Fire Alarm Flashcards
what are the basic components of a fire alarm system?
- Initiating Device
- Alarm/Signalling device
- Control Panel (Fire Alarm control unit)
List some examples of Initiating devices
- Smoke detectors
- Heat detectors
- Pull stations
- Flame detectors
List some examples of signalling devices.
- Bells
- Horns
- Strobes
What does the FACU contain?
Power supply and circuitry for operating, monitoring and troubleshooting
What is the Annunciator Panel and where is it typically located?
It is a monitoring panel to indicate the location or zone of the fire or trouble. Usually at main entrance and is graphical
List some examples of Ancillary devices.
- Fan shutdowns
- Fan start-ups
- Fire door magnets
- Door lock releases
- Elevator homing
- Plenum dampers
- Fire phones
- City tie module (CTM)
How does simplex communication work?
One way only
How does Half duplex communication work?
Both ways but only one at a time
How does full duplex communication work?
Both ways at the same time
How does a single stage system work?
any initiating device will cause all signalling devices to be activated
Where are single stage system recommended to be used?
- Schools
- Apartments
- Warehouses
- Industrial Plants
How does a two stage system work?
Any initiating device will first activate an alert signal for 2 - 5 - 15 mins and if not responded to then a general alarm will sound
Where are two stage systems used?
- Hospitals
- Rest homes
- Hotels
- Department stores
- AIrports
What is the alert signal for in a two stage system?
It is for designated persons who may activate the general alarm when they deem necessary. allows supervisory staff to investigate and plan for an orderly evacuation.
What is required for a two stage system?
Trained personal 24 hours/day
How long is the first alert signal? How long is the full alarm?
First alert = 20 bell strokes/min
Full alarm = 120 bell strokes/min
Where are usually all two stage and some single stage systems linked to?
the fire department for a faster response
What is a zone in buildings FA system?
- Defined location that is covered by initiating devices on one circuit (non addressable)
- Defined area with assigned initiating devices (addressable)
What typically determines the number of zones?
size of the building
How many zones do hospitals have?
100+
How many zones do nursing homes have?
2 per floor
What is A.H.J. ?
Authority having Jurisdiction
How do Pull stations work?
- Use a normally open single pole switch operated by a pull handle
- Glass or brittle plastic rod is used to indicated which station has been pulled
How do two stage pull stations work?
- Have a key operated switch along with the handle
- Handle initiates the alert
- Key switch initiates the alarm