Sayyed Fire Integration
Fire detection & alarm

Linear heat detection cable

Detection along cable trays, conveyors, car park decks and tunnels, where the detector is the cable and it sees the fire anywhere along its length.

Installation photo — heat sensor cable clipped along a cable tray
Scope
Survey → commissioning → AMC
Typical use
Cable galleries, conveyors, tunnels
What it is

The detector runs the whole length of the risk

Some risks are long and thin. A cable tray runs a kilometre through a plant; a conveyor runs from a stockpile to a crusher; a car park deck, a cable gallery, a tunnel, a baggage line — none of them is a room that a ceiling detector can watch. Linear heat detection covers them by making the cable itself the sensor, fixed directly to or above the thing being protected.

Two kinds are in common use and they answer different questions. Digital cable is a pair of conductors under a heat-sensitive polymer: at the rated temperature the polymer yields anywhere along the run, the pair shorts and the panel sees an alarm. It is cheap, robust and simple, and it tells you there is a fire on that run. Analogue and fibre-optic sensing goes further and reports the temperature profile along the cable, so the panel can locate the hot spot to within a few metres and alarm on rate of rise as well as absolute temperature.

Choosing between them is a matter of how much the location is worth: on a short tray run, knowing the tray is enough; on a two-kilometre conveyor or a road tunnel, knowing which metre is the whole point. We survey the route, select the type and temperature rating against the ambient the run actually sees, install it with the fixing centres the cable requires, interface it to the fire panel and heat-test it at commissioning.

Equipment

What the installation is built from

The cable, its interface, and the fixings — which matter more than they sound, because a sagging cable does not sense where you think it does.

Digital linear heat detection cableFixed-temperature short-circuit type, in the rating that suits the ambient along the run.
Analogue and fibre-optic sensing cableWhere the temperature profile and the location of the hot spot are needed, not just the alarm.
Zone interface and end-of-line unitBrings the run onto the fire panel as a monitored zone or loop device, with the run supervised for breaks.
Controller for locating systemsFor analogue and fibre systems — resolves the hot spot along the cable and logs the profile.
Fixings, clips and messenger wireAt the centres the cable specifies, so it stays in contact with the risk over its whole length.
Junction and transition boxesWhere the run passes through a wall, changes type or leaves a hazardous area.
Interface to suppression and plantConveyor stop, deluge release or damper closure driven off the detection rather than off a person.
Heat test and commissioning recordTested at the far end of each run, so the length as installed is proved rather than assumed.

Tell us about the project

Send the drawings or the BOQ and we will price it line by line. Most enquiries start with a site visit, because the site decides the system — not the catalogue.