DH100LP Air Duct Smoke Detector with Extended Air Speed Range

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WARNINGIn no case should more than 2 air inlet holes be cut off thetube. There must be a minimum of 10 holes in the tubeexposed to the air stream.[5.4.2] Installation For Ducts More Than 8 Feet WideNOTE: 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 accomplishedby using the ST-10 inlet sampling tube. If thetube is shorter than the width of the air duct, installthe end plug into the inlet tube as shown in Figure4 and support the end opposite the duct smokedetector.Install the inlet tube as follows:1. Drill a 3 ⁄4-inch hole in the duct opposite the hole alreadydrilled for the inlet tube. Drill the hole 1″ to 2″ below theinlet hole on the opposite side of the duct to allow formoisture drainage away from the detector.2. Slide the inlet tube with the flange into the housing bushingthat meets the air flow first. Position the tube so thatthe arrows point into the air flow. Secure the tube flangeto the housing bushing with two #6 self-tapping screws.3. From inside the duct, couple the other sections of theinlet tube to the section already installed using the1⁄2-inch conduit fittings supplied. Make sure that theholes on both of the air inlet tubes are lined up and facinginto the air flow.4. Trim the end of the tube protruding through the duct sothat 1″ to 2″ of the tube extend outside the duct. Plugthis end with the end plug and tape closed any holes inthe protruding section of the tube. Be sure to seal theduct when the tube protrudes.NOTE: An alternate method to using the ST-10 is to usetwo ST-5 inlet tubes. Remove the flange from oneof the tubes and install as described above. Afterthe installation, use electrical tape to close offsome of the sampling holes so that there are a totalof 10 to 12 holes spaced as evenly as possibleacross the width of the duct.NOTE: Air currents inside the duct may cause excessivevibration, especially when the longer sampling tubes areused. In these cases a 3 inch floor flange (available at mostplumbing supply stores) may be used to fasten the samplingtube to the other side of the duct. When using theflange/connector mounting technique, drill a 1 to 1 1 ⁄4 inchhole where the flange will be used.[5.4.3] Modifications of Inlet Sampling TubesThere may be applications where duct widths are not whatis specified for the installation. In such cases, it is permissibleto modify an inlet sampling tube that is longer thannecessary to span the duct width.Use a 0.193-inch diameter (#10) drill and add the appropriatenumber of holes so that the total number of holesexposed to the air flow in the duct is 10 to 12. Space theadditional holes as evenly as possible over the length of thetube.NOTE: This procedure should only be used as a temporaryfix. It is not intended as a permanent substitute forordering the correct length tubes.[5.5] Install The FiltersTo install the sampling tube filters, simply push the filtersinto the sampling and exhaust tube holes as shown inFigure 6. If a metal sampling tube is used, install the filterover the sampling tube.Figure 6. Sampling tube filter installation:WARNINGFilters require periodic cleaning or replacement, dependingon the amount of dust and dirt accumulated. Visuallyinspect the filters at least quarterly; inspect them moreoften if the dust accumulation warrants it. See Section [6]for more information. Replacement filters can be orderedfrom System Sensor, 3825 Ohio Ave., St. Charles, IL 60174.(Exhaust tube/intake tube filter P/N F36-09-11)[5.6] Field WiringWiring Installation GuidelinesAll wiring must be installed in compliance with theNational Electrical Code and the local codes having jurisdiction.Proper wire gauges should be used. The conductorsused to connect smoke detectors to control panels andaccessory devices should be color-coded to prevent wiringmistakes. Improper connections can prevent a system fromresponding properly in the event of a fire.D200-15-00 4 I56-0083-00
