Digital Linear Heat Detection Cable
Digital LHDC operates at fixed temperatures and is non-resettable. The Digital LHDC comprises of a twisted pair, two core cable. Each core is a tinned copper coated spring steel conductor and has special heat reactive polymer insulation. The cable has a protective chemical and UV resistant outer jacket / sheath. Additional mechanical protection is provided with optional Stainless Steel outer armour.
The Digital LHDC operates by reacting to heat (fire). The insulators between the two conductors plasticizes at the design temperature creating a switch circuit at the point of operation. The LHDC cable is employed in conjunction with an end of line terminating device for continuity monitoring and a zone monitoring controller to provide outputs for Fire and Fault. An LHDC controller with Distance Location (up to 2000m) to the point of operation is also available.
As the Digital LHDC provides a simple switched output on operation, the LHDC can be monitored by a conventional or Analogue Addressable zone monitor.
LHDC in Hazardous Areas
LHDC is suitable for use in hazardous areas by means of intrinsically safe (IS) zener barriers and the controllers located in the safe area. Similarly when the protected area is remote from the monitoring equipment, interposing cables may be employed between the monitoring equipment and the LHDC.
|LHDC in Hazardous Areas by means of Intrinsically Safe Barriers|