Maintenance; Air Filter; Indoor Blower And Motor; Flue Gas Passageways - Carrier 48SD Installation Instructions Manual

MAINTENANCE

To ensure continuing high performance and to minimize the
possibility of premature equipment failure, periodic maintenance
must be performed on this equipment. This unit should be inspected
at least once each year by a qualified service person. To troubleshoot
unit, refer to Table 10, Troubleshooting Chart.
NOTE TO EQUIPMENT OWNER: Consult your local dealer
about the availability of a maintenance contract.
WARNING
!
PERSONAL INJURY AND UNIT DAMAGE HAZARD
Failure to follow this warning could result in personal injury
or death and unit component damage.
The ability to properly perform maintenance on this
equipment requires certain expertise, mechanical skills, tools
and equipment. If you do not possess these, do not attempt to
perform any maintenance on this equipment, other than those
procedures recommended in the Owner's Manual.
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow these warnings could result in personal
injury or death:
1. Turn off electrical power to the unit before performing any
maintenance or service on this unit.
2. Use extreme caution when removing panels and parts.
3. Never place anything combustible either on or in contact
with the unit.
CAUTION
!
UNIT OPERATION HAZARD
Failure to follow this caution may result in improper
operation.
Errors made when reconnecting wires may cause improper
and dangerous operation. Label all wires prior to
disconnecting when servicing.
The minimum maintenance requirements for this equipment are as
follows:
1. Inspect air filter(s) each month. Clean or replace when
necessary.
2. Inspect indoor coil, drain pan, and condensate drain each
cooling season for cleanliness. Clean when necessary.
3. Inspect blower motor and wheel for cleanliness at the
beginning of each heating and cooling season. Clean when
necessary. For first heating and cooling season, inspect
blower wheel bi- -monthly to determine proper cleaning
frequency.
4. Check electrical connections for tightness and controls for
proper operation each heating and cooling season. Service
when necessary.
5. Ensure electric wires are not in contact with refrigerant
tubing or sharp metal edges.
6. Check and inspect heating section before each heating
season. Clean and adjust when necessary.
7. Check flue hood and remove any obstructions, if necessary.

AIR FILTER

IMPORTANT: Never operate the unit without a suitable air filter
in the return- -air duct system. Always replace the filter with the same
dimensional size and type as originally installed. See Table 1 for
recommended filter sizes.
Inspect air filter(s) at least once each month and replace
(throwaway- -type) or clean (cleanable- -type) at least twice during
each cooling season and twice during the heating season, or
whenever the filter becomes clogged with dust and lint.

INDOOR BLOWER AND MOTOR

NOTE: All motors are pre- -lubricated. Do not attempt to lubricate
these motors.
For longer life, operating economy, and continuing efficiency, clean
accumulated dirt and grease from the blower wheel and motor
annually.
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Disconnect and tag electrical power to the unit before cleaning
and lubricating the blower motor and wheel.
To clean the blower motor and wheel:
1. Remove and disassemble blower assembly as follows:
a. Remove unit access panel.
b. Disconnect motor lead from blower relay (BM).
Disconnect yellow lead from terminal L2 of the
contactor.
c. On all units remove blower assembly from unit. Remove
screws securing blower to blower partition and slide
assembly out. 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. Remove and clean blower wheel as follows:
a. Ensure proper reassembly by marking wheel orientation.
b. Lift wheel from housing. When handling and/or cleaning
blower wheel, be sure not to disturb balance weights
(clips) on blower wheel vanes.
c. Remove caked- -on dirt from wheel and housing with a
brush. Remove lint and/or dirt accumulations from wheel
and housing with vacuum cleaner, using soft brush
attachment. Remove grease and oil with mild solvent.
d. Reassemble wheel into housing.
e. Reassemble motor into housing. Be sure setscrews are
tightened on motor shaft flats and not on round part of
shaft.
f. Reinstall unit access panel.
3. Restore electrical power to unit. Start unit and check for
proper blower rotation and motor speeds during heating and
cooling cycles.

FLUE GAS PASSAGEWAYS

To inspect the flue collector box and upper areas of the heat
exchanger:
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