Detector Positioning - Menvier Security MAB50R Installation Manuals

Typical Minimum Beam Spacing
Beam Distance
10
20
30
40
50
In all installations the latest national fire standards must be consulted. If there is any doubt on the correct
mounting height, positioning may be determined by smoke tests.
3.1. Detector Positioning In Apex Of Sloping Ceiling.
A ceiling is defined as sloping if the distance from the top of the apex to the intersection of the ceiling and
adjacent wall is greater than 0.6 metres. See Fig. 1.
Slope if Χ ≥ 0.6 Metres
Fig. 1.
When a Detector is positioned in the apex of a ceiling (See Fig. 2), the lateral beam distance covered (Υ) can
be increased in relation to the angle of pitch (Φ), up to a maximum of 25%.
For Example:
If the pitch angle is 20 degrees, the lateral coverage can be increased from 7.5 metres either side of the beam
(Υ) to:
Υ = 7.5 + (7.5 x 20/100) metres
Υ = 9 metres
Therefore, with a roof pitch of 20 degrees the lateral coverage can be increased from 7.5 metres either side of
the beam to 9 metres either side of the beam, but only for the beam positioned in the apex. All other
calculations remain the same.
Angle of
Pitch
in degrees
22318.37.01 15.09.05
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Beam Spacing
0.87m
1.75m
2.62m
3.50m
4.37m
Χ
Limit to when a beam detector must be positioned in
roof apex
35.0
30.0
25.0
Beam detector must be positioned in apex
20.0
15.0
10.0
5.0
Roof can be defined as flat
0.0
0 5 10
Width of Room in metres
3
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Beam Distance Beam Spacing
60
70
80
90
100
Υ
Υ (max) = 7.5 + (7.5 x Φ/100)
Fig. 2.
15 20 25
5.25m
6.12m
7.00m
7.87m
8.75m
Υ
Φ