ICP PGN324 Installation Instructions Manual

Contents

10Step 9—Install Duct ConnectionsThe unit has duct flanges on the supply-- and return--airopenings on the side and bottom of the unit. For downshotapplications, the ductwork connects to the roof curb (SeeFig. 3 and 4 for connection sizes and locations).CONFIGURING UNITS FOR DOWNFLOW (VERTICAL)DISCHARGEELECTRICAL SHOCK HAZARDFailure to follow this warning could result in personalinjury or death.Before installing or servicing system, always turn offmain power to system. There may be more than onedisconnect switch. Turn off power supply to the unit andinstall lockout tag.! WARNING1. Open all electrical disconnects before starting anyservice work.2. Remove horizontal (metal) duct covers to accessvertical (downflow) discharge duct knockouts in unitbase.3. Use a screwdriver and hammer to remove the panels inthe bottom of the unit base (See Fig. 9).4. If unit ductwork is to be attached to vertical openingflanges on the unit base (jackstand applications only),do so at this time.PROPERTY DAMAGE HAZARDFailure to follow this caution may result in propertydamage.Collect ALL screws that were removed. Do not leavescrews on rooftop as permanent damage to the roofmay occur.CAUTION!5. It is recommended that the base insulation around theperimeter of the vertical return--air opening be securedto the base with aluminum tape. Applicable local codesmay require aluminum tape to prevent exposedfiberglass.6. Cover both horizontal duct openings with the providedduct covers. Ensure opening is air and water tight.7. After completing unit conversion, perform all safetychecks and power up unit.NOTE: The design and installation of the duct system mustbe in accordance with the standards of the NFPA forinstallation of nonresidence--type air conditioning andventilating systems, NFPA 90A or residence--type, NFPA90B; and/or local codes and ordinances.FIGURE 8 Supply and Return Duct OpeningSUPPLYDUCTOPENINGRETURNDUCTOPENINGVENT HOODSHIPPINGLOCATIONFIGURE 9 Vertical Duct Cover RemovedDUCT COVERS REMOVEDAdhere to the following criteria when selecting, sizing, andinstalling the duct system:1. Units are shipped for horizontal duct installation (byremoving duct covers).2. Select and size ductwork, supply--air registers, andreturn--air grilles according to American Society ofHeating, Refrigeration and Air Conditioning Engineers(ASHRAE) recommendations.3. Use flexible transition between rigid ductwork and unitto prevent transmission of vibration. The transition maybe screwed or bolted to duct flanges. Use suitablegaskets to ensure weather--tight and airtight seal.4. All units must have field--supplied filters or accessoryfilter rack installed in the return--air side of the unit.Recommended sizes for filters are shown in Table 1.5. Size all ductwork for maximum required airflow (eitherheating or cooling) for unit being installed. Avoid abruptduct size increases or decreases or performance maybe affected.6. Adequately insulate and weatherproof all ductworklocated outdoors. Insulate ducts passing throughunconditioned space, and use vapor barrier inaccordance with latest issue of Sheet Metal and Air