[email protected]

cable derating factor

15 Min Read
The Type 2S 11kV 3x95mm² cable has a base ampacity of 285 amperes when installed in free air at 40°C ambient temperature. However, in a typical underground mine substation where three or more feeder cables are installed side-by-side on a cable ladder, the practical usable current is reduced to approximately 228 amperes through application of temperature and grouping derating factors. This 228 A figure is the number that should govern your design calculations and equipment sizing for the substation feeder. Type 2S 11kV 3x95mm² 电缆在 40°C 环境温度的自由空气中安装时，其基础载流量为 285 安培。但在地下矿山变电站中，三根或更多馈电电缆并排安装在电缆桥架上的典型情况下，通过应用温度和编组降额系数，实际可用电流减少至约 228 安培。这个 228 A 的数字应该管理您的设计计算和变电站馈电的设备选型。
Technical Department
on06/03/2026

Ampacity Derating: Sizing Type 2S 11kV 3x95mm² for Underground Mine Substations (Ambient 40°C)

The Type 2S 11kV 3x95mm² cable has a base ampacity of 285 amperes when installed in free air at 40°C ambient temperature. However, in a typical underground mine substation where three or more feeder cables are installed side-by-side on a cable ladder, the practical usable current is reduced to approximately 228 amperes through application of temperature and grouping derating factors. This 228 A figure is the number that should govern your design calculations and equipment sizing for the substation feeder. Type 2S 11kV 3x95mm² 电缆在 40°C 环境温度的自由空气中安装时，其基础载流量为 285 安培。但在地下矿山变电站中，三根或更多馈电电缆并排安装在电缆桥架上的典型情况下，通过应用温度和编组降额系数，实际可用电流减少至约 228 安培。这个 228 A 的数字应该管理您的设计计算和变电站馈电的设备选型。
27 Min Read
The NSSHÖU-J 4G95 0.6/1kV industrial mining cable is technically rated for temporary water immersion and is commonly used in open-pit and underground mining environments, but it is not specifically qualified for permanent submersion in acidic mine water and using it in this application is classified as beyond its design envelope. While the cable's EPR insulation (3GI3) and CPE outer sheath (5GM5) provide adequate resistance to neutral water and brief acidic exposure, permanent submersion in acidic mine water with pH values of 2.0 to 4.0—typical of copper and gold mining operations—accelerates material degradation to the point where service life drops to approximately 18 to 36 months compared to 8 to 10 years in neutral water applications. The fundamental issue is not that the cable fails immediately when deployed in acidic water (it does not), but rather that the aggressive acidic environment causes progressive swelling of the jacket, penetration of H⁺ ions into the insulation layer, electrochemical corrosion of the tinned copper conductor, and cumulative electrical property loss that eventually results in insulation breakdown. This distinction between "survives temporary exposure" and "safe for permanent submersion" is critically important to understand: a cable can physically remain intact for months or even a year or more in acidic water, but the electrical properties are degrading silently, and catastrophic failure can occur suddenly when the insulation resistance drops below critical thresholds. For submersible pump applications in acidic mine water, engineers should specify cables explicitly designed for this service, such as H07RN8-F submersible pump cables with specialized halogen-free formulations, or upgrade to acidic-resistant variants of marine-grade cables rated for chemical exposure. The standard NSSHÖU-J cable can be used in acidic mine water applications only if the operational requirement is for temporary or seasonal service (less than 6 months per year), coupled with rigorous monitoring protocols and planned replacement intervals of 12 to 18 months rather than the standard 5 to 7 year intervals appropriate for neutral water service.
Technical Department
on28/02/2026

Submersible Pump Cable Safety: Can NSSHÖU-J 4G95 0.6/1kV Withstand Permanent Submersion in Acidic Mine Water?

