Material: High-purity electrolytic copper (minimum 99.95% purity). Copper is selected for its exceptional electrical conductivity (58 MS/m at 20°C), which minimizes power loss during transmission. Unlike aluminum, copper also offers superior ductility—allowing it to withstand bending and installation stress without cracking—and corrosion resistance, even in humid environments.

Sizes: Available in seven cross-sectional areas: 35 mm², 50 mm², 70 mm², 95 mm², 120 mm², 150 mm², and 185 mm². Each size corresponds to specific current-carrying capacities, as outlined in Table 1.

Stranding: Conductors are stranded (class 2 according to IEC 60228) to enhance Flexibility. Stranding involves twisting multiple thin Copper Wires into a single conductor, reducing stiffness and making the cable easier to route around obstacles in tight installations (e.g., underground trenches or building walls).

XLPE Insulation: Cross-linked polyethylene (XLPE) is applied to each conductor via extrusion. Key parameters include:

PVC Sheath: The outer sheath is made of flame-retardant PVC (FR-PVC), with the following properties:

Steel Tape Armour (STA/SWA): Two layers of galvanized steel tape (thickness: 0.3 mm–0.5 mm) are helically wrapped around the Insulated Conductors, with an overlapping rate of ≥25%. This design provides:

Corrosion Resistance: Galvanization (zinc coating) protects the steel tape from rust, even in damp soil or coastal environments (where saltwater vapor can accelerate corrosion).

Heavy Machinery Power Supply: Large industrial equipment (e.g., steel rolling mills, chemical reactors) requires high current-carrying capacity and resistance to vibration. The 95–185 mm² cable sizes are ideal here, as they can handle continuous currents of 235–370 A and withstand mechanical stress from machinery operation.

Factory Distribution Networks: Factories often have complex wiring systems, with cables routed through concrete floors or exposed to oils/chemicals. The XLPE insulation’s Chemical Resistance (resistant to mineral oils, solvents, and acids) and STA/SWA armour’s impact protection ensure long-term reliability. For example, in a car manufacturing plant, the cable supplies power to robotic assembly lines without degradation from lubricants.

High-Rise Buildings: Skyscrapers (offices, hotels, apartments) require cables that can handle vertical installation (up to 100+ floors) and meet strict fire safety standards. The 50–120 mm² sizes are commonly used for power distribution to HVAC systems, elevators, and lighting. The FR-PVC sheath’s low smoke emission is critical here—during a fire, it reduces smoke density, improving evacuation routes for occupants.

Data Centers: Data centers demand stable power to avoid server downtime. The 4-core design’s neutral conductor ensures balanced three-phase power, minimizing voltage fluctuations that can damage sensitive IT equipment. Additionally, the cable’s low EMI (electromagnetic interference) properties (due to copper’s conductivity and XLPE’s dielectric properties) prevent disruption to data transmission cables.

Underground Power Grids: Urban areas increasingly use Underground Cables to avoid the visual impact of Overhead Lines and reduce storm damage. The STA/SWA armour protects the cable from digging accidents (e.g., during road repairs) and soil pressure, while the PVC sheath resists moisture. Sizes 35–70 mm² are used for residential neighborhood distribution, while 150–185 mm² sizes power commercial districts.

Renewable Energy Facilities: Solar farms and wind parks require cables that can withstand outdoor exposure and transmit power efficiently. For solar farms, the 70–120 mm² cables connect solar panels to inverters—their UV-resistant PVC sheath and XLPE insulation’s high temperature tolerance (up to 90°C) handle direct sunlight. In wind turbines, the cable’s flexibility allows it to adapt to turbine rotation (via a cable tray) without fatigue.

Mining: Underground mines have harsh conditions (high humidity, dust, and mechanical impact). The STA/SWA armour’s rodent and impact resistance, combined with the cable’s flame retardancy, makes it suitable for powering mining equipment (e.g., drills, conveyors). The 95–150 mm² sizes are preferred for their high current capacity.

Transportation Hubs: Airports and railways require cables that can handle heavy foot traffic and vibration. The cable’s armour protects it from accidental damage (e.g., luggage carts at airports), while its low smoke properties enhance safety in terminal buildings.

