System Sensor DH200RPL manual Air duct detector sampling tube, orientations C and D

2.Slide the tube into the housing bushing that meets the air flow first. Position the tube so that the arrow points into the air flow, as shown in Figure 4.

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″ (25 to 50mm) 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 operation of the duct smoke detectors. The end cap is needed to create the proper air flow to the sensor of the duct smoke detector.

Figure 3. Installation of foam gaskets over sampling tube bushings:

SCREW HOLES FOR

ATTACHING HOUSING

TO DUCT WORK.

Table 1. Sampling tubes recommended for different duct widths:

Outside Duct Width	Sampling Tube Recommended*
1 to 2 ft. (0.3 to 0.6 m)	ST-1.5
2 to 4 ft. (0.6 to 1.2 m)	ST-3
4 to 8 ft. (1.2 to 2.4 m)	ST-5
8 to 12 ft. (2.4 to 3.7 m)	ST-10

*Must extend a minimum of 2⁄3 the duct width

Figure 4. Air duct detector sampling tube:

FLANGE	AIR HOLES	SAMPLING
		TUBE
		END CAP
	ARROW	AIR FLOW DIRECTION
MUST FACE

INTO AIR FLOW H0108-02

Figure 5. Tube mounting configurations with varying air flow direction:

	DOTS INDICATE POSITION OF
	SAMPLING TUBE HOLES
AIR FLOW			AIR FLOW
			DIRECTION
DIRECTION
DETECTOR			DETECTOR
HOUSING			HOUSING
	A.		B.
SAMPLING	EXHAUST	EXHAUST	SAMPLING
TUBE	TUBE	TUBE	TUBE
	HORIZONTAL MOUNTING OF HOUSING
			DETECTOR
			HOUSING
		EXHAUST
AIR FLOW		TUBE	AIR FLOW
DIRECTION			DIRECTION
DETECTOR	SAMPLING
	C.	TUBE	D.
HOUSING

VERTICAL MOUNTING OF HOUSING

NOTE: Only metal sampling tubes can be installed in

orientations C and D.

[4.2] Installation For Ducts More Than 8 Feet (2.4m) Wide

NOTE: To install sampling tubes in ducts more than 8 feet (2.4m) wide, work must be performed inside the air duct. Sampling of air in ducts wider than 8 feet (2.4m) is accomplished by using the ST-10 sampling 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 detec- tor.

Install the sampling tube as follows:

1.Drill a 3⁄4-inch (19mm) hole in the duct directly opposite the hole already drilled for the sampling tube. Make sure the hole is 1″ to 2″ (25 to 50mm) below the inlet hole on the opposite side of the duct to allow for moisture drainage.

2.Slide the sampling tube with the flange into the housing bushing 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.From inside the duct, couple the other sections of the sampling tube to the section already installed using the 1⁄2-inch conduit fittings sup- plied. Make sure that the holes on both of the sampling tubes are lined up and facing into the air flow.

4.Trim the end of the tube protruding through the duct so that 1″ to 2″ (25 to 50mm) 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: An alternate method to using the ST-10 is to use two ST-5 sam- pling 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.

D200-39-00 3 I56-1977-004R