System Sensor DH100ACDCLP Installation And Maintenance Instructions Manual page 3

Table 1. Sampling tubes recommended for different
duct widths:
Outside Duct Width
1 to 2 ft.
2 to 4 ft.
4 to 8 ft.
8 to 12 ft.
*Must extend a minimum of /
2
[5.4.1] Installation For Ducts Greater Than 11⁄2 Feet
But Less Than 8 Feet Wide
1. I f the tube is longer than the width of the air duct, drill a
hole in the duct opposite the hole already cut for the sam-
pling tube. Make sure the hole is 1˝ to 2˝ below the inlet hole
on the opposite side of the duct to allow moisture drainage
away from the detector. If the tube is shorter than the width
of the air duct, install the end cap into the sampling tube as
shown in Figure 4. Sampling tubes over 3 ft. long must be
supported at the end opposite the duct smoke detector.
2. S lide the tube into the housing bushing that meets the air flow
first. Position the tube so that the arrow points into the air flow.
3. S ecure the tube flange to the housing bushing with two #6
self-tapping screws.
4. F or tubes longer than the width of the air duct, the tube should
extend out of the opposite side of the duct. If there are more
than 2 holes in the section of the tube extending out of the
duct, select a different length using Table 1. Otherwise, trim
the end of the tube protruding through the duct so that 1" to
2" of the tube extend outside the duct. Plug this end with the
end cap and tape closed any holes in the protruding section of
the tube. Be sure to seal the duct where the tube protrudes.
NOTE: The sampling tube end cap is critical to the proper opera-
tion of the duct smoke detector. The end cap is needed to create
the proper air flow to the sensor of the duct smoke detector.
Figure 4. Air duct detector sampling tube:
AIR HOLES
FLANGE
ARROW
MUST FACE
INTO AIR FLOW
D200-14-00
Sampling Tube Recommended*
ST-1.5
ST-3
ST-5
ST-10
the duct width
3
SAMPLING
TUBE
END CAP
AIR FLOW DIRECTION
Figure 5. Tube mounting configurations with varying
air flow direction:
AIR FLOW
DIRECTION
DETECTOR
HOUSING
SAMPLING
TUBE
/ ˝
3
4
AIR FLOW
DIRECTION
DETECTOR
HOUSING
NOTE: Only metal sampling tubes may be used on orientations C and D.
[5.4.2] Installation For Ducts More Than 8 Feet Wide
NOTE: To install sampling tubes in ducts more than 8 feet wide,
work must be performed inside the air duct. Sampling of air in
ducts wider than 8 feet is accomplished by using the ST-10 sam-
pling tube. If the tube is shorter than the width of the air duct,
install the end cap into the sampling tube as shown in Figure 4
and support the end opposite the duct smoke detector.
Install the sampling tube as follows:
1. D rill a / ˝ hole in the duct directly opposite the hole already
3
4
drilled for the sampling tube. Make sure the hole is 1 to 2˝
below the inlet hole on the opposite side of the duct to allow
for moisture drainage.
2. S lide the sampling tube with the flange into the housing bush-
ing that meets the air flow first. Position the tube so that the
arrow points into the air flow. Secure the tube flange to the
housing bushing with two #6 self-tapping screws.
3. F rom inside the duct, couple the other sections of the sam-
pling tube to the section already installed using the
duit fittings supplied. Make sure that the holes on both of the
air inlet tubes are lined up and facing into the air flow.
4. T rim the end of the tube protruding through the duct so that
1 to 2˝ of the tube extend outside the duct. Plug this end
H0108-02
with the end cap and tape closed any holes in the protrud-
ing section of the tube. Be sure to seal the duct when the
tube protrudes.
NOTE: An alternate method to using the ST-10 is to use two ST-5
inlet tubes. Remove the flange from one of the tubes and install as
described above. After the installation, use electrical tape to close
off some of the sampling holes so that there are a total of 10 to 12
holes spaced as evenly as possible across the width of the duct.
NOTE: Air currents inside the duct may cause excessive vibra-
tion, especially when the longer sampling tubes are used. In these
cases a 3˝ floor flange (available at most plumbing supply stores)
may be used to fasten the sampling tube to the other side of the
duct. When using the flange/connector mounting technique, drill
a 1˝ to 1 ⁄ ˝ hole where the flange will be used.
1
4
3
DOTS INDICATE POSITION OF
SAMPLING TUBE HOLES
A.
EXHAUST
EXHAUST
TUBE
TUBE
HORIZONTAL MOUNTING OF HOUSING
EXHAUST
TUBE
SAMPLING
TUBE
C.
VERTICAL MOUNTING OF HOUSING
AIR FLOW
DIRECTION
DETECTOR
HOUSING
B.
SAMPLING
TUBE
DETECTOR
HOUSING
AIR FLOW
DIRECTION
D.
H0109-01
1 / ˝ con-
2
I56-0084-009R