1. Product-Specific Information
1.1 Specification Parameters
The single-core
Copper Electric Cable with crosslinked polyethylene (XLPE) insulation and PVC sheath is a high-performance medium and high-voltage power
Transmission Cable, with precise and comprehensive specification parameters that lay a solid foundation for its stable operation in various power systems.
1.1.1 Voltage Rating
The cable is primarily designed for medium and high-voltage applications, with voltage levels compatible with 10kV, 20kV, and 35kV systems (Um=12kV, 24kV, 40.5kV respectively, in line with IEC standards). This voltage range covers most medium-voltage power transmission and distribution scenarios, from urban secondary power grids to industrial park internal power supply networks. The 10kV version is widely used in urban residential area power distribution and small-scale industrial power supply; the 20kV variant is suitable for medium-sized industrial parks and regional power grid interconnections; the 35kV specification is mainly applied in large-scale new energy
Power Station (photovoltaic, wind power) grid-connected lines and long-distance regional power transmission projects. Each voltage level undergoes strict voltage withstand tests during production: for the
35kv Cable, a 95kV AC voltage is applied for 1 hour without breakdown, ensuring it can safely withstand transient overvoltages caused by lightning strikes or grid switching.
1.1.2 Conductor Specifications
The cable features a single-core
Copper Conductor, available in three cross-sectional area options: 240mm², 300mm², and 400mm². The conductor adopts a stranded structure, with the number of
Copper Strands varying by cross-sectional area. For the 240mm² conductor, it typically consists of 61 strands of 2.2mm-diameter
Copper Wires; the 300mm² conductor uses 61 strands of 2.5mm-diameter wires; and the 400mm² conductor is composed of 91 strands of 2.4mm-diameter wires. The stranded design enhances the conductor’s
Flexibility, making it easier to bend during on-site laying, especially in narrow spaces such as cable trenches or pipe galleries.
In terms of electrical performance, the high-purity copper conductor (purity ≥99.95%) ensures extremely low resistivity: at 20℃, the DC resistivity is ≤0.017241Ω・mm²/m, which is close to the theoretical limit of copper conductivity. This low resistivity directly translates to minimal line losses: for the 400mm² cable operating at full load (920A) over a 1km distance, the line loss is only about 3.2kW, significantly lower than cables with lower-purity copper or
Aluminum Conductors. The rated current-carrying capacity of each specification is strictly tested under standard conditions (lay the air at 30℃, avoid direct sunlight.): 240mm² reaches 650A, 300mm² achieves 780A, and 400mm² reaches up to 920A. When laid in soil (soil thermal resistivity 1.5K・m/W), the current-carrying capacity decreases slightly—240mm² to 580A, 300mm² to 700A, and 400mm² to 830A—still meeting the high-load power transmission needs of most industrial and civil scenarios.
1.1.3 Insulation Layer Parameters
The XLPE insulation layer is a core component determining the cable’s electrical performance. Its thickness varies with the voltage level: for
10kv Cables, the insulation thickness is 4.5mm; 20kV cables have a 6.0mm insulation layer; and 35kV cables feature an 8.0mm insulation thickness. This thickness design ensures sufficient insulation strength to prevent electrical breakdown. The XLPE material undergoes a strict crosslinking process, with a crosslinking degree of ≥75% (tested via the hot-set method: after heating at 200℃ under 0.2MPa load for 15 minutes, the deformation rate is ≤10%, and the recovery rate is ≥80%).
The insulation layer also exhibits excellent dielectric properties: at 50Hz, the dielectric constant is 2.2-2.4, and the dielectric loss tangent (tanδ) is ≤0.0005, which is far lower than traditional oil-paper insulation (tanδ ≥0.003). Low dielectric loss reduces energy consumption in the insulation layer, especially in long-distance high-voltage transmission, where it can save tens of thousands of kilowatt-hours of electricity annually for large power grids. Additionally, the XLPE insulation has a high thermal class: long-term allowable operating temperature is 90℃, short-circuit withstand temperature (duration ≤5s) is 250℃, and it can maintain stable performance even in high-temperature environments such as
Power Station Cable tunnels.
1.1.4 Sheath Layer Parameters
The PVC sheath layer primarily provides mechanical protection and environmental adaptation. Its thickness ranges from 2.0mm (240mm² cable) to 2.5mm (400mm² cable), with a uniform thickness tolerance of ±0.1mm. The PVC material used is a high-quality flame-retardant grade, with a limiting oxygen index (LOI) of ≥30%, meeting the GB/T 18380.1-2008 single vertical combustion test requirements: after 15 seconds of flame application, the flame self-extinguishes within 60 seconds, and no dripping matter ignites the cotton below.
In terms of mechanical properties, the PVC sheath has a tensile strength of ≥12MPa and an elongation at break of ≥150% at room temperature. After aging (100℃ for 168 hours), the tensile strength retention rate is ≥80%, and the elongation at break retention rate is ≥70%, ensuring long-term resistance to wear, impact, and extrusion during operation. The sheath also has good environmental adaptability: it can operate normally in the temperature range of -15℃ to 60℃, with no cracking or hardening at low temperatures (-15℃, 4-hour cold bend test with a bending radius of 10 times the cable outer diameter) and no softening or deformation at high temperatures (60℃, 168-hour heat aging test).
