Armoured XLPE medium Voltage Cable For Substation Main Feeder & Large Industrial MV Power Transmission

This YJV22 26/35kV medium-voltage steel-tape armored cable is manufactured entirely in accordance with the national medium-voltage power cable standard GB/T 12706.4-2020, fully complies with the international standard IEC 60502-2 for 30kV~50kV medium-voltage distribution cables, and meets EU CE LVD and EMC directives. It can be used for cross-border overseas power infrastructure bidding and customs clearance inspection.

All finished cable reels have passed full-type testing at a nationally accredited medium-voltage electrical laboratory, including tests specific to 35kV medium-voltage cables such as long-term partial discharge aging test, lightning strike medium-voltage withstand test, thermal cycling thermal stability test, heavy mechanical impact crush test, vertical flame spread test, long-term vertical water penetration test, and insulation material thermal oxidation aging test.

Each bulk order comes with a complete set of official factory-stamped filing documents free of charge: National Power Industry Full Type Test Report, Batch Factory Inspection Records, T2 Oxygen-Free Copper Raw Material Inspection Certificate, CE Certificate of Conformity, Independent Batch Traceability Documents, and Professional medium-Voltage Cable Terminal Production, Laying, and Grounding Operation Manuals. All materials fully comply with the filing requirements of power grid regulatory authorities, construction supervision review, fire protection acceptance, and overseas EPC project bidding review requirements.

YJ: Cross-linked polyethylene (XLPE) medium-voltage special insulating compound

V: Extruded PVC inner insulating sheath, used to isolate the metal shielding layer and armor layer

22: Double-layer overlapping galvanized steel strip armor + weather-resistant black anti-corrosion PVC outer sheath

Rated voltage level: U0/U = 26/35kV, matching a complete 35kV medium-voltage three-phase power distribution system, widely used as the main feeder of 35kV regional substations

Conductor configuration: Customizable three-core specifications, 50mm²～630mm² compacted copper core, meeting the medium-voltage incoming line requirements of small, medium and large capacity transformers

Class 2 compacted T2 oxygen-free copper conductor

medium-density round stranded pure copper core, DC resistance strictly controlled below the national standard upper limit. Low resistivity suppresses voltage drop in long-distance medium-voltage transmission, maintaining stable current carrying capacity under continuous full-load operation. medium compactness reduces the overall cable diameter, saving construction teams costs associated with trench excavation and cable tray layout. Zero addition of recycled copper ensures uniform conductivity across all production batches.

Extruded Inner Semiconductor Shielding Layer

The uniformly co-extruded semiconductor layer is tightly bonded to the copper core surface, eliminating micro-gaps between the conductor and the thickened medium-voltage insulation layer. This homogenizes the medium-intensity internal electric field, fundamentally suppressing the partial discharge breakdown risk unique to 35kV medium-voltage operating conditions.

Thickened XLPE medium-Voltage Main Insulation Layer

A thickened insulation layer specifically designed for 26/35kV voltage levels is used, employing ultra-low dielectric loss, medium-purity XLPE raw materials. It can withstand continuous operating temperatures up to 90℃; the instantaneous short-circuit heat resistance temperature can reach 250℃ within 5 seconds, enabling it to withstand severe overcurrent surges during medium-voltage grid short-circuit faults. The insulation layer maintains stable performance for decades under alternating medium voltage and extreme seasonal temperature cycling.

Outer Co-extruded Semiconductor Shielding Layer

The outer semiconductor layer is tightly bonded to the insulation layer, forming a closed electric field buffer layer together with the copper strip metal shielding layer. This prevents localized electric field concentration caused by cable bending, extrusion scratches, and long-distance traction friction during construction.

Fully Enclosed Continuous Copper Strip Metal Shielding Layer

A wide, overlapping soft copper strip shielding layer completely covers each insulated core wire, effectively conducting induced medium-voltage currents and large short-circuit ground fault currents in the 35kV medium-voltage power grid, isolating internal medium-frequency electromagnetic radiation, and preventing signal distortion and interference from adjacent control, monitoring, communication, and optical cables within the underground utility tunnel. The shielding layer cross-section meets the regional 35kV substation large short-circuit grounding capacity standard.

Seamless One-Piece PVC Extruded Inner Sheath

The one-piece 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 prevents corrosion of the metal shielding layer and XLPE medium-voltage insulation core by groundwater, soil salt ions, and weak acids and alkalis.

Double-Layer Galvanized Steel Strip Armored Protective Layer

The two layers of staggered, overlapping galvanized steel strip spiral winding structure possess extremely strong radial compression resistance, resisting abrasion from sharp rocks, long-term crushing by heavy trucks, impacts from construction machinery, and gnawing by underground rodents. Precise control of the winding gap prevents the steel strip edges from scratching the inner sheath during long-distance cable traction and multi-angle bending construction.

