System Sensor INNOVAIR DH100ACDCP - Manual (Page 3)

Figure 3. Installation of foam gaskets over sampling
tube bushings:
A78-2045-00
[5.4] Sampling Tube Installation for Ducts Greater
Than 1
1 ⁄
2
Feet Wide
The sampling tube is identified by a series of air inlet holes
on the tube. A plastic tube is included for ducts up to 18″
in width. All other lengths must be purchased separately.
Order the correct length, as specified in Table 1, for width
of the duct where it will be installed. The exhaust tube is
molded onto the base of the duct housing, and the A2440-00
Exhaust Tube Extension is available as an accessory in
those cases where the molded exhaust port does not extend
at least 2 inches into the duct.
The inlet tube is always installed with the air inlet holes
facing into the air flow. To assist proper installation, the
tube’s mounting flange is marked with arrows. Make sure
the inlet tube is mounted so that the arrows point into the
air flow (see Figure 4). Figure 5 shows the various combi-
nations of tube mounting configurations with respect to air
flow. Mounting the detector housing in a vertical orienta-
tion is acceptable, provided that the air flows directly into
the sampling tube holes as indicated in Figure 4.
Table 1. Inlet tubes required for different duct
widths:
Outside Duct Width Inlet Tube Required
1 to 2 ft. ST-1.5
2 to 4 ft. ST-3
4 to 8 ft. ST-5
8 to 12 ft. ST-10
[5.4.1] Installation For Ducts Greater Than 1 1 ⁄
2
Feet
But Less Than 8 Feet Wide
1. If the tube is longer than the width of the air duct, drill a
3 ⁄
4
″ hole in the duct opposite the hole already cut for the
inlet 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 plug into
the inlet tube as shown in Figure 4. Sampling tubes over
3 ft. long must be supported at the end opposite the duct
smoke detector.
2. Slide the tube into the housing bushing that meets the
air flow first. Position the tube so that the arrows point
into the air flow.
3. Secure the tube flange to the housing bushing with two
#6 self-tapping screws.
4. For 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 out-
side the duct. Plug this end with the end plug and tape
closed any holes in the protruding section of the tube.
Be sure to seal the duct where the tube protrudes.
Figure 4. Air duct detector inlet sampling tube:
A78-2047-00
Figure 5. Tube mounting configurations with varying
air flow direction:
AIR FLOW
DIRECTION
DETECTOR
HOUSING
DOTS INDICATE POSITION OF
SAMPLING TUBE HOLES
AIR FLOW
DIRECTION
DETECTOR
HOUSING
INLET
TUBE
EXHAUST
TUBE
AIR FLOW
DIRECTION
EXHAUST
TUBE
INLET
TUBE
INLET
TUBE
EXHAUST
TUBE
DETECTOR
HOUSING
AIR FLOW
DIRECTION
EXHAUST
TUBE
INLET
TUBE
DETECTOR
HOUSING
A. B.
C. D.
HORIZONTAL MOUNTING OF HOUSING
VERTICAL MOUNTING OF HOUSING
WARNING
In no case should more than 2 air inlet holes be cut off the
tube. There must be a minimum of 10 holes in the tube
exposed to the air stream.
[5.4.2] Installation For Ducts More Than 8 Feet Wide
NOTE: To install inlet 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 accom-
plished by using the ST-10 inlet sampling tube. If
the tube is shorter than the width of the air duct,
install the end plug into the inlet tube as shown
in Figure 4 and support the end opposite the duct
smoke detector.
D100-68-00 3 I56-1147-12R
SCREW HOLES FOR
ATTACHING HOUSING
TO DUCT WORK.
INLET
TUBE
END
PLUG
AIR HOLES
ARROWS
MUST FACE
INTO AIR FLOW
AIR FLOW DIRECTION
FLANGE
NOTE: Only metal sampling tubes may be used on ori-
entations C and D.