York Y9USC-09 B5R - Troubleshooting; Fan Motor Not Running; Intermittent Fan Motor Operation; Fan Motor Noise Issues

Service manual
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6. TROUBLESHOOTING
In general, possible trouble is classified in three kinds. One is called Starting Failure which is caused from an electrical defect, another is ineffective Air
Conditioning caused b a defect in the refrigeration circuit and improper application, and the other is called the Structure Damage.
ROOM AIRCONDITIONER
VOLTAGE LIMITS:
PROBLEM
POSSIBLE CAUSE
REMED
No power
Check voltage at electrical outlet. Correct if none.
Power supply cord
Check voltage at the power cord terminal. Replace the power cord if none.
Wire disconnected or connection
loose
Connect wire. Refer to wiring diagram for terminal identification. Repair or replace
loose terminal.
Main switch failure
Check and replace the main switch if failure.
Capacitor (Discharge capacitor
before testing)
Test capacitor.
Replace if not within +/-10% of manufacture's rating. Replace if shorted, open or
damaged.
Fan motor will not run.
Will not rotate
Fan blade hitting shroud or blower hitting scroll. Realign assembly.
Check fan motor bearings. Replace the motor if motor shaft do not rotate.
Check voltage. Call an electrician if not within limits.
Test capacitor.
Replace if not within +/-10% of manufacture's rating.
Check bearings. Replace the motor if the fan blade cannot rotate freely.
Fan motor runs
intermittently
Cycles on overload.
Pay attention to any change from high speed to low speed. Replace the motor if the
speed does not change.
Fan
Replace the fan if cracked, out of balance, or partially missing.
Blower
Replace the blower if cracked, out of balance, or partially missing.
Loose screws
Tighten them.
Fan motor noise.
Worn bearings
Replace the motor if knocking sounds continue when running or loose, or the motor
hums or noise appears to be internal while running.
NAMEPLATE RATING
MINIMUM
MAXIMUM
220~240V
196V
253V