Wire Drawing: For aluminum conductors, 9.5mm diameter aluminum rods (AA 1350 grade) are drawn through diamond dies to form 2.3mm strands. A continuous annealing process (heating to 350°C in a nitrogen atmosphere) softens the aluminum, enhancing flexibility. For copper conductors, 8mm copper rods are drawn to 2.0mm strands and annealed at 400°C.

Stranding: 37 strands are twisted together in a planetary stranding machine at 8–10 twists per meter. A tension control system ensures uniform strand spacing—any deviation (detected via laser diameter monitoring) triggers an automatic shutdown. The Stranded Conductor is wound onto a take-up reel (1000m capacity) for further processing.

Material Preparation: XLPE compound (polyethylene resin + 2–3% peroxide cross-linking agent + 0.5% antioxidant) is mixed in a high-speed mixer (120°C) to form a homogeneous melt.

Extrusion: The melt is fed into a single-screw extruder (temperature 160–180°C) and extruded over each stranded conductor. A crosshead die ensures the insulation layer is concentric (eccentricity ≤5%), critical for preventing voltage breakdown in underground environments.

Cross-Linking: The Insulated Conductor is passed through a vulcanization tube (200–220°C) for 5–10 minutes to activate peroxide cross-linking. This transforms the linear PE molecules into a three-dimensional network, eliminating thermoplastic properties.

Cooling & Sizing: The cross-linked conductor is cooled in a water bath (25°C) and passed through a laser sizer to verify insulation thickness. Defective sections (e.g., bubbles, thin spots) are marked for removal.

For 3-core cables: Two insulated live conductors and one insulated neutral conductor are fed into a cabling machine. A filler (polypropylene yarn) is added between the cores to maintain roundness, ensuring uniform armor application. The cores are twisted together at a pitch of 500mm to enhance flexibility.

For 4-core cables: Three live conductors and one neutral conductor are bundled, with additional filler to compensate for the extra core. The twisting pitch is reduced to 450mm to maintain structural stability.

The bundled cores are fed into an armor machine, where a 0.15mm thick copper tape is wrapped around the bundle in a spiral pattern. The tape overlap rate is set to ≥25% to ensure 100% coverage—any gap in the armor could allow moisture or soil particles to penetrate. A pressure roller ensures the tape adheres tightly to the insulated cores, preventing loosening during installation.

PVC compound (PVC resin + 15% plasticizer + 5% impact modifier + 2% carbon black) is fed into a twin-screw extruder (temperature 150–170°C) and extruded over the armored core bundle. A vacuum calibration tank ensures the sheath’s outer diameter is consistent (58–66mm, depending on core configuration).

Printing: A laser printer marks the cable with key information at 500mm intervals: cable type (e.g., “YJLV22 0.6/1KV 3×150mm²”), CSA, voltage rating, batch number, manufacturing date, and certification marks (CE, UL, CCC). The ink is UV-resistant and adheres to the PVC sheath for ≥20 years.

Residential Complexes: 3-core aluminum-conductor cables are used as feeder lines from substations to apartment buildings. The 250A CCC supports 50–60 households per cable, with the PVC sheath resisting moisture in urban soil (often contaminated with construction debris). Installation tip: Bury cables 80cm deep to avoid damage from landscaping equipment or road repairs.

Commercial Malls: 4-Core Copper-conductor cables power three-phase HVAC systems and retail lighting. The copper tape armor shields against EMI from nearby data cables, ensuring POS systems and security cameras operate without interference. Installation tip: Use HDPE ducts (100mm diameter) to separate power and data cables in the same trench.

Manufacturing Factories: 4-core aluminum-conductor cables supply power to heavy machinery (e.g., 50kW motors). The XLPE insulation withstands occasional oil spills, while the copper armor resists impact from forklifts. Installation tip: Use concrete trenches (1.2m deep) to protect cables from heavy equipment traffic.

Data Centers: 4-core copper-conductor cables with optional LSOH (Low Smoke Zero Halogen) sheath power backup generators. The copper conductor’s low resistance minimizes voltage drop, critical for uninterruptible power supply (UPS) systems. Installation tip: Install firestop collars at duct penetrations to prevent fire spread.

Farmland Irrigation: 3-core aluminum-conductor cables power irrigation pumps (10–15kW). The PVC sheath resists corrosion from fertilizers and pesticides, while the copper armor deters rodent chewing. Installation tip: Bury cables 60cm deep and mark trenches with GPS to avoid damage during plowing.