1.1.5 Overall Cable Dimensions and Weight
The outer diameter of the cable varies by specification: 240mm² (10kV) has an outer diameter of approximately 28mm, 300mm² (20kV) is about 32mm, and 400mm² (35kV) reaches around 38mm. These dimensions are crucial for selecting cable trays and conduits—for example, the 400mm² cable requires a conduit with an inner diameter of at least 57mm (1.5 times the cable outer diameter) to ensure smooth pulling during laying. The weight per meter of the cable is also specification-dependent: 240mm² weighs about 2.2kg/m, 300mm² is approximately 2.8kg/m, and 400mm² is around 3.5kg/m. This weight parameter is essential for transportation planning and on-site hoisting operations, as it determines the load capacity of cable drums and lifting equipment.
1.2 Feature Applications
Thanks to its excellent electrical performance, mechanical strength, and environmental adaptability, the single-
Core XLPE-insulated PVC-sheathed
Copper Cable has a wide range of feature applications across multiple industries.
1.2.1 Urban Power Grid Construction
In urban power grid upgrading and expansion projects, the cable is a core component of medium-voltage 主干 lines. For 10kV urban distribution networks, the 240mm² and 300mm² specifications are widely used in residential area power supply lines. For example, in a high-density residential community with 5,000 households, a 300mm² 10kV cable can supply power to 10-15 transformer stations (each with a capacity of 630kVA), ensuring stable electricity for household appliances, elevators, and public facilities. The 35kV 400mm² cable is used in urban main power grid interconnections, such as connecting two 220kV substations, with a transmission distance of up to 10km, meeting the power exchange needs of large urban areas.
The cable’s single-core structure is particularly advantageous in urban cable trenches: compared with
Multi-Core cables, it has a smaller bending radius (10-12 times the outer diameter vs. 15-20 times for multi-core), making it easier to lay in narrow trenches. Additionally, the XLPE insulation’s low dielectric loss reduces energy waste in urban grids, aligning with the goal of building "energy-saving smart grids."
1.2.2 Industrial Park Power Supply
Industrial parks, with their high-power equipment and complex power demands, are key application scenarios for this cable. Medium-sized machinery manufacturing parks (with 50-100 enterprises) often use 20kV 300mm² cables as the main distribution lines, supplying power to factory workshops. For example, a car parts factory with 10 sets of 100kW CNC machine tools requires a 300mm² 20kV cable to connect its dedicated transformer (2000kVA), ensuring stable power for continuous production.
Large-scale petrochemical or metallurgical parks, which have higher power loads and harsh environments, prefer the 35kV 400mm² cable. The cable’s XLPE insulation is resistant to oil and chemical corrosion (tested by immersing in 40℃ transformer oil for 168 hours, with no significant change in insulation resistance), and the PVC sheath’s flame-retardant property meets the fire safety requirements of petrochemical zones (where flammable gases may exist). In addition, the 400mm² cable’s high current-carrying capacity (920A) can support the operation of large-scale equipment such as 5MW industrial boilers or 10MW electric arc furnaces.
1.2.3 New Energy Power Station Grid Connection
With the rapid development of photovoltaic and wind power, this cable has become an essential part of new energy grid-connected systems. Large-scale photovoltaic power stations (100MW-1GW) use 35kV 400mm² cables as collection lines, connecting hundreds of photovoltaic inverters (each with a capacity of 500kW-1MW) to the station’s main transformer. For example, a 500MW photovoltaic power station requires approximately 50km of 35kV 400mm² cables, with each cable segment transmitting power over 1-2km. The cable’s low line loss (3.2kW/km at full load) ensures that the power generated by the photovoltaic panels is efficiently transmitted to the grid, reducing energy waste.
Wind power plants, especially offshore wind farms, also use this cable (with enhanced corrosion-resistant PVC sheath for offshore versions). The cable’s mechanical strength (PVC sheath tensile strength ≥12MPa) can withstand the vibration of wind turbine towers and the impact of seawater spray. The XLPE insulation’s resistance to moisture (insulation resistance ≥1000MΩ after 7 days of water immersion at 20℃) prevents insulation failure caused by high humidity in offshore environments.
1.2.4 Large Building Power Introduction
Super high-rise buildings (over 100 meters, such as skyscrapers, five-star hotels, and large shopping malls) rely on this cable for high-voltage power introduction. A 300-meter skyscraper typically uses two 20kV 300mm² cables as dual power supplies, connecting the city’s 10kV grid to the building’s 20/0.4kV transformer room. The cable’s single-core structure is easy to lay in the building’s vertical cable shafts, and the PVC sheath’s flame-retardant property meets the building’s fire safety standards (such as GB 50217-2018 "Code for Design of Cable Systems in Buildings").
