11
Installation
Description, Specifications, Installation, Operation, and Service Manual
Federal Signal
www.fedsig.com
FEMA studies indicate typical ambient sound levels vary by location as follows:
• Industrial Areas: 70+ dBC
• Urban Areas: 60 dBC
• Rural Areas: 50 dBC
Assuming a typical 10 dB loss per distance doubled and a 70 dB minimum sound level
required to warn a typical industrial area, the effective range for a Model 2 Siren is
approximately 910 feet (278 meters).
Optimum warning is obtained when the warning signal is at least 10 dB above ambient.
Do not expose personnel to sound levels above 123 dBC.
Wind speed and direction often affects the propagation of sound from the siren.
Consequently, the direction of the prevailing wind may be a significant factor to consider
when selecting the installation site(s) of a small, one or two site siren system. For
example, if the prevailing wind is from the west, it may be desirable to install the siren
toward the western edge of the area to be covered.
Other factors to consider when selecting the installation site(s) include the availability
of suitable electrical power, the access to and ease of installation and maintenance, the
height of surrounding obstructions, and security against vandalism.
Installing the Siren
Moving parts could cause severe cuts or amputation. DO NOT reach into the
siren openings.
Most siren installations are one of two types: Pole Mount or Flat Surface Mount. These
two configurations make it possible to install a siren in almost any situation. If the
installations in this manual are not suitable, modification of one of the configurations may
be practical.
A siren is typically installed 35 to 40 feet above the ground. If the installation is less
than 35 feet above the ground, the sound intensity at close range may increase, but the
effective range of the siren may be reduced. Conversely, if the siren is located more than
40 feet above the ground, the effective range of the siren may increase, but the sound
may skip over areas closer to the siren. These variables may make it desirable to test the
sound coverage of the siren at various heights and locations whenever possible. ALWAYS
ensure that the air intakes are clear when the siren is being tested and when it is installed
at its final location.
