Carrier FA4ANF Service Manual

clean cooling coil, remove coil access panel. If coil is coated withdirt or lint, vacuum it with a soft brush attachment.Be careful not to bend coil fins. If coil is coated with oil or grease,clean it with a mild detergent and water solution. Rinse coilthoroughly with clear water. Be careful not to splash water oninsulation.Inspect drain pan and condensate drain at the same time coolingcoil is checked. Clean drain pan and condensate drain by removingany foreign matter from pan. Flush pan and drain tube with clearwater.If drain tube is restricted, it can generally be cleared by high-pressure water. Cut plastic line and work outside condensate panand away from coil to clean drain tube.Do not use caustic household drain cleaners in the condensatepan or near the coil. Drain cleaners can quickly destroy a coil.Step 3—Blower Motor and WheelClean blower motor and wheel when cooling coil is cleaned.Disconnect electrical power before removing any accesspanels.To clean blower motor or blower wheel:1. Remove blower access panel.2. Remove motor leads from PCB. Note lead location for ease ofreassembly.3. Remove 2 outside screws holding blower/motor assemblyagainst blower-deck flange and slide assembly out of cabinet.4. Remove screw in strap holding motor capacitor to blowerhousing and slide capacitor out from under strap. Removescrew with green wire from blower housing. Mark blowerwheel, motor, and motor support in relation to blower housingbefore disassembly to ensure proper reassembly. Note positionof blades on wheel.5. Loosen setscrew holding blower wheel onto motor shaft.6. Remove 3 bolts holding motor mount to blower housing andslide motor and mount out of housing. Further disassemblyshould not be necessary as adequate clearance is available.7. Remove blower wheel from housing by removing cutoff platefrom blower housing outlet. Note wheel orientation and cutofflocation for reassembly. The blower motor and wheel may becleaned by using a vacuum with a soft-brush attachment.8. Remove grease with a mild solvent such as hot water anddetergent. Be careful not to disturb balance weights (clips) onblower-wheel vanes. Also, do not drop or bend wheel, asbalance will be affected.To reassemble blower:1. Place blower wheel back into housing. Be sure to positioncorrectly for proper location.2. Reassemble cutoff plate to housing using identified holes fromdisassembly procedure.3. Position motor and mount in same position as when blowerhousing was in unit. Secure motor mount on housing, usingremoved bolts. Make sure mount or motor is grounded toblower housing.4. Locate blower wheel setscrew over flat on motor shaft. Rotatewheel in housing. It should not rub housing and should becentered in inlet opening. If not, loosen setscrew and align asnecessary.5. Attach green wire to blower housing with screw.6. Secure motor capacitor under strap and tighten strap screw.7. Slide blower assembly to blower deck. Be sure (once bloweris within the unit casing) to force blower assembly towardcontrol box while sliding assembly into unit to ensure thatblower assembly engages deck properly.8. Fasten blower assembly to deck with screws previouslyremoved.9. Reconnect electrical leads to PCB.10. Reconnect electrical power to unit and test fan for properrotation.FF1A/FF1B/FF1C SERVICE AND TROUBLESHOOTINGNOTE: For FF1D Service and Troubleshooting refer to FA4A,FB4A, FF1D, FH4A, AND FX4A Circuit Board Function andTroubleshooting on page 2. (For FF1D typical wiring diagram, seeFig. 3B.)Before installation or servicing system, always turn off mainpower to system. There may be more than 1 disconnectswitch. Turn off accessory heater power if applicable. Elec-trical shock can cause personal injury or death.Step 1—Fan MotorThe motor is 2-speed direct drive. High-speed lead is black,low-speed lead is red, and common lead is violet. Be sure properblower speed has been selected. For units with electrical heat,low-speed tap can be used. For cooling, use high-speed tap.The motor is turned on through 2 different routes. The first occurswhen thermostat calls for the fan in cooling, heat pump, orfan-only mode. A 24-vac signal is sent to relay, causing relay toclose its normally-open contacts, turning fan on. The secondoccurs when there is a call for electric heat. A 24-vac signal is sentto heater sequencer/relay, causing it to close, directing 230vthrough the normally-closed contact of fan relay, turning fan on.The fan remains on until sequencer/relay opens. Refer toFF1A/FF1B/FF1C typical wiring diagram. (See Fig. 33.)If motor does run, test motor for an open winding or a windingshorted to motor case. If any 1 of the 2 is present, replace motor.Step 2—Electric Heater ServiceService can be completed with heater in place. Shut off powerbefore servicing.LIMIT SWITCHRefer to Electric Heater Function and Troubleshooting section ofthis manual.SEQUENCERRefer to Electric Heater Function and Troubleshooting section ofthis manual.TRANSFORMERA 40-VA transformer supplies 24-v power for control circuit.Check for 208/230v on primary side of transformer. If present,check for 24v on secondary side.NOTE: Transformer is fused. Do not short circuit.FAN RELAYRelay coil is 24 volts. Check for proper control voltage. Replacerelay if faulty.40