Purity and Conductivity: High-purity copper (99.95%+) is used because impurities (e.g., iron, oxygen) increase electrical resistance. For example, a 1% increase in impurity content can raise resistance by 0.5%, leading to higher power loss (calculated via the formula: P = I²R). The 35 mm² conductor’s DC resistance of 0.524 Ω/km ensures minimal loss—over a 1 km length, it loses only 0.524 W per ampere of current.

Ductility and Strength: Copper’s ductility (ability to be drawn into thin wires) allows for stranding, which enhances flexibility. Its tensile strength (220 MPa) ensures it can withstand installation stress (e.g., pulling through conduits) without breaking.

Cross-Linking Process: XLPE is created by cross-linking polyethylene (PE) molecules using peroxides, electron beams, or silane. This process forms a three-dimensional molecular network, which:

Moisture Resistance: XLPE is hydrophobic (repels water), preventing moisture ingress—a common cause of insulation failure in Underground Cables. Even if the outer sheath is damaged, XLPE acts as a secondary barrier against water.

Galvanized Steel Tape: The steel tape is made of low-carbon steel (0.15–0.25% carbon) for flexibility, with a zinc coating (thickness: 8–12 μm) for corrosion resistance. Zinc acts as a sacrificial anode—if the coating is scratched, it corrodes first, protecting the steel underneath.

Overlapping Design: The 25%+ overlap ensures no gaps in the armour, preventing soil, water, or rodents from penetrating the inner layers. This is critical for underground installation, where even small gaps can lead to cable failure.

Flame-Retardant Additives: FR-PVC contains additives such as antimony trioxide and aluminum hydroxide, which release water vapor when heated—cooling the sheath and suppressing flame spread. This meets global safety standards (e.g., UL 94 V-0 for vertical flame resistance).

UV Stabilizers: Carbon black or benzophenone-based stabilizers are added to the PVC to absorb UV radiation, preventing the sheath from becoming brittle and cracking in sunlight. This extends the cable’s outdoor service life to 20+ years.

Wire Drawing: High-purity copper rods (8 mm diameter) are drawn through diamond dies to reduce their diameter to 0.5–2.0 mm (depending on conductor size). This process is done at room temperature (cold drawing) to enhance copper’s strength.

Stranding: The drawn copper wires are twisted together in a stranding machine. For a 35 mm² conductor, 19 wires (1.5 mm diameter) are twisted in a concentric pattern (layered around a central wire) to form a single conductor. The machine ensures uniform tension to prevent wire breakage and maintain conductor roundness.

Pre-Heating: The Stranded Conductors are pre-heated to 80–100°C to remove moisture, which could cause insulation bubbles.

Extrusion: XLPE compound (pellets) is fed into an extruder, where it is melted at 180–220°C and forced through a die (shaped to the conductor’s size) to form a uniform insulation layer. The extruder’s speed is synchronized with the conductor’s movement to ensure consistent thickness (monitored via laser diameter gauges).

Cross-Linking: The insulated conductor passes through a vulcanization tube (filled with nitrogen at 200–250°C) to initiate cross-linking. For silane-crosslinked XLPE, the conductor is then cured in a water bath (60–80°C) for 4–8 hours to complete the process.

Core Assembly: Four insulated conductors (each color-coded: brown, black, gray, blue for phase and neutral) are twisted together in a cabling machine. A filling material (polypropylene yarn) is added between the conductors to fill gaps, ensuring the core is round and stable.

Binder Tape Wrapping: A layer of non-woven polyester tape is wrapped around the twisted core to hold the conductors in place and prevent abrasion between the core and armour.

Steel Tape Armouring: Two galvanized steel tapes are helically wrapped around the bound core using an armouring machine. The machine adjusts the wrapping angle (typically 30–45°) to ensure the required overlap and flexibility. Tension controls prevent the tape from wrinkling or breaking.

Sheath Extrusion: The Armoured Core is fed into a second extruder, where FR-PVC compound is melted and extruded over the core to form the outer sheath. The extruder’s die is sized to achieve the required sheath thickness, with temperature controls (160–190°C) ensuring the PVC adheres to the armour.

Cooling and Sizing: The Sheathed Cable is cooled in a water bath (20–30°C) to solidify the PVC, then passed through a sizing sleeve to ensure the outer diameter (OD) meets specifications.

