Carrier 58DLA Installation, Start-up, Operating And Service And Maintenance Instructions

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Carrier 58DLA Installation, Start-up, Operating And Service And Maintenance Instructions Manual pdf 47 page image

47The inducer and blower motors are pre--lubricated and require noadditional lubrication. These motors can be identified by theabsence of oil ports on each end of the motor.Clean blower motor and wheel as follows:1. Turn off electrical supply to furnace.2. Remove outer door.3. For downflow or horizontal furnaces having vent pipeswithin the furnace that pass in front of the blower accessdoor:a. Disconnect vent connector from furnace vent elbow.b. Disconnect and remove short piece of vent pipe fromwithin furnace.4. Remove two screws from blower access door and removeblower access door.5. All factory wires can be left connected, but field thermo-stat connections may need to be disconnected dependingon their length and routing.6. Remove two screws holding blower assembly to blowerdeck and slide blower assembly out of furnace.7. Clean blower wheel and motor using a vacuum with softbrush attachment. Blower wheel blades may be cleanedwith a small paint or flux brush. Do not remove or disturbbalance weights (clips) on blower wheel blades.8. Vacuum any loose dust from blower housing, wheel andmotor.9. If a greasy residue is present on blower wheel, removewheel from the blower housing and wash it with an appro-priate degreaser. To remove wheel:NOTE: Before disassembly, mark blower motor, and blowerhousing so motor and each arm is positioned at the same locationduring reassembly.a. Disconnect capacitor wires and ground wire attached toblower housing.b. Remove screws securing cutoff plate and remove cutoffplate from housing.c. Loosen set screw holding blower wheel on motor shaft(160+/--20 in.--lb. when reassembling).d. Remove bolts holding motor to blower housing and slidemotor out of wheel (40+/--10 in.--lb. when reassembling).e. Remove blower wheel from housing.f. Clean wheel and housing.10. Reassemble motor and blower by reversing steps 9athrough 9f, finishing with 9a. Be sure to reattach groundwire to the blower housing.11. Verify that blower wheel is centered in blower housingand set screw contacts the flat portion of the motor shaft.Loosen set screw on blower wheel and reposition if neces-sary.12. Spin the blower wheel by hand to verify that the wheeldoes not rub on the housing.13. Reinstall blower assembly in furnace.14. Reinstall two screws holding blower assembly to blowerdeck.15. Refer to furnace wiring diagram, and connect thermostatleads if previously disconnected.16. To check blower for proper rotation:a. Turn on electrical supply.b. Manually close blower access door switch.UNIT DAMAGE HAZARDFailure to follow this caution may result in shortened heatexchanger life.Heating fan speed(s) MUST be adjusted to provide properair temperature rise as specified on the rating plate.Recommended operation is at the midpoint of the rise rangeor slightly above. Refer to “SET TEMPERATURE RISE”under START--UP, ADJUSTMENT, and SAFETYCHECK.CAUTION!ELECTRICAL SHOCK HAZARDFailure to follow this warning could result in personalinjury, or death.Blower access door switch opens 115--v power tofurnace control. No component operation can occurunless switch is closed. Exercise caution to avoidelectrical shock from exposed electrical componentswhen manually closing this switch for service purposes.! WARNINGNOTE: If thermostat terminals are jumpered at the time bloweraccess door switch is closed, blower will run for 90 sec beforebeginning a heating or cooling cycle.c. Perform component self--test as shown at the bottom ofthe SERVICE label, located on the front of blower accessdoor.d. Verify blower is rotating in the correct direction.17. If furnace is operating properly, RELEASE BLOWERACCESS DOOR SWITCH. Remove any jumpers or re-connect any disconnected thermostat leads. Replaceblower access door.18. Downflow or horizontal furnaces with vent pipe throughfurnace only:a. Install and connect short piece of vent pipe inside furnaceto existing vent.b. Connect vent connector to vent elbow.19. Reinstall outer door.20. Cycle furnace through one complete heating and coolingcycle. Verify the furnace temperature rise as shown in“Adjustments” Section. Adjust temperature rise as shownin “Adjustments” Section. If outdoor temperature is below70_F, (21_C)turn off circuit breaker to outdoor unit beforerunning furnace in the cooling cycle. Turn outdoor circuitbreaker on after completing cooling cycle.Cleaning Heat ExchangerThe following steps should be performed by a qualifiedservice agency:NOTE: If the heat exchangers get a heavy accumulation of sootand carbon, they should be replaced rather than trying to cleanthem thoroughly. A heavy build--up of soot and carbon indicatesthat a problem exists which needs to be corrected, such asimproper adjustment of manifold pressure, insufficient or poorquality combustion air, incorrect size or damaged manifoldorifice( s), improper gas, or a restricted heat exchanger. Actionmust be taken to correct the problem.58DL