Carrier 58CTA/CTX instruction manual Unit Damage Hazard, Cleaning Heat Exchanger

Page 49

13.Verify that blower wheel is centered in blower housing and set screw contacts the flat portion of the motor shaft. Loosen set screw on blower wheel and reposition if neces- sary.

14.Spin the blower wheel by hand to verify that the wheel does not rub on the housing.

15.Reinstall blower assembly in furnace.

16.Reinstall control box assembly in furnace.

!CAUTION

UNIT DAMAGE HAZARD

Failure to follow this caution may result in shortened heat exchanger life.

Heating fan speed(s) MUST be adjusted to provide proper air temperature rise as specified on the rating plate. Recommended operation is at the midpoint of the rise range or slightly above. Refer to “SET TEMPERATURE RISE” under START-UP, ADJUSTMENT, and SAFETY CHECK.

NOTE: Refer to Table 13 for motor speed lead relocation if leads were not identified before disconnection.

17.Reconnect blower leads to furnace control. Refer to fur- nace wiring diagram, and connect thermostat leads if pre- viously disconnected.

18.To check blower for proper rotation:

a.Turn on electrical supply.

b.Manually close blower access door switch.

NOTE: If thermostat terminals are jumpered at the time blower access door switch is closed, blower will run for 90 sec before beginning a heating or cooling cycle.

c.Perform component self-test as shown at the bottom of the SERVICE label, located on the front of blower access door.

d.Verify blower is rotating in the correct direction.

19.If furnace is operating properly, RELEASE BLOWER ACCESS DOOR SWITCH. Remove any jumpers or re- connect any disconnected thermostat leads. Replace blower access door.

!WARNING

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury, or death.

Blower access door switch opens 115-v power to furnace control. No component operation can occur unless switch is closed. Exercise caution to avoid electrical shock from exposed electrical components when manually closing this switch for service purposes.

20.Downflow or horizontal furnaces with vent pipe through furnace only:

a.Install and connect short piece of vent pipe inside furnace to existing vent.

b.Connect vent connector to vent elbow.

21.Turn on gas supply and cycle furnace through one com- plete heating and cooling cycle. Verify the furnace temper- ature rise as shown in Adjustments Section. Adjust tem- perature rise as shown in Adjustments Section. If outdoor temperature is below 70_F (21_C) turn off circuit breaker to outdoor unit before running furnace in the cooling

cycle. Turn outdoor circuit breaker on after completing cooling cycle.

CLEANING HEAT EXCHANGER

The following steps should be performed by a qualified service agency:

NOTE: If the heat exchangers get a heavy accumulation of soot and carbon, they should be replaced rather than trying to clean them thoroughly. A build-up of soot and carbon indicates that a problem exists which needs to be corrected, such as improper adjustment of manifold pressure, insufficient or poor quality combustion air, incorrect size or damaged manifold orifice(s), improper gas, or a restricted heat exchanger. Action must be taken to correct the problem.

If it becomes necessary to clean the heat exchangers because of dust or corrosion, proceed as follows:

1.

Turn OFF gas and electrical power to furnace.

 

 

2.

Remove outer access door.

58CT

3.

Disconnect vent connector from furnace vent elbow.

 

4.

For downflow or horizontal furnace having an internal

 

 

vent pipe, remove internal vent pipe within the casing.

 

5.

Disconnect wires to the following components. Mark

 

 

wires to aid in reconnection of (be careful when discon-

 

 

necting wires from switches because damage may occur):

 

 

a. Draft safeguard switch.

 

 

b. Inducer motor.

 

 

c. Pressure switches.

 

 

d. Limit overtemperature switch.

 

 

e. Gas valve.

 

 

f. Hot surface igniter.

 

 

g. Flame-sensing electrode

 

 

h. Flame rollout switches.

 

6.

Remove screws that fasten the collector box assembly to

 

 

the cell panel. Be careful not to damage the collector box.

 

 

Inducer assembly and elbow need not be removed from

 

 

collector box.

 

7.

Disconnect gas line from gas manifold.

 

8.

