Step 2 -Care And Maintenance - Payne PG8J Installation Instructions Manual

9. Clean blower 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.
10. Vacuum any loose dust from blower housing, wheel and
motor.
11. If a greasy residue is present on blower wheel, remove
wheel from the blower housing and wash it with an appro-
priate 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 capacitor wires and 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 reas-
sembling).
e. Remove blower wheel from housing.
f. Clean wheel and housing.
12. Reassemble motor and blower by reversing steps 11f
through 11a, finishing with 11a. Be sure to reattach
ground wire to the blower housing.
13. 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 neces-
sary.
14. Spin the blower wheel by hand to verify that the wheel
does not rub on the housing.
15. Reinstall blower assembly in furnace.
16. Reinstall control box assembly in furnace.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in shortened heat
exchanger life.
Heating fan speed(s) MUST be adjusted to provide proper
air temperature rise as specified on the rating plate.
Recommended operation is at the midpoint of the rise range
or slightly above. Refer to SET TEMPERATURE RISE
under START- -UP, ADJUSTMENT,
CHECK.
NOTE: Refer to Table 9 for motor speed lead relocation if leads
were not identified before disconnection.
17. Reconnect blower leads to furnace control. Refer to fur-
nace wiring diagram, and connect thermostat leads if pre-
viously disconnected.
18. To check blower for proper rotation:
a. Turn on electrical supply.
b. Manually close blower access door switch.
NOTE: If thermostat terminals are jumpered at the time blower
access door switch is closed, blower will run for 90 sec before
beginning a heating or cooling cycle.
c. Perform component self- -test as shown at the bottom
of the SERVICE label, located on the front of blower
access door.
d. Verify blower is rotating in the correct direction
CLEANING HEAT EXCHANGER
The following steps should be performed by a qualified
service agency:
NOTE: If the heat exchangers get a heavy accumulation of soot
and carbon, they should be replaced rather than trying to clean
them thoroughly. A heavy build- -up of soot and carbon indicates
that a problem exists which needs to be corrected, such as
improper adjustment of manifold pressure, insufficient or poor
quality combustion air, incorrect size or damaged manifold
orifice( s), improper gas, or a restricted heat exchanger. Action
must be taken to correct the problem.
If it becomes necessary to clean the heat exchangers because of
dust or corrosion, proceed as follows:
and SAFETY
47
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.
19. If furnace is operating properly, RELEASE BLOWER
ACCESS DOOR SWITCH. Remove any jumpers or re-
connect any disconnected thermostat leads. Replace
blower access door.
20. Downflow or horizontal furnaces with vent pipe through
furnace only:
a. Install and connect short piece of vent pipe inside fur-
nace to existing vent.
b. Connect vent connector to vent elbow.
21. Reinstall casing door.
22. Turn on gas supply and cycle furnace through one com-
plete heating and cooling cycle. Verify the furnace temper-
ature rise as shown in Adjustments Section. Adjust tem-
perature rise as shown in Adjustments Section. If outdoor
temperature is below 70_F, turn off circuit breaker to out-
door unit before running furnace in the cooling cycle.
Turn outdoor circuit breaker on after completing cooling
cycle.
1. Turn OFF gas and electrical power to furnace.
2. Remove outer access door.
3. Disconnect vent connector from furnace vent elbow.
4. For downflow or horizontal furnace having an internal
vent pipe, remove internal vent pipe within the casing.
5. Disconnect wires to the following components. Mark
wires to aid in reconnection of (be careful when discon-
necting wires from switches because damage may occur):
a. Draft safeguard switch.
b. Inducer motor.
c. Pressure switch(es).
d. Limit overtemperature switch.
e. Gas valve.
f. Hot surface igniter.
g. Flame- -sensing electrode.
h. Flame rollout switches.
i. Remove NOx baffles on low NOx models.