Carrier 58PHA/PHX instruction manual Unit Damage Hazard, Cleaning Heat Exchanger

NOTE: The blower wheel should not be dropped or bent as balance will be affected. The following steps should be performed by a qualified service agency.

To ensure long life and high efficiency, clean accumulated dirt and grease from blower wheel and motor annually.

The inducer and blower motors are pre-lubricated and require no additional lubrication. These motors can be identified by the absence of oil ports on each end of the motor.

Clean blower motor and wheel as follows:

1.Turn off electrical supply to furnace.

2.Loosen the thumbscrew on outer door and remove outer door.

3.For downflow or horizontal furnaces having vent pipes within the furnace that pass in front of the blower access door:

a.Disconnect vent connector from furnace vent elbow.

b.Disconnect and remove short piece of vent pipe from within furnace.

4.Remove two screws from blower access door and remove blower access door.

5.Disconnect both harness connectors from blower motor instead of at the circuit board. This reduces the chances of a miswire when reconnecting wiring. The connectors are polarized to prevent connection in the wrong orientation.

6.Remove two screws holding control box to blower shelf.

7.Hang control box from front of furnace casing and away from blower compartment.

8.Remove two screws holding blower assembly to blower deck and slide blower assembly out of furnace.

9.Clean blower wheel and motor using a vacuum with soft brush attachment. Blower wheel blades may be cleaned with a small paint or flux brush. Do not remove or disturb balance weights (clips) on blower wheel blades.

10.Vacuum any loose dust from blower housing, wheel and motor.

11.If a greasy residue is present on blower wheel, remove wheel from the blower housing and wash it with an appropriate degreaser. To remove wheel:

NOTE: Before disassembly, mark blower motor, and blower housing so motor and each arm is positioned at the same location during reassembly.

a.Disconnect power choke wires (if used) and ground wire attached to blower housing.

b.Remove screws securing cutoff plate and remove cutoff plate 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 slide motor out of wheel (40+/-10 in.-lb. when reassembling).

e.Remove blower wheel from housing.

f.Clean wheel and housing.

12.Reassemble motor and blower by reversing steps 11f through 11a, finishing with 11a. Be sure to reattach ground wire to the blower housing.

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 necessary.

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 11 for motor speed lead relocation if leads were not identified before disconnection.

17.Reconnect blower leads to furnace control. Refer to furnace wiring diagram, and connect thermostat leads if previously disconnected.

18.To check blower for proper rotation: a. Turn on electrical supply.

!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.

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 reconnect any disconnected thermostat leads. Replace blower access door.

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.Reinstall casing door.

22.Turn on gas supply and cycle furnace through one complete heating and cooling cycle. Verify the furnace temperature rise as shown in “Adjustments” Section. Adjust temperature 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

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