In large data centers, which have high requirements for power stability and low energy consumption, the 10kV 240mm² cable is used in the power distribution system of the data center’s computer room. The XLPE insulation’s low dielectric loss reduces heat generation in the cable, which is crucial for maintaining a stable temperature in the computer room (where excessive heat can affect server operation). The cable’s high current-carrying capacity (650A) can support the power demand of hundreds of servers in a single computer room.
1.3 Material and Style
The cable’s conductor is made of high-purity electrolytic copper, sourced from reputable suppliers with copper purity ≥99.95%. This high purity is achieved through a multi-step refining process: raw copper ore is first smelted into blister copper (purity 98-99%), then purified via electrolysis (using sulfuric acid as the electrolyte, with pure copper as the cathode), resulting in electrolytic copper with impurities (such as iron, nickel, and sulfur) content ≤0.05%.
High-purity copper offers three key advantages: first, excellent electrical conductivity—its resistivity is only 0.017241Ω·mm²/m at 20℃, which is 30% lower than that of aluminum (0.028264Ω·mm²/m), ensuring minimal line losses; second, good thermal conductivity—thermal conductivity of 401W/(m·K), which is beneficial for dissipating heat generated during current transmission, preventing the conductor from overheating; third, strong ductility and malleability—the copper can be drawn into thin wires (diameter as small as 0.1mm) and stranded into conductors of various cross-sectional areas without cracking, enhancing the conductor’s flexibility.
To further improve the conductor’s performance, the copper strands undergo annealing treatment after drawing. The annealing process is carried out in a protective atmosphere (nitrogen or hydrogen) at 400-450℃ for 1-2 hours, which eliminates internal stress in the copper wires, restores their ductility (elongation at break increases from 10% to 30% after drawing to ≥40% after annealing), and ensures the conductor maintains stable performance during long-term operation.
The insulation layer uses high-quality XLPE material, which is a modified polyethylene obtained through crosslinking. The base material is low-density polyethylene (LDPE) with a melt flow rate (MFR) of 2-4g/10min (190℃, 2.16kg), which has good processability. To achieve crosslinking, two main processes are used: chemical crosslinking and radiation crosslinking.
Chemical crosslinking involves adding a crosslinking agent (typically dicumyl peroxide, DCP) to the LDPE matrix during mixing (addition amount 1.5-2.0%). The mixture is then extruded onto the conductor at 120-150℃ (below the decomposition temperature of DCP), and subsequently crosslinked in a high-temperature, high-pressure nitrogen tube (temperature 200-250℃, pressure 1.5-2.5MPa). Under these conditions, DCP decomposes to generate free radicals, which initiate the crosslinking reaction of polyethylene molecules, forming a three-dimensional network structure. This structure significantly improves the material’s heat resistance (long-term operating temperature from 70℃ for LDPE to 90℃ for XLPE), aging resistance (service life extended from 10 years to 30 years), and mechanical strength (tensile strength increased from 8MPa to 12MPa).
Radiation crosslinking uses electron beam radiation (energy 10-15MeV) to irradiate the extruded polyethylene insulation layer. The radiation energy breaks the C-C bonds in polyethylene molecules, generating free radicals, which then recombine to form cross-links. Radiation crosslinking has the advantages of no crosslinking agent residue (avoiding DCP decomposition by-products affecting insulation performance) and uniform crosslinking degree (crosslinking degree variation ≤5% along the cable length). However, it requires expensive radiation equipment and is mainly used for small-diameter cables; for large-cross-sectional area cables (such as 400mm²), chemical crosslinking is more commonly used due to cost and production efficiency considerations.
In addition to the base polymer and crosslinking agent, the XLPE material also contains additives to optimize performance: antioxidant (such as hindered phenol, addition amount 0.1-0.3%) to prevent thermal oxidation aging; ultraviolet absorber (such as benzophenone, addition amount 0.2-0.5%) to improve UV resistance for outdoor use; and nucleating agent (such as talc, addition amount 0.5-1.0%) to improve the material’s crystallization uniformity, enhancing dielectric properties.
1.3.3 Sheath Material: Flame-Retardant Polyvinyl Chloride (PVC)
The sheath layer is made of flame-retardant PVC material, which is a blend of PVC resin, plasticizers, flame retardants, stabilizers, and lubricants. The PVC resin used is a suspension polymerization resin with a K value of 65-70, ensuring good mechanical properties and processability. The plasticizer is mainly diisononyl phthalate (DINP), added at a dosage of 30-40 parts per hundred parts of resin (phr), which provides the sheath with flexibility. The flame retardant is a combination of aluminum hydroxide (ATH) and magnesium hydroxide (MDH), added at 50-60 phr, which gives the PVC a limiting oxygen index (LOI) of ≥30%. Stabilizers (e.g., calcium-zinc composite stabilizers, 2-3 phr) prevent PVC from decomposing at high temperatures during extrusion, and lubricants (e.g., polyethylene wax, 0.5-1 phr) improve the flowability of the PVC mixture and the smoothness of the sheath surface.
