Fire hoses run through cable trays

Fire hoses or any water-carrying pipes should not be run through cable trays containing electrical cables.Electrical Code and Safety ConsiderationsAccording to the National Electrical Code (NEC) section 300-8, cable trays are intended solely for electrical conductors, including power, signal, communication, and optical fiber cables. Mechanical piping, water, air, gas, or any non-electrical tubing is explicitly prohibited in cable trays that contain electrical conductors . This restriction exists to prevent electrical hazards, corrosion, and potential short circuits caused by leaks or condensation.Fire Risk and FirestoppingCable trays can act as conduits for fire spread, especially in vertical shafts. Fires in cable trays can propagate quickly due to insulation materials and closely packed cables . Introducing water hoses into the same tray could compromise firestopping measures, create gaps, or interfere with fire-resistant barriers designed to contain flames and smoke . Firestopping materials such as fire-rated boards, mineral wool, or firestop packs are used to seal openings around cable trays to prevent fire spread, and these systems are designed specifically for electrical penetrations .Recommended PracticesSeparate Systems: Fire suppression piping should be routed independently from cable trays, using dedicated supports or conduits.Firestopping Compliance: Ensure all cable tray penetrations through walls or slabs are properly sealed with UL-listed firestop materials to maintain fire ratings .Maintenance and Inspection: Regularly inspect cable trays for dust, debris, or signs of overheating, and maintain clear separation from mechanical systems .ConclusionRunning fire hoses through cable trays is not allowed and poses serious safety risks. Fire suppression systems should be installed separately, and cable trays should remain dedicated to electrical conductors only, following NEC guidelines and firestopping standards to ensure both electrical safety and fire protection .