FyreLine Digital PVC LHD Cable


Key Features

  • UL 521 approved
  • Cable based sensing allows detection at the point of risk
  • Low installation, maintenance and repair costs
  • Reliable solution for hazardous areas
  • Low material cost


The standard coating used on Digital cables is made from PVC and is suitable for most environments. However, PVC should not be used when the cables are directly exposed to UV (sunlight) or hazardous chemicals (eg. hydrocarbons) for long periods, or for applications where they may be exposed to regular mechanical abrasion.

Where the standard PVC is not recommended other materials/sheaths are available to provide a suitable solution.

Sensing Cable Construction

FyreLine linear fixed heat sensing cable is constructed using two twisted and tensioned, tri-metallic conductors. Each of the conductive cables are coated in a heat sensitive polymer which, when heated to its rated temperature, melts, causing the two cables to touch. The resulting short sends a signal to the fire alarm control panel, indicating that a fire (or excessive heat) has been detected. Once a fire has been detected the damaged length of cable is easily replaceable.


The FyreLine digital linear heat detection cables are fully approved by the Underwriters Laboratories (UL) and bears the CE mark to show that they comply with all the applicable Directives including the CPR, EMC and the Low Voltage Directive (LVD).

  • UL 521
    Heat detectors for fire protective signaling systems.

Tech Specs

ConstructionOverall insulated, twisted pair of tri-metallic cores
Insulation1kV tested protective outer coat
ApprovalsCE Marked, UL Listed
Maximum Zone Length 3,000m (10,000ft)
Overall Diameter3.60mm ± 0.12mm (0.142” ± 0.005”)
Minimum bend radius50mm (2”)
Max Voltage Rating30Vac, 42Vdc
Resistance~100Ω/km (29Ω/kft) per leg
Velocity of Propagation~55%
Capacitance88 – 150 pF/m (26 – 45 pF/ft)
Inductance540 – 1050 nH/m (165 – 320 nH/ft)