The flame-retardant PVC sheath offers excellent mechanical protection: its tensile strength of ≥12MPa and elongation at break of ≥150% allow it to withstand external impacts and wear during laying and operation. For example, when the cable is laid in a cable trench with gravel, the PVC sheath can resist scratches from gravel without being punctured. The sheath also has good environmental adaptability: it can operate in the temperature range of -15℃ to 60℃, with no cracking in cold environments and no softening in hot environments. In addition, the PVC sheath is easy to process and low in cost, making the cable more economical compared to cables with LSZH or PE sheaths.
1.3.4 Cable Style: Single-Core Compact Structure
The cable adopts a single-core compact structure, consisting of three main layers from the inside out: copper conductor, XLPE insulation layer, and PVC sheath layer. This simple yet efficient structure has several advantages. First, the single-core design eliminates the mutual electromagnetic interference between multiple cores, which is common in
Multi-Core Cables. In high-voltage transmission, electromagnetic interference can cause additional power losses and affect the stability of the power system— the single-core structure avoids this issue, ensuring smooth power transmission.
Second, the compact structure reduces the cable’s outer diameter and weight. Compared to multi-
Core Cables with the same total cross-sectional area, the
Single-Core Cable has a smaller outer diameter (e.g., a 400mm² single-core cable has an outer diameter of 38mm, while a 4-core 100mm² cable has an outer diameter of about 45mm) and lighter weight, making it easier to transport and lay. This is particularly important for large cross-sectional area cables (e.g., 400mm²), which would be extremely heavy and difficult to handle if designed as multi-core.
Third, the single-core structure allows for a smaller bending radius. The minimum bending radius of the cable is 10-12 times its outer diameter (depending on the specification), which is smaller than the 15-20 times required for multi-core cables. This makes the cable suitable for laying in narrow spaces, such as small cable shafts in buildings or tight cable trenches in urban areas.
The surface of the PVC sheath is usually marked with product information using inkjet printing technology. The marking includes the cable model, specification (conductor cross-sectional area, voltage level), manufacturer’s name, production date, and standard compliance (e.g., “GB/T 12706.3-2008”). The marking is durable and resistant to fading, ensuring easy identification and traceability during installation and maintenance.
1.4 Production Process
The production of the single-core XLPE-insulated PVC-sheathed copper cable is a sophisticated process involving multiple steps, each with strict quality control to ensure the final product meets the required standards.
1.4.1 Conductor Drawing and Stranding
Step 1: Copper Rod Preparation
The raw material for the conductor is high-purity electrolytic copper rods (diameter 8mm-12mm, purity ≥99.95%). Before drawing, the copper rods are inspected for surface defects (e.g., cracks, oxidation) and chemical composition to ensure they meet the standards. Any defective rods are rejected to avoid affecting the conductor’s performance.
Step 2: Copper Wire Drawing
The qualified copper rods are fed into a continuous wire drawing machine, which draws the rods through a series of diamond dies with decreasing diameters to form copper wires of the required size. The drawing process is divided into multiple passes (usually 5-8 passes) to prevent excessive deformation of the copper, which could reduce its conductivity. During drawing, a water-based lubricant is used to reduce friction between the copper rod and the die, cool the wire, and prevent surface scratches. The diameter of the drawn copper wire is strictly controlled: for the 240mm² conductor, the wire diameter is 2.2mm (tolerance ±0.02mm); for 300mm², it is 2.5mm; and for 400mm², it is 2.4mm.
After drawing, the copper wires undergo an annealing process to eliminate internal stress generated during drawing and restore their ductility and conductivity. The annealing is carried out in a continuous annealing furnace at 350-450℃ for 10-15 minutes under a protective nitrogen atmosphere (to prevent oxidation). After annealing, the copper wires are tested for conductivity—only those with a conductivity of ≥97% IACS (International Annealed Copper Standard) are accepted.
Step 3: Conductor Stranding
The annealed copper wires are stranded into conductors using a tubular stranding machine. The number of strands depends on the conductor’s cross-sectional area: 61 strands for 240mm² and 300mm², and 91 strands for 400mm². The stranding process adopts a concentric stranding method, where the wires are arranged in layers around a central wire, with each layer having a specific number of wires (e.g., 1 wire in the center, 6 in the first layer, 12 in the second layer, etc.). This method ensures the conductor has a round and compact structure, with uniform current distribution.
The stranding pitch (the distance between two adjacent turns of the wire) is strictly controlled: for 240mm² and 300mm² conductors, the pitch is 16-20 times the conductor diameter; for 400mm², it is 18-22 times. A suitable stranding pitch balances the conductor’s flexibility and mechanical strength—too small a pitch increases flexibility but reduces strength, while too large a pitch reduces flexibility. During stranding, a polyester binding tape is wrapped around the conductor to hold the strands together and prevent loosening. After stranding, the conductor’s diameter and roundness are inspected: the diameter tolerance is ±1%, and the roundness error is ≤0.5mm.
