How it Works
System Sensor
Loading...
DH400ACDCI
User Manual
16 pgs336.48 Kb0

System Sensor DH400ACDCI User Manual

INSTALLATION AND MAINTENANCE INSTRUCTIONS
DH400ACDC Air Duct Smoke Detector
A Division of Pittway
3825 Ohio Avenue, St. Charles, Illinois 60174
1-800-SENSOR2, FAX: 630-377-6495
Before Installing
Please thoroughly read the System Sensor Guide for Proper Use of Smoke Detectors in Duct Applications (I56-473),
which provides detailed information on detector spacing, placement, zoning, wiring, and special applications. Copies of this manual are available from System Sensor. NFPA Standards 72 and 90A should also be referenced for de­tailed information.
NOTICE: This manual should be left with the owner/user of this equipment.
IMPORTANT: This detector must be tested and maintained regularly following NFPA 72 requirements. The detector should be cleaned at least once a year.
Table of Contents Page
[1] General Description 1 [2] Exploded View of Duct Detector Components 2 [3] Contents of the Duct Detector Kit 2 [4] Limitations of Duct Detectors 2 [5] Installation Sequence 2 [6] Duct Detector Maintenance and Test Procedures 8 [7] Detector Cleaning Procedures 10 [8] Specifications 12 Warranty 13 Detector Test log 16
List of Tables and Figures Page
Fig. 1: Duct Detector Exploded View 2 Fig. 2: Installation of Sampling Tube Gaskets 3 Fig. 3: Mounting Location of Speed Nuts 3 Table 1: Inlet Sampling Tube Selection 3 Fig. 4: Inlet Sampling Tube 4 Fig. 5: Sampling Tube Mounting Configurations 4 Fig. 6: Wiring Diagram 6 Fig. 7: Wiring Diagram – No Control Panel 7 Fig. 8: Wiring Diagram – Accessories 8 Fig. 9: Sampling Tube Filter Installation 8 Fig. 10: Testing Detector Alarm 9 Fig. 11: Detector Head Removal 9 Fig. 12: RTS451/RTS451KEY Test Coil Installation 10 Fig. 13: Photo Head Exploded View 11 Fig. 14: Ion Head Exploded View 11
[1] General Description
An HVAC system supplies conditioned air to virtually every area of a building. Smoke introduced into this air duct sys­tem will be distributed to the entire building. Smoke detec­tors designed for use in air duct systems are used to sense the presence of smoke in the duct.
Model DH400ACDC Air Duct Smoke Detectors are supplied with model 1451DH ionization detector heads or model 2451 photoelectronic detector heads. These two smoke de­tection methods are combined with an efficient housing de­sign that samples air passing through a duct and allows detection of a developing hazardous condition. When suffi­cient smoke is sensed, an alarm signal is initiated at the fire control panel monitoring the detector, and appropriate ac­tion can be taken to shut off fans and blowers, change over air handling systems, etc. These actions can facilitate the management of toxic smoke and fire gases throughout the areas served by the duct system.
For testing, the alarm can be enabled by a magnet activated test switch, by insertion of a calibrated test card into the sensing chamber (photoelectronic version only), or by the optional remote test station. The duct smoke detectors latch into alarm state when alarm occurs. LEDs on each de­tector illuminate to provide local alarm indication, and op­tional accessories offer a variety of annunciation capabilities.
The detector can be reset by a momentary power interrup­tion, by the magnet activated reset switch, or by the op­tional remote test station.
D400-13-00 1 I56-555-08
[2] Figure 1. Exploded view of duct detector components:
CONDUIT HOLES
FOAM
GASKETS
TUBE PLUG
DETECTOR BASE
HOUSING
MOUNTING SCREWS
FILTER ADAPTER
TEST MAGNET
END
INLET SAMPLING TUBE
(SUPPLIED SEPARATELY)
EXHAUST
DETECTOR HEAD
O-RINGS
SAMPLING TUBE
FILTERS
[3] Contents Of The Duct Detector Kit
1. Complete housing base and cover assembly
2. Two #10 sheet metal mounting screws
3. Two sampling tube filters
4. One test magnet
5. Drilling template
6. Two 5/16 O-rings
7. Two rubber tube bushing seals
8. Four #6 self-tapping mounting screws for the sampling and optional exhaust tube extension
9. One filter adapter
10.One inlet tube end plug
11.Two #10 speed nuts
NOTE: The inlet sampling tube must be ordered sepa-
rately. It must be the correct length for the width of the duct where it will be installed. See Table 1 on page 4 to determine the inlet tube required for dif­ferent duct widths.
