Linear Heat Detection Cable

Applications

Linear heat detection excels in environments where smoke detectors fail or respond too late — dusty warehouse conveyors, industrial cable trays carrying high-load electrical feeders, car park ceilings with vehicle exhaust, and floating roof tank rim seals in chemical plants.

Gujarat industrial facilities in Gandhidham warehouses, Dahej chemical plants, and food processing conveyors commonly use LHD as primary detection in areas where point detectors would require excessive maintenance due to dust contamination.

• Belt conveyors in warehouses, food processing plants, and manufacturing facilities
• Cable tray and electrical riser protection in industrial buildings and substations
• Car park and tunnel linear detection where vehicle exhaust contaminates smoke detectors
• Floating roof tank rim seal monitoring in chemical and petroleum storage installations
• Industrial process areas with dust, fumes, or high airflow preventing reliable smoke detection

Technical Specifications

LHD cable types include digital (alarm at fixed temperature along entire cable length) and analogue (continuous temperature monitoring with location identification along cable). Analogue types provide earlier warning by detecting rate-of-rise and absolute temperature thresholds.

Common alarm temperatures: 68°C, 78°C, 88°C, and 105°C for general industrial applications; higher ratings for kitchen and high-ambient environments. Cable outer jacket materials include PVC for general areas and fluoropolymer for chemical exposure environments.

Maximum zone length typically 2,000–3,000 metres per controller module depending on manufacturer. Location accuracy for analogue systems: 1–3 metres depending on cable type and controller resolution.

Integration and Selection Guidance

LHD connects to addressable monitor modules or dedicated LHD controllers reporting exact alarm location along the cable length to the fire alarm panel. Cause-and-effect programming triggers appropriate response — conveyor shutdown, deluge pre-action, panel annunciation, or BMS notification.

Select alarm temperature based on maximum normal operating temperature in the protected area plus safety margin. Conveyor bearing failures typically show temperature rise before open flame — analogue LHD with rate-of-rise detection provides earliest warning.

Install LHD cable directly on the surface being protected — conveyor belt underside, cable tray base, tank rim seal — not suspended below on unsupported brackets. Direct contact ensures fastest heat transfer and earliest detection.

Supply and Commissioning

Rachna Fire & Safety supplies LHD cable with compatible controllers and addressable interface modules as part of industrial fire alarm packages. We design cable routing, specify alarm temperatures per hazard analysis, and commission with heat test verification at representative points.

Include LHD in fire alarm design during project planning — retrofit installation on operating conveyors requires production shutdown for cable routing and testing.