Bosch FAS-420-TM, Operation Manual

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FAS-420-TM Aspirating Smoke Detector Planning | en 35
Bosch Sicherheitssysteme GmbH Operation Guide F.01U.088.878 | 4.1 | 2010.11
– U -pipe: pipe system that branches into two pipe branches.
– M -pipe: pipe system that branches into three pipe branches.
– Double U -pipe: pipe system that branches symmetrically into four pipe branches.
Change of direction
Elbows and bends in the pipe system increase flow resistance. Therefore, they should only be
used where they cannot be avoided for structural engineering reasons.
If elbows or bends are used, the maximum total length of the pipe system is reduced.
Testing
For critical applications, test the secure detection with activation attempts. Check also
whether there is airflow at the individual air sampling openings.
Figure 3.2 Pipe configurations
I I-pipe system
U U-pipe system
M M-pipe system
U/U Double U-pipe system
Corresponds to a straight pipe length of
Pipe elbow 1.5 m
Pipe bend 0.3 m
I
FAS / FCS
FAS / FCS
FAS / FCS
U
U/U
FAS / FCS
M
FAS / FCS
4U
NOTICE!
It is preferable to use pipe bends rather than pipe elbows.
The detection time will be influenced significantly by too high a number of changes of
direction.
NOTICE!
In order to increase transport speed in critical application areas, the fan voltage can be
increased from 6.9 V to 9 V.