Three-Core Steel Tape Armoured XLPE Medium Voltage Cable for Large Transformer & Heavy-Load Industrial Main Grid

This three-core YJV22 8.7/15kV 3×185 medium-voltage cable strictly adheres to the national standard GB/T 12706.3-2020 "6kV~35kV Medium-Voltage Power Cables," fully complies with international standard IEC 60502-2, and meets EU CE LVD and EMC directives, satisfying cross-border infrastructure bidding and customs clearance requirements.

All finished cable reels undergo full-scale third-party testing by a nationally accredited power laboratory. Testing items include:

• Partial discharge testing
• Power frequency withstand voltage testing
• Lightning impulse withstand testing
• Long-term thermal cycling aging testing
• Heavy mechanical compression testing
• Vertical flame propagation testing
• Long-term vertical water penetration aging testing

Each batch of goods comes with a complete set of official factory-stamped documents, requiring no additional application:

• Authoritative type test report
• Batch factory inspection record
• T2 oxygen-free copper raw material inspection certificate
• CE certificate of conformity
• Unique batch traceability document
• Professional cable terminal production and laying technical manual

All documents meet the requirements for power grid bureau acceptance, construction supervision review, fire protection inspection, and overseas EPC project bidding and filing.

• YJ: Medium-voltage cross-linked polyethylene high-performance insulation
• V: Extruded PVC inner insulating sheath
• 22: Double-layer overlapping galvanized steel strip armor + weather-resistant black PVC outer protective sheath
• Rated Voltage Rating: U0/U = 8.7/15kV, compatible with 15kV three-phase medium-voltage power distribution systems
• Core Configuration: 3×185mm² three independent compacted copper cores, standard main incoming line layout, suitable for 2000kVA~2500kVA large-capacity transformers

Class 2 high-voltage compacted T2 oxygen-free copper conductor (single core 185mm²)

High-density round stranded pure copper conductor, DC resistance far below the standard value, meeting the upper limit of national standards. Ultra-low resistivity minimizes voltage drop over long distances under heavy loads, perfectly matching the full-current output requirements of large transformers. The compact stranded structure reduces the cable's outer diameter, saving construction teams space for trench excavation and reducing cable tray layout costs. Zero-doped recycled copper ensures consistent current-carrying capacity across all production batches.

Co-extruded Inner Semiconductor Shielding Layer

A uniform semiconductor layer is tightly bonded to the copper core surface, eliminating micro-gaps between the conductor and the main insulation layer, and uniformly distributing the internal electric field, fundamentally suppressing the risk of partial discharge under long-term 15kV high-voltage operation.

15kV Extra-Thick XLPE Main Insulation Layer

The insulation layer thickness is customized according to the 8.7/15kV voltage level, using high-purity cross-linked polyethylene compound with an ultra-low dielectric loss tangent. Long-term sustainable operating temperature: 90℃; short-circuit instantaneous withstand temperature can reach 250℃ within 5 seconds, capable of withstanding severe overcurrent impacts during power grid short-circuit faults. Insulation performance remains stable under alternating high voltage and annual seasonal temperature cycling.

Outer Semiconductor Shielding Layer

The co-extruded outer semiconductor layer is attached to the outer layer of the insulation layer, forming a closed electric field buffer layer together with the copper strip metal shielding layer, avoiding localized electric field concentration caused by cable bending, extrusion scratches, and construction traction damage.

Continuous Overlapping Copper Tape Metal Shielding Layer

A spirally wound soft copper tape shielding layer covers each insulated core wire, conducting induced currents and short-circuit ground fault currents in the 15kV power grid, isolating internal high-frequency electromagnetic radiation, and preventing signal distortion from adjacent control, monitoring, and communication cables within the integrated utility tunnel. The shielding layer cross-section meets the standard short-circuit grounding capacity requirements of heavy-duty 15kV distribution networks.

Seamless PVC Extruded Liner

An integrated extruded PVC inner sheath encases the three-core shielding assembly, isolating the copper strip shielding layer from the outer steel strip armor layer. This effectively blocks underground moisture, soil salt ions, and weak acids and alkalis from corroding the metal shielding layer and XLPE insulation core.

Double-Layer Galvanized Steel Strip Armor Layer

Two layers of staggered, overlapping galvanized steel strip spiral winding structure provide strong radial compression resistance, resisting friction from sharp rocks, crushing by heavy vehicles, impacts from construction machinery, and gnawing by underground rodents. The uniform and controllable winding gap prevents the steel strip edges from scratching the lining during long-distance cable traction and bending construction.