Rural Communities: 3-core aluminum-conductor cables connect remote villages to main power grids. The lightweight aluminum conductor reduces transportation costs in remote areas with limited road access, while the copper armor protects against damage from wildlife (e.g., burrowing animals). Installation tip: Use rock guards (HDPE sleeves) around cables in rocky terrain to prevent sheath abrasion.

Subway Stations: 4-core copper-conductor cables with LSOH sheath power lighting and ventilation systems. The LSOH material releases no toxic gases during a fire, complying with subway safety standards (e.g., EN 50268-2). Installation tip: Install cables in fire-rated ducts (1-hour fire resistance) to protect against tunnel fires.

Airports: 3-core aluminum-conductor cables power ground support equipment (e.g., luggage conveyors). The PVC sheath resists jet fuel spills, while the copper armor shields against EMI from radar systems. Installation tip: Bury cables 1m deep to avoid damage from aircraft tugs or maintenance vehicles.

Cost Efficiency: Aluminum costs ~50% less per kg than copper, reducing material costs for large-scale projects (e.g., a 10km residential feeder line saves ~$20,000 with aluminum conductors).

Weight Reduction: Aluminum has a density of 2.7g/cm³, compared to 8.9g/cm³ for copper—an aluminum 150mm² cable weighs 70% less, simplifying transportation and installation (requires smaller trench diggers and fewer workers).

Corrosion Resistance: Aluminum forms a dense oxide layer (Al₂O₃) that prevents further corrosion in underground soil. For coastal areas, an optional aluminum-zinc alloy coating enhances saltwater resistance.

High Current Density: Copper’s lower resistance (0.012Ω/km vs. 0.128Ω/km for aluminum) reduces voltage drop in long runs (e.g., 1km Copper Cable has a 3.36V drop at 280A, vs. 32V for aluminum), critical for data centers or industrial machinery with strict voltage tolerance.

Frequent Overloads: Copper’s higher thermal conductivity (401W/m·K vs. 237W/m·K for aluminum) dissipates heat faster during overloads, making it suitable for factories with variable machinery loads.

Thermal Stability: PVC softens at 70°C, limiting its use in hot climates or high-load scenarios. XLPE operates at 90°C continuously, withstanding short-term overloads up to 130°C—ideal for desert regions where underground temperatures can reach 45°C.

Moisture Resistance: PVC absorbs moisture over time, leading to insulation degradation. XLPE is hydrophobic, with a water absorption rate of ≤0.1% (vs. 0.5% for PVC), ensuring long-term performance in humid soil.

Longevity: XLPE’s cross-linked structure prevents aging from soil chemicals or temperature cycles, extending service life to 25 years (vs. 15 years for PVC-Insulated Cables).

Mechanical Protection: Soil compaction in urban areas can exert pressures up to 50kN/m²—enough to crush Unarmored Cables. The 0.15mm copper tape, with its overlapping spiral design, withstands these pressures without deformation. In impact tests, it resists damage from 1kg rocks dropped from 1m, a common hazard during trench backfilling.

EMI Shielding: Underground trenches often contain both power and communication cables. The copper tape acts as a shield, reducing EMI by ≥60dB at 100MHz—preventing power cable interference from disrupting fiber optic data transmission or Ethernet signals in smart city networks.

Chemical Resistance: It resists common soil contaminants, including fertilizers (ammonium nitrate), pesticides (organophosphates), and industrial chemicals (motor oil). In 72-hour immersion tests, it shows no swelling or weight gain in 10% HCl or NaOH.

UV Stability: The 2–3% carbon black additive blocks UV radiation, preventing sheath cracking in shallow trenches (≤50cm depth) exposed to sunlight. This is critical for temporary installations (e.g., construction site power) or areas with thin soil cover.

Flexibility: Unlike rigid HDPE sheaths, PVC remains flexible at -15°C, allowing the cable to adapt to minor ground shifts (e.g., due to freeze-thaw cycles) without cracking.

Cable Drums:

Palletization: Small drums (250m) are placed on 1200×1000mm wooden pallets (2 drums per pallet) and secured with steel straps and stretch film. This allows forklift handling and reduces damage during loading/unloading at construction sites.

Coils: Lengths of 50m or 100m are wound into compact coils (600mm diameter) with a steel core to prevent deformation. Each coil is wrapped in PE film and placed in a heavy-duty corrugated cardboard box (printed with UV-resistant ink) that includes:

Accessory Kits: Optional kits for installers include:

Indoor Storage: Store in a dry, well-ventilated warehouse with temperature 0°C–30°C and humidity ≤60%. Avoid proximity to heat sources (e.g., heaters) or chemicals (e.g., solvents), which can degrade PVC and XLPE.