Remove the 5 screws that attach the burner assembly to

 

 

the cell panel. The gas valve and individual burners need

 

not be removed from support assembly. Remove NOx baffles if installed.

NOTE: Be very careful when removing burner assembly to avoid breaking igniter. See Fig. 58 and 59 for correct igniter location.

A05025

Fig. 58 - Igniter Position-Side View

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Contents Ama Furnace Reliability Hazard Safety ConsiderationsCUT Hazard Introduction DimensionsClearances to Combustibles Codes and Standards Electrostatic Discharge ESD Precautions ProcedureGeneral LocationCarbon Monoxide Poisoning and Unit Damage Hazard Fire Hazard FIRE, Injury or Death HazardProperty Damage Hazard Location Relative to Cooling EquipmentFurnace Corrosion Hazard AIR for Combustion VentilationCarbon Monoxide Poisoning Hazard Outdoor Combustion Air MethodAir for Combustion, Ventilation, and Dilution for Outdoors Upflow Installation InstallationHorizontal Installation Downflow InstallationFIRE, EXPLOSION, and Carbon Monoxide Poisoning Hazard Suspended Furnace SupportRoll-Out Protection Platform Furnace SupportDuct Flanges Opening dimensions In. mmHorizontal Unit Suspension AIR Ducts Filter Arrangement Carbon Monoxide Poisoning HazardGeneral Requirements Ductwork Acoustical Treatment Supply Air ConnectionsFurnace Air Delivery CFM With FilterSpeed External Static Pressure IN. WC Size Inlet Downflow Furnaces Air Delivery CFM With Filter*Return Air Connections GAS Piping Fire or Explosion HazardUpflow Return Air Configurations and Restrictions Furnace Damage Hazard Maximum Capacity of PipeElectrical Connections Electrical Shock Hazard WiringElectrical Shock and Fire Hazard Furnace MAY not Operate HazardBOX Relocation Electrical DataElectrical Connection to J-BOX BX. Cable Installation in Furnace J-BOX Power Cord Installation in Furnace J-BOXElectrical Box on Furnace Casing Side. See Fig Fire or Electrical Shock HazardTwo-Stage Furnace with Two-Speed Air Conditioner See notes 2, 11, and 12 on the page following these figures Venting AccessoriesMasonry Chimney Requirements General Venting RequirementsChimney Inspection Chart Internal Area of Chimney Appliance Application RequirementsVent Height Upflow Application-Vent Elbow Up Downflow Application-Vent Elbow Up then Left Horizontal Left Application Vent Elbow Left Diameter Vent Height Orientation INPUTBTUH/HR Furnace VentUsing Tin Snips to Cut Tie Points General START-UP, ADJUSTMENT, and Safety CheckBurn Hazard Adjustments Start-Up ProceduresStage Furnace Setup Switch Description Fire and Explosion HazardRedundant Automatic Gas Control Valve Altitude Derate Multiplier for U.S.AOrifice Hole Furnace Overheating Hazard Gas Rate cu ft. /hrSeconds Size of Test Dial For Revolution Color Speed AS Shipped Speed SelectionChecklist Check Safety ControlsStage Furnace Blower OFF delay Setup Switch Desired Heating Mode Setup Switch Blower OFF Delay SECA08485 Orifice Size and Manifold Pressures In wc for Gas Input Rate A08219 A08219A Introduction Service and Maintenance ProceduresCarbon Monoxide Poisoning and Fire Hazard Care and MaintenanceWiring Diagram Filter Size Information IN. / MM Cleaning AND/OR Replacing AIR FilterBlower Motor and Wheel Unit Damage Hazard Cleaning Heat ExchangerIgniter Position-Top View Sequence of Operation58CT Thermidistat Mode Single-Stage Thermostat and Two-Speed Cooling Adaptive ModeSingle-Speed Cooling Troubleshooting Wiring DiagramsContinuous Blower Mode Troubleshooting Guide 2-Speed KitAdapter Chimneyin Usedswitch Shutoffvent Blocked Catalog No58CT---10SI
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