UV-Stable Anti-Corrosion Black PVC Outer Sheath

An anti-aging, anti-ozone, antibacterial, and anti-corrosion composite outer sheath. Suitable for direct underground burial, pipeline crossings, cable trenches, and semi-outdoor laying; provides stable salt spray resistance in coastal industrial areas and port projects.

• ZA/ZB/ZC-YJV22 8.7/15kV 3×185: Flame retardant rating, suitable for enclosed public tunnels, chemical plants, and underground commercial complexes.
• WDZ-YJV22 8.7/15kV 3×185: Low-smoke halogen-free improved version, suitable for large hospitals, data center main substations, and airport distribution substations.
• Reinforced salt spray resistant outer sheath: Customized for coastal heavy industrial parks and offshore wind power distribution projects.

• Rated AC Operating Voltage: 8.7/15kV Three-phase Medium Voltage System
• Power Frequency Withstand Voltage Test: 39kV, no breakdown or abnormal discharge within 15 minutes
• Lightning Impulse Withstand Voltage: 105kV, positive and negative pole impulse tests passed completely
• Partial Discharge Performance: Discharge quantity less than 10pC of rated operating voltage, stable during long-term continuous operation
• Reference Continuous Current Carrying Capacity: Standard direct burial 362A; Layered cable trench parallel laying 315A
• Low Dielectric Loss Design: Reduces self-heating loss under long-term heavy load operation, improving the overall energy efficiency of the power grid

• Minimum Allowable Bending Radius: 15 times the outer diameter of the finished cable
• Static Heavy-Load Compression Resistance: Passes the national standard compression test; insulation layer shows no cracking or permanent deformation.
• Ambient Temperature Requirements: Standard type: ≥0℃; Low-Temperature Customized Version: Supports laying at -20℃ without preheating.
• Tensile Strength: Optimized overall structural tensile performance to prevent internal core material displacement during long-distance pipeline traction; suitable for road laying.

• Design Service Life under Standard Buried Laying Environment: Over 35 years
• Resistance to Vertical Water Permeability: Passes a 100-meter long-term immersion aging test; suitable for water-rich foundations, cable trenches across rivers, and areas near underground sewage pipes.
• Chemical Corrosion Resistance: Resistant to long-term corrosion from weak soil acids, weak alkalis, and chloride ions.
• UV Aging Resistance: Supports long-term semi-outdoor cable trench laying without sheath cracking or powdering.
  

• 4.1 Multi-layer Balanced Electric Field Structure Significantly Reduces the Probability of Heavy-Load Circuit Failures

  The integrated design of an inner semi-conductive shielding layer + thickened cross-linked polyethylene insulation layer + outer semi-conductive shielding layer + all-copper metal shielding layer effectively solves the core failure factor of 15kV heavy-load medium-voltage cables: partial discharge breakdown. This 3×185 specification is suitable for lines operating 24/7, such as main incoming lines of large-capacity transformers and trunk lines of heavy production equipment. The composite shielding structure significantly reduces the risk of unplanned power outages and reduces the workload of daily power grid inspections and equipment maintenance for the operation and management team. Compared with single-layer shielded medium-voltage cables, it exhibits a significant reliability advantage after long-term full-load operation.

• 4.2 Double-layer Steel Strip Armor Fully Adapts to Harsh and Complex Underground Construction Environments

  Double-layer steel strip mechanical protection is suitable for high-risk laying environments such as municipal main road crossings, mountain rock foundation trenches, underground pipelines in heavy truck parking lots, and integrated pipe corridors in large industrial areas. It can effectively avoid the insulation layer damage caused by foundation settlement, temporary construction vehicle rolling and friction from underground sharp rocks, which are common in large-scale power grid expansion projects, thereby reducing the capital investment of general contractors in cable replacement and line maintenance in the later stage.

• 4.3 The 185mm² Three-Core Specification Meets the Economic Matching Logic of Large-Capacity Transformers

  The 185mm² three-core specification is the optimal mainstream cross-sectional area for 15kV 2000kVA~2500kVA transformer incoming cables. It can handle the ample full-load current required by large industrial production lines, energy storage equipment, and heavy-duty power demands in ports, while avoiding the wasteful procurement costs associated with using excessively large 240mm² cables. Electrical design engineers tend to choose this specification in projects such as large industrial parks, logistics hubs, and centralized photovoltaic booster stations to balance load-bearing capacity and project construction budgets.

• 4.4 Integrated Three-Core Circular Structure Optimizes On-Site Construction Efficiency

  The three insulated cores are filled with non-hygroscopic flexible filler, forming a neat circular cable body. Compared to three individually laid single-core armored cables, this three-core product saves cable tray space, reduces the number of duct openings and repetitive cable pulling work, significantly shortens the electrical wiring construction cycle for EPC contractors, and reduces labor costs for large projects.

