LSZH Armoured MV Cable Underground Substation Power Transmission Cable for Fire Safety Critical Projects

WDZBN-YJY73 is a high-grade fire-resistant and safe medium-voltage power cable with a rated voltage of 8.7/15kV, manufactured strictly in accordance with IEC, IEEE, and international medium-voltage transmission design standards. It employs oxygen-free copper conductors, cross-linked polyethylene insulation, a low-smoke halogen-free inner sheath, high-density steel wire armor, and a WDZBN-grade fire-resistant outer sheath, integrating fire resistance, low-smoke halogen-free environmental performance, strong mechanical protection, and high-voltage insulation stability.

Unlike traditional ordinary medium-voltage armored cables, this model combines Class B fire resistance with low-smoke halogen-free characteristics. Even in open flame environments, it can maintain normal power supply for a certain period while releasing halogen-free corrosive gases with extremely low smoke concentration, effectively preventing obstruction of personnel evacuation and secondary corrosion of equipment caused by fire accidents.

The high-density steel wire armor structure of the Type 73 cable has significantly higher tensile and axial tensile strength than traditional steel tape armor, making it suitable for vertical laying, long-distance overhead shaft laying, deep buried crossings, and other applications requiring high tensile strength. The cable has passed numerous rigorous tests, including fire resistance tests, high-voltage partial discharge tests, mechanical tensile fatigue tests, and harsh weather aging tests, and has gained widespread recognition from global fire protection engineers, power plant contractors, and large infrastructure procurement groups, becoming the preferred cable for key global high-standard fire protection projects.

This cable achieves WDZBN fire resistance rating, maintaining stable power transmission for a specified time under flame impact and high-temperature baking environments. It ensures the normal operation of emergency lighting, fire-fighting linkage systems, disaster monitoring equipment, and critical load circuits, making it a core wiring material for the fire safety assurance system of key buildings.

All insulation and sheath materials use halogen-free environmentally friendly formulas. In the event of a fire, it will not release toxic or corrosive halogen gases, and smoke dispersion is extremely low. It maintains clear visibility of evacuation routes and protects precision electrical equipment, communication systems, and metal building structures from chemical corrosion damage, perfectly meeting high standards of public safety construction requirements.

Compared to steel-tape armored medium-voltage cables, high-density steel wire armor significantly improves longitudinal tensile strength and overall structural strength. It can withstand large axial tensile forces and is suitable for laying in high-drop vertical shafts, mountain crossings, and deep underground crossings. It can also resist external pressure, rock compression, and impact from construction machinery, greatly expanding the applicable laying environment.

High-purity cross-linked polyethylene insulation exhibits excellent high-voltage resistance, low partial discharge value, and stable dielectric loss performance. Even under long-term medium-voltage load operation and voltage fluctuations, it maintains a stable insulation state, effectively slowing down insulation aging. The overall design service life can reach over 35 years, reducing the frequency of mid-term circuit replacement and system maintenance.

Optimized low-smoke halogen-free composite sheath material possesses excellent resistance to ultraviolet radiation, damp heat, and freeze-thaw cycles. It can operate stably even in high-temperature tropical regions, cold temperate regions, and coastal high-humidity areas, without performance degradation due to long-term outdoor exposure and complex atmospheric environments.

Unified standards for medium-voltage cable outer diameter, wire diameter, and electrical parameters ensure high compatibility with mainstream global medium-voltage cable joints, terminals, substation switchgear, and distribution accessories. Engineers can adopt common industry design solutions, accelerating project design progress and improving on-site installation and commissioning efficiency.

Precise Application Scenarios

Main power input and output lines of urban central substations, medium-voltage trunk lines of urban core power supply networks, ring main unit connection cabling, and dedicated regional power dispatch lines.

Underground medium-voltage power supply lines in highway tunnels, railway tunnels, and urban integrated utility tunnels; dedicated fire emergency distribution lines in underground spaces.

Vertical medium-voltage main power lines for super high-rise buildings, dedicated fire emergency cables, and main transmission systems in the basements of high-rise buildings.

Regional medium-voltage power distribution in airport terminals, main power lines for subway stations, and emergency fire protection power lines for rail transit.

Core medium-voltage power supply for general hospitals, medical parks, and university campuses; backup fire safety power lines for key public buildings.

Chemical industrial parks, oil and gas storage and transportation areas, and other flammable and explosive locations; using fire-resistant, low-smoke, halogen-free cables to reduce operational safety risks.