For signal wiring, (the wiring between interconnecteddetectors or from detectors to auxiliary devices), it is usuallyrecommended that single conductor wire be no smallerthan 18 gauge. The duct smoke detector terminalsaccommodate wire sizes up to 12 gauge. The last foot ofconduit should be flexible conduit (available in electricalsupply houses), which facilitates easier installation andputs less strain on the conduit holes in the housing. Solidconduit connections may be used if desired.Smoke detectors and alarm system control panels havespecifications for allowable loop resistance. Consult thecontrol panel manufacturer’s specifications for the totalloop resistance allowed for the particular model controlpanel being used before wiring the detector loop.Wiring InstructionsThe DH100LP detectors are designed for easy wiring. Thehousing provides a terminal strip with clamping plates.Wiring connections are made by stripping about 3/8-inchof insulation from the end of the wire, sliding the bare endunder the plate, and tightening the clamping plate screw.The DH100LP duct smoke detector is designed to operatewith 12 or 24 VDC UL listed 2-wire compatible control panels.Alarm current must be limited by the control panel to100mA or less. An example of a UL listed compatible controlpanel is the Fire-Lite model Sensiscan 1000 using zonecard ANC-2 and compatibility identification “A”. Install perinstallation instruction S1000/801. A maximum of 20 detectorsmay be installed per zone.[5.7] Perform Detector Check1. Perform STANDBY AND TROUBLE TEST per Section[6.2.1].2. Perform MAGNET TEST per Section [6.2.2.1]. TheRTS451 test of Section [6.2.2.2] may substitute for thisrequirement.3. Perform AIR FLOW TEST per Section [6.1.1].4. Perform SMOKE RESPONSE TEST per Section [6.1.2].5. Perform SENSITIVITY TEST per Section [6.2.3].[5.8] Install The CoverInstall the cover using the six screws that are captured inthe housing cover. Be certain filters are installed as specifiedin Section [5.5]. Make sure that the cover fits into thebase groove and that all gaskets are in their proper positions.Tighten the six screws.[6] Duct Smoke Detector Maintenance And TestProceduresTest and maintain duct smoke detectors as recommendedin NFPA 72. The tests contained in this manual weredevised to assist maintenance personnel in verification ofproper detector operation.Before conducting these tests, notify the proper authoritiesthat the smoke detection system will be temporarily out ofservice. Disable the zone or system under test to preventunwanted alarms.[6.1] Smoke Entry Tests[6.1.1] Air FlowThe DH100LP is designed to operate over an extended airspeed range of 100 to 4000 FPM. To verify sufficient samplingof ducted air, turn the air handler on and use a manometer tomeasure the differential pressure between the two samplingtubes. The differential pressure should measure at least0.0015 inches of water and no more than 1.2 inches of water.Because most commercially available manometers cannotaccurately measure very low pressure differentials, applicationswith less than 500 FPM of duct air speed may requireone of the following: 1) the use of a current-sourcing pressuretransmitter (Dwyer model numbers 607-1 or 607-01) see fieldbulletin Z75-79-00 or; 2) the use of aerosol smoke per section6.1.2.[6.1.2] Air Flow Test using Aerosol SmokeDrill a 1 ⁄4″ hole 3 feet upstream from the duct smoke detector.With the air handler on, measure the air velocity withan anemometer. Air speed must be at least 100 FPM. If theair speed is greater than 500 FPM, use a conventionalmanometer to measure differential pressure between thesampling tubes. Spray aerosol smoke* into the duct throughthe 1 ⁄4″ hole for five seconds. Wait two minutes for the ductsmoke detector to alarm. If the duct smoke detector alarms,air is flowing through the detector. Remove the duct smokedetector cover and blow out the residual aerosol smoke fromthe chamber and reset the duct smoke detector. Use ducttape to seal the aerosol smoke entry hole.*Aerosol smoke can be purchased from Home Safeguard Industries,Malibu, CA. Phone: 310/457-5813.To determine if smoke is capable of entering the sensingchamber, visually identify any obstructions. Plug theexhaust and inlet tube holes to prevent ducted air from carryingsmoke away from the detector head, then blow smokesuch as cigarette, cotton wick, or punk directly at the headto cause an alarm. REMEMBER TO REMOVE THE PLUGSAFTER THIS TEST, OR THE DETECTOR WILL NOT FUNC-TION PROPERLY.[6.1.3] Filter ReplacementThe filters do not substantially affect smoke performanceeven when up to 90% of the filter is clogged. Quarterlyvisual inspection usually suffices to determine whether thefilters should be replaced because only a high percentage ofcontamination affects performance. If further testing isrequired, compare differential pressure readings with andwithout the filters installed. If the difference exceeds 10%replace the filters. In no case should the pressure differentialfall below 0.0015 inches of water.D200-15-00 5 I56-0083-00
Page 3: [5.3] Secure The Detector Housing T
Page 7: [6.2.2] Alarm Tests[6.2.2.1] M02-04

DH100LP Air Duct Smoke Detector with Extended Air Speed Range

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