BS 6724 armoured cable is the low smoke, zero halogen equivalent of BS 5467. The electrical construction is the same — XLPE insulated cores, armour, 600/1000 V, 90 °C — but the bedding and outer sheath are halogen-free compounds that produce little smoke and no acid gas when burnt. It is specified wherever a fire in a cable would put people or sensitive equipment at risk: escape routes, public buildings, tunnels and enclosed plant rooms.
Key applications
- Submains and distribution in hospitals, schools and transport buildings
- Risers and escape routes in public and high-occupancy buildings
- Plant rooms, tunnels and underground enclosed spaces
- Data centres and installations with sensitive electronic equipment
- Any project where the specification calls for halogen-free cable throughout
Features and benefits
- Low smoke emission, which keeps escape routes visible in a fire
- Halogen-free, so no corrosive acid gas to damage equipment and structure
- Same 600/1000 V and 90 °C electrical performance as BS 5467 armoured cable
- Steel wire armour for multicore, aluminium wire for single core, as the standard requires
- Available in the same core counts and sizes as the PVC-sheathed range
Specification notes and limitations
Low smoke and zero halogen does not mean fire resistant. BS 6724 cable will not maintain a circuit in a fire; where circuit integrity is required — sprinkler pumps, smoke control, fire alarm and emergency lighting — the specification calls for a fire-resistant cable to BS 7846 or BS 8434, and substituting BS 6724 is a serious error. LSOH sheaths are generally stiffer and less abrasion-resistant than PVC, so pulling tensions, bending radii and protection over edges need more care, and the compound is more sensitive to prolonged water immersion. Armour earthing, gland selection, the 90 °C limit at equipment and burial requirements are all as for BS 5467. Single core versions must use the aluminium wire armour version for a.c. circuits.
