Kidde Fire Systems DS Series, Application Manual

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K-76-1000 -16- July 2016
If the beams project:
•
Less than or equal to 4 in. (100 mm) below the ceiling, mount the detector on the ceiling with normal
ceiling spacing. See Figure 9, item 1.
• More than 4 in. (100 mm) below the ceiling, mount the detector on the ceiling. Do not exceed 66% of
the listed spacing at right angles to the beam direction. Treat the spacing in the direction parallel to
the beams separately. See Figure 9, item 2.
• Less than 12 in. (300 mm) in depth and are spaced less than 96 in. (2.44 m) on center, mount the
detectors on the bottom of the beams. See Figure 9, item 3.
• Greater than 18 in. (460 mm) below the ceiling and are more than 96 in. (2.44m) on center, treat each
bay created by the beams as a separate area. See Figure 9, item 4.
• For additional details, see NFPA 72.
Figure 9. Heat Detector Spacing for Beam Construction
D = Depth of beam
W = Beam spacing
1. D =
≤ 4 in. (100 mm)
2. D = > 4 in. (100 mm)
3. D = > 12 in (300 mm,
W = < 96 in. (2.4 m)
4. D = > 18 in. (460 mm),
W = > 96 in. (2.4 m)
5. Ceiling Section
6. Heat detector
7. Solid beam
8. Side view
W
W
W
D
D
D
D
5
5
5
5
1
6
6
6
6
6
2
3
4
7
7
7
7
8
8
8
8
> 4 in.
(100 mm)
> 12 in.
(300 mm)
> 18 in.
(460 mm)
4 in.
(100 mm)
≤
< 96 in. (2.44 m)
> 96 in. (2.44 m)