Bosch FAS-420-TM-R Operation Manual page 15

Aspiration smoke detector LSN improved
The airflow sensor can – depending on the configuration of the pipe system (see Principles of
pipe planning, page 31 ) and the setting of the airflow sensors - detect an obstruction of a
single air sampling opening. Airflow monitoring is temperature-compensated and can be set
depending on the air pressure.
On expiry of a defined delay, the malfunction is displayed on the aspirating smoke detector
and the message is transmitted to the fire panel. The monitoring window thresholds can be
modified to suit the environmental conditions (see Airflow Monitoring, page 33 ).
The principal signal curve of the airflow sensor is indicated in Airflow Monitoring.
S
Example of the signal process of the Airflow sensor in case of
malfunctions
Resetting via fire panel
A malfunction message is reset via the connected fire panel. Alarm and malfunction messages
are displayed simultaneously on the unit via the Local SecurityNetwork LSN using the reset
function on the detector line.
Calibrating the airflow sensor
The airflow sensor calibration of the FAS-420-TM Aspirating Smoke Detector is performed
automatically when the detection module is inserted into the housing base, provided that the
X4 jumper has been plugged into another socket first. This plug-and-play feature makes the
FAS-420-TM considerably easier to commission. In addition, the calibration can also be
performed using the FAS‑ASD‑DIAG Diagnostic Software. The initialization phase is therefore
carried out according to or independently of the air pressure as desired.
Pipe system
A pipe system with an overall length of up to 50 m can be connected to FAS-420-TM series
Aspirating Smoke Detectors over a maximum of 12 aspiration points. A maximum of 5
aspiration points can be connected with ROOM·IDENT.
Bosch Sicherheitssysteme GmbH
1
2
7
8
3
Operation guide
Technical specifications | en
S Airflow sensor signal
4
t Time
1 Normal airflow
6
2 Airflow too weak
3 Airflow too strong
5
4 Breakage
t
5 Obstruction
6 Monitoring window
7 Delay
8 Malfunction message
2020.04 | 5.1 | F.01U.088.878
15