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

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Carrier 58MCA Installation, Start-up, And Operating Instructions Manual Manual pdf 18 page image

through unconditioned space should be insulated to enhancesystem performance. When air conditioning is used, a vaporbarrier is recommended.Maintain a 1-in. clearance from combustible materials to supply airductwork for a distance of 36 in. horizontally from the furnace. SeeNFPA 90B or local code for further requirements.Step 2—Ductwork Acoustical TreatmentMetal duct systems that do not have a 90 degree elbow and 10 ftof main duct to the first branch take-off may require internalacoustical lining. As an alternative, fibrous ductwork may be usedif constructed and installed in accordance with the latest edition ofSMACNA construction standard on fibrous glass ducts. Bothacoustical lining and fibrous ductwork shall comply with NFPA90B as tested by UL Standard 181 for Class 1 Rigid air ducts.Step 3—Supply Air ConnectionsUPFLOW FURNACESConnect supply-air duct to 3/4-in. flange on furnace supply-airoutlet. The supply-air duct attachment must ONLY be connectedto furnace supply-/outlet-air duct flanges or air conditioning coilcasing (when used). DO NOT cut main furnace casing to attachsupply side air duct, humidifier, or other accessories. All accesso-ries MUST be connected external to furnace main casing.DOWNFLOW FURNACESConnect supply-air duct to supply-air opening on furnace. Thesupply-air duct attachment must ONLY be connected to furnacesupply/outlet or air conditioning coil casing (when used), wheninstalled on non-combustible material. When installed on combus-tible material, supply-air duct attachment must ONLY be con-nected to an accessory subbase or factory approved air condition-ing coil casing. DO NOT cut main furnace casing to attach supplyside air duct, humidifier, or other accessories. All accessoriesMUST be connected external to furnace main casing.HORIZONTAL FURNACESConnect supply-air duct to supply air opening on furnace. Thesupply-air duct attachment must ONLY be connected to furnacesupply/outlet or air conditioning coil casing (when used). DO NOTcut main furnace casing to attach supply side air duct, humidifier,or other accessories. All accessories MUST be connected externalto furnace main casing.Step 4—Return Air ConnectionsUPFLOW FURNACESThe return-air duct must be connected to bottom , sides (left orright), or a combination of bottom and side(s) of main furnacecasing as shown in Fig. 1. Bypass humidifier may be attached intounused side return air portion of the furnace casing. DO NOTconnect any portion of return-air duct to back of furnace casing.DOWNFLOW AND HORIZONTAL FURNACESThe return-air duct must be connected to return-air openingprovided as shown in Fig. 1. DO NOT cut into casing sides or backto attach any portion of return-air duct. Bypass humidifier connec-tions should be made at ductwork or coil casing sides exterior tofurnace.ELECTRICAL CONNECTIONSSee Fig. 22 for field wiring diagram showing typical field 115-vand 24-v wiring. Check all factory and field electrical connectionsfor tightness.Blower access panel door switch opens 115-v power tocontrol center. No component operation can occur. Do notbypass or close switch with panel removed. Failure to followthis warning could result in personal injury or death.Furnace control must be grounded for proper operation orcontrol will lock out. Control is grounded through green wirerouted to gas valve and burner box screw.Step 1—115-v WiringBefore proceeding with electrical connections, make certain thatvoltage, frequency, and phase correspond to that specified on unitrating plate. Also, check to be sure that service provided by utilityis sufficient to handle load imposed by this equipment. Refer torating plate or Table 4 for equipment electrical specifications.Make all electrical connections in accordance with NationalElectrical Code (NEC) ANSI/NFPA 70-1999 and any local codesor ordinances that might apply. For Canadian installations, allelectrical connections must be made in accordance with CanadianElectrical Code CSA C22.1 or subauthorities having jurisdiction.Fig. 22—Heating and Cooling Application Wiring Diagram A99408115-V FIELD-SUPPLIEDDISCONNECTAUXILIARYJ-BOX24-VTERMINALBLOCKTHREE-WIREHEATING-ONLYFIVE WIRENOTE 1NOTE 2FIELD-SUPPLIEDDISCONNECTCONDENSINGUNITTWOWIREFURNACECONTROLRGCOMW C R G YGNDGNDFIELD 24-V WIRINGFIELD 115-, 208/230-, 460-V WIRINGFACTORY 24-V WIRINGFACTORY 115-V WIRING208/230- OR460-VTHREEPHASE208/230-VSINGLEPHASEBLOWER DOOR SWITCHWHTBLKWHTBLKNOTES: Connect Y-terminal in furnace as shown for proper blower operation.Some thermostats require a "C" terminal connection as shown.If any of the original wire, as supplied, must be replaced, usesame type or equivalent wire.WYGNDTHERMOSTATTERMINALS1.2.3.18