Medium-voltage power distribution lines for photovoltaic power plants and wind power plants, and high-safety transmission lines inside energy storage power plants.

In a municipal transportation tunnel upgrade project in Western Europe, the project team uniformly selected WDZBN-YJY73 type 15kV fire-resistant medium-voltage cables. These cables, with their low-smoke, halogen-free characteristics and excellent fire resistance, fully meet local tunnel fire safety construction specifications. Their steel wire armored structure adapts to complex underground laying conditions, ensuring the long-term safe and stable operation of the tunnel's power system.

A large-scale super high-rise building project in Southeast Asia used our WDZBN-YJY73 type medium-voltage cables for vertical trunk line laying. The excellent tensile strength of the steel wire armor perfectly solved the laying load problem of ultra-high vertical drop, and its high-level fire resistance met the local high-standard building fire protection acceptance specifications, successfully completing the construction of the entire building's power distribution system.

This series of medium-voltage cables was selected for the construction of a large-scale energy storage base in the Middle East desert region. This product can adapt to local high temperature, strong ultraviolet radiation and dry harsh environment, has stable medium voltage transmission performance and fire safety guarantee capability, and can support long-term stable grid connection and power transmission of energy storage equipment.

When designing the circuit scheme, factors such as laying method, ambient temperature, cable laying density, and soil heat dissipation conditions must be comprehensively considered to calculate the actual current carrying capacity. We provide a complete 8.7/15kV medium-voltage current carrying capacity reference table and thermal stability calculation data.

During vertical laying, the laying length of each section and the number of auxiliary fixing points should be reasonably controlled according to the cable's own tensile bearing parameters to avoid excessive concentrated tension that could lead to structural deformation.

It is recommended to lay WDZBN fire-resistant cables in a separate dedicated cable channel, separate from ordinary power cables, to prevent the spread of external fire sources from affecting emergency power circuits.

The use of matching medium-voltage cold-shrink terminals and cable joints with the same fire resistance rating is supported to ensure that the fire resistance and insulation performance of the entire line system meets a unified standard.

For coastal salt spray and long-term humid underground environments, a customized version with enhanced corrosion resistance for the outer sheath is adopted to further improve long-term operational stability.

In accordance with international medium-voltage cable acceptance standards, on-site partial discharge tests, insulation resistance tests, and fire resistance sampling inspections were completed to ensure the project successfully passed safety acceptance.

All WDZBN-YJY73 medium-voltage fire-resistant cables are manufactured strictly according to the entire process of medium-voltage cable production specifications. From the incoming inspection of high-purity copper materials, the three-layer co-extrusion processing of XLPE insulation, the uniform armoring of steel wires, to the high-voltage withstand voltage test and fire resistance performance sampling test of the finished product, strict control is implemented throughout the entire process.

The products have obtained CE certification, IEC standard product certification, RoHS environmental certification, and multiple regional power industry access qualifications. We can provide complete medium-voltage cable type test reports, fire resistance performance test reports, factory inspection certificates, and raw material composition identification documents, fully meeting the document requirements for international project bidding, project filing, and cross-border customs clearance.

• We are a professional medium-voltage cable manufacturer with extensive experience in the R&D and production of fire-resistant cables. Our raw material supply is stable and reliable, enabling us to meet the consistent delivery needs of large-volume orders. We can also customize production cycles according to customer requirements.
• We have a professional team of medium-voltage electrical engineers providing one-stop technical services, including medium-voltage circuit scheme optimization, cable model selection, laying scheme design, and overseas remote technical guidance.
• We support diversified personalized customization services, adjusting fire resistance ratings, sheath anti-aging formulas, cable outer diameter parameters, and special environmental resistance performance according to different national power industry standards and project-specific requirements.
• Before shipment, we strictly implement 100% offline high-voltage full inspection to eliminate insulation hazards and substandard products from the source, ensuring the long-term safe operation of medium-voltage systems.
• We use professional reinforced packaging for medium-voltage cables for export to prevent armor deformation and insulation damage during long-distance sea transport and provide complete export trade documents.
• In line with global trends in green building and safe power grid development, our low-smoke, halogen-free environmentally friendly design helps clients obtain green project evaluation qualifications and safety engineering certifications.
• We have established a long-term global partner service mechanism, providing professional after-sales technical consultation and subsequent system maintenance guidance to jointly ensure the long-term stable operation and benefits of the project.