Code of Practice for Fire Safety in Cable Runs
1988 Edition

The standard applies to fire safety in electrical cable runs found in industrial environments and multi-storey buildings. It encompasses power, control, communication, and signal cables installed horizontally or vertically within trays, conduits, ducts, and shafts. The focus is on minimizing fire risks, ensuring fire resistance, proper separation, and safeguarding operational continuity during fire events.

To limit fire propagation in cable tunnels, the standard advises subdividing these tunnels using fire-resistant walls spaced no more than 30 meters apart. All openings should be sealed with fire stops having fire resistance equal to or exceeding that of the building components, tested as per relevant IS codes. Fire-rated doors must be installed on access points within these barriers. Only fire protection-related services are permitted inside cable tunnels, and fire escape routes must be designed so no individual is more than 30 meters from an exit.

The code specifies the use of automatic fire alarm systems covering the entire cable runs. Approved detectors include smoke detectors (as per IS 11360-1985), point heat detectors (IS 2175-1988), and linear heat detectors for extensive or bundled cables. Cable runs should be subdivided into zones for detection purposes. In areas without compartmentation, physical fire barriers of at least one meter in length spaced every 30 meters, especially at cable bends and junctions, are mandated. These barriers must match the fire resistance rating of the building structure.

The recommended suppression media include carbon dioxide (CO₂), conforming to IS 6382-1984, ideal for electrical fires due to its non-conductive and residue-free nature, and high expansion foam, effective in filling cable trenches or tunnels to smother flames and inhibit fire spread. Selection depends on operational needs, with CO₂ preferred for sensitive electrical areas and foam for enclosed cable galleries.

Cable tunnels and galleries must be divided into compartments by fire-resistant walls at intervals not exceeding 30 meters to restrict fire spread. Openings in these walls must be sealed with fire stops whose fire resistance meets or surpasses that of the building components, verified by IS 12458-1988 and IS 3809-1979. Fire-rated doors matching barrier ratings are required at wall openings. In open cable installations where compartmentation isn't feasible, physical barriers at least one meter long should be installed every 30 meters, including at cable direction changes and junctions, with fire resistance equivalent to the building construction. No non-fire protection services are allowed within these cable zones, and fire escapes must ensure maximum travel distance to safety is 30 meters.