1.4.2 XLPE Insulation Extrusion and Crosslinking
Step 1: Material Preparation
The
XLPE Insulation Material is prepared by mixing LDPE resin, DCP crosslinking agent, antioxidant (e.g., 2,6-di-tert-butyl-p-cresol, 0.1-0.2 phr), and other additives in a high-speed mixer. The mixing is carried out at 80-100℃ for 10-15 minutes to ensure uniform dispersion of the additives. The mixed material is then granulated using a twin-screw extruder to form XLPE pellets, which are stored in a dry environment (moisture content ≤0.1%) to prevent moisture absorption.
Step 2: Insulation Extrusion
The
Stranded Conductor is fed into a 3-layer co-extrusion machine (though only the XLPE insulation layer is used here) to extrude the insulation layer. The extruder has three temperature-controlled zones: the feeding zone (120-150℃) to melt the pellets, the compression zone (180-220℃) to further melt and homogenize the material, and the metering zone (200-230℃) to control the extrusion rate. The die of the extruder is custom-designed according to the conductor diameter and insulation thickness—for example, a 35k 400mm² cable uses a die with an inner diameter of 28mm to ensure the 8.0mm insulation thickness. During extrusion, the extrusion speed is synchronized with the conductor’s feeding speed (usually 60-80m/min for 240mm² cables, 50-70m/min for 400mm² cables) to maintain uniform insulation thickness. The insulation layer’s surface is inspected in real-time using a laser diameter gauge—any deviations beyond the ±0.1mm tolerance trigger an alarm, and the production process is adjusted immediately.
Step 3: Chemical Crosslinking (Vulcanization)
After extrusion, the cable enters a continuous vulcanization (CV) tube for crosslinking. The CV tube is divided into three sections: preheating, vulcanization, and cooling. In the preheating section (temperature 180-200℃), the XLPE insulation is heated to activate the DCP crosslinking agent. The vulcanization section uses high-temperature, high-pressure nitrogen (temperature 220-250℃, pressure 1.5-2.5MPa) to promote the crosslinking reaction—polyethylene molecules form a three-dimensional network structure, enhancing the insulation’s heat resistance and mechanical strength. The crosslinking time varies by cable specification: 2-3 minutes for 240mm² cables, 3-4 minutes for 400mm² cables.
In the cooling section, the cable is cooled with circulating water (temperature 20-30℃) to solidify the crosslinked XLPE insulation and prevent deformation. After cooling, the insulation layer is tested for crosslinking degree using the hot-set method: a 100mm-long insulation sample is loaded with 0.2MPa pressure and heated at 200℃ for 15 minutes. A crosslinking degree of ≥75% (deformation rate ≤10%, recovery rate ≥80%) is required to ensure the insulation meets performance standards.
1.4.3 PVC Sheath Extrusion
Step 1: PVC Material Preparation
The flame-retardant PVC material is prepared by mixing PVC resin (K value 65-70), DINP plasticizer (30-40 phr), ATH/MDH flame retardants (50-60 phr), calcium-zinc stabilizers (2-3 phr), and polyethylene wax lubricants (0.5-1 phr) in a low-speed mixer. The mixing is done at 60-80℃ for 15-20 minutes to avoid overheating (which could cause PVC decomposition). The mixture is then extruded into PVC pellets using a single-screw extruder, with the barrel temperature controlled at 140-170℃. The pellets are stored in a ventilated environment to prevent moisture absorption (moisture content ≤0.2%).
Step 2: Sheath Extrusion
The XLPE-
Insulated Conductor is fed into a single-screw extruder for sheath extrusion. The extruder’s temperature zones are set as follows: feeding zone (110-130℃), compression zone (150-170℃), metering zone (160-180℃). The die is designed to match the insulated conductor’s outer diameter and the required sheath thickness—for example, a 35kV 400mm² cable (insulated outer diameter 28mm) uses a die with an inner diameter of 33mm to achieve a 2.5mm sheath thickness.
The extrusion speed is adjusted to 40-60m/min (slower than insulation extrusion to ensure uniform sheath coverage). During extrusion, a vacuum sizing sleeve is used to control the sheath’s outer diameter and roundness—vacuum pressure (0.04-0.06MPa) ensures the sheath adheres tightly to the insulation layer without air gaps. After extrusion, the cable passes through a water cooling tank (temperature 20-25℃) for 5-10 minutes to solidify the PVC sheath.
Step 3: Sheath Surface Treatment
After cooling, the cable’s sheath surface is inspected for defects (e.g., bubbles, scratches, uneven thickness). A laser diameter gauge checks the outer diameter (tolerance ±0.2mm), and a thickness gauge measures the sheath thickness at 4 points around the circumference (variation ≤0.1mm). The inkjet printer then marks the sheath surface with product information (model, specification, manufacturer, production date) using UV-resistant ink, ensuring the marking remains legible for at least 10 years.
1.4.4 Final Product Testing
Step 1: Electrical Performance Testing
DC Resistance Test: Using a DC resistance tester, the conductor’s resistance is measured at 20℃. For 240mm² conductors, the maximum resistance is 0.0727Ω/km; for 400mm², it is 0.0432Ω/km. Values exceeding this indicate poor conductor quality.
