Steel Tape Armoured XLPE Medium Voltage Cable for Ultra-Large Capacity Transformer & Heavy-Duty Main Grid Distribution

• YJ: High-purity cross-linked polyethylene (XLPE) medium-voltage primary insulation
• V: Extruded PVC inner insulating sheath, used for metal layer isolation
• 22: Double-layer overlapping galvanized steel tape armor + weather-resistant black PVC outer anti-corrosion sheath
• Rated Voltage Rating: U0/U = 8.7/15kV, suitable for complete 15kV three-phase medium-voltage distribution networks
• Core Wire Arrangement: 3×300mm² three-phase fully compacted copper core, specifically designed for the main incoming cable of 3150kVA～4000kVA ultra-large capacity box-type transformers and main substation feeders

• ZA/ZB/ZC-YJV22 8.7/15kV 3×300: Multi-level flame retardant type, suitable for enclosed public utility tunnels, chemical production parks, and large underground commercial complexes.
• WDZ-YJV22 8.7/15kV 3×300: Low smoke and halogen-free type, suitable for central hospitals, main substations of large data centers, and core power stations of airports.
• Enhanced salt spray and chemical corrosion resistant outer sheath: Customized for coastal chemical zones, sewage treatment plants, and adjacent power pipelines.

• Rated AC Operating Voltage: 8.7/15kV Three-phase Medium Voltage Power System
• Power Frequency Withstand Voltage Test: 39kV, no breakdown or abnormal discharge for 15 consecutive minutes
• Lightning Impulse Withstand Voltage: 105kV, positive and negative pole impulse tests passed
• Partial Discharge Characteristics: Discharge amplitude less than 10pC at rated operating voltage, stable performance after thousands of hours of continuous cyclic testing
• Reference Continuous Current Carrying Capacity: Standard direct burial 445A; Multi-layer parallel cable trench laying 386A
• Ultra-low Dielectric Loss Design: Reduces self-heating loss of cables under 24-hour full-load operation, improving the overall energy utilization 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 destructive test; insulation layer shows no cracking, delamination, or permanent deformation.
• Laying Environment Temperature Standard: Standard model installation environment ≥ 0℃; Low-temperature customized version supports laying at -20℃ without preheating treatment.
• Overall Tensile Strength: Optimized multi-layer composite structure tensile performance prevents core material displacement during long-distance cross-road pipeline traction construction.

• Design Service Life under Standard Buried Laying Conditions: Over 35 years
• Vertical Water Permeability Resistance: Passes a 100-meter long-term immersion aging test; suitable for water-rich foundations, cross-river cable trenches, and pipelines adjacent to underground drainage systems.
• Chemical Corrosion Resistance: Resistant to long-term corrosion from weak acids, weak alkalis, and chloride ions in the soil.
• UV Aging Resistance: Supports long-term semi-outdoor cable trench laying without sheath cracking, powdering, or performance degradation.

The composite structure of an inner semi-conductive shielding layer + thickened cross-linked polyethylene (XLPE) insulation layer + outer semi-conductive shielding layer + all-copper tape metal shielding solves the most common fault source in ultra-high current 15kV medium-voltage cables: partial discharge breakdown. This 3×300 specification is widely used in the main feeders of large transformers above 3000kVA and the trunk cables of heavy-duty production lines operating 24 hours a day. The multi-layer shielding structure significantly reduces the probability of unplanned power outages, reduces the workload of daily power grid inspections and equipment maintenance for the operation and management team, and demonstrates significant long-term reliability advantages under continuous full-load operation compared to single-layer shielded medium-voltage cables.

The double-layer steel tape mechanical protection structure is suitable for harsh laying scenarios such as urban main road crossings, mountain rock foundation trenches, underground pipelines in heavy-duty logistics parks, and integrated pipe corridors in large industrial areas. It effectively avoids insulation layer damage caused by foundation settlement, temporary construction vehicle crushing, and friction from underground sharp rocks, which are common in large-scale power grid expansion and industrial park power transformation projects, thereby reducing the capital expenditure of general contractors for cable replacement and line maintenance in the later stages.

