System Sensor 7251DH Manual

I Ohio Avenue St Charles Illinois 60174 FAX 630 377 6495 AND MAINTENANCE INSTRUCTIONS Intelligent Duct Smoke Detector Temperature Range Humidity Range Air Velocity Range Current nominal current nominal inches 36.7 cm inches 12.7 cm inches 8.9 cm lbs 1.1 kg to 100 0 to 38 to 93 Relative Humidity 4000 ft min 32 VDC Peak at 24 VDC no communication at 24 VDC one communication every 5 sec with LED enabled at 24 VDC Installing thoroughly read System Sensor Guide for Proper Use of Detectors in Duct Applications I56 473 XX which pro detailed information on detector spacing placement zon wiring and special applications Copies of this manual are from System Sensor NFPA Standards 72 76 and 90A also be referenced for detailed information This manual should be left with the owner user of equipment sensors must be tested after installation and periodically there Testing methods must satisfy the Authority Having Jurisdic AHJ Sensors offer maximum performance when tested and in compliance with NFPA 72 Description HVAC system supplies conditioned air to virtually every area a building Smoke introduced into this air duct system will be to the entire building Smoke detectors designed for in air duct systems are used to sense the presence of smoke the duct In facilities with large air changes per hour airflow carry smoke particles directly to the HVAC system Per NFPA Very Early Warning Fire Detection VEWFD sensors shall be to monitor return air from the space The 7251DH can be to monitor the return air from the space in order to meet 76 requirements 7251DH Air Duct Smoke Detector uses a 7251 laser smoke This smoke detection method combined with an efficient design that samples air passing through a duct provides detection of a developing hazardous condition When suf smoke is sensed an alarm signal is initiated at the fire panel monitoring the detector and appropriate action can taken to shut off fans and blowers change over air handling etc This can prevent the distribution or isolation of smoke and fire gases throughout the areas served by the system as well as provide an alert of a developing hazardous in a facility LEDs on each detector latch ON to provide a local alarm There is also a remote alarm output for use with aux devices The 7251DH has remote test capability with the Remote Test Station of the Duct Detector Housing Kit 7251DH consists of the following items See Figure 1 Table 1 on Page 2 for inlet sampling tube and detector sup information Complete laser duct assembly Two 10 sheet metal mounting screws Two sampling tube filters One test magnet Drilling template Two 5 16 O rings Two rubber tube bushings seals Four 6 self tapping mounting screws for the sampling tube One filter adapter One inlet tube end plug Four 6x7 10 cover mounting screws Two 10 speed nuts One test coil and parts bag The inlet sampling tube must be ordered separately It be the correct length for the width of the duct where it will installed See Table 1 to determine the inlet tube required for duct widths Sequence 1 Determine duct mounting application 2 2 Verify duct air flow direction and velocity 2 3 Drill the mounting holes 2 4 Secure the housing base to the duct 2 5 the inlet sampling tube 2 6 Field wiring 4 7 the filters and check pressure differential 4 8 Perform detector check 4 9 the cover 5 10 Perform the final system check Testing 7 1 Verify Duct Air Flow Direction and Velocity Early Warning Fire Protection VEWFP NFPA 76 calls sensors to be mounted at the return air location for a space 8.5.3.1.2.3 A stand alone packed HVAC units installed sensors or ports shall be installed where return air is back to the unit B or ports shall be installed that each covers no greater than 0.4sq m 4sq ft of the air opening The System Sensor duct smoke detector is to satisfy NFPA 76 for VEWFD 1 SAMPLING TUBE SEPARATELY STRIP HOLES DETECTOR DETECTOR TUBE BASE SCREWS ADAPTER HEAD SEPARATELY MAGNET TUBE 7251DH duct smoke detector should be mounted as follows Location Mount detector on the room side up stream of any filter NOTICE Mounting detector after filter may filter out particles and is not recommended Coverage Each detector pipe length should be mounted the longer direction of the return air opening length One detector and one standard pre drilled pipe should be installed for every 2ft of return air open width When more than one detector is required widths than 2ft detector housings should be staggered on ends of the opening length refer to illustration Hole Direction holes facing directly into flow for positive effect Insure adequate pressure differential across the detector hous according to step 8.1 of this document 2 APPLICATION EXAMPLES 2 Verify Duct Air Flow Direction and Velocity 7251DH is designed to be used in air handling systems having velocities of 300 to 4000 feet per minute Be sure to check en specifications to ensure that the air velocity in the duct within these parameters If necessary an Alnor Model 6000 velocity meter Dwyer 460 differential pressure gauge or their may be used to check the air velocity in the duct 3 Drill the Mounting Holes the paper backing from the top and bottom of the tem Affix the template to the air duct at the desired mounting Make sure the template lies flat and smooth on the air Center punch hole targets and remove the template Drill the as indicated on the template Slide the two speed nuts over two small holes Hole A next to the sampling tube bushing Hole B previously drilled in the duct See Figure 3A 4 Mount Duct Housing the duct housing cover Slide the foam gaskets over the bushings as shown in Figure 3B Make sure the two small in the gaskets line up with the two base mounting holes Put 5 16 O ring over each of the two 10 sheet metal screws Use two sheet metal screws to secure the duct housing to the duct not overtighten the screws 1 Sampling Inlet Tubes Duct Width to 2 ft 0.3 to 0.6 m to 4 ft 0.6 to 1.2 m to 8 ft 1.2 to 2.4 m to 12 ft 2.4 to 3.7 m 3A Speed nut mounting location B 3B Installation of foam gaskets over sam tube bushings A SAMPLING BUSHING DETECTOR TUBE BUSHING GASKETS 5 Install the Inlet Tube inlet tube shown in Figure 4 is identified by a series of air holes on the tube This tube must be purchased separately the correct length as specified in Table 1 for the width of duct where it will be installed The exhaust tube is molded the base of the duct housing inlet tube is always installed in the right house bushing with air inlet holes facing into the air flow To assure proper instal the tube mounting flange is marked with arrows Mount inlet tube so that the arrows point into the air flow Figure 5 the various combinations of tube mounting configurations respect to air flow 4 Air duct detector inlet sampling tube HOLES FACE AIR FLOW FLOW DIRECTION