Chapter 2: Installation and assembly
18 LaserSense HSSD-2 Aspirating Smoke Detector Installers Handbook
Figure 11: Locating the detector outside the protected area
(1) Sampling pipe
(2) Sampling hole
(3) Detector
(4) Exhaust pipe
(5) False ceiling
Pipework
Sampling pipes should be made from a non-hazardous material and should be
clearly identified. The ideal internal diameter of sampling pipes is 22mm. Other
sizes will often work but will provide different response times.
Ideally, if the total length of sampling pipe is greater than 50 metres, then multiple
pipes should be used. When using multiple sampling pipes, care should be taken
to achieve a reasonable degree of balance (say within 10% of airflow) to ensure
even suction from the pipes.
Maximum recommended total sampling pipe length is 200 metres. This is 4
lengths of 50 metres, or 2 lengths of 100 metres.
In order for the installation to conform to EN 54-20, pipes must conform at least
to EN 61386-1 Class 1131.
To Next Page
Loading...
