BS 7846 F120 Fire Performance Cable

What is BS 7846 F120 Armoured Fire Performance Power Cable?

The BS 7846 F120 Armoured Fire Performance Power Cable is a 0.6/1kV low-voltage emergency circuit cable specifically engineered to maintain electrical circuit integrity during severe fire incidents involving falling structural debris and fire brigade water jets. Fully compliant with British Standard BS 7846-F120, it is qualified through the grueling 120-minute testing regime defined in BS 8491, making it a Category 3 power cable under BS 8519 for life-safety and fire-fighting emergency installations.

Engineered for mission-critical applications, the cable combines Class 2 stranded copper conductors wrapped with protective mica glass tape (MGT) beneath heat-resistant XLPE insulation. A dual glass tape barrier system combined with galvanized steel wire armour (SWA) provides mechanical crush resistance against collapsing building debris. Furthermore, its low-smoke zero-halogen (LSZH) compound prevents the release of acidic fumes and toxic gases during combustion, maintaining visibility in emergency evacuation passages and protecting mission-critical control hardware from corrosive chemical damage.

BS 7846 F120 Armoured Fire Performance Power Cable Construction

• Conductor: Class 2 stranded plain annealed copper conductors offering high electrical conductivity and structural integrity.
• Fire Barrier: High-temperature mica glass tape (MGT) helically wrapped directly over conductors to ensure circuit integrity under fire.
• Insulation: Cross-Linked Polyethylene (XLPE) thermoset compound rated for continuous operation up to +90°C.
• Inner Barrier: High-tensile woven glass tape layer wrapped over assembled insulated cores.
• Bedding: Thermoplastic Low Smoke Zero Halogen (LSZH) bedding compound providing core cushioning.
• Armour: Galvanized Steel Wire Armour (SWA) delivering mechanical impact protection and longitudinal tensile strength.
• Outer Barrier: High-performance woven glass tape layer applied over the armour layer.
• Outer Sheath: UV-resistant, flame-retardant Low Smoke Zero Halogen (LSZH) protective compound.
• Core Identification: 2 core: Brown, Blue; 3 core: Brown, Black, Grey; 4 core: Brown, Black, Grey, Blue; 5 core: Brown, Black, Grey, Blue, Green/Yellow.
• Sheath Colour: Black.

Applications

BS 7846 F120 armoured fire performance power cables are specified for active life safety and fire-fighting systems requiring 120 minutes of electrical circuit survivability:

• Smoke Exhaust & Pressurization Systems: Power circuits feeding smoke extraction fans, pressurized staircase ventilation, and basement air dampers in high-rise buildings.
• Fire Suppression Infrastructure: Power supply lines for fire water booster pumps, sprinkler systems, and deluge fire pump sets.
• Emergency Egress & Evacuation Services: Primary feeds for dedicated fire-fighting elevators, emergency lighting central batteries, and life-safety distribution panels.
• High-Occupancy Public Infrastructure: Underground transit hubs, railway stations, airport passenger terminals, healthcare hospitals, and hyperscale data centers.

Specifications & Dimensions

Huadong Cable Group manufactures the full range of BS 7846 F120 cables across 2-core configurations from 4mm² to 35mm², 3-core configurations from 4mm² to 400mm², 4-core configurations from 4mm² to 400mm², and 5-core configurations from 4mm² to 16mm². Operating at a rated voltage of 0.6/1kV across a continuous temperature spectrum of -20°C to +90°C, the series requires a minimum installation bending radius of 8 times the overall cable diameter. Nominal overall diameters range from 23.4mm (3 × 4mm²) up to 82.5mm (4 × 400mm²), with corresponding nominal unit weights spanning 950 kg/km to 21,000 kg/km. Conductor DC resistance values at 20°C strictly follow standard limits (4.61 Ω/km for 4mm² down to 0.047 Ω/km for 400mm²), delivering air-rated three-phase current capacities up to 766A under balanced operating loads in full conformity with BS 7846 and BS 8519 dimensional and electrical requirements.

Standards

Fire Resistance & Performance Standards: BS 7846-F120, BS 8491 (120 mins fire, direct impact, and water jet test), BS 6387 CAT CWZ, BS 8519 Category 3
Flame Retardancy: IEC 60332-3 Cat C (Bunched vertical flame spread), IEC 60332-1-2 (Single cable vertical test)
Halogen-Free & Low Smoke: IEC 60754-1/2 (Zero halogen acid gas emissions), IEC 61034-1/2 (Smoke density transmittance)
Third-Party Approvals: BASEC Approved (British Approvals Service for Cables), LPCB Certified (Loss Prevention Certification Board, Red Book Live listed)
Electrical & Thermal Ratings: Voltage Rating Uo/U: 0.6/1kV; Operating Temperature: -20°C to +90°C; Installation Bending Radius: 8 × OD
Regulatory Directives: Low Voltage Directive 2014/35/EU, RoHS Directive 2015/65/EU, REACH EC 1907/2006, CE Marked, UKCA Marked

Frequently Asked Questions

Q: What makes the BS 8491 test protocol critical for BS 7846 F120 cables?
A: BS 8491 tests large-diameter power cables under combined flame exposure, mechanical impact, and high-pressure water jets, ensuring circuits remain operational for 120 minutes during structural collapse and active fire fighting.

Q: What is the significance of the BS 8519 Category 3 designation?
A: BS 8519 Category 3 defines power cables for life safety and fire fighting that must maintain circuit integrity for 120 minutes, which is required for critical evacuation and active smoke clearance in major infrastructure projects.

Q: What role does the Galvanized Steel Wire Armour (SWA) play during a fire?
A: Beyond providing physical crush resistance and earth fault return paths, SWA shields internal mica and XLPE layers from physical shock, falling debris, and structural movement during building fires.

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

BS 7846 F120 Fire Performance Cable – Why Choose Huadong Cable?

Huadong Cable Group manufactures BS 7846 F120 armoured fire performance power cables in full accordance with BS 7846 and BS 8491 specifications, ensuring performance under sustained fire, direct physical impacts, and water immersion. Using high-purity electrolytic copper, our production lines apply dual-layer mica glass tape barriers with precise overlaps to prevent barrier cracking during high-temperature exposure. Combined with computerized XLPE extrusion, galvanized steel wire armouring, and zero-halogen compounding, our cables achieve balance between mechanical durability and flame-retardant performance.

With more than 20 years of specialized cable engineering expertise, Huadong Cable Group maintains quality management facilities certified to ISO 9001, CE, and UKCA standards. Supplying directly from our manufacturing facility eliminates intermediary agent markups, allowing us to offer competitive factory pricing, 100% Mill Test Certificates (MTC) tested in accredited testing facilities, continuous project drum lengths on ISPM 15 heat-treated export wooden reels, and dependable logistics for international EPC contractors and mechanical-electrical engineering projects.