TBD-8100
© 2017
– Telefire Fire & Gas Detectors Ltd
Revision 1.00 November 2017
– Page 3 of 10 –
In order to decrease detection time, a proper positioning of the detector is most
important.
Based on experience, it is well known that smoke rising from a fire does not go straight
upwards, but tends to flow sideways; as a result of air flows and the effect of
temperature gradients among the various air layers, the smoke creates a "mushroom"
shape at a certain elevation.
The time interval between the actual time that the fire started and the time that the
smoke detector alarm sets off depends upon the location and elevation of the beam
detector, the detection zone, the amount of smoke emitted, the ceiling's shape and the
ventilation.
The detection coverage on each side of the beam is 9 meters maximum. Place the
detector up to 9 meters from the wall, or 18 meters from the next, similar, parallel
detector, under a flat ceiling.
i
Note
Install the detector horizontally with the red light down on the right side.
Figure 1 Placing the Detectors
Commonly, rising smoke tends to spread sideways before it reaches the ceiling because
a layer of hot air near the ceiling prevents the smoke’s further rise. Therefore, the
detector should be installed on the building’s wall, at least 50 cm but no more than 1
meter below the ceiling in order to comply with the UL 268 / NFPA 72 and the SI 1220-3
2014 edition.
i
Note
Measure the wiring to ensure there are no shorts before connecting the wiring
to the control panel.
Connecting or adding inputs, outputs, and extinguishing devices shall be
done when all power to the control power is disconnected (AC and batteries
disconnected).
