Fire Alarms Flashcards
4 most common types of ignition
Chemical
Electrical
Mechanical
Thermal
How dose conventional fire alarm panel operate
A monitoring current flows through the system when smoke is detected at a smoke head current drops activates alarm
Two types of fire alarm systems
Addressable
Conventional EOL
Advantages of addressable fire alarms
Simple wiring
Suitable for large buildings
3 types of design categories in fire alarm systems
P
L
M
What dose L1 represent
Provides automatic detection to every space
What dose L2 represent
Automatic detection at escape routes and adjoining rooms and special rooms
What dose L3 represent
Automatic detection for escape routes and adjoining rooms
What dose L4 represent
Automatic detection of escape routes only
What dose L5 represent
Installed for specific risk only
What a are the categories of life protection
L1-L5
Category’s of p property’s protection
P1 protects agents whole building
P2 is installed in defined parts only
Provide earliest warning of a fire
Guidelines for zoning
Guidelines of zoning in fire zones
If the total floor area of each floor of a building is less then 300m2 then the building only needs one zone
The total floor area should not exceed 2000m2
Stair wells should be on there own system
What’s the benefit of a short circuit ioslator in fire alarm system
To isolate the area where the fault is so that the whole zone dosnt have to be turned off
Name the 6 defector types
Ionizition smoke
optical smoke
Rate of rise heat detector
Fixed temperature heat
Carbon monoxide alarm CO2
Optical beam detector detects smoke
What is the minimum alarm sounder dB
65dB or 5dB higher then any back ground noise
What is the benefit of a diode in a conventional fire alarm system
Reverse biased diode prevents the flow of the monitoring current through the sounder. When a detector activates the polarity changes at the control panel forward baising the diode sounding the alarm
What power supply does a fire alarm need and how long should it remain on battery’s
Two power supply’s mains 230v or batteries 12 or 24v
The battery’s should last for 30 mins on full load and 24 hours on stand by
What are the routine tests on a fire alarm system
Daily visual
Weekly sounder test
Quarterly 25% of fire equipment to be tested
annualy 4 quarters test whole system tested
List 4 locations where manual call points should be located
final exit
Landings of stair wells
Defined escape routes
Resection areas
Control room
What is the max search distance in relation to call points
30m
What is the most sensitive fire alarm system
Air sampling system
Describe where Category M of a fire alarm can be used and what it is
manual system that does not use automatic detectors
Name 3 types of smoke detectors
Optical smoke
Photo electric
Combine technologies
3 considerations which influence the the choice of fire alarm detectors
Cost of the detector
Speed of response required
Suitable for the application