[4] Limitations Of Duct Detectors
WARNING
The National Fire Protection Association has established that DUCT DETECTORS MUST NOT BE USED AS A SUB­STITUTE FOR OPEN AREA DETECTOR PROTECTION as a means of providing life safety. Nor are they a substitute for early warning in a building’s regular fire detection system.
DUCT DETECTOR
HOUSING
TERMINAL STRIP
PC BOARD
INSULATOR
DUCT DETECTOR
COVER
SAMPLING TUBE
MOUNTING
SCREWS
A78-1927-01
WARNING
Frequently, fire situations may cause an interruption of power. The system safeguards should be discussed with your local fire protection specialist.
WARNING
This device does not sense smoke unless the ventilation system is operating.
CAUTION
For this detector to function properly, it MUST be installed according to the instructions in this manual. Furthermore, the detector MUST be protected from the elements and op­erated within ALL electrical and environmental specifica­tions listed in this manual. Failure to comply with these requirements may prevent the detector from activating when smoke is present in the air duct.
[5] Installation Sequence
Step Page
[5.1] Verify duct air flow direction and velocity 2 [5.2] Drill the mounting holes 3 [5.3] Secure the detector housing to the duct 3 [5.4] Install the sampling tube 3 [5.5] Complete the field wiring 5 [5.6] Install the filters and check pressure differential 8 [5.7] Perform detector check 8 [5.8] Install the cover 8
[5.1] Verify Duct Air Flow Direction And Velocity
Model DH400ACDC detectors are designed to be used in air handling systems having air velocities of 500 to 4000 feet
UL 268A.
D400-13-00 2 I56-555-08
per minute. Be sure to check engineering specifications to ensure that the air velocity in the duct falls within these pa­rameters. If necessary, use a velocity meter to check the air velocity in the duct.
[5.2] Drill The Mounting Holes
Remove the paper backing from the mounting template supplied. Affix the template to the duct at the desired mounting location. Make sure the template lies flat and smooth on the duct. Center punch holes A and B. Drill the holes as indicated on the template. Slide the two speed nuts over the two small holes (hole A) next to the sampling tube bushing holes (hole B) previously drilled in the duct. (See Figure 3.)
[5.3] Secure The Detector Housing To The Duct
Remove the duct housing cover. Slide the foam gaskets over the tube bushings as shown in Figure 2. Make sure the two small holes in the gaskets line up with the two base mount­ing holes. Put one 5/16-inch O-ring over each of the two #10 sheet metal screws. Use the two sheet metal screws to screw the detector housing to the duct. CAUTION: Do not overtighten the screws.
Figure 2. Installation of foam gaskets over sampling tube bushings:
DUCT DETECTOR
HOUSING
EXHAUST TUBE
(EXTENSION BUSHING)
FOAM GASKETS
MOUNTING
SCREWS
O-RINGS
INLET SAMPLING
TUBE BUSHING
of air inlet holes on the tube. This tube 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 into 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 in the centermost housing bushing, with 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. Figure 5 shows the various combinations of tube mounting configurations with respect to air flow.
