A fixed automatic fire detection system (Fire alarm) has the function of detecting, through appropriate detectors, a fire principle and signaling it as soon as possible. The fire alarm system can and must in some cases be integrated with components for the manual insertion of equipment by man. In both cases the fire alarm signal will be transferred to the control / management center and transmitted by it to the various signaling components (optical / acoustic panels, sirens, voice evacuation systems, etc.).
An Evacuation Siren Systems essentially has the purpose of favoring a timely exodus of the premises by people and / or animals as well as the clearing of assets, giving at the same time a way to activate the intervention plans provided for the personnel in charge.
Components
The components of the fixed automatic fire detection systems (Fire alarm) as specified in the UNI EN 54-12 standards, must in any case include automatic fire detectors, manual reporting points, central control and signaling and fire alarm devices.
Fire detectors or Evacuation Siren Systems must comply with the UNI EN 54 series. The following elements must be taken into consideration when selecting the detectors:
The environmental conditions (air movements, humidity, temperature, vibrations, presence of corrosive substances, presence of flammable substances that can cause explosion risks, etc.) and the nature of the fire in its initial phase, relating them to the operating characteristics of the detectors, declared by the manufacturer and attested by the tests;
the geometric configuration of the environment in which the detectors operate.
The particular functions required by the system (for example: activation of a fire extinguishing installation, exodus of persons, etc.). The detectors must be installed so that they can detect any type of foreseeable fire in the monitored area, from its initial stage and in order to avoid false alarms. The number of detectors required and their position must be determined on the basis of various factors.
The operating temperature of the static element of point-type heat detectors must be greater than the highest ambient temperature that can be reached in their vicinity. The position of the detectors must be chosen so that the temperature in their immediate vicinity cannot reach, under normal conditions, values such as to give rise to false alarms.
Aerosols possibly produced in the normal processing cycle can cause false alarms. It is therefore necessary to avoid installing detectors near the areas where these aerosols are emitted in sufficient concentration to operate the detection system. Some criteria for the installation of point smoke detectors. In rooms equipped with air conditioning and / or forced ventilation systems, precautions must be taken to prevent an air speed greater than 1 m/s from being detected near the detector.
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