0.6/1kV Direct-Burial Fire-Safe Trunk Cable for Underground Grid, Basement

Industry-standard abbreviation for "Flame Retardant." By default, it corresponds to the Class C (ZC) flame-retardant rating under the GB/T 19666 standard; the cable passes the single-cable vertical burning test, is self-extinguishing after the ignition source is removed, and limits longitudinal flame propagation along the cable line. For stricter fire safety specifications, it can be upgraded to ZA-YJV22 (Class A, the highest rating) or ZB-YJV22 (Class B, a medium-to-high rating).

Cross-linked polyethylene (XLPE) insulation, offering a long-term heat resistance rating of 90°C. Compared to PVC insulation, it provides superior resistance to water-treeing and electrical-treeing aging, as well as enhanced dielectric stability.

Flame-retardant modified PVC inner bedding and outer sheath, providing resistance to atmospheric aging, mild soil acidity/alkalinity, and surface mechanical abrasion.

Double-layer overlapping galvanized steel-tape armor structure. Serving as the primary mechanical protection layer, it withstands soil pressure, installation impacts, rock punctures, and rodent damage, enabling cost-effective direct-burial installation without the need for additional heavy-duty protective conduits.

Passes rigorous bunched-cable combustion tests with minimal flame propagation; suitable for super-high-rise buildings, core circuits in underground utility tunnels, hazardous chemical zones, and critical national infrastructure.

Offers medium-to-high flame retardancy; suitable for high-rise commercial buildings, main circuits in underground parking garages, and auxiliary power circuits for rail transit projects.

Passes standard single-cable vertical combustion tests and offers the best cost-performance ratio; meets fire safety acceptance standards for the majority of residential, commercial, and general industrial/civil engineering projects.

Flame-retardant (Class C by default); complies with GB/T 18380 single-cable vertical burning test requirements; inhibits continuous flame propagation along the cable length.

XLPE (Cross-linked Polyethylene) insulation; 90°C long-term rated operating temperature; low dielectric loss; excellent aging resistance and resistance to water treeing.

Flame-retardant modified PVC sheath; good weather resistance; mild chemical corrosion resistance.

Double-layer overlapping galvanized steel tape armor; resistant to compression, impact, and rodent damage; designed for direct burial installation.

Rated insulation voltage U₀/U = 0.6/1kV; suitable for standard three-phase four-wire/five-wire low-voltage distribution networks.

Precision compacting and stranding processes enhance conductor roundness and density, thereby reducing DC resistance and temperature rise during long-term full-load operation. The copper material exhibits minimal creep under terminal crimping pressure, ensuring stable contact resistance for over 30 years and eliminating the terminal overheating risks commonly associated with aluminum conductors; the smooth conductor surface ensures reliable crimping compatibility with specialized armored cable terminals and accessories.

Features extruded cross-linked polyethylene (XLPE) insulation of uniform thickness, with in-line eccentricity monitoring during production. Its three-dimensional cross-linked molecular structure enables a long-term rated operating temperature of 90°C, offering thermal stability far superior to PVC insulation; it effectively resists water-tree and electrical-tree aging in environments such as damp direct-buried conduits and enclosed cable trenches. Formulated with flame-retardant additives, the insulation ensures the cable does not sustain combustion after ignition and possesses self-extinguishing properties, meeting Class C flame-retardancy requirements.

Fills the interstices between insulated cores to maintain a uniform, circular cable profile; cushions against compression and friction between cores during pulling and installation, preventing surface scratches on the insulation; blocks moisture ingress and stabilizes the cable's roundness, facilitating smoother passage through conduits with multiple bends or during trench installation.

A continuous cushioning and separation layer formed via extrusion, positioned between the insulated core assembly and the steel tape armor; prevents the sharp edges of the steel tape from cutting into the internal insulation during cable bending or deformation under pressure; also inhibits electrochemical corrosion between the galvanized steel armor and internal copper components in moist, underground soil environments.

Composed of two layers of galvanized steel tape helically wrapped with a standard overlap ratio, this serves as the critical functional layer for direct-burial applications. It effectively withstands damage from vertical soil pressure, excavation impacts, sharp rock punctures, and rodent gnawing; the galvanized coating enhances rust resistance in moist and mildly acidic or alkaline soils, enabling direct-burial installation without the need for large-diameter protective conduits.

The outer sheath utilizes a specialized, integrally flame-retardant PVC formulation, imparting overall flame-retardant properties to the cable. It offers resistance to UV aging, soil acidity/alkalinity, and mold, as well as protection against mechanical abrasion and scratching; this effectively safeguards the internal armor and insulation structures, ensuring stable long-term underground operation.

Replace aging overhead low-voltage lines across 23 residential complexes with direct-buried armored cables; high cable volume required; mandatory specifications included rodent resistance, soil corrosion resistance, and Class C flame retardancy; must pass inspections by local power and fire authorities; strict control of the total investment budget.

Bulk supply of ZR-YJV22 flame-retardant armored cables (specifications: 4×185mm² and 5×95mm²), totaling 67.9 km in length.