Mounting the detector housing in a vertical orientation 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
SCREW HOLES FOR ATTACHING DETECTOR HOUSING TO DUCT
A78-2045-00
Figure 3. Speed nut mounting location:
HOLE B
HOLE A
DUCT WALL
SPEED
NUT
78-2046-00
[5.4] Install The Inlet
The inlet tube (shown in Figure 4) is identified by a series
D400-13-00 3 I56-555-08
Figure 4. Air duct detector inlet sampling tube:
FLANGE
AIR HOLES
ARROWS
AIR FLOW DIRECTION
MUST FACE
INTO AIR FLOW
Figure 5. Tube mounting configurations with varying air flow direction:
DOTS INDICATE POSITION OF
SAMPLING TUBE HOLES
AIR FLOW
DIRECTION
DUCT DETECTOR HOUSING
EXHAUST
TUBE
EXHAUST
TUBE
INLET
TUBE
INLET TUBE
EXHAUST
TUBE
AIR FLOW
DIRECTION
INLET TUBE
INLET TUBE END PLUG
AIR FLOW
DIRECTION
DUCT DETECTOR HOUSING
A78-2047-00
DUCT DETECTOR HOUSING
AIR FLOW
DIRECTION
[5.4.1] Installation For Ducts 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 directly opposite the hole al­ready cut for the inlet 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. Sampling tubes over 3 ft. long must be supported at the end opposite the duct detector.
2. Slide the tube into the centermost housing bushing. 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 inches of the tube extend outside the duct. Plug this end with the end plug and
DUCT DETECTOR HOUSING
EXHAUST
TUBE
INLET TUBE
A78-1812-01
tape closed any holes in the protruding section of the tube. Be sure to seal the duct when the tube protrudes.
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 accomplished 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 detector.
D400-13-00 4 I56-555-08
Install the inlet tube as follows:
1. Drill a 3/4-inch hole in the duct directly opposite the
hole already drilled for the inlet tube.
2. Slide the inlet tube with the flange into the centermost
housing bushing. Position the tube so that the arrows point 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 section of the in-
let tube to the section already installed using the 1/2­inch conduit fitting supplied. Make sure that the holes on both of the air inlet 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 inches of the tube extend outside 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 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 is a total of 10 to 12 holes spaced as evenly as possible across the width of the duct.
[5.5] Field Wiring Wiring Installation Guidelines
All wiring must be installed in compliance with the Na­tional Electrical Code and the local codes having jurisdic­tion. Proper wire gauges should be used. The conductors used to connect smoke detectors to control panels and ac­cessory devices should be color-coded to reduce the likeli­hood of wiring errors. Improper connections can prevent a system from responding properly in the event of a fire.
For signal wiring, (the wiring between interconnected de­tectors or from detectors to auxiliary devices), it is usually recommended that single-conductor wire be no smaller than 18 gauge. The duct detector terminals accommodate wire sizes up to 14 gauge. The last foot of conduit should be flexible steel conduit (available in electrical supply houses), which facilitates installation and puts less strain on the conduit holes in the housing. Solid conduit connec­tions may be used, if desired.
Smoke detectors and alarm system control panels have specifications for allowable loop resistance. Consult the control panel manufacturer’s specifications for the total loop resistance allowed for the particular model control panel being used before wiring the detector loop.
Air currents inside the duct may cause excessive vibration, especially when the longer sampling tubes are used. In these cases a 3 inch 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 inch to 1-1/4-inch hole where the flange will be used.
[5.4.3] Modifications Of Inlet Sampling Tubes
There may be applications where duct widths are not what is specified for the installation. In such cases, it is permis­sible to modify an inlet sampling tube that is longer than necessary to span the duct width.
Use a 0.193-inch diameter (#11) drill and add the appropri­ate number of holes so that the total number of holes ex­posed to the air flow in the duct is 10 to 12. Space the additional holes as evenly as possible over the length of the tube.
Wiring Instructions
The DH400ACDC detectors are designed for easy wiring. The housing provides a terminal strip with clamping plates. Wiring connections are made by stripping about 3/8-inch of insulation from the end of the wire, sliding the bare end under the plate, and tightening the clamping plate screw.
The DH400ACDC duct detector is designed to operate from 24 VDC, 24 VAC, 120 VAC, or 240 VAC.
The detector may be wired for interconnection to UL listed control panels, or for stand alone service per NFPA 90A. Refer to the wiring diagrams of Figures 6, 7, and 8 to select the appropriate circuit for your application.
D400-13-00 5 I56-555-08
Loading...
+ 11 hidden pages
Buy Points How it Works FAQ Contact Us Questions and Suggestions Privacy Policy Cookie Policy Terms of Use