Why Go with an Addressable Fire Alarm System?
By Douglas Krantz - Technician's Corner
When a fire alarm system is addressable, all devices in the building are identified separately so the fire fighters, the building owners, and the service technician can find the distinct device that is active or in trouble.
Well, in most addressable fire alarm systems, this is only partially true. Often devices like horns and strobes are typically clustered together (zoned) by the area of the building, rather than addressed specifically by device.
However, all fire alarm systems are Fire Detection and Alarm Systems (FDAS).
Technically, the basic difference between a conventional FDAS and an addressable FDAS is only in the building circuitry. In other words:
----- The input devices still detect fire the same way
----- The Supervised output devices still sound the alarm the same way
----- The control relays still activate other systems the same way
It's the building's circuits that determine whether the system will be addressable, conventional, or both.
----- Some panels only connect to conventional circuits
----- Some panels are hybrid and connect to both types of circuits
----- A few panels connect to addressable circuits only
Details
The difference between an addressable fire alarm system and a conventional fire alarm system is in the details. To be fully addressable (fully detailed):
----- Each device is its own input zone and the address is for the panel to identify the device
----- Each horn or strobe on the Notification Appliance Circuit (NAC) has its own address
----- Each non-supervised output device is its own address
The limiting factor is the number of input and output zones that are practical. Fire marshals and building owners want to see a little more detail - they want to see exactly where the fire is located.
Often, people servicing the fire alarm system want to have more detail on where trouble is located.
Even on smaller systems, nowadays, there has to be lots of detail on the input and output zones. Elevator capture is an example that requires at least three to four individual (addressed) detectors for the three to four customized (addressed) output relays.
With all the required details, it's much easier to use addressable wiring than conventional wiring.
Also, years after the original installation, changing the system or adding to the system becomes easier when the system was designed as an addressable (detailed) system in the first place.