UV-Stable Anti-Corrosion Black PVC Outer Sheath

A composite outer sheath that resists aging, ozone, and microbial corrosion. Suitable for direct underground burial, pipeline crossings, cable tunnels, and semi-outdoor laying scenarios; exhibits excellent salt spray resistance in coastal industrial areas, port heavy industry, and offshore power projects.

• ZA/ZB/ZC-YJV22 26/35kV: Multi-level flame-retardant type, suitable for enclosed underground pipelines, chemical production parks, and large underground commercial complexes.

• WDZ-YJV22 26/35kV: Low-smoke halogen-free type, suitable for central hospitals, main medium-voltage substations of large data centers, and airport core power stations.

• Reinforced Salt Corrosion and Chemical Corrosion Resistant Outer Sheath: Customized for medium-voltage pipelines near coastal chemical zones and sewage treatment plants.

• Low-Temperature Resistant Special Sheath: Suitable for medium-altitude low-temperature construction environments.

• Rated AC Working Voltage: 26/35kV Three-phase medium-voltage power distribution system

• Power Frequency Withstand Voltage Test: 76kV, no breakdown or abnormal discharge for 15 consecutive minutes

• Lightning Impulse Withstand Voltage: 200kV positive and negative polarity impulse test passed.

• Partial discharge characteristics: Discharge amplitude less than 10pC under rated operating voltage; performance stable after thousands of hours of continuous cyclic aging test.

• Reference continuous current carrying capacity: Corresponding to each cross-sectional specification, the maximum current carrying capacity meets the national design standards for buried and trenched medium-voltage cables.

• Ultra-low dielectric loss design: Reduces the self-heating loss of the cable under 24-hour full-load operation, improving the overall energy utilization efficiency of the medium-voltage power grid.

• Minimum Allowable Bending Radius: 15 times the outer diameter of the finished cable

• Static Heavy-Load Compression Resistance: Passes the national standard medium-voltage cable compression destructive test; insulation layer shows no cracking, delamination, or permanent deformation.

• Laying Environment Temperature Standard: Standard type construction environment ≥ 0℃; Low-temperature customized version supports laying at -20℃ without preheating treatment.

• Overall Tensile Strength: Optimized multi-layer composite structure tensile performance effectively prevents core wire displacement during long-distance road and pipeline crossings of large-diameter medium-voltage cables.

• Design service life under standard buried laying conditions: Over 40 years, longer than 10kV/15kV medium voltage cables.

• Vertical water penetration resistance: Passes a 100-meter long-term immersion aging test, suitable for water-rich foundations, cable trenches crossing rivers, and pipelines adjacent to underground drainage systems.

• Chemical corrosion resistance: Resistant to long-term corrosion from weak acids, weak alkalis, and chloride ions in soil.

• UV aging resistance: Supports long-term semi-outdoor cable trench laying without sheath cracking, powdering, or insulation performance degradation.

The composite structure, consisting of an inner semi-conductive shielding layer, an ultra-thick XLPE medium-voltage insulation layer, an outer semi-conductive shielding layer, and a full copper tape metal shield, addresses the main failure factor of 35kV medium-voltage cables: partial discharge breakdown caused by uneven medium-intensity electric fields. This series of products is suitable for main feeders of regional 35kV substations, medium-voltage trunk cables in heavy industry, and other lines operating 24/7. The multi-layer shielding structure significantly reduces the probability of unplanned large-scale power outages, reduces the workload of daily medium-voltage grid inspections and equipment maintenance for power operation management teams, and demonstrates a significant long-term reliability advantage under continuous full-load operation compared to single-layer shielded medium-voltage cables.

The double steel strip mechanical protection structure is suitable for harsh medium-voltage laying scenarios such as crossing urban main roads, trenches in mountain rock foundations, underground pipelines in heavy-duty logistics parks, and large-scale municipal integrated pipe corridors. It effectively avoids insulation damage commonly caused by foundation settlement, temporary construction vehicle traffic, and friction from underground sharp rocks in regional 35kV power grid expansion and heavy industrial park power renovation projects, thereby reducing the capital expenditure for general contractors in subsequent medium-voltage cable replacement and line maintenance.

The three-core conductor cross-section covers 50mm² to 630mm², perfectly matching small-capacity distributed energy booster stations, medium-sized industrial 35kV transformers, and main feeders of large regional central substations. Electrical design engineers can select the appropriate specifications based on transformer capacity, transmission distance, and load requirements, eliminating the need to change cable suppliers and simplifying overall project procurement classification and warehouse management.

The three insulated cores are filled with non-hygroscopic flexible filler, forming a neat, large-diameter circular cable shape. Compared to three independently laid single-core armored medium-voltage cables, this three-core product saves cable tray layout space, reduces the number of duct excavations and repetitive heavy cable pulling operations, significantly shortens the medium-voltage electrical wiring construction cycle for EPC contractors, and reduces labor costs for large-scale regional power grid renovation projects.

The dedicated fully automated medium-voltage cable 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 are strictly controlled within standard tolerances. This consistency in electrical parameters across all cable reels eliminates the risks of localized overheating and uneven voltage distribution that may occur when multiple cables operate in parallel in a large-capacity 35kV regional distribution network.

• Municipal Regional Power Grid Engineering: 35kV regional central substation main outgoing lines, county-level centralized medium-voltage distribution networks, heavy-current medium-voltage distribution lines for large-scale municipal integrated pipe corridors.

• Heavy Industrial Manufacturing Engineering: 35kV transformer main incoming lines for large industrial parks, medium-voltage trunk lines for steel smelting and non-ferrous metal forging workshops, heavy-load ground-based medium-voltage distribution lines in open-pit mines.

• Large-scale new energy infrastructure: Main feeder lines for gigawatt-level centralized photovoltaic booster stations, auxiliary 35kV power cables for large-scale shared energy storage stations, and centralized medium-voltage connection circuits for onshore wind farms.

• Port, logistics, and core public infrastructure: Centralized medium-voltage power supply cables for container yards in mega-ports, underground lines for dedicated 35kV transformers in ultra-large intelligent logistics parks, and power supply circuits for main medium-voltage substations in regional airports and Class A tertiary hospitals.

1. Case 1: 35kV substation expansion project in a county-level area

   A county-level power grid expansion project procured a large quantity of YJV22 26/35kV three-core armored cables as the underground outgoing main cables for eight large-capacity 35kV box-type substations, serving the surrounding industrial cluster area. The construction area spanned multiple county-level main roads and river embankments with water-bearing ditches. The double-layer steel belt armor effectively resists the crushing and squeezing during subsequent municipal road widening projects; the complete and authoritative medium-voltage full-type test documents provided by our factory eliminate the need for additional sampling tests, and the system passed the regional power bureau's acceptance test on the first attempt. After five years of continuous operation of the medium-voltage power grid, no partial discharge or insulation aging faults have occurred, and the daily labor cost for medium-voltage power grid inspection and maintenance has been reduced by 75%.

2. Case Study 2: 800MW Centralized Photovoltaic Substation 35kV Main Collector Line Project

   A large-scale ground-mounted photovoltaic power station uses ZC flame-retardant modified YJV22 26/35kV medium-voltage cables as the main collector line between the substation and thousands of photovoltaic combiner boxes. The project site is subjected to long-term intense ultraviolet radiation, and the local soil has a medium residual chloride content. The UV-resistant and corrosion-resistant outer sheath and all-copper shielding structure effectively resisted the harsh open-air environment and electromagnetic interference between dozens of parallel medium-current medium-voltage lines. Complete standardized medium-voltage certification documents accelerated the grid connection audit process for the EPC contractor, enabling the project to achieve full-load power generation 22 days ahead of schedule.

3. Case Study 3: Dedicated 35kV Transformer Power Supply Project for a Large-Scale Chemical Heavy Industrial Park

   A fine chemical processing industrial park constructed 10 sets of large-capacity 35kV box-type transformers, all of the same model YJV22 26/35kV, as the underground main incoming cable. The underground soil contains residual weakly acidic chemical wastewater discharged from the production workshops. The customized, enhanced corrosion-resistant outer sheath solves the common problems of early sheath aging and metal shielding corrosion in old medium-voltage circuit cables in chemical industrial parks. Stable current carrying capacity and balanced medium-voltage electric field performance ensure uninterrupted 24-hour power supply to large-scale chemical synthesis production equipment, reducing economic losses caused by medium-voltage circuit maintenance and downtime by more than 90% annually.

• Transformer Capacity and Cross-section Matching Standards: Match the appropriate copper core cross-section based on the rated capacity of the 35kV transformer, transmission distance, and annual average load rate. For projects with transmission distances exceeding 800 meters, complete project electrical parameters must be submitted to our internal professional medium-voltage technical team for free voltage drop simulation calculations to avoid excessive terminal voltage loss affecting the stable operation of heavy industrial production and new energy equipment.

• Laying Environment Classification Matching Rules: Standard YJV22 type is used for neutral soil in ordinary cities; reinforced 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 medium-voltage substations in densely populated public buildings; low-temperature resistant type is used in medium-altitude areas.

• Mandatory Shielding Structure Confirmation: All buried 35kV three-core medium-voltage cables must maintain a complete and continuous copper strip metal shielding layer; the use of unshielded cables for replacement is strictly prohibited to prevent serious electromagnetic interference to adjacent monitoring cables, communication cables, and fiber optic low-current cables.

• Ambient Temperature Control Requirements: The ambient temperature for laying standard medium-voltage cables must not be lower than 0℃. During low-temperature construction in winter, low-temperature modified cables must be used to prevent brittle cracking of the outer sheath during bending and pulling operations of large-diameter cables.

• Bending Radius Limit Standards: The bending radius for all bends, conduit installations, and transformer terminal connections must be ≥ 15 times the cable's outer diameter. Forced sharp-angle bends are prohibited to prevent cracking of the internal thick XLPE medium-voltage insulation layer and significant partial discharge hazards.

• 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 barriers should be installed in the cable trenches between medium-voltage cable laying areas and medium/low-voltage cable laying areas.

• Road intersection reinforcement and protection measures: Lay a thick reinforced concrete protective layer above the cable layer under the main motor vehicle road to withstand the rolling load of heavy vehicles over a long period of time; reserve sufficient cable length at both ends of the 35kV transformer and distribution cabinet to facilitate future replacement of medium-voltage cable terminals and maintenance of circuit faults.

• Before the acceptance work begins, check the batch factory inspection certificate, third-party medium-voltage full-type test report, and copper material certificate of origin.

• After cable laying and medium-voltage cable terminal manufacturing are completed, complete the power frequency withstand voltage test and long-term partial discharge test.

• Measure the insulation resistance value of each phase core wire to ensure that all test data meet the national 35kV 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 medium-voltage power grid safety operation specifications.

• Each delivery includes a complete set of officially certified materials stamped by the factory free of charge: authoritative medium-voltage 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, professional medium-voltage cable terminal production and laying guidance manual. 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, thus avoiding project construction delays caused by incomplete qualification materials for medium-voltage bidding projects.

• Our professional medium-voltage cable R&D team provides free technical consultation services throughout the entire lifecycle: 35kV transformer full-load current carrying capacity calculation, long-distance medium-voltage drop simulation, cable cross-section specification matching recommendations, flame retardant rating selection, and overall underground medium-voltage laying scheme optimization design. For large-scale municipal power grids, gigabit new energy projects, and heavy industrial bulk orders, professional medium-voltage engineers provide remote video on-site construction guidance, promptly solving technical problems for construction teams such as large-diameter cable traction, medium-voltage terminal manufacturing, 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 each batch of products is shipped, samples are taken for comprehensive medium-voltage laboratory performance testing. Throughout the entire production process, the thickness of the medium-voltage thick insulation, the copper shield overlap rate, and the tightness of the steel tape armor winding are monitored online in real time to ensure the stable and consistent electrical performance of all cable rolls, eliminating the risk of cross-batch parameter deviations, which is crucial for the safe operation of the medium-voltage power grid.

• Our dedicated intelligent automated medium-voltage cable production workshop maintains ample inventory of mainstream cross-section YJV22 26/35kV three-core cables, ready for immediate shipment. For key municipal power grids, large-scale new energy, and heavy industrial EPC projects, we prioritize the production of customized flame-retardant, low-smoke halogen-free, enhanced corrosion-resistant, and low-temperature modified medium-voltage cables to fully align with the construction schedules of engineering contractors.

• Each roll of large-diameter medium-voltage cable is marked with a unique production batch number, production date, voltage rating, and core wire specifications, enabling full production traceability from raw material supply to finished product delivery. Large-volume medium-voltage engineering orders enjoy extended factory quality assurance periods. 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 replacement and delivery services to minimize the operational risks for large-scale power supply for purchasers and long-term medium-voltage engineering partners.

The YJV22 26/35kV three-core steel-tape armored cross-linked polyethylene medium-voltage cable is the designated standard feeder cable for 35kV regional substations and large-capacity industrial medium-voltage power distribution systems worldwide. It is widely recognized and recommended by power design institutes, municipal power grid companies, and global heavy industry and new energy EPC contractors. Its unique four-layer medium-voltage electric field balance shielding design, all-around steel tape mechanical damage resistance protection, and 40-year long-life corrosion-resistant outer sheath enable the cable to adapt to various complex underground medium-voltage laying environments, reasonably balancing the initial medium-voltage project procurement investment and long-term operation and maintenance costs for project owners and contractors.

Our factory integrates independent medium-voltage cable R&D, intelligent automated medium-voltage production, and a fully standard medium-voltage testing laboratory. We focus on providing stable, fully compliant, and cost-effective YJV22 series 35kV armored medium-voltage cables to buyers in global heavy industry, municipal regional power grids, large-scale new energy, and port logistics infrastructure. We support long-term, stable, and bulk supply cooperation for various large-scale 35kV medium-voltage power distribution projects.