Carrier 48KHA - Manual (Page 19)

Top Removal Air Filter
NOTE: When performing maintenance or service
procedures that require removal of unit top, be sure
to perform all routine maintenance procedures that
require top removal, including: inspection of heat
exchanger area, coil inspection and cleaning, and
condensate drain pan inspection and cleaning.
When performing maintenance and service pro­
cedures that require unit top removal, refer to
following top removal procedures:
1. Turh off gas supply, then disconnect electric
power to unit.
2. Remove vent cap and combustion-air assemblies.
Do not damage gasket. Refer to Venting section
and reverse assembly procedures shown.
3. Remove all screws that secure unit top, including
screws around 4 sides and those on top that screw
into internal divider panels. Save all screws.
4. Tape all side panels at each seam near unit top.
Use tape strips that are at least 5 in. long to pre­
vent sides from falling when top is removed.
5. Carefully lift top from unit. Set top on edge
and ensure that it is supported by unit side that is
opposite duct (or plenum) side. Use extreme care
to prevent damage to either seal that isolates heat
exchanger and flue products, or the fan blades,
motor and insulation.
6 .
7 .
Carefully replace and secure unit top to unit,
using screws removed in step 3 when maintenance
and/ or service procedures are concluded. Be sure
to use original screws that have rubber washers to
seal out water when securing top to internal
divider panels.
Reinstall vent cap and combustion-air assem­
blies. Refer to Venting section.
Inspect field-supplied air filter(s) at least once
each month and replace (disposable type) or clean
(cleanable type) at least twice during each heating
and cooling season or whenever the filter(s) becomes
clogged with dust and lint.
Evaporator Blower Wheel and Motor — For
longer life, operating economy and continuing effi­
ciency, clean accumulated dirt and grease from
blower wheel and motor annually.
Lubricate motor every 5 years if motor is used
intermittently (thermostat FAN switch in AUTO,
position), or every 2 years if motor is used continu­
ously (thermostat FAN switch in ON position).
Clean and lubricate blower motor and wheel as
follows:
1. Remove and disassemble blower assembly.
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
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, 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.
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