The 300mm² three-core specification is the most cost-effective high-current cross-section specification for 15kV 3150kVA~4000kVA transformer incoming cables. It provides sufficient current-carrying capacity to meet the full-load current requirements of heavy metallurgical equipment, large energy storage systems, and centralized power loads in port container yards, while avoiding unnecessary increases in procurement costs due to the use of excessively large 400mm² cables. Electrical design engineers prioritize this specification in projects such as ultra-large industrial parks, centralized new energy booster stations, and municipal substations to balance high current demands with the overall project construction budget.

The three insulating cores are filled with non-hygroscopic flexible filler, forming a neat circular cable shape. Compared to laying three single-core armored cables separately, this three-core product saves cable tray layout space, reduces the number of pipe openings and repetitive cable pulling work, greatly shortens the electrical wiring construction cycle for EPC contractors, and reduces labor costs for large-scale projects.

The fully automated integrated production line is equipped with real-time online thickness detection equipment to inspect the thickness of the insulation, shielding, and armor layers. The insulation thickness, copper tape overlap rate, and steel tape winding tightness of each batch of products are strictly controlled within standard tolerances. This consistency in electrical parameters across all cable reels effectively avoids the risks of localized overheating and uneven voltage distribution when multiple cables are connected in parallel in an overloaded 15kV distribution network.

• Municipal Ultra-Large-Scale Power Grid Projects: Main substation outgoing lines in urban centers, centralized 15kV distribution networks in industrial clusters, heavy-current distribution lines in municipal integrated utility tunnels
• Heavy Industrial Manufacturing Projects: Main incoming lines of 3000kVA+ ultra-large transformers, medium-voltage main lines in steel smelting and non-ferrous metal forging workshops, heavy-load ground distribution lines in open-pit mines
• Large-Scale New Energy Infrastructure: Main receiving lines of gigawatt-level centralized photovoltaic booster stations, auxiliary 15kV distribution lines of large-scale shared energy storage stations, centralized medium-voltage grid-connected lines for onshore wind farms
• Ports, Logistics, and Core Public Infrastructure: Centralized power supply cables for large port container yards, underground lines for dedicated transformers in ultra-large intelligent logistics parks, and power supply circuits for main substations of central airports and Class A tertiary hospitals.

1. Case 1: High-Current Feeder Project for the Renovation of a Municipal Central Substation

   A provincial capital city's power grid expansion project procured a large quantity of YJV22 8.7/15kV 3×300 type cables as the main outgoing cables for 12 4000kVA box-type transformers, serving a newly built heavy industrial cluster. The construction area spanned multiple urban main roads and river embankments with water-bearing ditches. The double-layer steel strip armor effectively resisted the crushing and squeezing during subsequent municipal road widening projects; our factory provided complete and authoritative testing documents, eliminating the need for additional sampling tests, and the project passed the power grid bureau's acceptance on the first attempt. After four years of continuous power grid operation, no partial discharge or insulation aging faults occurred, and daily power grid inspection and maintenance manpower input was reduced by 72%.

2. Case Study 2: 500MW Centralized Photovoltaic Substation Main Combination Circuit Project

   A large-scale ground-mounted photovoltaic power station uses ZC flame-retardant modified YJV22 8.7/15kV 3×300 type cables as the main medium-voltage combination circuit between the substation and thousands of photovoltaic combiner boxes. The project site is subjected to strong ultraviolet radiation for a long time, and the local soil has a high residual chloride content. The ultraviolet-resistant and corrosion-resistant outer sheath and the all-copper strip shielding structure effectively resist the harsh open-air environment and electromagnetic interference between dozens of parallel high-current medium-voltage circuits. Complete standardized certification documents accelerated the grid connection audit progress of the EPC contractor, enabling the project to achieve full-load power generation 20 days ahead of schedule.

