Carrier 58MCA Installation, Start-up, And Operating Instructions Manual

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Carrier 58MCA Installation, Start-up, And Operating Instructions Manual Manual pdf 17 page image

Gas valve shutoff switch MUST be facing forward or tiltedupward. Failure to follow this warning could result inproperty damage or death.Never purge a gas line into a combustion chamber. Never usematches, candles, flame, or other sources of ignition forpurpose of checking leakage. Use a soap-and-water solutionto check for leakage. Failure to follow this warning couldresult in fire, explosion, personal injury, or death.Use proper length of pipe to avoid stress on gas controlmanifold. Failure to follow this warning could result in a gasleak resulting in fire, explosion, personal injury, or death.Install a sediment trap in riser leading to furnace. Trap can beinstalled by connecting a tee to riser leading to furnace sostraight-through section of tee is vertical. Then connect a cappednipple into lower end of tee. Capped nipple should extend belowlevel of gas controls. Place a ground joint union between gascontrol manifold and manual gas shutoff valve. (See Fig. 21.)If a flexible connector is required or allowed by authorityhaving jurisdiction, black iron pipe shall be installed at gasvalve and extend a minimum of 2 in. outside furnace casing.An accessible manual shutoff valve MUST be installed upstreamof furnace gas controls and within 6 ft of furnace. A 1/8-in. NPTplugged tapping, accessible for test gage connection, MUST beinstalled immediately upstream of gas supply connection tofurnace and downstream of manual shutoff valve.NOTE: The gas valve inlet press tap connection is suitable to useas test gage connection providing test pressure DOES NOT exceedmaximum 0.5 psig (14-in. wc) stated on gas valve. (See Fig. 44.)Piping should be pressure tested in accordance with local andnational plumbing and gas codes before furnace is attached. InCanada, refer to current edition of NSCNGPIC. If pressureexceeds 0.5 psig (14-in. wc), gas supply pipe must be disconnectedfrom furnace and capped before pressure test. If test pressure isequal to or less than 0.5 psig (14-in. wc), turn off electric shutoffswitch located on gas valve before test. It is recommended thatground joint union be loosened before pressure testing. After allconnections have been made, purge lines and check for leakage.AIR DUCTSStep 1—General RequirementsThe duct system should be designed and sized according toaccepted national standards such as those published by: AirConditioning Contractors Association (ACCA), Sheet Metal andAir Conditioning Contractors National Association (SMACNA) orAmerican Society of Heating, Refrigerating and Air ConditioningEngineers (ASHRAE). Or consult factory The Air Systems DesignGuidelines reference tables available from your local distributor.The duct system should be sized to handle the required systemdesign CFM at the design static pressure.When a furnace is installed so that the supply ducts carry air toareas outside the space containing the furnace, the return air mustalso be handled by a duct(s) sealed to the furnace casing andterminating outside the space containing the furnace.Secure ductwork with proper fasteners for type of ductwork used.Seal supply- and return-duct connections to furnace with codeapproved tape or duct sealer.Flexible connections should be used between ductwork andfurnace to prevent transmission of vibration. Ductwork passingFig. 20—Removing Bottom Closure PanelA93047BOTTOMCLOSUREPANELFRONT FILLERPANELTable 3—Maximum Capacity of Pipe*NOMINALIRONPIPESIZE(IN.)INTERNALDIAMETER(IN.)LENGTH OF PIPE (FT)10 20 30 40 501/2 0.622 175 120 97 82 733/4 0.824 360 250 200 170 1511 1.049 680 465 375 320 2851-1/4 1.380 1400 950 770 660 5801-1/2 1.610 2100 1460 1180 990 900* Cubic ft of gas per hr for gas pressures of 0.5 psig (14-in. wc) or less, anda pressure drop of 0.5-in. wc (based on a 0.60 specific gravity gas).Ref: Table 10-2 NFPA 54-1999.Fig. 21—Typical Gas Pipe ArrangementA93324UNIONSEDIMENTTRAPMANUALSHUTOFFVALVE(REQUIRED)GASSUPPLY17