Carrier 50CR Installation Instructions Manual

Also see for Infinity 50CR Series: Owner's information manual

Contents

9Step 5—Select and Install DuctworkThe design and installation of the duct system must be in accordancewith the standards of the NFPA for installation of non--residencetype air conditioning and ventilating systems, NFPA 90A orresidence type, NFPA 90B and/or local codes and ordinances.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 openings onthe side of the unit.ELECTRICAL OPERATION HAZARDFailure to follow this warning could result in personal injuryor death.For vertical supply and return units, tools or parts could dropinto ductwork, therefore, install a 90 degree turn in the returnductwork between the unit and the conditioned space. If a 90degree elbow cannot be installed, then a grille of sufficientstrength and density should be installed to prevent objectsfrom falling into the conditioned space. Units with electricheaters require 90 degree elbow in supply duct.! WARNINGWhen designing and installing ductwork, consider the following:1. All units should have field--supplied filters or accessory filterrack 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 is installed,use fireproof canvas (or similar heat resistant material) connectorbetween ductwork and unit discharge connection. If flexible duct isused, insert a sheet metal sleeve inside duct. Heat resistant ductconnector (or sheet metal sleeve) must extend 24--in. from electricheater element.3. Size ductwork for max cooling air quantity (400 cfm/ton).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.CONVERTING HORIZONTAL DISCHARGE UNITS TODOWNFLOW (VERTICAL) DISCHARGE UNITSELECTRICAL SHOCK HAZARDFailure to follow this warning could result in personal injuryor death.Before installing or servicing system, always turn off mainpower to system. There may be more than one disconnectswitch.Turn off accessory heater power switch if applicable.! WARNING1. Open all electrical disconnects and install lockout tag beforestarting any service work.2. Remove side duct covers to access bottom return and supplyknockouts.NOTE: These panels are held in place with tabs similar to anelectrical knockout.3. Use a screwdriver and hammer to remove the panels in thebottom of the composite unit base.4. Ensure the side duct covers are in place to block off thehorizontal air openings (See Fig. 11).Step 6—Provide for Condensate DisposalNOTE: Ensure that condensate--water disposal methods complywith local codes, restrictions, and practices.The units dispose of condensate through a 3/4 in. NPT female fittingthat exits on the compressor end of the unit. Condensate water canbe drained directly onto the roof in rooftop installations (wherepermitted) or onto a gravel apron in ground level installations.Install a field--supplied condensate trap at end of condensateconnection to ensure proper drainage. Make sure that the outlet ofthe trap is at least 1 in. lower than the drain--pan condensateconnection to prevent the pan from overflowing. Prime the trap withwater. When using a gravel apron, make sure it slopes away from theunit.If the installation requires draining the condensate water away fromthe unit, install a field--supplied 2--in. trap at the condensateconnection to ensure proper drainage. Condensate trap is availableas an accessory or is field--supplied. Make sure that the outlet of thetrap is at least 1 in. lower than the unit drain--pan condensateconnection to prevent the pan from overflowing. Connect a draintrough using a minimum of field--supplied 3/4 --in. PVC orfield--supplied 3/4 --in. copper pipe at outlet end of the 2 --in. trap(See Fig. 12). Do not undersize the tube. Pitch the drain troughdownward at a slope of at least 1 in. for every 10 ft. of horizontal run.Be sure to check the drain trough for leaks. Prime the trap at thebeginning of the cooling season start--up.50CR