clean cooling coil, remove coil access panel. If coil is coated with
dirt or lint, vacuum it with a soft brush attachment.
Be careful not to bend coil fins. If coil is coated with oil or grease,
clean it with a mild detergent and water solution. Rinse coil
thoroughly with clear water. Be careful not to splash water on
insulation.
Inspect drain pan and condensate drain at the same time cooling
coil is checked. Clean drain pan and condensate drain by removing
any foreign matter from pan. Flush pan and drain tube with clear
water.
If drain tube is restricted, it can generally be cleared by high-
pressure water. Cut plastic line and work outside condensate pan
and away from coil to clean drain tube.
Do not use caustic household drain cleaners in the condensate
pan or near the coil. Drain cleaners can quickly destroy a coil.
Step 3—Blower Motor and Wheel
Clean blower motor and wheel when cooling coil is cleaned.
Disconnect electrical power before removing any access
panels.
To clean blower motor or blower wheel:
1. Remove blower access panel.
2. Remove motor leads from PCB. Note lead location for ease of
reassembly.
3. Remove 2 outside screws holding blower/motor assembly
against blower-deck flange and slide assembly out of cabinet.
4. Remove screw in strap holding motor capacitor to blower
housing and slide capacitor out from under strap. Remove
screw with green wire from blower housing. Mark blower
wheel, motor, and motor support in relation to blower housing
before disassembly to ensure proper reassembly. Note position
of blades on wheel.
5. Loosen setscrew holding blower wheel onto motor shaft.
6. Remove 3 bolts holding motor mount to blower housing and
slide motor and mount out of housing. Further disassembly
should not be necessary as adequate clearance is available.
7. Remove blower wheel from housing by removing cutoff plate
from blower housing outlet. Note wheel orientation and cutoff
location for reassembly. The blower motor and wheel may be
cleaned by using a vacuum with a soft-brush attachment.
8. Remove grease with a mild solvent such as hot water and
detergent. Be careful not to disturb balance weights (clips) on
blower-wheel vanes. Also, do not drop or bend wheel, as
balance will be affected.
To reassemble blower:
1. Place blower wheel back into housing. Be sure to position
correctly for proper location.
2. Reassemble cutoff plate to housing using identified holes from
disassembly procedure.
3. Position motor and mount in same position as when blower
housing was in unit. Secure motor mount on housing, using
removed bolts. Make sure mount or motor is grounded to
blower housing.
4. Locate blower wheel setscrew over flat on motor shaft. Rotate
wheel in housing. It should not rub housing and should be
centered in inlet opening. If not, loosen setscrew and align as
necessary.
5. Attach green wire to blower housing with screw.
6. Secure motor capacitor under strap and tighten strap screw.
7. Slide blower assembly to blower deck. Be sure (once blower
is within the unit casing) to force blower assembly toward
control box while sliding assembly into unit to ensure that
blower assembly engages deck properly.
8. Fasten blower assembly to deck with screws previously
removed.
9. Reconnect electrical leads to PCB.
10. Reconnect electrical power to unit and test fan for proper
rotation.
FF1A/FF1B/FF1C SERVICE AND TROUBLESHOOTING
NOTE:
For FF1D Service and Troubleshooting refer to FA4A,
FB4A, FF1D, FH4A, AND FX4A Circuit Board Function and
Troubleshooting on page 2. (For FF1D typical wiring diagram, see
Fig. 3B.)
Before installation or servicing system, always turn off main
power to system. There may be more than 1 disconnect
switch. Turn off accessory heater power if applicable. Elec-
trical shock can cause personal injury or death.
Step 1—Fan Motor
The motor is 2-speed direct drive. High-speed lead is black,
low-speed lead is red, and common lead is violet. Be sure proper
blower speed has been selected. For units with electrical heat,
low-speed tap can be used. For cooling, use high-speed tap.
The motor is turned on through 2 different routes. The first occurs
when thermostat calls for the fan in cooling, heat pump, or
fan-only mode. A 24-vac signal is sent to relay, causing relay to
close its normally-open contacts, turning fan on. The second
occurs when there is a call for electric heat. A 24-vac signal is sent
to heater sequencer/relay, causing it to close, directing 230v
through the normally-closed contact of fan relay, turning fan on.
The fan remains on until sequencer/relay opens. Refer to
FF1A/FF1B/FF1C typical wiring diagram. (See Fig. 33.)
If motor does run, test motor for an open winding or a winding
shorted to motor case. If any 1 of the 2 is present, replace motor.
Step 2—Electric Heater Service
Service can be completed with heater in place. Shut off power
before servicing.
LIMIT SWITCH
Refer to Electric Heater Function and Troubleshooting section of
this manual.
SEQUENCER
Refer to Electric Heater Function and Troubleshooting section of
this manual.
TRANSFORMER
A 40-VA transformer supplies 24-v power for control circuit.
Check for 208/230v on primary side of transformer. If present,
check for 24v on secondary side.
NOTE:
Transformer is fused. Do not short circuit.
FAN RELAY
Relay coil is 24 volts. Check for proper control voltage. Replace
relay if faulty.
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