Aluminium Split Concentric BS 7870 LSZH Cable

What is Aluminium Split Concentric BS 7870 LSZH Cable?

The Aluminium Split Concentric BS 7870 LSZH Cable is a specialized 0.6/1kV low-voltage power distribution and service connection cable featuring a Class 1 solid aluminium phase conductor, XLPE insulation, a split concentric layer of polymer-coated copper neutral wires and bare copper earth continuity wires separated by non-hygroscopic strings, and an orange LSZH outer jacket complying with BS 7870-3-21 and IEC/EN 60332-1-2 standards. It is engineered primarily for Distribution Network Operators (DNOs) to establish final low-voltage service connections to domestic properties and multi-occupancy dwellings.

Engineered for enhanced electrical safety and tamper prevention, the split concentric geometry provides separate, dedicated metallic pathways for neutral return and protective earthing around the central aluminium core. This design ensures instant circuit disconnection via upstream protection devices if physical damage or penetration occurs, while the halogen-free LSZH thermoplastic compound eliminates acidic gas emissions and dark smoke during fire incidents, making it ideal for high-rise riser ducts, sub-main risers, and street lighting grids.

Aluminium Split Concentric BS 7870 LSZH Cable Construction

• Conductor: Class 1 solid circular aluminium conductor per BS EN 60228 offering high electrical conductivity and lightweight mechanical handling.
• Insulation: Cross-Linked Polyethylene (XLPE) delivering low dielectric loss and continuous thermal overload endurance up to 90°C.
• Neutral Conductor: A concentric layer of plain copper wires individually covered with a blue polymeric compound.
• Earth Continuity Conductor: Concentric plain copper wires running alongside the neutral layer.
• String Separator: Non-hygroscopic string separators positioned between the insulated neutral wires and bare earth continuity wires to ensure distinct physical separation.
• Outer Sheath: Thermoplastic Low Smoke Zero Halogen (LSZH) compound, flame retardant per IEC/EN 60332-1-2 and UV-resistant.
• Sheath Colour: Orange.

Applications

Aluminium Split Concentric BS 7870 LSZH cables are engineered for public utility incoming mains, domestic electrical service connections, and high-density indoor distribution where anti-tamper security and low-smoke fire safety are critical.

• DNO Service Connections: Final underground service connection from the low-voltage distribution network to domestic meter boxes and cut-out units.
• High-Rise Buildings & Sub-Main Distribution: Vertical riser networks feeding individual apartments and tenant distribution boards requiring LSZH materials.
• Public Street Lighting Systems: Power distribution networks supplying street illumination columns, highway telemetry, and municipal transit signage.
• Commercial Facilities & Residential Complexes: Enclosed riser shafts, cable conduits, and wall-clipped indoor distribution networks operating up to 70°C ambient temperatures.

Specifications & Dimensions

The Aluminium Split Concentric BS 7870 LSZH cable portfolio covers 1-core (single-phase) and 3-core (three-phase) configurations in nominal cross-sectional areas of 25mm² and 35mm², featuring overall diameters ranging from 15mm up to 26mm and nominal weights from 490 kg/km to 1030 kg/km. Designed for an operating voltage of 0.6/1kV, it functions across ambient temperatures of -15°C to +70°C, supports a continuous conductor operating temperature of 90°C, and requires a minimum bending radius of 8 times the overall diameter. Maximum conductor DC resistance values at 20°C strictly conform to BS 7870-3-21 standards (Phase: 1.2 Ω/km for 25mm², 0.868 Ω/km for 35mm²; Neutral: 1.2 Ω/km for 25mm², 0.76 Ω/km for 35mm²; Earth: 1.2 Ω/km for both 25mm² and 35mm²), with current ratings up to 158A in air, 147A clipped direct, and 128A enclosed in conduit on a wall.

Standards

Design & Conductor Standards: BS 7870-3-21, EN 60228 (Class 1 Solid Aluminium)
Flame Retardancy: IEC/EN 60332-1-2 (Self-extinguishing)
Voltage Rating (Uo/U): 0.6/1kV
Temperature Spectrum: Service range: -15°C to +70°C; Conductor operating temperature: 90°C
Minimum Bending Radius: 8 × overall diameter
Regulatory Directives: CE Marked, European Regulation EN 50575 (CPR Compliant), Low Voltage Directive 2014/35/EU, RoHS Directive 2015/65/EU, REACH Directive EC 1907/2006

Frequently Asked Questions

Q: What is the primary operational difference between Straight Concentric and Split Concentric cables?
A: Straight concentric cables feature a single combined concentric layer functioning as a combined neutral and earth (PEN) for TN-C-S networks, whereas split concentric cables provide separately isolated neutral and bare earth wires divided by non-hygroscopic strings for separate neutral and protective conductor (TN-S) electrical supply.

Q: Why is an LSZH outer sheath specified for split concentric cables in high-rise buildings?
A: Low Smoke Zero Halogen (LSZH) materials emit minimal non-toxic smoke and zero corrosive halogen acid gases during thermal combustion, keeping escape corridors clear and preventing catastrophic acid corrosion on indoor infrastructure and sensitive electronic equipment.

Q: What are the installation bending radius requirements for Aluminium Split Concentric cables?
A: The cable requires a minimum bending radius of 8 times the overall diameter (8× OD) to ensure conductor integrity and prevent structural deformation of the split concentric copper wire layer during fixed installation.

Q: What payment terms does Huadong Cable accept for international utility export orders?
A: We accept standard international commercial payment terms including Telegraphic Transfer (T/T, with 30% advance deposit and 70% against shipping documents) and 100% Irrevocable Letter of Credit (L/C) at sight.

Aluminium Split Concentric BS 7870 LSZH Cable – Why Choose Huadong?

Huadong Cable Group manufactures Aluminium Split Concentric BS 7870 LSZH cables in strict compliance with BS 7870-3-21 and EN 60228 standards, verified by comprehensive laboratory testing for conductor resistance, concentric wire spacing, and halogen-free combustion properties. Utilizing high-purity electrical grade solid aluminium conductors combined with dry-cured XLPE insulation, our advanced multi-core lay-up machinery precisely arranges the blue-coated copper neutral wires and bare copper earth continuity conductors separated by high-grade non-hygroscopic strings. Encapsulated in a UV-resistant, flame-retardant orange LSZH outer sheath, our cables ensure thermal stability up to 90°C and long-term mechanical reliability across utility networks.

With more than 20 years of precision cable engineering expertise, Huadong Cable Group operates fully automated wire drawing, concentric stranding, and specialized thermoplastic extrusion facilities certified to ISO 9001, CE, CPR (EN 50575), RoHS, and REACH protocols. By eliminating intermediary markups, we deliver competitive factory-direct pricing, 100% Mill Test Certificates (MTC) tested in accredited testing facilities, tailored continuous drum lengths on ISPM 15 heat-treated export wooden reels, and dependable door-to-port global logistics for DNO utility contractors, commercial EPC builders, and electrical wholesalers worldwide.