Addressable fire alarm systems, designed and installed in Lebanon.
Every detector, call point and sounder carries its own address, so the panel names the device and the room rather than pointing at a floor. Designed to NFPA 72, built from listed components, programmed to a cause-and-effect matrix and handed over commissioned.
What an addressable system is.
An addressable system gives every device on it a unique digital address. Detectors, manual call points, sounder beacons and interface modules all sit on one circuit that leaves the panel, runs the building and comes back into the panel at the other end. That circuit is the signalling line circuit, though nobody on site calls it anything but the loop. When something operates, the panel does not tell you the second floor is in alarm. It tells you which detector, under the text label that was programmed against its address: second floor, east corridor, outside room 214.
The panel polls every address on the loop in turn, continuously. An analogue addressable detector answers with an actual sensor reading rather than a yes-or-no contact, which moves the decision about what counts as a fire from the detector to the panel: it can hold a pre-alarm threshold, compensate for the dust that accumulates in a detector chamber over years, and run different sensitivity by day and by night. Because the loop returns to the panel, a single break still leaves every device reachable from one side or the other, and short-circuit isolators divide the loop into sections so a short takes out a section rather than the whole run.
What a complete addressable system consists of.
Every part below does a job. Leave one out and the system will not behave the way the design says it should.
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Addressable control panel
Polls the loop, holds the cause-and-effect programming, and displays the device in alarm by address and text label.
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Signalling line circuit
The loop itself. Out of the panel, around the building, and back into the panel, so no device sits at a dead end.
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Short-circuit isolators
Divide the loop into sections. A short between two isolators drops that section and leaves the rest of the loop polling.
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Addressable optical detectors
The general-purpose detector. Reports a sensor value the panel reads against its own thresholds, not a contact that has already decided.
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Addressable heat detectors
For kitchens, plant rooms, car parks and anywhere a smoke detector would spend its life in false alarm.
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Multi-criteria detectors
Optical, thermal and CO sensing in one head, weighed together. Fewer false alarms in the places that generate them.
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Addressable manual call points
A person who has seen the fire is still the fastest detector in the building. Each one is addressed like everything else.
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Loop-powered sounder beacons
Sound and light from one device, drawing power from the loop, so the alarm reaches a sleeping occupant and a deaf one.
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Monitor modules
Bring a dry contact onto the loop with its own address: sprinkler flow switches, valve tamper switches, an existing conventional zone.
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Control modules
Take the panel's decision out to plant: door holders, dampers, air handling shutdown, lift homing, gas suppression release.
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Aspirating smoke detection
Draws air out of the protected space continuously through a sampling pipe and reads it in a detector chamber, for rooms that need warning before there is visible smoke. Beam detectors answer the other case a point detector cannot: a space too high to reach.
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Repeat panel
The same display at a second entrance, so the fire service reads the building from wherever they arrive.
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Power supply and standby batteries
Sized by calculation from the actual standby and alarm load, not by whatever fits the cabinet.
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Fire-resistant cabling
Rated to keep the circuit alive while the building is burning, which is the only period the system exists for.
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Cause-and-effect matrix
The document that says what happens when each device operates. It is programmed into the panel and it is what commissioning tests against.
The numbers.
| Standard | NFPA 72, National Fire Alarm and Signaling Code |
|---|---|
| Circuit | Signalling line circuit (SLC), wired out from the panel and back into it |
| Loop capacity | Commonly 99 to 250 addressable points per loop, depending on the panel |
| Panel capacity | One loop upwards; large sites run several panels networked together |
| Pathway class | Class A (out and back, survives a single open) or Class B (radial spur) |
| Fault isolation | Short-circuit isolators on the loop. NFPA 72 requires a single fault not to cost more than 50 addressable devices |
| Resolution | The individual device, by address and programmed text label |
| Detection | Analogue optical, heat, and multi-criteria detectors combining optical, thermal and CO sensing |
| Special areas | Beam detectors for high spaces, aspirating detection for rooms that need the earliest possible warning |
| Interfaces | Monitor modules to bring plant status in, control modules to drive plant out |
| Notification | Loop-powered sounder beacons, or separate notification circuits, or voice evacuation |
| Secondary power | 24 hours in standby followed by 5 minutes in alarm, or 15 minutes where the system carries voice evacuation |
| Approvals | UL-listed or EN 54-certified components |
The buildings this suits.
Residential and mixed-use towers
Many floors, many tenants, and a panel that has to name the flat rather than the storey.
Hospitals and clinics
Phased evacuation, plant interfaces and areas that cannot simply be emptied. Addressable is the only sensible answer.
Hotels
Guest rooms behind closed doors, staff who did not design the building, and a fire service arriving cold.
Schools and universities
Large sites on one system, and enough manual call points that finding the operated one matters.
Offices and commercial buildings
Interfaces to air handling, door holders and lifts, all driven from the same loop.
Warehouses and industrial buildings
High spaces where beam detection covers what a ceiling-mounted point detector never would.