The NSSHÖU-J 4G95 0.6/1kV industrial mining cable is technically rated for temporary water immersion and is commonly used in open-pit and underground mining environments, but it is not specifically qualified for permanent submersion in acidic mine water and using it in this application is classified as beyond its design envelope. While the cable’s EPR insulation (3GI3) and CPE outer sheath (5GM5) provide adequate resistance to neutral water and brief acidic exposure, permanent submersion in acidic mine water with pH values of 2.0 to 4.0—typical of copper and gold mining operations—accelerates material degradation to the point where service life drops to approximately 18 to 36 months compared to 8 to 10 years in neutral water applications. The fundamental issue is not that the cable fails immediately when deployed in acidic water (it does not), but rather that the aggressive acidic environment causes progressive swelling of the jacket, penetration of H⁺ ions into the insulation layer, electrochemical corrosion of the tinned copper conductor, and cumulative electrical property loss that eventually results in insulation breakdown. This distinction between “survives temporary exposure” and “safe for permanent submersion” is critically important to understand: a cable can physically remain intact for months or even a year or more in acidic water, but the electrical properties are degrading silently, and catastrophic failure can occur suddenly when the insulation resistance drops below critical thresholds. For submersible pump applications in acidic mine water, engineers should specify cables explicitly designed for this service, such as H07RN8-F submersible pump cables with specialized halogen-free formulations, or upgrade to acidic-resistant variants of marine-grade cables rated for chemical exposure. The standard NSSHÖU-J cable can be used in acidic mine water applications only if the operational requirement is for temporary or seasonal service (less than 6 months per year), coupled with rigorous monitoring protocols and planned replacement intervals of 12 to 18 months rather than the standard 5 to 7 year intervals appropriate for neutral water service.
20 Min Read
Type SHD-GC 3/C #1 AWG 8kV trailing cable has a DC resistance of approximately 0.161 ohms per kilometer measured at the reference temperature of 20°C (68°F). This DC resistance value represents the pure ohmic resistance of the copper conductor when direct current flows through it—a condition that occurs in short-circuit analysis and DC testing procedures. However, when this same cable carries the alternating current typical of mining equipment operations (at the standard operating temperature of 90°C), the AC resistance increases to approximately 0.363 ohms per kilometer due to the combined effects of temperature rise and skin effect phenomena. The substantial difference between 0.161 Ω/km (DC, 20°C) and 0.363 Ω/km (AC, 90°C)—more than a 2.25 times increase—demonstrates a critical principle that engineers must account for in real-world voltage drop calculations: laboratory DC resistance values are not directly applicable to field voltage drop analysis. The cable features three 107.2 mm² (1 AWG equivalent) phase conductors of Class 5 tinned copper, with an additional ground-check conductor for continuous monitoring of cable integrity during operation, an outer diameter of approximately 53–58 mm, and a total weight of approximately 6,200–6,800 kg/km. Understanding both the DC baseline resistance and the elevated AC resistance at operating temperature is essential for accurately predicting voltage drop over long cable runs in open-pit mining operations where power distribution distances frequently exceed 500 meters.
Technical Department
on28/02/2026

Voltage Drop Calculation: Resistance (Ohms/km) for Type SHD-GC 3/C #1 AWG 8kV Trailing Cable

Type SHD-GC 3/C #1 AWG 8kV trailing cable has a DC resistance of approximately 0.161 ohms per kilometer measured at the reference temperature of 20°C (68°F). This DC resistance value represents the pure ohmic resistance of the copper conductor when direct current flows through it—a condition that occurs in short-circuit analysis and DC testing procedures. However, when this same cable carries the alternating current typical of mining equipment operations (at the standard operating temperature of 90°C), the AC resistance increases to approximately 0.363 ohms per kilometer due to the combined effects of temperature rise and skin effect phenomena. The substantial difference between 0.161 Ω/km (DC, 20°C) and 0.363 Ω/km (AC, 90°C)—more than a 2.25 times increase—demonstrates a critical principle that engineers must account for in real-world voltage drop calculations: laboratory DC resistance values are not directly applicable to field voltage drop analysis. The cable features three 107.2 mm² (1 AWG equivalent) phase conductors of Class 5 tinned copper, with an additional ground-check conductor for continuous monitoring of cable integrity during operation, an outer diameter of approximately 53–58 mm, and a total weight of approximately 6,200–6,800 kg/km. Understanding both the DC baseline resistance and the elevated AC resistance at operating temperature is essential for accurately predicting voltage drop over long cable runs in open-pit mining operations where power distribution distances frequently exceed 500 meters.