Carrier 48EZ(N)-A Limit Switch, Burner Ignition, Main Burners, Flue Gas Passageways

Page 33

f.Connect 5 pin plug and 4 pin plug to indoor blower motor.

g.Reinstall blower access panel (see Fig. 18).

3.Restore electrical power to unit. Start unit and check for proper blower rotation and motor speeds during heating and cooling cycles.

1.Remove the induced draft blower assembly according to directions in the Induced Draft Blower Assembly section.

2.Remove the 11 screws holding the flue collector box cover (See Fig. 17) to the heat exchanger assembly. Inspect the heat exchangers.

3.Clean all surfaces, as required, using a wire brush.

Limit Switch

Fan Partition

Flue

 

Mounting

Collector

Inducer

Bracket

Box

Blower

 

 

 

 

Housing

Integrated Gas Unit Controller (IGC)

Auto Transformer

fuses used on 460

volt units only.

(Hidden)

Interface Fan

Board (IFB)

Induced Draft

Motor

Rollout

Burner Mounting Switch

Rack Screw

Remove blower access panel (see Fig. 18). Limit switch is located on the fan partition.

Burner Ignition

Unit is equipped with a direct spark ignition 100 percent lockout system. Ignition module (IGC) is located in the control box (See Fig. 17). Module contains a self-diagnostic LED. During servicing, refer to label diagram or Table 5 in these instructions for LED interpretation.

If lockout occurs, unit may be reset by either momentarily interrupting power supply to unit or by turning selector switch to OFF position at the thermostat.

Main Burners

A

A09193

Fig. 17 - Blower Housing and Flue Collector Box

At the beginning of each heating season, inspect for deterioration or blockage due to corrosion or other causes. Observe the main burner flames and adjust, if necessary.

Removal of Gas Train

To remove the gas train for servicing:

48EZ --

COMPRESSOR

CONTROL

BLOWER ACCESS

ACCESS PANEL PANEL

1.

Shut off main gas valve.

2.

Shut off power to unit and install lockout tag.

3.

Remove control access panel (See Fig. 18).

4.

Disconnect gas piping at unit gas valve.

5.

Remove fan partition mounting bracket (2 screws located

 

on the left side of the control compartment on the fan parti-

 

tion panel). Slide bracket forward, bottom first, to remove

 

(See Fig. 17).

6.

Remove wires connected to gas valve. Mark each wire.

7.

Remove the mounting screw that attaches the burner rack to

 

the unit base (See Fig. 17).

8.

Partially slide the burner rack out of the unit (see Fig. 17

 

and 20). Remove ignitor and sensor wires at the burner as-

ACCESS PANEL

A09207

Fig. 18 - Unit Access Panels

Induced Draft (combustion air) Blower Assembly

The induced-draft blower assembly consists of the inducer motor, the blower housing, and the induced-draft blower wheel.

Clean periodically to assure proper airflow and heating efficiency. Inspect blower wheel every fall and periodically during the heating season. For the first heating season, inspect blower wheel bimonthly to determine proper cleaning frequency.

To inspect blower wheel, remove draft hood assembly. Shine a flashlight into opening to inspect wheel. If cleaning is required, remove induced-draft blower assembly as follows:

1.Remove control access panel (See Fig. 18).

2.Remove the 5 screws that attach induced-draft blower as- sembly to the flue collector box cover.

3.Slide the assembly out of the unit. (See 20). Clean the blower wheel. If additional cleaning is required, continue with Steps 4 and 5.

4.To remove blower wheel, remove 2 setscrews.

5.To remove inducer motor, remove screws that hold the inducer motor to the blower housing.

6.To reinstall, reverse the procedure outlined above.

Flue Gas Passageways

To inspect the flue collector box and upper areas of the heat exchanger:

 

sembly. Remove rollout switch wires.

9.

Slide the burner rack out of the unit (See Fig. 17 and 20).

10.

To reinstall, reverse the procedure outlined above.

Outdoor Coil, Indoor Coil, and Condensate Drain Pan

Inspect the outdoor coil, indoor coil, and condensate drain pan at least once each year. The coils are easily cleaned when dry; therefore, inspect and clean the coils either before or after each cooling season. Remove all obstructions, including weeds and shrubs, that interfere with the airflow through the condenser coil.