Data centres and technical rooms
Aspirating detection for the earliest warning, and the interface that releases a gas suppression system.
Malls and retail
Large floor plates, staged evacuation, and a fire service that needs the exact unit.
Built to NFPA 72, from listed components.
We design to NFPA 72 and build from components that are UL-listed or certified to EN 54. Detection coverage comes out of the ceiling heights and the compartments rather than out of a device count, standby batteries are sized by calculation from the real standby and alarm load, and the whole system is programmed to a written cause-and-effect matrix before anyone tests anything.
Commissioning proves it: every device operated, every zone or address confirmed against its label, sounder audibility checked through the building, and each line of the cause-and-effect tested in turn. What is handed over is the as-built drawings, the zone plan or address schedule, the cause-and-effect and the commissioning record, with a log book left at the panel. Those documents are what an insurer, an inspector or the next maintainer will ask for, and a system that cannot produce them cannot be shown to have been designed for the building it is sitting in.
What people ask about addressable systems.
What is the difference between an addressable and a conventional fire alarm system?
What the panel can tell you, and how it is wired. A conventional system tells you which zone is in alarm; an addressable system tells you which device, by its programmed text label. A conventional system runs one radial circuit per zone; an addressable system runs one loop that leaves the panel, passes every device and returns to it. The addressable loop also survives a single cable fault, because every device stays reachable from one end or the other.
What does a complete addressable fire alarm system consist of?
An addressable control panel, the signalling line circuit itself, short-circuit isolators, addressable optical and heat detectors, multi-criteria detectors where false alarms are a problem, addressable manual call points, loop-powered sounder beacons, monitor modules for incoming contacts, control modules for outgoing plant, beam or aspirating detection in the spaces a point detector cannot cover, a repeat panel where the fire service needs a second display, a power supply with standby batteries sized by calculation, fire-resistant cabling, and the cause-and-effect matrix programmed into the panel.
How many devices can one loop take?
It depends on the panel. Common capacities run from 99 to around 250 addressable points on a single loop. In practice the address count is rarely what runs out first. The loop's current budget goes before it, especially once loop-powered sounders are hanging off the same pair, and NFPA 72 does not let a single fault cost more than 50 addressable devices. That rule sets the isolator spacing long before the address limit becomes interesting.
What is a short-circuit isolator and do I actually need them?
It is a device on the loop that detects a short either side of itself and opens, cutting the faulted section out so the rest of the loop keeps working. Without them, one crushed cable takes the whole loop off-line and the building is unprotected until someone finds the crush. They are not optional on any loop we design, and where they go is a design decision, not something to be worked out on site.
Should the loop be wired Class A or Class B?
Class A wires out and back to the panel, so a single open circuit leaves everything reachable from one side or the other. Class B is a spur, and everything past a break is lost. Class A costs more cable and is what we specify by default on anything where the building is occupied at night or evacuation is phased. It is worth asking what a quote assumed, because it moves the price and it is not always stated.
Can an addressable system take over an existing conventional installation?
Partly, and this is the usual way a building is upgraded without stripping it. A monitor module brings an existing conventional zone onto the loop as a single address, so the old wiring keeps working while the new system takes over the panel, the interfaces and the notification. You lose device-level resolution on the old zones, which is the honest trade. Replacing them properly is a phase, not a compromise you have to accept forever.
Can the fire alarm system release the gas suppression system?
Yes, and on most sites it should. A control module on the loop drives the releasing panel, and a monitor module brings the discharge confirmation back, so the fire alarm knows the system fired. The releasing sequence itself stays on its own listed releasing panel with its own cross-zoned detection. Firing an agent into a room is not a job to hand to a general fire alarm panel.
What is a cause-and-effect matrix?
A table of what the system does when each thing happens: which sounders operate, which doors release, which dampers close, which lifts come home, whether the whole building evacuates or one floor does. It is written before the system is programmed, it is what commissioning tests line by line, and it is handed over with the system. If nobody can produce one for a system you already own, nobody currently knows what that system will do.
How much does an addressable fire alarm system cost in Lebanon?
It scales with the number of devices and the number of loops, and both of those come out of the building's area, its compartments and how it is occupied. Nobody can price it honestly off a per-square-metre rate. A single-loop system in a small office block and a networked system across a tower are not in the same bracket. Send us the floor plans and tell us how the building is used, and we will design it properly before we quote it.
How often does it need testing and servicing?
Devices are tested on a rotating schedule so that every one of them is operated over the service cycle, the batteries are load tested, the panel's fault and disablement log is reviewed, and the cause-and-effect is re-proved wherever the building has been altered. Partitions moved and ceilings changed are what quietly invalidate a design, and they are what a service visit is looking for as much as a dirty detector.
Related data sheets.
Send us the floor plans. We will design the system around them.
How many floors, what is on each one, and how the building is used at night. That is enough for us to come out, walk it, and put a real zone plan or device schedule behind the price.