Carrier DELUXE 58DXC - Manual (Page 3)

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 access doors.
3. Downflow furnace only — disconnect vent pipe, elbow, and
auxiliary limit switch. (See Fig. 6.)
a. Remove vent pipe enclosure from top side of blower shelf
and position to 1 side.
b. Loosen hose clamps on outlet elbow and remove elbow.
c. Loosen hose clamp on extension pipe outside of furnace
and remove pipe.
d. Disconnect wires from auxiliary limit on blower housing.
4. Note location of wires for reassembly, then remove electrical
leads from numbered side of blower speed selector. (See Fig.
4 and 6.)
5. Upflow furnaces only —remove drain trap and control box.
a. Remove control box from bottom side of blower shelf and
position to 1 side.
b. Using backup wrench, disconnect drain pipe at coupling in
blower compartment.
c. Loosen hose clamp and remove 7/8-in. diameter drain hose
from drain trap.
d. Loosen hose clamp and disconnect 5/8-in. diameter drain
hose at bottom of inducer housing located under blower
shelf.
e. Remove screw securing drain trap assembly.
6. Remove screws securing blower assembly to blower shelf and
slide blower assembly out of furnace.
7. Squeeze side tabs of blower speed selector and pull from
blower housing bracket.
8. Loosen screw in strap holding motor capacitor to blower
housing and slide capacitor from strap.
9. Mark blower wheel location on shaft before disassembly to
insure proper reassembly.
10. Loosen setscrew holding blower wheel on motor shaft.
NOTE: Mark blower mounting arms, and blower housing so each
arm is positioned at the same hole location during reassembly. This
will insure that oilers point up.
11. Remove bolts holding motor mount to blower housing and
slide motor and mounts out of housing. Disconnect ground
wire attached to blower housing before removing motor.
12. 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 oil to be absorbed by each
bearing.
d. After oiling motor, wipe excess oil from motor housing.
e. Replace dust caps or plugs on oil ports.
13. Remove blower wheel from housing.
a. Mark blower wheel orientation and cutoff plate location to
insure proper reassembly.
b. Remove screws securing cutoff plate and remove cutoff
plate from housing.
c. Remove blower wheel from housing.
14. Clean blower wheel and motor by using a vacuum with soft
brush attachment. Be careful not to disturb balance weights
(clips) on blower wheel vanes. Do not drop or bend wheel as
balance will be affected.
15. Reassemble blower by reversing items 13.a. through 13.c.
Ensure wheel is positioned for proper rotation.
16. Reassemble motor and blower by reversing items 6 through
11. If motor has ground wire, be sure it is reconnected.
A CAUTION
Ensure the motor is properly positioned in the blower
housing. The motor oil ports must be at a minimum of 30°
above the horizontal centerline of the motor after the blower
assembly has been reinstalled in the furnace.
17. Reinstall blower assembly in furnace.
18. Upflow furnace only—reinstall drain trap and control box.
a. Inspect drain trap and hoses to ensure they are not blocked
or restricted. Reinstall drain trap and hoses. Be sure to
tighten hose clamps.
b. Using backup wrench, attach drain pipe and tighten com­
pression coupling.
c. Reinstall control box on bottom side of blower shelf. Be
sure edge connector is connected through top of blower
shelf.
19. Downflow furnace only — reconnect vent pipe, elbow, and
auxiliary limit switch.
a. Reinstall outlet elbow and extension pipe. Be sure connec­
tions are tight and leak proof.
AUXILIARY
LIMIT
SWITCH
Fig. 6—Model 58DXC Downflow Furnace