ClimateMaster ACL2120CAZ, Installation Instructions Manual, Page: 42 / 52

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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