3. Case Study 3: Dedicated Transformer Power Supply Project for a Large Metallurgical Heavy Industrial Park

   A steel processing industrial park constructed 14 sets of 4000kVA box-type transformers, all of the same model YJV22 8.7/15kV 3×300, as the underground main incoming cable. The underground soil contains residual weak acid pickling wastewater discharged from the metal surface treatment workshop. The customized, enhanced corrosion-resistant outer sheath solves the common problems of early sheath aging and metal shielding corrosion in aging cables in metallurgical industrial parks. Stable current carrying capacity and balanced electric field performance ensure uninterrupted 24-hour power supply to large rolling mills and forging equipment, reducing annual economic losses due to line maintenance and downtime by more than 88%.

• Transformer Load Matching Standard: This 3×300mm² specification is suitable for 3150kVA～4000kVA 15kV large-capacity transformers. For transmission distances exceeding 500 meters, please submit the transformer's rated capacity, transmission distance, and annual average load factor to our company's internal professional technical team for free voltage drop simulation calculations to avoid excessive terminal voltage loss affecting the stable operation of heavy production equipment.
• Laying Environment Classification Matching Rules: Standard YJV22 model 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 pipe corridors and main substations in densely populated public buildings.
• Mandatory Shielding Structure Confirmation: All buried 15kV three-core high-current cables must maintain a complete continuous copper tape metal shielding layer; the use of unshielded cables is strictly prohibited to prevent electromagnetic interference to adjacent monitoring, communication, and automatic control low-current cables.

• Ambient Temperature Control Requirements: The ambient temperature for standard cable laying shall not be lower than 0℃; in winter, low-temperature modified cables must be used to avoid brittle cracking of the outer sheath during bending and pulling operations.
• Bending Radius Limitation Standards: The bending radius for all turns, conduit installations, and transformer terminal connections must be ≥ 15 times the cable's outer diameter; forced sharp-angle bending is prohibited to prevent cracking of the internal cross-linked polyethylene (XLPE) insulation layer and the risk of hidden partial discharge.
• 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; isolation baffles should be installed in cable trenches to separate medium-voltage and low-voltage cable laying areas.
• 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 maintenance.

• Before the acceptance process begins, check the batch factory inspection certificate, third-party full-type test report, and copper material certificate of origin.
• After cable laying and cable terminal manufacturing are completed, perform power frequency withstand voltage testing and partial discharge detection.
• Measure the insulation resistance value of each phase core wire to ensure all test data comply with the national 15kV medium-voltage cable acceptance standard.
• Complete reliable grounding connections for the copper tape shielding layer and steel tape armor layer, and test the grounding resistance to ensure compliance with power grid safety operation specifications.

Each delivery includes a complete set of officially certified materials stamped by the factory free of charge: authoritative full-type test report from the national power industry, IEC certificate of conformity, CE certification documents, copper material certificate of origin, batch production inspection records, and a professional cable terminal production and laying guide. The documents fully comply with the requirements for power grid bureau filing, construction supervision review, fire protection acceptance, and customs clearance for overseas EPC projects, eliminating project construction delays caused by incomplete qualification materials.

Our professional medium-voltage cable R&D team provides free technical consultation services throughout the entire lifecycle: 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 design. For large-scale municipal, new energy, and heavy industrial bulk orders, professional engineers provide remote video on-site construction guidance, promptly helping construction teams solve technical problems suchs as terminal manufacturing, long-distance cable laying, and acceptance.

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

We have a professional, intelligent, automated production workshop for medium-voltage cables, maintaining ample inventory of mainstream YJV22 8.7/15kV 3×300 finished products 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 coordinate with the construction schedules of engineering contractors.

Each reel of cable is printed with a unique production batch number, production date, voltage rating, and core specifications, enabling full traceability from raw material supply to finished product delivery. Large-volume engineering orders enjoy a longer factory quality guarantee period. If defects in insulation, shielding, or armor caused by non-human-caused damage during the factory production process occur within the warranty period, we will provide free replacement and product replacement services, minimizing project operational risks for purchasers and long-term engineering partners.