• 4.5 Fully Automated Online Production Monitoring Ensures Batch Parameter Consistency

  The intelligent integrated production line can monitor the thickness of the insulation, shielding, and armor layers in real time online. The insulation thickness, copper tape overlap rate, and steel tape winding tightness of each batch of products are strictly controlled within standard tolerances. All cable reels have consistent electrical parameters, eliminating the risks of localized overheating and uneven voltage distribution that can occur when multiple cables operate in parallel in a heavy-duty 15kV power distribution system.

  

• Municipal Large-Scale Power Grid Construction: Outgoing trunk lines of urban central substations, centralized 15kV distribution networks in industrial zones, heavy-current distribution lines for municipal integrated utility tunnels
• Heavy Industrial Manufacturing Projects: Main incoming lines of 2000kVA+ transformers in large factories, medium-voltage trunk lines in steel and non-ferrous metal workshops, heavy-load ground distribution lines in mining areas
• New Energy Large-Scale Infrastructure: Centralized photovoltaic booster station collection trunk lines, auxiliary 15kV power cables for large energy storage stations, medium-voltage grid-connected lines for onshore wind farms
• Logistics and Port Public Infrastructure: Centralized power supply for large port container yards, buried cables for dedicated transformers in ultra-large logistics parks, distribution lines for main substations in central hospitals and airports

1. Case 1: 15kV Outgoing Cable Expansion Project for a Central Urban Substation

   A prefecture-level central power grid expansion project used YJV22 8.7/15kV 3×185 type bulk cables as the buried outgoing main cables for 16 2500kVA box-type transformers, serving an industrial cluster area. The construction scope covered multiple intersections of municipal main roads and water-bearing ditches along riverbanks. The double-layer steel strip armored structure effectively resisted the crushing and squeezing during subsequent municipal road reconstruction; the complete set of authoritative testing documents provided by our factory passed the power grid bureau's acceptance on the first attempt, requiring no additional sampling inspection. After four years of continuous grid-connected operation, no partial discharge or insulation aging faults occurred, reducing the daily inspection and maintenance workload of the power grid by 70%.

2. Case Study 2: 300MW Centralized Photovoltaic Substation Medium-Voltage Gathering and Transmission Project

   A large-scale ground-mounted photovoltaic power station selected ZC flame-retardant modified YJV22 8.7/15kV 3×185 type cables as the main medium-voltage gathering and transmission line between the substation and the photovoltaic combiner boxes. The project site experienced long-term intense ultraviolet radiation and high levels of residual chloride in the local soil. The UV-resistant and corrosion-resistant outer sheath and complete copper strip shielding structure effectively resisted the harsh open-air environment and electromagnetic interference between dozens of parallel medium-voltage lines. Complete standardized certification documents accelerated the grid connection audit process for the EPC contractor, enabling the project to achieve full-load power generation 15 days ahead of schedule.

3. Case Study 3: Power Supply Project for Dedicated Transformers in a Heavy Equipment Manufacturing Industrial Park

   A heavy machinery manufacturing industrial park constructed 15 sets of 2500kVA box-type transformers, uniformly selecting YJV22 8.7/15kV 3×185 as the underground main incoming cable. The underground soil contained residual weakly acidic chemical wastewater discharged from the metal surface treatment workshop. Customized reinforced anti-corrosion outer sheaths solved the common problems of early sheath aging and metal shielding corrosion found in older circuit cables in similar industrial parks. Stable current carrying capacity and balanced electric field performance ensured uninterrupted 24-hour power supply to large stamping and forging production equipment, reducing annual circuit maintenance and downtime losses by more than 85%.

• Transformer Load Matching Standard: This 3×185mm² specification is suitable for 2000kVA~2500kVA 15kV transformers. For transmission distances exceeding 500 meters, please submit the transformer's rated capacity, transmission distance, and annual average load factor to our internal technical team so that we can perform free voltage drop simulation calculations to avoid excessive terminal voltage loss affecting the operation of production equipment.

• Laying Environment Classification and Matching Rules: Standard YJV22 type is used for neutral soil in ordinary cities; enhanced anti-corrosion customized version is used for coastal salt spray areas and chemical residue soils; flame-retardant/low-smoke halogen-free modified type is used for enclosed pipeline corridors and main substations in densely populated public buildings.

• Mandatory Confirmation of Shielding Structure: All buried 15kV three-core heavy-load cables must maintain a complete and continuous copper tape metal shielding layer; the use of unshielded cables is strictly prohibited to prevent electromagnetic interference to nearby monitoring, communication, and automatic control low-current cables.

