Carrier 58EFA - Manual (Page 2)

A WARNING
Turn OFF the gas and electrical supplies to the unit before
performing any maintenance or service. Follow the operating
instructions on the label attached to the furnace. Failure to
follow this warning could result in personal injury.
The minimum maintenance that should be performed on this
equipment is as follows:
1. Check and clean or replace air filter each month, or as
required. (See Step 1.)
2. Check blower motor and wheel for cleanliness and lubrication
each heating and cooling season. Clean and lubricate as
necessary. (See Step 2.)
3. Check electrical connections for tightness and controls for
proper operation each heating season. Service as necessary.
4. Check for blockages of vent pipe.
A CAUTION
As with any mechanical equipment, personal injury could
result from sharp metal edges, etc. Be careful when removing
parts, panels, or components.
Step 1—Air Filter Cleaning and Replacement
The air filter arrangement may vary depending on the application.
Each furnace may be supplied with a permanent, washable filter
and wire filter retainer option. If so, the filter is normally located
in the return-air plenum opening before the blower. (See Fig. 2.)
Fig. 2—Blower Compartment
Table 1—Horizontal Furnace Filters
A91175
FURNACE SIZE
(INPUT BTUH)
FILTER SIZE
(IN.)
FILTER TYPE
50,000 (1) 13x23x1 Cleanable
75,000 (1) 13x23x1 Cleanable
100,000 (1) 16x23x1 Cleanable
125,000 (1) 20x23x1 Cleanable
A CAUTION
Never operate unit without a filter or with filter access door
removed. Failure to follow this warning could result in a fire
or personal injury.
To clean or replace the filters, proceed as follows;
WA
1. Turn OFF electrical supply to unit.
2. Remove blower access door located at inlet (return air) end of
furnace; 4 screws must be removed.
3. Bend wire filter retainer until it clears furnace flange and
swing it toward the blower.
4. Remove filter from furnace. If filter is tom, replace it.
5. Furnaces may be equipped with permanent, washable filters.
Clean these filters by spraying cold tap water through filter in
opposite direction of airflow. A mild liquid detergent may be
used if necessary.
6. Rinse filters and let dry. Oiling or coating of filters is not
recommended or required for factory-supplied filters.
7. Reinstall filters with cross-mesh binding facing blower.
8. Replace blower access door and reinstall 4 screws.
9. Turn ON electrical supply to furnace.
Step 2—Blower Motor and Wheel Maintenance
For long life, economy, and high efficiency; clean accumulated
dirt and grease from blower wheel and motor annually.
The following items should be performed by a qualified service
technician:
Some motors have prelubricated, sealed bearings and require no
lubrication. These motors can be identified by the absence of oil
ports on each end of the motor. For motors with oil ports, lubricate
as follows:
Lubricate motor every 5 years if motor is used for intermittent
operation (thermostat FAN switch in AUTO position), or every 2
years if motor is in continuous operation (thermostat FAN switch
in ON position).
Clean and lubricate as follows:
1. Turn OFF electrical supply to unit.
2. Remove blower access door; 4 screws must be removed.
3. Remove blower assembly as follows:
a. Remove 4 screws securing front blower support bracket
and remove bracket. (See Fig. 2.)
b. Using a 3/8-in. ratchet with a 3-in. extension, reach through
4-in. diameter holes in rear blower support bracket and
remove 2 screws securing bracket to blower shelf. (See Fig.
2.)
c. Disconnect motor leads from motor speed selector. (See
Fig. 2.)
d. Remove blower assembly from unit.
4. Mark blower wheel location on shaft before disassembly to
insure proper reassembly.
5. Loosen setscrew holding blower wheel on motor shaft.
6. Disconnect ground wire from blower housing.
7. Remove bolts holding motor mount to blower housing and
slide motor and mount out of housing.
8. Lubricate motor (when oil ports are provided).
a. Remove dust caps or plugs from oil ports located at each
end of motor. If motor does not have these caps or plugs,
bearings are sealed and need no further lubrication.
b. Use a good grade of SAE 20 nondetergent motor oil and
add 1 teaspoon (5 cc, 3/16 oz, or 16 to 25 drops) in each oil
port. The use of other types or grades of oil will damage the
motor. Excessive oiling can cause premature bearing fail­
ures.
c. Allow time for total quantity of oU to be absorbed by each
bearing.