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PG80MSU: Installation, Start-up, Operating and Service and Maintenance Instructions
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.
9. Reassemble motor and blower by reversing steps 8f finishing with
8a. Be sure to reattach ground wire to the blower housing.
10. 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.
11. Spin the blower wheel by hand to verify that the wheel does not rub
on the housing.
12. Reinstall blower assembly in furnace.
13. Reinstall two screws securing blower assembly to blower deck.
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, and
SAFETY CHECK.
NOTE: Refer to
Table 9
for motor speed lead relocation if leads were
not identified before disconnection.
14. Refer to furnace wiring diagram, and connect thermostat leads if
previously disconnected.
15. 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.
16. If furnace is operating properly, RELEASE BLOWER ACCESS
DOOR SWITCH. Remove any jumpers or reconnect any
disconnected thermostat leads. Replace blower access door.
17. Reinstall outer door.
18. Cycle furnace through one complete heating and cooling cycle.
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.
Flame Sensor Cleaning and Servicing Igniter
Cleaning Flame Sensor
The following items must be performed by a qualified service
technician. If the flame sensor develops an accumulation of light dirt or
dust, it may be cleaned by using the following procedure:
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
!
ELECTRICAL SHOCK AND FIRE HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Turn off the gas and electrical supplies to the furnace and install lockout
tag before performing any maintenance or service. Follow the operating
instructions on the label attached to the furnace.
Refer to
Fig.
38.
1. Disconnect power at external disconnect, fuse or circuit breaker.
2. Turn off gas at external shut-off or gas meter.
3. Remove control door and set aside.
4. Turn electric switch on gas valve to OFF.
5. Disconnect Flame Sensor wire from Flame Sensor.
6. Remove the flame sensor from the burner assembly.
7.
(Optional) Remove the Hot Surface Igniter (HSI) and bracket with
igniter gasket
from the burner assembly.
8. Check igniter resistance. Nominal resistance is 40 to 70 ohms at
room temperature and is stable over the life of the igniter.
9. Clean the flame sensor with fine steel wool (0000 grade). Do not
use sand paper or emery cloth.
To reinstall igniter and flame sensor:
1. Install the Hot Surface Igniter (HSI) and bracket with igniter gasket
into burner assembly.
2. Install flame sensor into burner assembly.
3. When installing the HSI and flame sensor, ¼" screws that are the
same size of those removed must be used. Do not use longer
screws.
NOTE: If insulation assembly is damaged, do not attempt to repair,
must be replaced with insulation kit.
NOTE: Proper use of Personal Protective Equipment (PPE) must be
followed, including safety glasses, gloves, and dust mask when
removing and reinstalling the heat exchanger insulation assembly.
4. Connect the wire for the flame sensor.
5. Connect the wire for the Hot Surface Igniter.
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Never purge a gas line into a combustion chamber. Never test for gas
leaks with an open flame. Use a commercially available soap solution
made specifically for the detection of leaks to check all connections. A
fire or explosion may result causing property damage, personal injury
or loss of life.
6. Turn gas on at electric switch on gas valve and at external shut-off
or meter
7. Turn power on at external disconnect, fuse or circuit breaker.
8. Run the furnace through two complete heating cycles to check for
proper operation
9. Install control door when complete.
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
32
WARNING
WARNING
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