Insulation Resistance Test: A 2500V megohmmeter measures the insulation resistance between the conductor and ground. The minimum resistance is 1000MΩ·km for all specifications—lower values suggest insulation defects (e.g., moisture absorption, pinholes).
Step 2: Mechanical Performance Testing
Step 3: Flame Retardant Test
The cable undergoes the GB/T 18380.1-2008 single vertical combustion test: a 600mm-long sample is vertically mounted, and a 1kW flame is applied to the bottom for 15 seconds. After removing the flame, the sample must self-extinguish within 60 seconds, with no dripping matter igniting the cotton placed 1m below. The limiting oxygen index (LOI) is also measured, requiring ≥30%.
Only cables that pass all tests are labeled and packaged for shipment.
2. Product General Information
2.1 Packaging
The single-core XLPE-insulated PVC-sheathed copper cable is packaged to protect it from mechanical damage, moisture, and dust during storage and transportation, with packaging specifications tailored to the cable’s length and cross-sectional area.
2.1.1 Primary Packaging: Cable Drums
Wooden Drums (for 240mm² and 300mm² Cables)
Wooden drums are used for cables with lengths of 200-500m (240mm²: 500m/drum, weight ~1100kg; 300mm²: 400m/drum, weight ~1120kg). The drums are made of high-density plywood (thickness 18-22mm) with a steel shaft (diameter 50-60mm) for easy rotation during unwinding. The drum’s flange diameter is 800-1000mm, and the barrel diameter is 400-500mm—this design prevents the cable from tangling during winding. The inner surface of the drum is lined with a 2mm-thick polyethylene film to isolate the cable from the wood, avoiding sheath scratches.
Steel Drums (for 400mm² Cables)
400mm² cables (length 300-400m, weight ~1260-1400kg) use galvanized steel drums to withstand heavier loads. The drum’s steel plate thickness is 2.5-3mm, with a flange diameter of 1200mm and barrel diameter of 600mm. The steel surface is galvanized (zinc coating thickness ≥80μm) to prevent rust during outdoor storage. A rubber gasket is installed between the flange and barrel to seal out moisture.
2.1.2 Secondary Packaging: Protective Layers
Moisture-Proof Wrap: The entire wound cable on the drum is wrapped with a 0.2mm-thick HDPE (high-density polyethylene) film, which is heat-sealed at the seams to prevent water ingress. For outdoor storage (≥7 days), an additional layer of waterproof asphalt paper is wrapped around the HDPE film.
Labeling: Each drum has two labels (one on each flange) made of weather-resistant PVC material. The label includes: product model, specification (cross-sectional area, voltage level), length, weight, production batch number, manufacturer’s name and contact information, storage instructions (“Store in a dry, ventilated area, avoid direct sunlight”), and warning signs (“Heavy Load—Use Lifting Equipment”).
2.1.3 Special Packaging for Export
For international shipments, the drums are further reinforced: wooden drums undergo heat treatment (compliant with ISPM 15) to prevent pest infestation, and steel drums are equipped with anti-corrosion paint (epoxy resin coating) to resist salt spray during sea transportation. The drum is also fitted with a steel pallet (size 1200×1000mm) to facilitate loading/unloading with forklifts.
2.2 Transportation
The transportation of the cable is managed by professional logistics partners with experience in handling heavy electrical equipment, ensuring on-time and damage-free delivery.
2.2.1 Transportation Modes
Road Transportation (Domestic): For distances ≤500km, 10-ton to 20-ton trucks with flatbeds are used. The drums are secured to the flatbed using steel straps (tension ≥500kg) and wooden blocks (to prevent rolling). The maximum number of drums per truck depends on the drum size: 4-6 wooden drums (240mm²/300mm²) or 2-3 steel drums (400mm²).
Rail Transportation (Long-Distance Domestic): For distances ≥500km, rail freight is used. The drums are placed in covered railcars to avoid exposure to rain. A non-slip mat is laid on the railcar floor, and the drums are fixed with steel chains (breaking strength ≥2000kg) to withstand train vibrations.
Sea Transportation (Export): Cables are shipped in 20ft or 40ft containers. The drums are arranged in a single layer (to avoid stacking pressure) and secured with container corner fittings. Desiccant bags (500g each, 10-15 bags per container) are placed inside to absorb moisture. The container is labeled with “Fragile—Handle with Care” and “Keep Dry” signs.
2.2.2 Transportation Precautions
Temperature Control: During transportation in extreme temperatures (≤-15℃ or ≥60℃), the truck/container is equipped with insulation or heating/cooling devices. At ≤-15℃, the cable must not be bent (to avoid sheath cracking) until it reaches room temperature.
Route Planning: For road transportation, routes with smooth surfaces and minimal potholes are selected to reduce drum vibration. The driver is provided with a “Transportation Guide” including the drum weight, center of gravity, and emergency contact information.
2.3 Shipment
The shipment process is designed to be transparent and efficient, with clear communication between the manufacturer, logistics provider, and customer.
