-catching identification can quickly identify its grounding function, avoid misconnection, and ensure the correctness of the grounding system.​ In terms of performance, the three earth cables perform excellently and consistently. The long-term operating temperature range is -15℃ to 70℃, which can adapt to most indoor and outdoor environments; the short-term overload temperature can reach 105℃, which can maintain structural stability when fault currents pass through instantly. The flame retardancy of the PVC insulation layer meets relevant standards (such as IEC 60332-1-2), which can delay combustion and reduce the risk of fire spread in case of fire. The insulation resistance is all ≥100MΩ·km, and the leakage current is small, effectively preventing electric leakage accidents. The bending radius varies slightly according to specifications, usually 12 times the outer diameter for fixed laying and 15 times the outer diameter for flexible laying, which is convenient for installation in narrow spaces.​ Application scenarios differ according to specifications: the 120mm² cable is often used in the total grounding loop of commercial buildings, grounding of medium-sized industrial equipment (such as injection molding machines, CNC machine tools), and grounding of server rooms in data centers; the 150mm² is suitable for heavy machinery in large industrial plants (such as metallurgical blast furnaces, chemical reactors) and grounding main lines of high-voltage distribution systems; the 240mm² is mainly used in grounding networks of super-high-power systems such as large substations, thermal power plants, wind farms, and grounding of traction substations in urban rail transit. Together, the three cover the full range of grounding needs from commercial to industrial, from small and medium power to super-high power.​ In terms of production process, all three cables strictly follow international standards, with precise control from copper purification, strand stranding to PVC insulation extrusion. The stranding process adopts concentric stranding technology to ensure uniform distribution of copper wires and reduce the skin effect during current transmission; during insulation extrusion, by precisely controlling temperature and pressure, the PVC material is tightly attached to the conductor surface, preventing moisture intrusion and insulation layer detachment, ensuring long-term reliability.​ In terms of installation and maintenance, the operation specifications of the three earth cables are similar. Due to the use of stranded conductors, they can be laid in various ways such as open laying, concealed laying, and pipe threading. During installation, excessive bending and stretching should be avoided. Special grounding terminals (select appropriate models according to specifications) must be used for terminal connection to ensure firm connection and good conductivity. In daily maintenance, regular inspections should be carried out to check whether the insulation layer is aged, cracked, or worn, and whether the conductor is oxidized or loose, ensuring that the grounding loop is unobstructed and the grounding resistance meets the standard (usually required to be <4Ω).​ To sum up, the 450/750V 120mm², 150mm², and 240mm² green/yellow earth cable series, with their different conductor cross-sectional areas, reliable performance, clear identification, and wide applicability, provide comprehensive grounding solutions from small and medium to super-high power for various electrical systems, and are indispensable key components in the electrical safety system.