Bryant FA4A - Manual (Page 21)

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BLOWER
WHEEL
INLET
RING
FD3A SERVICE AND TROUBLESHOOTING
WARNING: Btfom instaJlation or servicing system,
always turn off main powet to system. There may be
more than 1 disconnect switch/Turn off accessory beater
power if applicable. Electrical shock can cause personal
injury or death.
1. FAN MOTOR
The motor is 2-spccd direct drjve. 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 shown in Fig. 18.
li. ELECTRIC HEATER SERVICE
Service can be completed with heater in place. Shut off power
before servidng-
A. Limit Switch
Malfunction prevents heating element from coming on. Replace
switch if malfunction occurs,
B. Sequencer
Malfunction causes heater not to come on or never shut off.
Replace sequencer.
C. Transformer
A 60-va transformer supplies 24-v power for control circuit.
Replace transformer if faulty.
NOTE: Transformer is fused. Do not short circuit.
AÔËÛOS
D. Fan Beley
Malfunction causes unit fan not to run or run continuously.
Replace relay.
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 he&ter element is same as when removed.
ML cleaning OB 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, 19,
4. Remove refrígerapt flow-control device piston retainer.
Avoid damaging 6-xing 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.
A CAUTION: When cleaning piston orifice, be careful not
to scratch or enlarge opening as this will affect operation.
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