Straighten bent fins with a fin comb. If coated with dirt or lint, clean the coils with a vacuum cleaner, using the soft brush attachment. Be careful not to bend the fins. If coated with oil or grease, clean the coils with a mild detergent-and-water solution. Rinse coils with clear water, using a garden hose. Be careful not to splash water on motors, insulation, wiring, or air filter(s). For best results, spray outdoor coil fins from inside to outside the unit. On units with an outer and inner condenser coil, be sure to clean between the coils. Be sure to flush all dirt and debris from the unit base.

Inspect the drain pan and condensate drain line when inspecting the coils. Clean the drain pan and condensate drain by removing all foreign matter from the pan. Flush the pan and drain tube with clear water. Do not splash water on the insulation, motor, wiring, or air filter(s). If the drain tube is restricted, clear it with a “plumbers snake” or similar probe device. Ensure that the auxiliary drain port above the drain tube is also clear.

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Contents Safety Considerations Table of ContentsIntroduction Receiving and InstallationCheck Equipment Provide Unit Support48EZ-A24-36 Unit Dimensions 48EZ-A42-60 Unit Dimensions Number Roof Curb DimensionsProvide Clearances Field Fabricate DuctworkRig and Place Unit InspectionInstall Gas Piping Install Flue HoodConnect Condensate Drain Rigging/Lifting of Unit See FigSediment Trap Fire or Explosion HazardConfiguring Units for Downflow Vertical Discharge Install Duct ConnectionsPhysical Data Unit 48EZ-A Physical Data Unit 48EZ-A Cont’d Maximum Gas Flow CapacityHeating Inputs Special Procedures for 208-V Operation Install Electrical ConnectionsHigh-Voltage Connections Unit Component Damage HazardPRE-START-UP Balance Point Setting-Thermidistat or Hybrid ThermostatControl Voltage Connections Transformer ProtectionSTART-UP Start-up Heating and Make Adjust- mentsCheck for Refrigerant Leaks Unit Sequence of OperationAdjust Gas Input Check Gas InputUnit Damage Hazard Start-up Cooling and Make Adjust- ments Indoor Airflow and Airflow Adjustments Checking and Adjusting Refrigerant ChargeGas Heating Fan Speed Set-up Unit Operation HazardTwo Cooling Fan Speeds Set-up Dehumidification feature used Continuous Fan OperationColor Coding for Indoor Fan Motor Leads Dry Coil Air Delivery* Horizontal Unit 48EZ-A24-60 Unit Heating Rise MotorRange Speed Color Dry Coil Air Delivery* Horizontal Discharge Unit 48EZ-A24-60 1354 1290 1226 1158 1102 1046 981 918 843 55oF Heating Rise Medium1 48EZ ---,NA48090 48EZ ---,NA48130 Unit Heating Rise Motor Wire Unit Standard CFM Scfm Size Horizontal and Downflow Filter Pressure Drop Table IN. W.CDownflow Cooling Standard CFM Scfm Economizer + Tons Cooling Standard CFM Scfm48EZ a 208/230-1-60 Ladder Wiring Diagram, Unit 48EZ-A 208/230-3-60 Connection Wiring Diagram, Unit 48EZ-A Cont. 208/230-3-60 Ladder Wiring Diagram, Unit 48EZ-A Cooling Charging Table-Subcooling Cleaning the Blower Motor and Wheel MaintenanceAir Filter Indoor Blower and MotorInduced Draft combustion air Blower Assembly Limit SwitchBurner Ignition Main BurnersElectrical Controls and Wiring Outdoor FanRefrigerant Circuit Loss of Charge Switch Pressure SwitchesGas Input Indoor AirflowHigh-Pressure Switch Copeland Scroll Compressor Puron RefrigerantExplosion Hazard Unit Operation and Safety Hazard Refrigerant SystemCompressor Oil Troubleshooting START-UP ChecklistPuronr R-410A Quick Reference Guide Symptom Cause Remedy Troubleshooting Guide Cooling or Heat Pump Heating ModeTroubleshooting Guide-Heating Troubleshooting Guide-LED Error CodesLED OFF Remove and Store in Job Files TemperaturesPreliminary Information Model no III. START-UP Electrical Supply Voltage Compressor Amps