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9.0 DIAGNOSTICS & TROUBLESHOOTING
9.3 Service Analyzer Charts (cont.)
COMPRESSOR OVERHEATING (cont.)
SYMPTOM
POSSIBLE CAUSE
CHECK OR REMEDIES
Short cycling of
compressor (cont.)
Low charge
Check system charge.
Low evaporator airflow
Dirty coil
Dirty filter
Duct too small or restricted
Faulty run capacitor
Replace.
Faulty internal overload
Replace compressor.
Faulty Compressor
Valves or scrolls
Fast equalization/Low pressure difference
Replace compressor and examine system to
locate reason.
ELECTRICAL
SYMPTOM
POSSIBLE CAUSE
CHECK OR REMEDIES
Voltage present
on load side of
compressor
contactor and
compressor
won't run
Internal overload
Allow time to reset.
Compressor windings
Check for correct ohms.
Voltage present
on line side of
compressor
contactor only
Thermostat
Check for control voltage to contactor coil.
Compressor control circuit
High-pressure switch
Low-pressure switch
Ambient thermostat
Solid-state protection control or internal thermal sensors
Compressor timed off/on control or interlock
No voltage on line
side of compressor
contactor
Blown fuses or tripped circuit breaker
Check for short in wiring or unit.
Improper wiring
Recheck wiring diagram.
Improper voltage
High voltage
Wrong unit
Power supply problem
Low voltage
Wrong unit
Power supply problem
Wiring undersized
Loose connections
Single Phasing (3 phase)
Check incoming power and fusing.
FLOODED STARTS
SYMPTOM
POSSIBLE CAUSE
CHECK OR REMEDIES
Liquid in the
compressor shell
Faulty or missing crankcase heater
Replace crankcase heater.
Too much liquid in
system
Incorrect piping
Check piping guidelines.
Overcharge
Check and adjust charge.
Diagnostics
Summary of Contents for ACL2120CAZ
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