2.3.1 Order Processing and Shipment Scheduling
After receiving the customer’s order, the production department confirms the delivery time (usually 7-15 days for standard specifications, 20-30 days for custom voltage levels). Once production is complete and the cable passes testing, the sales team sends a “Shipment Confirmation” to the customer, including the order number, product details, drum quantity, total weight, estimated departure date, and logistics provider information.
The customer can request a pre-shipment inspection (PSI) to verify the product quality before shipment. The manufacturer provides access to the factory or test reports (e.g., electrical performance test records) for inspection.
2.3.2 Documentation
The following documents are provided with each shipment:
Commercial Invoice: Details of the product, quantity, unit price, total amount, and payment terms.
Certificate of Quality (COQ): Includes test results (electrical, mechanical, flame retardant), production date, batch number, and compliance with standards (GB/T 12706.3-2008, IEC 60502-1).
All documents are provided in both Chinese and English (for export) and can be sent electronically (PDF) or in hard copy (included in a waterproof envelope attached to the drum).
2.3.3 Tracking and Delivery Notification
The logistics provider assigns a unique tracking number to each shipment, which the customer can use to track the shipment status via the provider’s website or app. The manufacturer also sends real-time updates: departure notification (with tracking number) when the shipment leaves the factory, transit updates (e.g., “Arrived at Shanghai Port”) every 24 hours, and delivery reminder (24-48 hours before arrival) to allow the customer to prepare for unloading.
Upon delivery, the customer inspects the drum’s packaging for damage (e.g., broken flanges, torn HDPE film). If no damage is found, the customer signs the delivery receipt; if damage is detected, the customer takes photos and notifies the manufacturer within 24 hours for claim processing.
2.4 Samples
The manufacturer provides free or low-cost samples to help customers verify the cable’s quality and suitability before placing bulk orders.
2.4.1 Sample Specifications and Request Process
Sample Details: Samples are 1-3 meters long, available for all specifications (240mm²/300mm²/400mm², 10kV/20kV/35kV). Each sample includes a small label with the same information as the bulk cable (model, specification, production date).
Request Method: Customers can request samples via the manufacturer’s website (online sample request form), email, or phone. The request form requires the customer’s name, company, contact information, desired sample specifications, and application scenario (e.g., “10kV urban power grid project”).
2.4.2 Sample Delivery and Support
Delivery: Samples are packaged in a cardboard box (size 30×15×10cm) with foam padding to prevent bending. Domestic delivery is via express (e.g., SF Express) with a delivery time of 2-3 days; international delivery is via DHL/FedEx, taking 5-7 days. The manufacturer covers the shipping cost for customers who place a bulk order (≥10 drums) after sample testing.
Technical Support: A “Sample Test Guide” is included with each sample, detailing how to conduct basic tests (e.g., visual inspection of the sheath, measurement of conductor diameter). The manufacturer’s technical team is available via phone/email to answer test-related questions (e.g., “How to measure the insulation thickness”) and provide additional documents (e.g., material safety data sheets for XLPE/PVC).
2.4.3 Sample Feedback and Follow-Up
After the customer receives the sample, the sales team follows up within 7-10 days to collect feedback (e.g., “Is the cable’s flexibility suitable for your project?”). If the customer is satisfied, the sales team assists with bulk order placement (e.g., confirming the delivery schedule, providing a quotation). If the customer has concerns (e.g., “The sheath is too hard”), the technical team analyzes the issue and provides a revised sample (e.g., adjusting the PVC plasticizer dosage) if necessary.
2.5 After-Sales Service
The manufacturer provides comprehensive after-sales service to ensure the cable’s stable operation and address any customer issues promptly.
2.5.1 Warranty Policy
Warranty Period: 5 years from the date of delivery. The warranty covers defects in materials and workmanship (e.g., insulation breakdown due to poor XLPE quality, sheath cracking due to substandard PVC). It does not cover damage caused by improper installation (e.g., bending beyond the minimum radius), improper storage (e.g., long-term exposure to water), or external forces (e.g., mechanical impact during construction).
Warranty Claim Process: To file a warranty claim, the customer must submit a written request to the manufacturer within 7 days of discovering the defect, including the following documents:
A copy of the delivery receipt (proving the purchase date and product batch).
Detailed photos/videos of the defect (showing the damage location, extent, and surrounding environment).
A brief report on the installation and operation process (to rule out improper use).
The manufacturer’s after-sales team reviews the claim within 3 working days and may send technical engineers to the site for inspection (for domestic customers, within 48 hours; for international customers, within 72 hours). If the defect is confirmed to be covered by the warranty, the manufacturer offers three solutions:
Free Replacement: For severely damaged cables (e.g., insulation breakdown), a new cable of the same specification is shipped to the customer within 5-7 days, with the manufacturer covering all transportation costs.
On-Site Repair: For minor defects (e.g., local sheath cracking), the manufacturer dispatches engineers to repair the cable using professional tools and materials (e.g., heat-shrinkable sleeves for sheath repairs) at no cost.
