Carrier PERFORMANCE 50VT-A Installation Instructions Manual

Also see for COMFORT 50VT-A: Owner's information manual Owner's information manual Installation instructions

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Carrier PERFORMANCE 50VT-A Installation Instructions Manual Manual pdf 7 page image

7Step 5 — Select and Install DuctworkThe design and installation of the duct system must be inaccordance with the standards of the NFPA for installation ofnon--residence type air conditioning and ventilating systems,NFPA 90A or residence--type, NFPA 90B and/or local codes andordinances.Select and size ductwork, supply--air registers, and return air grillesaccording to ASHRAE (American Society of Heating,Refrigeration, and Air Conditioning Engineers) recommendations.The unit has duct flanges on the supply-- and return--air openingson the side of the unit.PERSONAL INJURY HAZARDFailure to follow this warning could result in personalinjury or death.For vertical supply and return units, tools or parts coulddrop into ductwork Install a 90 degree turn in the returnductwork between the unit and the conditioned space. If a90 degree elbow cannot be installed, then a grille ofsufficient strength and density should be installed toprevent objects from falling into the conditioned space.Units with electric heaters require 90 degree elbow insupply duct.! WARNINGWhen designing and installing ductwork, consider the following:1. All units should have field--supplied filters or accessoryfilter rack installed in the return--air side of the unit.Recommended sizes for filters are shown in Table 1.2. Avoid abrupt duct size increases and reductions. Abruptchange in duct size adversely affects air performance.IMPORTANT: Use flexible connectors between ductwork andunit to prevent transmission of vibration. Use suitable gaskets toensure weather tight and airtight seal. When electric heat isinstalled, use fireproof canvas (or similar heat resistant material)connector between ductwork and unit discharge connection. Ifflexible duct is used, insert a sheet metal sleeve inside duct. Heatresistant duct connector (or sheet metal sleeve) must extend 24--in.(610 mm) from electric heater element.3. Size ductwork for cooling air quantity (cfm). The minimumair quantity for proper electric heater operation is listed inTable 2. Heater limit switches may trip at air quantitiesbelow those recommended.4. Seal, insulate, and weatherproof all external ductwork. Seal,insulate and cover with a vapor barrier all ductwork passingthrough conditioned spaces. Follow latest Sheet Metal andAir Conditioning Contractors National Association(SMACNA) and Air Conditioning Contractors Association(ACCA) minimum installation standards for residentialheating and air conditioning systems.5. Secure all ducts to building structure. Flash, weatherproof,and vibration--isolate duct openings in wall or roofaccording to good construction practices.CONFIGURING UNITS FOR DOWNFLOW(VERTICAL) DISCHARGEELECTRICAL SHOCK HAZARDFailure to follow this warning could result in personalinjury or death.Before performing service or maintenance operations on thesystem, turn off main power to unit and install lockout tag.There may be more than one disconnect switch.! WARNING1. Open all electrical disconnects and install lockout tag beforestarting any service work.2. Remove horizontal (metal) ductcovers to access vertical(downflow) discharge duct knockouts in unit basepan. (SeeFig. 6.)3. To remove downflow return and supply knockout covers,break front and right side connecting tabs with ascrewdriver and hammer. Push cover down to break rearand left side tabs.Horizontal Duct CoversA09076BasepanDownflow(Vertical)SupplyKnockoutBasepanDownflow(Vertical)ReturnKnockoutA09093Fig. 6 -- Supply and Return Duct OpeningNOTE: These panels are held in place with tabs similar to anelectrical knockout. Reinstall horizontal duct covers (Fig. 6)shipped on unit from factory. Insure openings are air andwatertight.NOTE: The design and installation of the duct system must be inaccordance with the standards of the NFPA for installation ofnonresidence--type air conditioning and ventilating systems, NFPA90A or residence--type, NFPA 90B; and/or local codes andordinances.Adhere to the following criteria when selecting, sizing, andinstalling the duct system:1. Units are shipped for side shot installation.2. Select and size ductwork, supply--air registers, andreturn--air grilles according to American Society of Heating,Refrigeration and Air Conditioning Engineers (ASHRAE)recommendations.3. Use flexible transition between rigid ductwork and unit toprevent transmission of vibration. The transition may be50VT-- A