Testing The Airflow - Siemens FDA241 Technical Manual

7.5
Display Designation
a) LED yellow
b) LED green
c) LED yellow
Building Technologies
Fire Safety

Testing the airflow

At the time of commissioning, the airflow through the aspirating smoke detector is
measured and this value is saved (normalization [➙ 90]). During operation, the
aspirating smoke detector measures the current airflow continually. The current
measured value is compared with the saved measured value and any deviations
are indicated on the airflow indicator.
If the current value matches the standard value, the central LED lights up green.
In the event of deviations, the LED moves up (higher airflow) or down (lower
airflow). When the topmost or bottommost LED is reached, it starts to flash once
the alarm delay time has expired.
Function
If a yellow LED lights up, the airflow has increased.
As the deviation increases, the light moves upwards.

If the topmost LED flashes, the airflow has exceeded the upper limit and the alarm delay
time has expired.
One of the green LEDs lights up.
The airflow is normal.
If a yellow LED lights up, the airflow is too low.
As the deviation increases, the indicator moves downwards.

If the bottommost LED flashes, the airflow has fallen below the lower limit and the alarm
delay time has expired.
The 'FXS2051 ASD Configuration Tool' software can be used among other things
to display the current airflow in [l/min]/[cfm]. The values displayed can provide
information about faults. Possible causes of an airflow fault are leaks or blockages
in the pipe system.
Possible types of leak:
Cracks in the pipe

Loose connections

Possible types of blockage:
Particles at the aspirating hole

Deposits in the pipe

Condensation water

Ice

You will find more information in the 'Checking the pipe system [➙ 93]' chapter.
Commissioning
7
Testing the airflow
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2015-09-29