2.5.2 Fault Handling and Technical Support
24/7 Emergency Support: The manufacturer operates a 24-hour technical support hotline (available in Chinese and English) to address urgent faults (e.g., cable short-circuit causing power outages). When a fault is reported, the support team first collects key information (cable specification, installation location, fault symptoms) and provides preliminary troubleshooting guidance over the phone—for example, advising the customer to check for external damage or measure insulation resistance using a megohmmeter. If the fault cannot be resolved remotely, the manufacturer arranges for on-site support: domestic customers receive on-site engineers within 24-48 hours, while international customers are supported via local authorized service partners (with response times varying by region, typically 3-5 days).
Root Cause Analysis: After resolving the fault, the manufacturer conducts a detailed root cause analysis to prevent recurrence. For example, if a cable’s insulation breaks down, the technical team may collect insulation samples for laboratory testing (e.g., dielectric strength test, Fourier transform infrared spectroscopy to check for material degradation) to determine whether the issue stems from production defects, aging, or external factors (e.g., chemical corrosion). A written analysis report is provided to the customer, including preventive measures—such as recommending regular insulation resistance testing or adding anti-corrosion coatings if the cable is installed in a chemical environment.
2.5.3 Regular Maintenance Guidance
To extend the cable’s service life (typically 20-30 years under proper maintenance), the manufacturer provides a “Cable Maintenance Guide” to customers, outlining recommended maintenance schedules and procedures:
Daily Inspection: Customers are advised to visually inspect the cable’s sheath weekly for signs of damage (scratches, cracks, bulges) and check the surrounding environment for potential hazards (e.g., water accumulation in cable trenches, nearby construction activities). Any issues should be recorded and reported to the manufacturer if necessary.
Insulation Resistance Test: Using a 2500V megohmmeter, measure the insulation resistance between the conductor and ground. If the resistance drops below 500MΩ·km (half of the initial value), the cable may be damp or degraded, requiring further inspection.
Conductor Temperature Monitoring: Use an infrared thermometer to measure the cable’s surface temperature during full-load operation. The temperature should not exceed 70℃ (for PVC sheath, which has a maximum operating temperature of 60℃, with a 10℃ safety margin). If the temperature is too high, the cause (e.g., overloading, poor heat dissipation) should be identified and addressed.
Cable Trench/Conduit Inspection: For buried or conduit-laid cables, inspect the trench/conduit for water ingress, rodent damage, or sediment accumulation, and clean or repair as needed.
Connection Point Inspection: Check the cable’s termination and joint points (e.g., cable lugs, junction boxes) for loose connections or overheating (using an infrared camera), as these are common fault points.
The manufacturer also offers optional maintenance services, such as annual on-site maintenance by professional engineers, which includes comprehensive testing and a detailed maintenance report.
2.5.4 Customer Feedback and Continuous Improvement
The manufacturer values customer feedback as a key driver for product and service improvement. Feedback can be submitted via multiple channels: online feedback form on the website, email, or post-maintenance surveys. The feedback is categorized and analyzed quarterly by the after-sales team:
Product Feedback: Comments on cable performance (e.g., “The PVC sheath is too stiff in cold weather”) are shared with the R&D and production departments. For example, if multiple customers report stiffness issues, the R&D team may adjust the PVC formula (e.g., increasing the proportion of plasticizer) to improve low-temperature flexibility, with revised samples tested and provided to customers for evaluation.
Service Feedback: Feedback on after-sales service (e.g., “Slow response to international fault reports”) is used to optimize service processes—such as expanding the network of local service partners in regions with high customer density or providing additional training to partners to improve technical capabilities.
Annually, the manufacturer publishes a “Customer Satisfaction Report” summarizing feedback trends, improvement measures, and future service plans, which is shared with key customers to demonstrate its commitment to continuous improvement.
Conclusion
The single-core copper electric cable with crosslinked polyethylene (XLPE) insulation and PVC sheath stands out as a reliable, cost-effective solution for medium and high-voltage power transmission, thanks to its well-designed specifications, high-quality materials, and rigorous production processes. From a product-specific perspective, its three large cross-sectional area options (240mm², 300mm², 400mm²) cater to diverse load demands, while the XLPE insulation ensures excellent electrical performance and heat resistance, and the PVC sheath provides robust mechanical protection at an economical cost. The strict production process—from conductor stranding to final testing—guarantees consistent quality that meets international standards.
From the perspective of general product information, the cable’s thoughtful packaging (wooden/steel drums with moisture-proof and impact-resistant layers) protects it during transportation, while flexible transportation modes (road, rail, sea) and transparent shipment processes ensure timely delivery. The provision of samples and comprehensive after-sales service—including a 5-year warranty, 24/7 technical support, and tailored maintenance guidance—further enhance customer confidence and satisfaction.
Whether used in urban power grids, industrial parks, new energy stations, or large buildings, this cable delivers stable performance and long-term reliability. The manufacturer’s commitment to quality, customer-centric services, and continuous improvement ensures that the cable not only meets current market needs but also adapts to future developments in power transmission technology—such as higher voltage levels and more stringent environmental requirements. For customers seeking a balance of performance, cost, and support in medium and high-
Voltage Cable solutions, this product remains an ideal choice.
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