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935SB: Installation, Start-up, Operating and Service Maintenance Instructions
The inducer and blower motors are pre-lubricated and require no
additional lubrication.
Clean blower motor and wheel as follows:
1. Turn off electrical supply to furnace.
2. Remove blower door.
3. All factory wires can be left connected, but field thermostat
connections may need to be disconnected depending on their length
and routing.
4. Remove two screws holding blower assembly to blower deck and
slide blower assembly out of furnace.
5. On 66100M21 size, the top screw securing blower to shelf must be
removed in order to remove the blower. (See
wheel and motor using a vacuum with soft brush attachment.
Blower wheel blades may be cleaned with a small paint or flux
brush. Do not remove or disturb balance weights (clips) on blower
wheel blades.
6. Vacuum any loose dust from blower housing, wheel and motor.
7. If a greasy residue is present on blower wheel, remove wheel from
the blower housing and wash it with an appropriate degreaser. To
remove wheel:
NOTE: Before disassembly, mark blower motor, and blower housing so
motor and each arm is positioned at the same location during
reassembly.
a. Disconnect ground wire attached to blower housing.
b. Remove screws securing cutoff plate and remove cutoff plate
from housing.
c. Loosen set screw holding blower wheel on motor shaft (160+/-20
in.-lb. when reassembling).
d. Remove bolts holding motor to blower housing and slide motor
out of wheel (40+/-10 in.-lb. when reassembling).
e. Remove blower wheel from housing.
f. Clean wheel and housing.
8. Reassemble motor and blower by reversing steps 7d finishing with
7a. Be sure to reattach ground wire to the blower housing.
9. On , ensure that the blower wrapper sits on top of the two tabs on
blower sidewalls.
(Fig.
67)Verify that blower wheel is centered in
blower housing and set screw contacts the flat portion of the motor
shaft. Loosen set screw on blower wheel and reposition if
necessary.
10. Spin the blower wheel by hand to verify that the wheel does not rub
on the housing.
11. Reinstall blower assembly in furnace.
12. Reinstall two screws securing blower assembly to blower deck.
13. Refer to furnace wiring diagram, and connect thermostat leads if
previously disconnected.
14. To check blower for proper rotation:
a. Turn on electrical supply.
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury, or death.
Blower access door switch opens 115-V power to furnace control. No
component operation can occur unless switch is closed. Exercise
caution to avoid electrical shock from exposed electrical components
when manually closing this switch for service purposes.
b. Manually close blower access door switch.
c. Verify blower is rotating in the correct direction.
15. If furnace is operating properly, RELEASE BLOWER ACCESS
DOOR SWITCH. Remove any jumpers or reconnect any
disconnected thermostat leads.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
16. Replace blower access door.
17. Cycle furnace through one complete heating and cooling cycle.
Fig.
67)Clean blower
57
Verify the furnace temperature rise as shown in "Adjustments"
Section. Adjust temperature rise as shown in "Adjustments"
Section. If outdoor temperature is below 70_F, (21_C) turn off
circuit breaker to outdoor unit before running furnace in the cooling
cycle. Turn outdoor circuit breaker on after completing cooling
cycle.
Fig. 66 – Blower Assembly
A11584
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