Bosch FAS-420-TM Operation Manual page 15

FAS-420-TM Aspirating Smoke Detector
Figure 2.8 Phase 4: Identification of fire source by reversing the fan's direction of flow
Once the fire source has been identified, it is displayed via a corresponding display on the
FAS-420-TM-R/-RVB and on the operating and display unit of the fire panel.
Detection
Depending on the response sensitivity set on the detector module (0.5%/m to 2%/m light
obscuration), the FAS-420-TM-R/-RVB triggers the main alarm when the appropriate light
obscuration is reached. The sensitivities can also be set at intervals of 0.1%/m using the
FAS-ASD-DIAG Diagnostic Software. The alarm is displayed via the alarm display on the unit
and forwarded to the fire panel connected. The alarm thresholds and the display and
transmission of malfunctions can be allocated different delay times. The intelligent
LOGIC·SENS signal processing hides misleading values that are similar to those shown in the
event of a fire, and ensures a high level of security against false alarms.
Alternative sensitivity
The LSN improved fire panel allows the sensitivity set on the detector module to be changed if
necessary. Changes to the sensitivity of the detector module can be made in the following
intervals: 2.0 / 1.0 or 0.5%/m light obscuration.
Changing the detector module's sensitivity setting allows you to adjust smoke detection to
process-specific disturbance values, such as those caused by
–
–
etc.).
Monitoring unit
The detector module is monitored for contamination and for signal malfunction. A malfunction
is displayed on the unit and forwarded to the fire panel. Malfunctions caused by brief
environmental fluctuations can be eliminated with a time-delayed setting.
Airflow Monitoring
An airflow sensor checks the connected pipe system for breakage and obstruction.
The airflow sensor can – depending on the configuration of the pipe system (see
Section 3.2 Principles of Pipe Planning, page 34) and the setting of the airflow sensors - detect
Bosch Sicherheitssysteme GmbH
E
D
C
B
A
E 10
9
8
D
7
6
C
5
4
B
3
2
A 1
FAS-420-TM series
an increase in the aerosol or contamination levels in the monitoring range due to the time
of day (day/night mode)
an increase in the aerosol or contamination levels in the monitoring range due to the
operation currently in progress (e.g. installation work, welding or increased generation of
water vapor, exhaust fumes and dust
Operation Guide
10
9
8
7
6
5
4
3
2
1
Technical Specifications | en
F.01U.088.878 | 4.1 | 2010.11
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