Quality Testing: Every batch of cable undergoes rigorous testing, including:

Drum Packaging: For orders ≥100 meters, the cable is wound onto wooden or steel drums.

Labeling: Each drum is labeled with:

Coil Packaging: For orders <100 meters, the cable is wound into coils (diameter: 300–500 mm) and wrapped in a heavy-duty polyethylene bag (0.2 mm thick) with a zip-lock closure. The bag is labeled with the same information as drum packaging and placed in a cardboard box (corrugated, 5-ply) for additional protection. Each box can hold 1–5 coils (e.g., 5 coils of 20 meters each for 35 mm² cable).

Custom Packaging: Upon request, customers can opt for waterproof packaging (for outdoor storage) or anti-static packaging (for sensitive environments like data centers). Waterproof packaging uses a PVC-coated fabric bag with heat-sealed seams, while anti-static packaging includes a conductive polyethylene layer to prevent electrostatic discharge.

Road Transportation: Used for domestic and short-distance deliveries (≤500 km). Cables are transported in closed trucks (with temperature control for extreme weather) equipped with load-securing devices (straps, padding). The truck bed is lined with a rubber mat to prevent abrasion, and drums are secured with steel straps (25 mm wide, 2 mm thick) to prevent rolling. Road transportation typically takes 1–3 days for domestic deliveries.

Rail Transportation: Suitable for medium-distance deliveries (500–1500 km). Cables are loaded into rail containers (20 ft or 40 ft) with wooden pallets to distribute weight evenly. Rail containers are weatherproof and have shock-absorbing floors, reducing the risk of damage from vibration. Rail transportation takes 3–7 days and is more cost-effective than road transport for large orders.

Sea Transportation: For international deliveries, cables are shipped in 20 ft or 40 ft shipping containers (ISO-certified). Steel drums are preferred for sea transport due to their corrosion resistance, and each container is loaded with a maximum of 12 steel drums (40 ft container) or 6 wooden drums (20 ft container). The container is ventilated to prevent moisture buildup, and a desiccant bag (500 g) is placed inside to absorb humidity. Sea transportation takes 15–45 days, depending on the destination (e.g., 15 days to Europe, 45 days to Australia).

Air Transportation: Used for urgent orders (e.g., emergency repairs). Cables are packaged in coil form (≤50 kg per coil) and shipped in air cargo containers. Air transportation is limited to small quantities (≤500 meters) due to weight restrictions, but it ensures delivery within 2–5 days globally.

Loading/Unloading: Drums are lifted using a forklift with a drum clamp (not a hook, which can damage the drum flange). Coils are lifted using a spreader bar to avoid deformation.

Transit Protection: During transit, drums are separated by wooden blocks (100 mm thick) to prevent collision, and the truck/container floor is lined with foam padding (10 mm thick) to absorb vibration.

Weather Protection: In case of rain during loading/unloading, cables are covered with a waterproof tarpaulin immediately. For sea transport, containers are inspected for leaks before loading.

Commercial Invoice: Details the product description, quantity, unit price, total value, and payment terms. It is used for customs valuation and tax calculation.

Packing List: Specifies the number of packages (drums/coils), each package’s weight and dimensions, and the total shipment weight. This helps in verifying the shipment’s completeness upon arrival.

Certificate of Conformity (CoC): Issued by the manufacturer, it confirms that the cable meets all applicable standards (e.g., IEC 60502-1, BS 6346) and has passed all quality tests.

Material Safety Data Sheet (MSDS): Provides information on the cable’s materials (copper, XLPE, PVC, steel), potential hazards (e.g., PVC may release toxic fumes if burned), and safety precautions for handling and disposal.

Bill of Lading (BOL) / Air Waybill (AWB): For sea/air transport, this is a legal document issued by the carrier that serves as a receipt for the goods, a contract of carriage, and a document of title to the goods.

Order details (cable size, quantity, specifications).

Delivery address and contact information.

ETA (based on production lead time and transportation method).

Payment status (e.g., deposit received, balance due before shipment).

For standard sizes (35–120 mm²) and quantities ≤10,000 meters: 7–10 working days.

For larger sizes (150–185 mm²) or quantities >10,000 meters: 10–15 working days.

