System Sensor DH100LP Secure The Detector Housing To The Duct, duct widths, Outside Duct Width

[5.3] Secure The Detector Housing To The Duct

Slide the foam gaskets over the tube bushings as shown in Figure 3. Use the two 11⁄4″ long sheet metal screws to screw the detector housing to the duct.

CAUTION: Do not overtighten the screws.

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

SCREW HOLES FOR

ATTACHING HOUSING

TO DUCT WORK.

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[5.4] Sampling Tube Installation of Ducts Greater Than 11⁄2 Feet Wide

The sampling tube is identified by a series of air inlet holes on the tube. One 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. It is recommended that the sampling tube length extend at least 2⁄3″ across the duct width for optimal performance. 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 sampling 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 an arrow. Make sure the sampling tube is mounted so that the arrow points into the air flow (see Figure 4). Figure 5 shows the various combinations of tube mounting configurations with respect to air flow. Mounting the detector housing in a vertical ori- entation is acceptable, provided that the air flows directly into the sampling tube holes as indicated in Figure 4.

Table 1. Sampling tubes recommended for different

duct widths:
Outside Duct Width		Sampling Tube Recommended*
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

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

[5.4.1] Installation For Ducts Greater Than 11⁄2 Feet But Less Than 8 Feet Wide

1.If the tube is longer than the width of the air duct, drill a 3⁄4-inch hole in the duct opposite the hole already cut 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. 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 detector.

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.

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 cap and tape closed any holes in the protruding section of the tube. Be sure to seal the duct when the tube protrudes.

NOTE: The sampling tube end cap is critical to the proper operation 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 inlet sampling tube:

FLANGE	AIR HOLES	SAMPLING
		TUBE
		END CAP

ARROW

MUST FACEAIR FLOW DIRECTION

INTO AIR FLOW

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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

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NOTE: Only metal sampling tubes may be used on ori- entations C and D.

D200-15-00 3 I56-0083-07R