Linear Heat Detection (LHD) is a line-type form of fixed temperature heat detection used in common commercial and industrial environments. This linear cable can detect a fire anywhere along its entire length and is available in multiple temperatures.
You begin with any new or existing fire alarm control panel which will be used for monitoring the Linear Heat Detection system. If required, the optional distance locating module may be connected directly to the fire alarm panel or addressable module. Leader wires are then connected to the distance locating module and run in conduit to the hazard zone where they are connected to the beginning of the Linear Heat Detection cable run. Linear Heat Detection cable may also be connected directly to the distance locating module without using leader wires.
A Junction Box is used at the beginning of each zone where the leader wires are connected to the Linear Heat Detection cable using a Screw Terminal. The Linear Heat Detection cable exits the J-Box through a moisture proof Strain Relief Connector which seals the enclosure. Immediately after exiting the J-Box, a 6 inch (15cm) loop is made in the cable to allow for expansion and contraction. Mounting hardware which allows the Linear Heat Detection cable to freely expand and contract is placed every 3 – 5 ft. (1 – 1.5 m). Several types of Linear Heat Detection cable mounting hardware are available which are specifically designed for different types of hazards.
Linear Heat Detection cable may be spaced a maximum of 35 feet (10.7 meters) between runs and half the listed spacing from any sidewall. If it is an integral part of a pre-action sprinkler system, it may be strapped to the sprinkler pipe using double loop mounting straps. At the end of each zone, another expansion/contraction loop is made before entering the End of Line Resistor-Box through another Strain Relief Connector. The End of Line Resistor, supplied by your panel manufacturer, is then connected to the Linear Heat Detection cable using another Screw Terminal. It’s that easy.
Linear Heat Detection cable does not require you to purchase any expensive proprietary panels that require additional maintenance and cost. Simply add Linear Heat Detection cable to your existing conventional panel, or add a contact monitor module to your existing addressable system.