16
D200-41-00
Pittway Tecnologica S.r.l, Via Caboto 19/3, 34147 Trieste, Italy
3. Using Other Sensors with the A300
If the A300 units are to be used with sensors other than the
recommended 7251, please observe the following information:
3.1 Sensors Certified for use with the A300
The following sensors have been independently tested and certified to
CEA 4022 for use in the A300 unit. The table shows the limits which
should not be exceeded if the installation is to conform to this
requirement.
No.
1
2
3
4
5
6
7
8
9
10
Dist(m)
99.5
95
90
85
80
75
70
65
60
55
Size(mm)
3.4
3.4
3.4
3.4
3.4
3
3
3
3
3
No.
11
12
13
14
15
16
17
18
19
20
Dist(m)
50
45
40
35
30
25
20
15
10
5
Size(mm)
2.5
2.5
2.5
2.5
2.5
2
2
2
2
2
SINGLE PIPE VARIABLE HOLE CONFIGURATION
Sensor Model
Sensitivity Level
Sampling Hole Limits
Max Pipe Length (m)
2251EM
Standard (2200)
1 x 8mm End
50
2251EM
High (1800)
2 x 5mm
50
ECO1003
N/A
2 x 5mm
50
7251
Alarm Level 3
13 x 3mm, 6mm End
100
7251
Alarm Level 1
18 x 3mm, 6mm End
100
7251
Alarm Level 1
20 x Variable Size
100
FSL-751E/
LZR-1M
Alarm Level 1
18 x 3mm, 6mm End
100
FSL-751E/
LZR-1M
Alarm Level 1
20 x Variable Size
100
4.
UNUSUAL APPLICATIONS
In these different and variable situations, it is vital to perform smoke
tests to establish the air movements.
4.1 Freezer rooms
Freezer rooms often introduce extra difficulties into the design of a
system. The air temperatures at which the room operates must be
taken into account.
If the aspirating pipe network is inside the cold room the following points
should be noted:
1) The pipes should be suspended (or attached) further away than
usual from the ceiling or wall as these may contract and expand
with large changes in air temperature.
2) Sampling holes should be drilled on the
side of the pipes to
minimise the risk of blockage owing to ice formation.
3) Vertical pipes running into the room from outside, and areas where
condensation could collect, must be avoided.
Figure 4.1: Typical Freezer Room Example
Heater
Element
Pipe Falls Towards
Heater
Seal
Stand-Off
300mm Minimum
Holes Drilled in Side of Pipe
Aspirating
Detector
Insulate From Wall
Air Return
Freezer Room
Water
Trap
Aspirating Detector and Associated Equipment
Located Outside Freezer Room
Seal
Temperature changes may cause expansion or contraction in the
aspirating pipe. ABS pipe has a linear coefficient of expansion of
around 10
-4
/°C and large temperature changes can have a significant
effect. These changes typically occur as the system is run to
operational temperature. So the air can easily vary from +18°C at
installation to -35°C in operation, representing a 53°C differential. This
drop applied to a 50m pipe run gives an expected end to end pipe
movement of 265mm. If the design of the system gives no allowance
for such variation in the pipe length, it is advisable to incorporate one or
more simple ‘U’ bends to act as an expansion/contraction point as
shown:
