Carrier 48GH - Manual (Page 19)

WARNiNG: Turn off gas suppiy» then dis­
connect electricai power to unit l^fore cieaning
and iubncatbg biower motor and wheei.
Clean and lubricate blower motor and wheel
as follows;
1. Remove and disassemble blower assembly as
follows:
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 appropriately if lead terminations
were not previously marked.) Pull leads into
blower compartment.
c. Remove blower assembly from unit. Be care­
ful 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 as follows:
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, 3/16 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 as follows:
a. Ensure proper reassembly by marking wheel
orientation and 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 balance weights (clips) on blower
wheel vanes, and be sure not to drop or bend
wheel.
d. Remove caked-on dirt from wheel and hous­
ing with a brush. Remove lint and/or dirt
accumulation from wheel and housing with
vacuum cleaner, using soft brush attachment.
Remove grease and oil with mild solvent.
e. Reassemble wheel and cutoff plate into
housing.
4. Reassemble motor into housing. Be sure set-
screw(s) is tightened on motor shaft flats and not
on round part of shaft.
5. Reinstall blower assembly into unit, route
blower leads into control compartment and
reconnect all blower motor leads to proper
termination points in unit control box. Replace
panels.
6. 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 effi­
cient heating operating by inspecting heating
section before each heating season and cleaning
when necessary.
Proceed as follows to inspect and clean heating
section:
1. Turn off gas supply, (hen disconnect electrical
power to unit.
2. inspect and clean heating section as follows:
a. Remove control access door.
b. Remove unit top following procedures under
Top Removal.
c. Remove secondary-air shield, flue baffles,
pilot, and burners. (Flue baffles may be re­
moved after partial loosening of collector
front panel.) Inspect and clean all of these
components.
d. Clean flue ways with brush and/or vacuum,
and inspect heat exchanger for leaks 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 Heating Section Start-Up and Adjustments
- ADJUSTING BURNER AIR SHUTTERS.
WARNING: Never use a match or other flame
to check for gas leaks.
4. Inspect gas control area for gas leaks, using
a soap-and-water solution.
5. Replace control access panel.
Pilot
— See Fig. 10. Inspect pilot and clean (when
necessary) at beginning of each heating season.
Remove accumulation of soot and carbon from only
the outside of pilot. The pilot flame must be high
enough to touch the flame-sensing element and to
light burners.
Condenser Coil, Evaporator Coil, and Con­
densate Drain Pan
— Inspect condenser coil,
evaporator coil, and condensate drain pan at least
once each year. Proper inspection and cleaning
requires the removal of unit top. See Top Removal.
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