What is the primary purpose of a fire stop in a cable run?

A fire stop is a passive fire protection system used to seal openings in fire-resistance rated walls or floors, to prevent the spread of fire or smoke through cable penetrations (Clause 5).

Should power and instrumentation cables be run on the same tray?

No, the code recommends segregating power cables from control and instrumentation cables, preferably on separate trays, to prevent fire propagation and electromagnetic interference (Clause 4).

What fire rating is recommended for barriers separating cable runs?

Barriers, partitions, and fire stops separating cable runs should generally have a fire resistance rating of not less than two hours (Clause 5.1).

Is ventilation required in cable tunnels?

Yes, proper ventilation is crucial to dissipate heat generated by cables and to control smoke in the event of a fire. Both natural and mechanical ventilation systems are discussed (Clause 6).

IS 12459

: 1988

Code of Practice for Fire Safety in Cable Runs

CurrentSpecializedCode of PracticeBIMFire Safety · Fire Safety

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This standard provides guidelines for ensuring fire safety in electrical cable runs within buildings and industrial installations. It covers aspects like segregation of cables, use of fire stops and seals in openings, ventilation of cable galleries, and requirements for fire detection and extinguishing systems. The objective is to prevent the spread of fire along cable routes and maintain circuit integrity during a fire.

Code of Practice for Fire Safety in Cable Runs

Quick Reference Values

recommended fire rating for barriers2 hours

minimum vertical spacing between cable trays300 mm

minimum horizontal spacing between cable trays225 mm

maximum cable tray fill for power cables50% of cross-sectional area

Practical Notes

Ensure that any fire stopping material used is certified for the required fire rating and is compatible with the cable sheath material.

Regularly inspect fire seals and barriers, as they are often damaged or improperly restored during subsequent cable additions or maintenance activities.

Pay close attention to segregating power cables from control/instrumentation cables to prevent both fire propagation and electromagnetic interference.