Detection In The Bypass - Bosch FAS-420-TT Series Operation Manual

90 en | Installation of the pipe system
Positioning the air sampling opening depending on air
speed
6.4.2

Detection in the Bypass

Notice!
For detection in airflows ≥ 2 m/s, additionally feed the exhaust from the FAS-420 back into
the airflow area. Cut the end of the air-return pipe at an angle of 45°.
Positioning the air-return pipe – example with an air-
conditioning duct (bypass)
For details on connecting the air return, please see Air-return Pipe, page 92 .
For FAS-420 planning in these applications, see Planning for forced airflow, page 67 .
Refer to
–
–
2020.04 | 6.1 | F.01U.029.275
1
2 3
1
3
Air-return Pipe, page 92
Planning for forced airflow, page 67
2
1/2 b
b
4
Operation guide
Aspiration smoke detector LSN improved
1 Aspiration pipe with air
sampling openings
2 Exhaust speed < 0.5 m/s
3 Exhaust speed > 0.5 m/s
1 Air-conditioning duct
2 Duct adapter
3 Aspiration
4 Air-return Pipe
b Width of air-conditioning duct
Bosch Sicherheitssysteme GmbH