All fire alarm systems are "Detect Fire and Warn People" systems. Usually, because they detect fires, they take action on their own to "Protect People and Property from Fires".
The basic fire alarm system is, if a smoke detector goes into alarm, if a pull station is activated, if a waterflow switch is activated, the horns and strobes warn people to "take action".
Sometimes, other automatic measures are taken:
- Close the fire doors to slow down the spread of fire and smoke
- Shut down the ventilation to slow down the spread of fire and smoke
- Activate fire suppression systems to protect people and help slow down the spread of fire
- Turn off the gas and electricity to protect people and to help slow down the spread of fire
Fire alarm systems, because they are there to always protect people and property, have internal supervision of the detect and warn systems. The power sources, and a lot of the circuits are redundant, and are often designed to survive longer in case of fire.
There are many ways a fire alarm system can work, depending on the features. There can be more detectors or less detectors, more pull stations or less pull stations, more circuits or less circuits, more horns and strobes or less horns and strobes. One fire alarm system might only sound off the horns and strobes while another fire alarm system in another building also shuts the fire doors, closes air dampers, and shuts down the air handlers.
The bottom line, though, for a fire alarm system is that it "Detects", "Warns", and often "Protects People and Property". Whether there're three detectors and horns, or three-thousand detectors and horns, each detector or horn by itself is a detector or horn; whether there're two circuits or two-hundred circuits, each circuit by itself is a circuit; whether there's one panel or ten panels, each panel by itself is a panel.
One of the best ways to learn about fire alarm systems is to inspect systems that are working. See how other people have installed fire alarm systems. Work with others to get an idea of how the fire alarm systems are installed.
Yes, you can learn some things about fire alarm system through information on the web, and even a little bit over email. A far greater teacher, though, is experience.