Bosch FAS-420-TT Series - Page 50

50 en | Planning Aspiration smoke detector LSN improved
2020.04 | 6.1 | F.01U.029.275 Operation guide Bosch Sicherheitssysteme GmbH
U-pipe system activation thresholds per pipe system
Activation
thresholds
Number of openings 2 4 6 8 10 12 14
1 obstructed opening III II I — — — —
2 obstructed openings 0 III II I — — —
3 obstructed openings 0 0 III II I — —
4 obstructed openings 0 0 0 III II I —
5 obstructed openings 0 0 0 0 III II I
6 obstructed openings 0 0 0 0 0 III II
… will be recognized by the setting level x
— not possible, 0 not practical
Example
If 3 of a total of 10air sampling openings are found to be obstructed, the switch for setting
the airflow monitoring should be set to level I.
Notice!
When planning in accordance with EN 54‑20 or ISO 7240-20, level I or II must always be set
for airflow monitoring.
M-pipe system - single-hole monitoring
1 pipe system
FAS-420-TP1
FAS-420-TT1
2 pipe systems
FAS-420-TP2
FAS-420-TT2
d
d
A
B C D
A
B C D
FAS / FCS
FAS / FCS
M-pipe system for space protection
Limiting values Min. distance FAS-420 – last T-fitting 4m