For custom specifications (e.g., LSZH sheath, special armour thickness): 15–20 working days.

Visual Inspection: Checking for any physical defects (e.g., cracks in the PVC sheath, uneven armour wrapping, damaged conductors).

Dimensional Check: Verifying the cable’s outer diameter, conductor cross-sectional area, and insulation/sheath thickness using calipers and micrometers.

Electrical Testing: Conducting insulation resistance tests (using a megohmmeter, minimum 100 MΩ at 1 kV) and continuity tests (to ensure no breaks in the conductors).

Mechanical Testing: For a sample of the cable, performing a bending test (bending the cable to the minimum bending radius 10 times and checking for damage) and a tensile test (measuring the conductor’s tensile strength to ensure it meets IEC 60228 standards).

The number of packages matches the packing list.

There is no visible damage to the packaging (e.g., broken drum flanges, torn polyethylene bags).

The cable inside the packaging is in good condition (if the packaging is damaged).

Cable specifications (size, core count, insulation/sheath material, armour type).

Quantity of samples (minimum 1 meter per size, maximum 10 meters per size).

Delivery address and contact information.

Purpose of the sample (e.g., testing, demonstration, approval by end customer).

Visual and dimensional checks.

Insulation resistance and continuity tests.

Flame retardancy tests (for the PVC sheath, in compliance with IEC 60332-1-2).

Mechanical tests (bending and tensile tests).

Confirm that the sample has been received and is in good condition.

Address any questions or concerns the customer may have about the sample’s quality or performance.

Discuss the customer’s feedback and next steps (e.g., placing a bulk order, requesting modifications to the sample).

Installation Manual: A detailed manual is provided with each order, which includes step-by-step instructions for installation (e.g., cable pulling, termination, grounding), tools required, and safety precautions. The manual also includes diagrams and photos to simplify the installation process.

On-Site Support: For large or complex projects (e.g., power substations, solar farms), the manufacturer can send a technical engineer to the customer’s site to provide on-site installation guidance. The engineer can supervise the installation team, check for compliance with the installation manual, and resolve any on-site issues. On-site support is available for a fee, which is quoted based on the project’s location and duration.

Training Workshops: The manufacturer organizes regular training workshops for customers’ installation teams, covering topics such as cable handling, installation best practices, and troubleshooting. The workshops are held at the manufacturer’s facility or the customer’s site (for large teams) and include hands-on training with the cable.

Notify the manufacturer in writing within 30 days of discovering the defect, providing details of the defect (e.g., photos, description of the issue), the order number, and the date of delivery.

Allow the manufacturer’s QC team to inspect the defective cable (either on-site or by returning a sample) to determine the cause of the failure.

Replace the defective cable free of charge, including the cost of transportation.

Reimburse the customer for any reasonable costs incurred due to the defect (e.g., installation costs for replacing the cable), subject to prior approval.

Improper installation (e.g., exceeding the minimum bending radius, incorrect grounding).

Misuse (e.g., using the cable outside the specified temperature or voltage range).

Environmental factors beyond the cable’s design limits (e.g., exposure to strong acids or alkalis).

Natural disasters (e.g., floods, earthquakes).

Troubleshooting: Resolving issues such as cable overheating, insulation breakdown, or poor conductivity. The team may request test data (e.g., insulation resistance readings) or photos of the cable to diagnose the problem and recommend a solution.

Application Advice: Helping customers select the right cable size and specifications for their specific application (e.g., determining the required current-carrying capacity for a factory’s machinery).

Compliance with Standards: Providing information on how the cable complies with international and local standards (e.g., UL standards for the North American market, GB standards for the Chinese market) to help customers meet regulatory requirements.

Copper Conductors: Copper is a highly recyclable material, and most scrap metal recyclers accept copper conductors. The customer can strip the conductors from the cable (using a cable stripper) and sell them to a recycler, which helps reduce waste and generate additional revenue.

XLPE Insulation and PVC Sheath: These plastic materials can be recycled into other plastic products (e.g., plastic pipes, packaging materials) if they are separated from the metal components. The manufacturer can recommend local recycling facilities that accept XLPE and PVC.

Steel Armour: The galvanized steel tape can be recycled with other steel scrap, as the zinc coating does not affect the recycling process.