Carrier 48KHA - Manual (Page 18)

a. Remove blower and control access panels.
b. Refer to unit wiring label and disconnect blower
motor leads from their termination points in unit
control box. Be sure to mark wiring label appropri­
ately if lead terminations were not previously
marked. Pull leads into blower compartment.
c. Remove blower assembly from unit. Be careful not
to tear insulation in blower compartment.
d. Ensure proper reassembly by marking blower wheel
and motor in relation to blower housing before
disassembly.
e. Loosen setscrew(s) that secures wheel to motor
shaft, remove screws that secure motor mount
brackets to housing, and slide motor and motor
mount out of housing.
2. Lubricate motor.
a. Thoroughly clean all accumulations of dirt or grease
from motor housing.
b. Remove dust caps or plugs from oil ports located at
each end of motor.
c. Use a good grade of SAE 20 nondetergent motor oil
and put one teaspoon, 5 cc, ®/ie oz., or 16 to 25 drops
in each oil port.
d. Allow time for oil to be absorbed by each bearing,
then wipe excess oil from motor housing.
e. Replace dust caps or plugs in oil ports.
3. Remove and clean blower wheel.
a. Ensure proper reassembly by marking wheel orien­
tation emd cutoff plate location.
b. Remove screws holding cutoff plate, and remove
plate from housing.
c. Lift wheel from housing. When handling and/or
cleaning blower wheel, be sure not to disturb bal­
ance weights (clips) on blower wheel vanes.
d. Remove caked-on dirt from wheel and housing with
a brush. Remove lint and/or dirt accumulation from
wheel emd housing with vacuum cleaner, using soft
brush attachment. Remove grease and oil with mild
solvent.
e. Reassemble wheel and cutoff plate into housing.
f. Reassemble motor into housing. Be sure setscrews
are tightened on motor shaft flats and not on round
peirt of shaft.
4. Reinstall blower assembly into unit. Route blower
motor leads into control compartment and reconnect
all blower motor leads to proper termination points in
unit control box. Replace panels.
5. Restore electrical power, then gas supply, to unit. Start
unit and check for proper blower rotation and motor
speeds during heating and cooling cycles.
Heating Section— Ensure dependable and efficient heating
operation by inspecting heating section before each heating
season and cleaning when necessary. Proceed as follows;
1. Turn off gas supply, then disconnect electrical power to
unit.
2. Inspect emd clean heating section.
a. Remove control access door.
b. Remove unit top following procedures under Top
Removal.
c. Remove second£iry-air shield, flue baffles, pilot and
burners. Flue baffles may be removed after partial
loosening of collector front panel. Inspect and deem
all of these components. Be sure to remove any resi­
due that may have collected on a component.
d. Clean flue ways with brush and/or vacuum, and
inspect heat exchanger for leгlks and cracks.
e. Inspect indoor-air passages in unit for cleanliness
and check tightness of screws and parts.
f. Replace all components removed in step c, and
replace unit top.
3. Restore electrical power, then gas supply to unit. Start
heating cycle and adjust burner air shutters. See Heat­
ing Section Start-Up and Adjustments—Adjusting
Burner Air Shutters.
A WARNING
Never use a match or other flame to check for gas leaks.
Failure to adhere to this warning may cause an
explosion.
4. Inspect gas control area for gas leaks, using a soap-
and-water solution.
5. Replace control access panel.
Pilot— Inspect the pilot and clean (when necessary) at begin­
ning of each heating season. Remove accumulation of soot
and carbon from pilot. The pilot flame must be high enough
to properly touch flame-sensing element and to light
burners.
Condenser Coil, Evaporator Coil and Condensate Drain
Pan—
Inspect condenser coil, evaporator coil and conden­
sate drain pan at least once each year. Proper inspection
and cleaning requires removal of unit top. See Top Removal
section.
Coils are easily cleaned when dry; therefore, inspect and
clean coils either before or after each cooling season.
Remove all obstructions including weeds and shrubs that
interfere with edrflow through condenser coil. Straighten
bent fins with a fin comb. If coated with dirt or lint, clean
coils with a vacuum cleaner, using soft brush attachment.
Be careful not to bend fins. If coated with oil or grease,
clean coils with 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 condenser coil fins from inside to
outside of unit. On units with an outer and inner condenser
coil, be sure to clean between coils. Be sure to flush all dirt
and debris from unit base.
Inspect drain pan and condensate drain line when inspect­
ing the coils. Clean dreun pan and condensate drain by
removing edl foreign matter from pan. Flush pern and drain
tube with clear water. Do not splash water on insulation,
motor, wiring or ear filter(s). If drain tube is restricted, clear
it with a plumber’s snake or similar probe device.
The bottom of dreun tube has a Vs-in. diameter hole. This hole
is located in the portion of the dreiin tube that runs through
drain pan. Clean this hole with a stiff wire that has a %-in.
long, 90 degree bend.
Condenser Fan
A CAUTION
Keep condenser fan free of edl obstructions to ensure
proper cooling operation. Never place eu-ticles on top of
unit.
Inspect fan blades for cracks or bends each year. Ensure
that blades clear the motor by exactly % inch. If blade
assembly has slipped down motor shaft, adjust fan position
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