Bosch FAD‑420‑HS‑EN Manual Del Usuario página 55

Duct Smoke Detector
Sample tubes can be combined for wider ventilation ducts and must be sealed with an end
plug. All sample tubes have a locating pin threaded through and an end plug. When combining
two sample tubes, the end plug of the first sample tube and the locating pin and locating
screw of the second sample tube must be removed.
Limits
Caution!
A sample tube must have at least 12 extraction holes and be at least 30 cm long. The
!
maximum permissible length is 3 m!
Steps for combining two sample tubes:
1.
2.
3.
4.
5.
Example: You require a 2.13 m long sample tube.
Combine a D344-3 (0.91 m) and a D344-5 (1.52 m). Then shorten the D344-5 by 30 cm and
insert the end plug.
Sample tubes that are longer than 90 cm must be supported by the ventilation duct.
The support hole in the ventilation duct should be positioned 2.5 cm–5 cm below the entry
hole to allow any condensate to drain.
Figure 4.2: Supporting the sample tube
Seal the gap between ventilation duct and sample tube.
If the D344-1.5 Sample Tube is installed in ventilation ducts that are 30–45 cm wide, cover
some of the extraction holes.
Figure 4.3: Covering the extraction holes
Bosch Sicherheitssysteme GmbH
Remove the end plug from the first sample tube.
Remove the locating pin and locating screw from the second sample tube.
Connect the two sample tubes.
Align the holes on the sample tubes and screw in the locating screws.
Insert the end plug.
c 2.5 cm–5 cm (1 in.–2 in.)
d Put duct tape over these holes.
Installation Guide
Installation | en 55
2019.02 | 9 | F.01U.033.733