Outdoor Storage (Temporary): If outdoor storage is necessary (e.g., at a construction site), place drums on elevated pallets (100mm height) to prevent waterlogging. Cover with a UV-resistant waterproof tarpaulin (rated for 50+ UV hours) and secure with bungee cords. Storage time should not exceed 3 months—prolonged UV exposure can fade the PE film and reduce sheath UV resistance.

Handling: Use Drum Rollers for wooden drums or forklifts with drum clamps for steel drums. Do not drag drums across the ground, as this can damage the PE film and scratch the sheath. When unwinding the cable, use a drum stand to keep the drum stable and prevent tangling.

Truck Shipping:

Delivery Timelines:

Tracking: Customers receive a unique tracking number via email/SMS within 24 hours of dispatch. They can monitor the shipment in real time via the logistics provider’s platform (e.g., DHL, FedEx, or local carriers like XPO Logistics in the U.S.).

Container Shipping:

Customs Documentation: A complete document package is provided to facilitate clearance, including:

Freight Options:

Insurance: All international shipments are insured against damage (e.g., container drops, storms) or loss (e.g., piracy). The insurance coverage is 110% of the order value, with claims processed within 7 days of damage verification (requires photos/videos of the damaged goods and packaging).

Pre-Shipment Inspection (PSI): 3–5 days before shipment, a third-party inspector (e.g., SGS, TÜV) conducts a random sample test—verifying conductor CSA, insulation thickness, and armor overlap rate—to ensure compliance with the customer’s specifications. A PSI report is shared with the customer for approval; production is paused if any issues are found.

Documentation Finalization: Once PSI is approved, the commercial invoice, packing list, and shipping documents are prepared. For L/C payments, the documents are sent to the issuing bank for verification.

Dispatch Notification: The customer is notified 24 hours before shipment, with details of the carrier, tracking number, and estimated arrival date. For large orders, a delivery schedule is shared (e.g., “Delivery will take place between 8:00–12:00 on November 20; please have a forklift available”).

Delivery Confirmation: Upon receipt, the customer inspects the shipment for damage. A delivery receipt (digital or physical) is signed to confirm acceptance. Any damage must be reported within 48 hours of delivery to initiate an insurance claim.

Standard Samples: Available for all cable variants (aluminum/copper conductor, 3/4-core, XLPE/PVC sheath). Each standard sample is 5m in length and includes a technical datasheet with key parameters (e.g., CCC, insulation resistance, armor shielding effectiveness) and a compatibility guide (e.g., “Suitable for direct burial in clay soil”).

Custom Samples: For unique requirements—such as LSOH sheath, double copper tape armor, or custom core configurations—custom samples are produced within 7–10 business days. The minimum length for custom samples is 10m, with a nominal fee (\(100–\)300, depending on complexity) that is fully refundable if a bulk order of ≥1000m is placed within 30 days of sample receipt.

Sample Kit Add-Ons: Optional add-ons for underground testing include:

Insulation test: Check thickness with a laser caliper and dielectric strength (1kV AC for 1 minute).

Armor test: Verify copper tape overlap rate via visual inspection and EMI shielding effectiveness with a handheld EMI tester.

24/7 Underground-Specific Hotline: A team of engineers with expertise in subterranean cable systems is available 24/7 to resolve urgent issues—such as “cable damage from trench collapse” or “insulation failure due to chemical contamination in industrial soil.” The hotline can be reached via phone, email, or our mobile app, with a response time of ≤1 hour for critical requests (e.g., “power outage in a residential complex caused by cable fault”).

On-Site Technical Assistance: For large projects (≥5km cable length) or complex issues (e.g., “EMI interference between power and fiber optic cables in a smart city trench”), we dispatch certified technicians to the site. Services include:

Online Underground Resources: Our website hosts a dedicated library for underground cable users, including:

Standard Warranty: All YJLV22 150mm² cables come with a 15-year warranty from the date of installation (or 18 months from delivery, whichever comes first). The warranty covers:

Warranty Exclusions: The warranty does not cover damage caused by:

Warranty Claim Process:

Preventive Maintenance Schedule: We recommend underground cable-specific maintenance intervals to extend lifespan to 25+ years:

Lifespan Extension Tips: