Armoured XLPE Power Cable | Anti-Extrusion Direct Buried MV Cable for Municipal Grid & Industrial External Trunk Line

WDZ-YJY23 is a medium-voltage, low-smoke, halogen-free steel-tape armored fixed-lay power cable with a rated voltage of 26/35kV. It employs a composite structure of all-copper conductor + XLPE insulation + double-layer steel tape armor + modified low-smoke, halogen-free inner padding layer + PE outer sheath, specifically developed for underground direct burial, cable trench, and urban integrated pipe gallery medium-voltage trunk power transmission.

WDZ:

Low-smoke, halogen-free; the inner padding layer and filling materials are made of halogen-free flame-retardant polymers derived from halogen-free PVC raw materials, providing core protection for fire safety in confined spaces;

YJ:

High-purity cross-linked polyethylene insulation, used for tightly wrapped copper conductors;

Y:

Low-smoke, halogen-free extruded inner padding layer between the insulation core layer and the armor layer;

23:

Double-layer galvanized steel tape overlapping and winding armor + black PE anti-corrosion outer sheath, a classic steel tape armor structure that effectively resists external mechanical damage and soil corrosion.

Compared to YJY73 round steel wire armored cables, YJY23 flat steel strip armored cables feature a more compact outer diameter, lower unit cost, and superior resistance to compression and puncture by sharp objects on the ground. They are more suitable for direct burial in conventional urban soil and dense installation in utility tunnels. The WDZ full LSZH configuration makes it the designated model for fire-resistant municipal utility tunnel projects, widely used in industrial park trunk lines, urban power grid upgrades, photovoltaic/wind power station booster lines, and external power supply for chemical plants. The standard three-core integral stranded structure can be customized with single-core structures according to special engineering design requirements.

• Rated U0/U Operating Voltage: 26/35kV, matching 50Hz urban power distribution network and primary power distribution system of new energy booster stations;
• Long-term Allowable Continuous Operating Temperature of Copper Conductor: 90℃ under full load stable operation;
• Maximum Allowable Instantaneous Short-Circuit Temperature within 5-second Short-Circuit Duration: 250℃;
• Factory Standard Power Frequency Withstand Voltage Test: 78kV/15min without insulation breakdown;
• Lightning Impulse Withstand Voltage Test: Each batch of products passes the 200kV standard lightning impulse withstand voltage test;
• Partial Discharge Control: The partial discharge test results of the finished cable under rated voltage are lower than the specified threshold, effectively suppressing insulation hazards during long-term underground damp operation.

• Conductor Standard: Class 2 tightly stranded annealed copper conductor conforming to IEC60228 and GB/T3956 standards. Tight stranding reduces internal gaps and optimizes heat dissipation.
• Standard Conductor Cross-Section Specifications: 3×50mm²~3×630mm²; Extra-large cross-sections and non-standard single-core specifications can be customized according to customer engineering drawings.
• DC Resistance Testing: The conductor's DC resistance at 20℃ is strictly controlled below the standard upper limit, facilitating engineers to accurately calculate the voltage drop of long-distance buried trunk lines.

• Tight Copper Conductor: Smooth stranded surface avoids local electric field concentration, maintaining stable conductivity even after long-term underground temperature changes;
• XLPE Insulation Layer: Continuously high-speed extruded cross-linked polyethylene with uniform wall thickness, possessing excellent anti-aging and anti-partial discharge characteristics, providing core wire insulation protection for 35kV medium-voltage systems;
• LSZH Halogen-Free Flame-Retardant Filler: Environmentally friendly filler makes the cable shape rounded, improving the overall flame-retardant performance when multiple cables are densely laid in a pipe gallery;
• LSZH Inner Buffer Layer (Y): Extruded halogen-free buffer layer isolates the insulated core wire and steel tape armor, preventing cable bending and scratches from sharp edges of the armor during laying;
• Double-Layer Galvanized Steel Tape Armor (23): Double-layer overlapping galvanized steel tape, high compressive strength, resistant to stone impact and rodent bites, suitable for underground burial environments;
• Anti-Aging Polyethylene Outer Sheath: Modified polyethylene sheath with additives to resist soil microbial erosion and alkaline soil, suitable for general urban soil and mildly corrosive industrial soil laying environments.

• Minimum fixed installation ambient temperature ≥ 0℃;
• Minimum installation bending radius ≥ 18 times the outer diameter of the finished cable;
• Standard applicable installation altitude ≤ 3000m; For power projects in high-altitude mining areas at altitudes above 3000m, customized low-pressure withstand insulation formulas are available.

• WDZ Low Smoke Halogen-Free Fireproof Safety Performance: Passes GB/T19666 WDZ flame retardant test, smoke density ≥70% under combustion conditions, no corrosive halogen acid gas leakage, meeting the mandatory standards for fire protection acceptance of enclosed integrated utility tunnels;
• Double-Layer Steel Strip Armored Mechanical Protection: The double-layer overlapping steel strip structure can withstand ground settlement and compression, accidental impact from construction machinery, and puncture by underground hard and sharp objects, achieving direct burial protection without auxiliary steel pipes, saving on-site construction accessory costs;
• Cross-linked Polyethylene Insulation, Stable Electrical Performance: Low dielectric loss factor, small capacitance change under grid load fluctuations, reducing power consumption in long-distance trunk line operation, and improving the overall grid transmission efficiency;
• Light Soil Corrosion Resistance: Galvanized steel strip + modified polyethylene outer sheath composite protection, suitable for long-term underground use in general urban soils and lightly acid- or alkali-contaminated industrial soils;
• Compact structure and cost advantage: Compared to the YJY73 with round steel wire armor, the flat steel strip armor structure has a smaller outer diameter and lower raw material consumption, achieving a balance between cost and mechanical performance in conventional buried engineering projects;
• Long service life and excellent anti-aging performance: The optimized sheath formula effectively resists underground moisture and soil microbial erosion, with a designed service life of up to 30 years under standard buried conditions.

• Compared to traditional PVC-sheathed YJV23, it is fully upgraded to low-smoke halogen-free (LSZH) materials: Ordinary YJV23 uses halogenated PVC lining and sheath, which releases toxic and corrosive fumes when burned; WDZ-YJY23's entire inner non-conductive layer uses halogen-free compounds, complying with green municipal utility tunnel fire protection standards;
• Compared to YJY73 round steel wire armored cables, cost optimization: YJY73 round steel wire armored cables are designed for environments with severe mechanical damage; the YJY23 flat steel strip design reduces the unit procurement cost for ordinary urban underground projects (without particularly harsh geological conditions), avoiding the waste of investment in excessive specifications;
• Flexible customized production mechanism: Supports small-batch trial orders, customized production of non-standard single cores and ultra-large cross-sections, and mixed-specification consolidated shipments to reduce the buyer's idle inventory capital occupation;
• Full-process online quality monitoring: Equipped with a fully automated continuous extrusion production line with online insulation thickness and armor overlap rate testing equipment, each batch of finished products undergoes flame retardancy and partial discharge sampling tests before leaving the factory.

• Urban Old Town Power Grid Renovation Projects: Upgrading and renovation of the 35kV municipal power distribution trunk line in the city center, direct burial of cables in roadside trenches, and centralized laying of some pipe corridors (must meet LSZH fire protection requirements);
• External access lines for large industrial parks and fine chemical plants: 35kV access cables for main substations in industrial areas, buried power trunk lines at factory boundaries, and laying environments in slightly corrosive soils;
• Centralized photovoltaic and onshore wind farm booster station projects: 35kV outgoing trunk lines of new energy power stations, direct burial in the field section, and centralized wiring in indoor pipe corridors of booster stations;
• Urban Underground Integrated Utility Tunnel Construction: Medium-voltage trunk lines within municipal integrated utility tunnels are densely laid in enclosed spaces, strictly adhering to fire safety acceptance regulations;
• County-level Urban-Rural Integrated Power Construction: New 35kV distribution network projects in suburban rural areas, with direct burial in roadside soil.

• Conventional Urban Soil Direct Burial: In ordinary non-corrosive urban soil, the burial depth is ≥1.0m, with double-layer steel tape armor eliminating steel pipe protection, shortening the construction period and reducing auxiliary material costs;
• Dense Cable Laying in Utility Tunnels: All medium-voltage cables within utility tunnels must use WDZ type instead of halogen-containing YJV23 type to successfully pass the final acceptance by the fire department;
• Laying in Lightly Polluted Industrial Soil: For laying around chemical industrial parks, a customized version with corrosion-resistant reinforced PE sheath is selected to delay chemical aging of the sheath;
• Cost-Controlled Municipal Bidding Projects: For conventional urban buried trunk cables, WDZ-YJY23 is preferred over the higher-specification YJY73 to balance mechanical protection performance and the overall project budget.

The following is a multi-faceted checklist from power EPC procurement managers, electrical engineers from design institutes, and overseas regional electrical distributors:

• Raw Material Qualification Audit: Suppliers are required to provide third-party inspection reports for low-smoke halogen-free compounds and electrolytic copper raw materials before signing bulk contracts. The mixing of recycled inferior raw materials into finished cables is prohibited.
• Pre-shipment Third-Party Sampling Clause: A random sampling inspection agreement is included in the sales contract. The buyer can designate a locally authorized electrical testing laboratory to test flame retardancy, partial discharge performance, and armor mechanical performance before container loading.
• Pre-order Parameter Matching Consultation: The project geological survey report and power distribution design drawings are submitted to our technical team. Medium-voltage engineers will optimize the cross-section selection based on the laying distance and soil environment to avoid on-site rework losses due to incorrect procurement specifications.
• Delivery Schedule: Mainstream standard specifications are maintained in factory stock for rapid delivery within 7-10 working days. Non-standard customized specifications have a fixed production cycle confirmed during the pre-negotiation stage to coordinate the overall power project construction schedule.
• Export packaging optimization: Exported medium-voltage cables are packaged in thickened fumigated wooden reels with sealed moisture-proof plastic film. The logistics team has optimized container stacking layout to improve space utilization and reduce unit ocean freight costs for importers of bulk cargo.

All WDZ-YJY23 series products have passed multiple authoritative professional inspections and can provide complete English certification documents for overseas power bidding and destination customs clearance:

Domestic Standards:

GB/T12706 Medium Voltage Power Cable Standard, GB/T19666 Flame Retardant Low Smoke Halogen-Free Cable Specification, GB/T2952 Armored Cable Manufacturing Standard;

International Reference Standards:

Manufactured according to the core clauses of IEC60840, IEC60332, and IEC61034, conforming to the mainstream power grid connection specifications of emerging market countries in Southeast Asia, the Middle East, Central Asia, and Africa;

Complete Certifications:

CCC mandatory certification, fire protection product type approval certificate, CNAS accredited laboratory test report, ISO9001 quality management system and ISO14001 environmental management system certifications, and a complete set of English certification documents required for bid preparation;

Customs Clearance Assistance Services:

Assisting the buyer in issuing certificates of origin and supporting customs documents to expedite customs clearance at the destination port.

• Professional Dedicated Medium-Voltage Technical Team: Equipped with senior electrical engineers and geological application technicians specializing in medium-voltage cables, providing free pre-order cross-section matching consultation services based on power design drawings and project geological data, and offering remote online troubleshooting support to the on-site engineering team.
• End-to-end traceability and quality management: Each roll of finished cable has a unique batch tracking code, covering raw material inspection, online production monitoring, and finished product sampling inspection, facilitating full-cycle quality traceability during project completion and acceptance.
• Diverse international trade cooperation models: Supports multiple trade settlement methods including FOB/CIF/CFR, offering a dual cooperation plan of small-batch trial orders and annual long-term framework contracts. Long-term contracted clients enjoy tiered bulk purchase discount policies.
• Stable inventory and globally integrated logistics deployment: Standard and common specifications are maintained, with real-time updates to factory inventory. Partnerships with multiple top international freight forwarders ensure cost-effective customized transportation solutions, avoiding delivery delays caused by port congestion and seasonal logistics fluctuations.
• Flexible reserved capacity: Reserved medium-voltage production line capacity for long-term strategic partners to quickly respond to emergency replenishment needs during the later stages of power project construction.