• Ambient Temperature Control Requirements: The ambient temperature for standard cable laying must not be lower than 0℃; low-temperature modified type must be selected for winter low-temperature construction to avoid brittle cracking of the outer sheath during bending and pulling.

• Bending Radius Limit Standard: The bending radius for all bends, conduit insertion, and transformer terminal connection operations must be ≥ 15 times the cable outer diameter; forced sharp-angle bending is prohibited to prevent cracking of the internal XLPE insulation layer and potential partial discharge risks.

• Heat dissipation requirements for parallel cable laying: Sufficient heat dissipation gaps should be reserved between parallel medium-voltage cables to avoid heat accumulation leading to a decrease in actual current carrying capacity; medium-voltage and low-voltage cable laying areas should be separated, and isolation baffles should be installed in the cable trenches.

• Road crossing reinforcement and protection measures: A reinforced concrete protective layer should be laid above the cable layer under the main motor vehicle road to withstand the rolling load of heavy vehicles over a long period; sufficient cable length should be reserved at both ends of transformers and distribution cabinets for future cable terminal replacement and circuit fault repair.

• Before starting the acceptance work, verify the batch factory inspection certificate, third-party full-type test report, and copper material raw material certificate.
• After cable laying and cable terminal manufacturing are completed, complete the power frequency withstand voltage test and partial discharge detection.
• Measure the insulation resistance value of each phase core wire to ensure that all data meet the national 15kV medium-voltage cable acceptance standard.
• Complete the reliable grounding connection of the copper tape shielding layer and steel tape armor layer, and test the grounding resistance to ensure that it meets the power grid safety operation specifications.

• Each delivery includes a complete set of official certification documents stamped by the factory free of charge: authoritative type test reports from the national power industry, IEC certificates of conformity, CE certification documents, copper origin certificates, batch production inspection records, and professional cable terminal production and laying guidance manuals. These documents fully meet the requirements for power grid bureau filing, construction supervision review, fire protection acceptance, and customs clearance for overseas EPC projects, avoiding project delays due to incomplete documentation.

• Our professional medium-voltage cable design team provides free technical consultation services: transformer full-load current carrying capacity calculation, long-distance voltage drop simulation, cable specification matching recommendations, flame retardant rating selection, and overall laying scheme optimization. For large-scale municipal, new energy, and heavy industrial orders, professional engineers provide remote video on-site construction guidance, promptly resolving technical difficulties encountered by the construction team in terminal manufacturing, long-distance cable laying, and acceptance.

• We have established a long-term, exclusive strategic partnership with a top-tier T2 oxygen-free copper smelter, completely prohibiting the use of recycled copper raw materials. Before shipment, samples of each batch undergo comprehensive high-voltage laboratory performance testing. Throughout the entire production process, insulation thickness, copper shielding overlap rate, and steel tape armor winding tightness are monitored online in real time to ensure the consistency and stability of the electrical performance of all cable reels, eliminating the risk of batch-to-batch parameter deviations.

• Our professional intelligent automated medium-voltage cable production workshop maintains ample inventory of mainstream YJV22 8.7/15kV 3×185 finished products, ready for immediate shipment. For key municipal projects, new energy projects, and heavy industrial EPC projects, we prioritize the production of customized flame-retardant, low-smoke halogen-free, and reinforced corrosion-resistant modified cables to fully support the construction schedules of engineering contractors.

• Each cable roll is printed with a unique production batch number, production date, voltage rating, and core specifications, enabling full production traceability from raw material supply to finished product delivery. Large-volume engineering orders enjoy a longer factory quality guarantee period. If, during the warranty period, defects occur in insulation, shielding, or armor due to non-human-caused damage during the factory production process, we will provide free replacements and product exchanges to minimize project operational risks for both the purchaser and engineering partners.

YJV22 8.7/15kV 3×185 three-core steel-tape armored cross-linked polyethylene medium-voltage cable is a cost-effective mainstream heavy-load cable suitable for the main incoming line of 15kV large-capacity transformers. It is widely recognized and specified by power design institutes, municipal power grid companies, and global heavy industry EPC contractors. Its multi-layer electric field balance shielding design, all-round steel tape mechanical damage resistance protection, and long-life anti-corrosion outer sheath enable the cable to adapt to various underground heavy-load medium-voltage laying environments, reasonably balancing the initial project procurement investment and long-term operation and maintenance costs for project owners and contractors.

Our factory integrates independent R&D, intelligent automated production, and a full-standard high-voltage testing laboratory for medium-voltage cables. We focus on providing stable, fully compliant, and cost-effective YJV22 series medium-voltage armored cables to buyers in global heavy industry, municipal power grids, new energy, and port logistics infrastructure, supporting long-term stable batch supply for various large-scale 15kV heavy-load power distribution projects.