Incite Fire ASD 532, Operating Manual

Page: 48 / 121

Planning
48 / 121
4.5.5 Sampling fixtures and sampling holes in equipment monitoring
The size and number of sampling holes in a sampling fixture are based on the size of the object’s ventilation slot. The following
approximate values apply:
Size of the ventilation slot
(length x width in cm)
Shape of the
sampling fixture
Number of
sampling holes
Hole diameter
(mm)
< 20 x < 15 I-shaped 2 4.5
or according to
“ ASD PipeFlow ”
calculation
< 30 x < 15 I-shaped 3 4
< 40 x < 15 I- or T-shaped 4 3.5
< 80 x < 20 T-shaped 4 3.5
< 40 x < 40 U-shaped 4 3.5
> 40 x > 40 H-shaped 4 3.5
Notice
•
The sampling fixtures and their sampling holes must be placed directly in front of the object’s airflow.
•
The sampling holes must be facing the outflowing air.
•
On objects with a high air-flow rate (strong ventilation), the sampling holes should be fitted with SF ABS sam-
pling funnels for optimal smoke detection.
•
Symmetry is not required for the sampling fixture.
Below are the system limits for a direct pipe conveyed via electrical or server cabinets as shown in Fig. 11. Except for the fol-
lowing specified hole diameters in the upper part of the table (e.g. for system modernisations), the hole diameter and alarm
threshold are to be specified by an “
ASD PipeFlow ” calculation:
Electrical cabinet
monitoring
(as in Fig. 11)
Shape of the
sampling pipe
Number
of sampling
holes
Number of
cabinets
Hole diameter
(mm)
With internal partitions I-shaped 12 6
4 x 3.5
4 x 4.0
4 x 4.5
(only class B and C
possible)
or according to
“ ASD PipeFlow ”
calculation
acc. to EN 54-20, class A „I”/„U”/„T”/„H” shaped 8 4
Calculation with “ ASD PipeFlow ”
acc. to EN 54-20, class B „I”/„U”/„T”/„H” shaped 12 6
acc. to EN 54-20, class C „I”/„U”/„T”/„H” shaped 16 8
4.6 Air recirculation
In applications where the sampling holes and the detector housing are in different climate zones, the sampled air has to be re-
circulated back to the climate zone of the sampling holes. It is imperative that the “ASD PipeFlow” calculation software is used
to calculate the sampling pipe. The maximum length of the pipe for the air recirculation must not exceed 20 m from the detec-
tor housing.
Fig. 12 Air recirculation for differing climate zones
ASD 532
Climate zone A Climate zone B
Air recirculation
Sampling holes End cap
Pipe network
Open pipe end
max. 20 m
ASD532 Operating Manual