The steel-tape armored structure eliminated the need for conduit installation along the entire route, reducing combined civil engineering and material costs by 28%; Class C flame retardancy ensured smooth fire safety filing and project acceptance; stable post-delivery operation with no underground mechanical damage or insulation breakdown failures within five years; local power authorities designated the ZR-YJV22 model as the standard, cost-effective underground armored cable for future residential grid renovation tenders.

Installation of armored trunk feeder cables for the basement power distribution rooms of multi-story warehouses; routing of certain lines beneath roadside green belts; and compliance with warehouse fire safety standards requiring cables to possess flame-retardant properties while offering protection against rodent damage and potential mechanical damage during subsequent maintenance work.

Selection of ZR-YJV22 armored cables (3-core, 4-core, and 5-core configurations) in various specifications, with a total supply length of 42.5 kilometers.

The ZR flame-retardant design met mandatory warehouse fire safety regulations; the direct-burial installation method accelerated the overall construction schedule; and throughout four years of continuous operation, the system experienced no insulation breakdowns or external damage, consistently passing annual fire safety inspections and routine electrical audits.

Prior to selecting ZR-YJV22 cables, it is essential to perform current-carrying capacity calculations, voltage drop checks, soil corrosivity assessments, and building fire-rating verifications. Our technical team can provide comparative reports on specifications for ZR-YJV22, ZB-YJV22, and ZC-VV22 cables to help you mitigate risks associated with insufficient current-carrying capacity and avoid inappropriate selection grades or unreasonable costs.

Termination work must utilize compatible armored cable accessories and armored cable grounding clamps; strict adherence to steel tape grounding procedures and standardized stripping techniques for inner and outer insulation layers is mandatory. Arbitrary cutting of the steel tape or improper grounding can create hazards related to circulating voltages and fails to meet the requirements of electrical engineering acceptance standards.

Prescribed bending radius limits must be strictly observed throughout the installation process; sharp bends can cause tearing of internal bedding layers, deformation of steel tapes, and compression damage to the insulation—creating potential insulation defects and accelerating long-term insulation aging. Chamfered protective sleeves must be installed at pipe inlets and outlets to prevent abrasion of the outer sheath during cable pulling.

In accordance with electrical standards, the steel tape armor layer at both the starting and terminating ends of the cable must be reliably connected to the protective grounding system; this suppresses induced circulating currents within the armor and eliminates risks of and electromagnetic interference during long-term underground operation.

The maximum continuous operating temperature for ZR-YJV22 XLPE-insulated cables is 90°C; they should not be installed near high-temperature boilers or steam pipelines, nor in enclosed spaces subject to sustained high temperatures (specialized high-temperature cables should be used in such environments). They are not suitable for long-term full submersion in water; specialized waterproof armored cables should be selected for underwater installations.

Cable reels must be stored on flat, solid ground within a dry, well-ventilated warehouse to prevent the flame-retardant sheath from aging prematurely due to prolonged exposure to sunlight and rain. During loading, unloading, and transport, care must be taken to avoid severe impacts, crushing, or tipping of the reels, which could cause defects such as sheath cracking, armor deformation, or internal conductor displacement.

All products are manufactured in strict accordance with GB/T 12706, GB/T 19666, and relevant IEC international standards. We offer—free of charge—a complete package of factory qualification documents, comprehensive type test reports, flame-retardancy test records, third-party inspection certificates, and editable technical data sheets tailored for tenders. This ensures full compliance with global engineering project requirements regarding document review, bid submission, fire safety inspections, and final project acceptance.

We utilize premium flame-retardant cross-linked polyethylene (XLPE) compounds, galvanized steel tape, and high-purity copper rods specifically designed for armored cables. Key manufacturing stages—such as stranding, insulation extrusion, cabling, armor wrapping, and sheathing—are equipped with real-time online monitoring systems for outer diameter and concentricity. These measures ensure consistent conductor resistance, uniform insulation thickness, stable flame-retardant performance, and precise armor wrapping overlap, thereby minimizing the risk of batch rejection during incoming inspections for large-scale tender orders.

For all ZR-YJV22 specifications (covering various core counts and cross-sectional areas), we offer services tailored to customer drawings and specific engineering needs. These include options for flame-retardant grade selection (ZA, ZB, or ZC), fixed-length cutting, customized core coloring, packaging in wooden reels or export-grade steel reels, and bespoke bulk packaging solutions.

We operate our own cable manufacturing facility, eliminating intermediary markups. We support small-batch sample orders to meet tender pre-qualification needs and prioritize production for large-volume orders. Ready stock is maintained for mainstream ZR-YJV22 cable specifications to ensure rapid delivery, meeting the tight schedules of municipal and industrial projects.

Our team of professional cable design engineers provides free current-carrying capacity calculations, comparative analysis of the total lifecycle costs between ZR-YJV22 and ZC-VV22 cables, consultation on optimizing underground routing, remote on-site installation guidance, and standardized after-sales quality tracking. Backed by a formal, long-term product warranty policy, we comprehensively address the technical and quality concerns of procurement and engineering teams throughout the post-order execution phase.