Fire Alarm
fire alarm system has a number of devices working together to detect and warn
people through visual and audio appliances when smoke, fire, carbon monoxide or other emergencies are present.
These alarms may be activated automatically from smoke detectors, and heat detectors or
may also be activated via manual fire alarm activation devices such as manual call points
or pull stations.
Alarms can be either motorized bells or wall mountable sounders or horns.
They can also be speaker strobes which sound an alarm, followed by a voice evacuation message which warns people inside the building not to use the elevators.
Fire alarm sounders can be set to certain frequencies and different
tones including low, medium and high, depending on the country and manufacturer of the device.
Most fire alarm systems in Europe sound like a siren with alternating frequencies.
Fire alarm electronic devices are known as horns in the United States
and Canada, and can be either continuous or set to different codes. Fire alarm
warning devices can also be set to different volume levels.
Design
After the fire protection are established – usually by referencing the minimum
levels of protection mandated by the appropriate model building code, insurance
agencies, and other authorities – the fire alarm designer undertakes to detail specific
components, arrangements, and interfaces necessary to accomplish these goals.
Equipment specifically manufactured for these purposes is selected and standardized installation methods are anticipated during the design.
Parts
Fire Alarm Speaker and switch
Fire alarm control panel (FACP) AKA fire alarm control unit (FACU);
This component, the hub of the system, monitors inputs and system
integrity, controls outputs and relays information.
Primary power supply: Commonly the non-switched 120 or 240-volt alternating
current source supplied from a commercial power utility. In non-residential
applications, a branch circuit is dedicated to the fire alarm system and its constituents.
“Dedicated branch circuits” should not be confused with “Individual branch circuits” which supply energy to a single appliance.
English 
Arabic