Bosch FAS-420-TM Operation Manual page 16

16 en | Technical Specifications
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 Section 3.3 Airflow Monitoring, page 36).
The principal signal curve of the airflow sensor is indicated in Figure 2.9.
Figure 2.9 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 detector 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 8 aspiration points. A maximum of 5
aspiration points can be connected with ROOM·IDENT.
F.01U.088.878 | 4.1 | 2010.11
S
1
2
7
8
3
Operation Guide
FAS-420-TM Aspirating Smoke Detector
S Airflow sensor signal
t Time
4
1 Normal airflow
2 Airflow too weak
6
3 Airflow too strong
4 Breakage
5
5 Obstruction
6 Monitoring window
t
7 Delay
8 Malfunction message
Bosch Sicherheitssysteme GmbH