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3. Slide blower wheel onto motor shaft with setscrew upward
and aligned with shaft flat portion. Vertically position
wheel along shaft to position marked during disassembly.
NOTE: If previous shaft was not marked or if replacing previous
motor, set blower wheel position by sliding blower wheel along
motor shaft to 1-1/8 in. above rubber grommets. (See Fig. 34.)
4. Hold blower wheel in place and carefully tighten setscrew.
5. Position motor and blower wheel assembly to blower
housing as originally oriented.
6. Secure motor mount to blower housing using bolts previ-
ously removed.
7. Attach green wire to blower housing with screw.
8. Connect electrical and capacitor leads to original terminals.
9. Replace blower access door and tighten all 4 screws.
10. Reinsert disconnect pullout only after blower access door is
secured. Test blower for proper operation.
FD3A SERVICE AND TROUBLESHOOTING
WARNING: 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. Electrical shock can cause personal
injury or death.
I. FAN MOTOR
The motor is 2-speed direct drive. High-speed lead is black,
low-speed lead is red, and common lead is yellow.
NOTE: Unused fan speed leads must be tapped off to prevent
direct short to cabinet surface.
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, causing it to close, directing 230v through the
normally-closed contact of fan relay, turning fan on. The fan
remains on until sequencer opens. Refer to FD3A typical wiring
diagram. (See Fig. 35.)
II. ELECTRIC HEATER SERVICE
Service can be completed with heater in place. Shut off power
before servicing.
A. Limit Switch
Refer to Electric Heater Function and Troubleshooting section of
this manual.
B. Sequencer
Refer to Electric Heater Function and Troubleshooting section of
this manual.
C. Transformer
A 60-VA transformer supplies 24-v power for control circuit.
Check for 208/230-v on primary side of transformer. If present,
check for 24-v on secondary side. Replace transformer if faulty.
NOTE: Transformer is fused. Do not short circuit.
D. Fan Relay
Relay coil is 24 volts. Check for proper control voltage. Replace
relay if faulty.
E. Heater Removal
Disconnect wiring, remove 2 sheet metal screws, and pull heater
out through open hinged access panel. When replacing heater,
ensure orientation of heater element is same as when removed.
III. CLEANING OR REPLACING REFRIGERANT
FLOW-CONTROL DEVICE
1. Pump down outdoor unit. Close service valves at outdoor
unit.
CAUTION: Damage may occur to the scroll compressor
if operated at a negative suction pressure during a system
pumpdown.
2. Bleed and (if possible) recover remaining refrigerant from
tubing and coil through gage port on vapor-tube service
valve.
3. Disconnect liquid refrigerant tube from refrigerant flow-
control device. Refer to Fig. 36.
4. Remove refrigerant flow-control device piston retainer.
Avoid damaging O-ring or machined surfaces on piston,
bore, and retainer.
5. Using small wire with a hook on end of it, remove piston
from refrigerant flow-control device body.
PISTON
BODY
PISTON
Fig. 36—Refrigerant Flow-Control Device
CAUTION: When cleaning piston orifice, be careful not
to scratch or enlarge opening as this will affect operation.
CAUTION: Use a backup wrench and do not over-
tighten as deformation of refrigerant flow-control device
body will occur, causing piston to lodge in a partially
open or closed position.
6. Install new or cleaned piston in refrigerant flow-control
device body.
7. Install new retainer (because of probable damage which
occurred in initial removal).
8. Reconnect refrigerant tube to refrigerant flow-control de-
vice.
9. Pressurize tubing and coil, then leak-check.
10. Evacuate tubing and coil as necessary.
IV. LIQUID TUBE STRAINER
The refrigerant flow-control device is protected on indoor coil by
a wire mesh strainer. If strainer becomes plugged:
1. Complete items 1 and 2 under Cleaning or Replacing
Refrigerant Flow-Control Device section.
2. Loosen flare fitting joint connecting refrigerant flow-
control device to coil liquid refrigerant tube.
—44—
THREAD
PROTECTOR
RUBBER
O-RING
(For FD3A and FG3A)
RETAINER
A92219
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Table of Contents
Troubleshooting
