User Manual

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54
Fire & Security Products
Siemens Building Technologies Group
06.2002
The required number of detectors (M = A/A
M
) are distributed on the joists so that s or ½s is
not exceeded.
Example: A
M
100m
2
35m
2.9m
31.9m
Fig. 65 Example of detector arrangement on a ceiling with joists (A
U
>0.9A
M
)
Frequently the number of joists prevents symmetrical distribution.
Example: A
M
100m
2
35m
2.9m
26.1m
Fig. 66 Example of an unsymmetrical detector arrangement on a ceiling with joists
(A
U
>0.9A
M
)