Specifications

17
Troubleshooting
PROBLEM
Compressor short cycles.
Noisy compressor.
System short of capacity.
POSSIBLE CAUSE
Low line voltage causing
compressor electric motor to
overheat.
Dirty or icy evaporator
(reduce air flow).
Lack of refrigerant (bubbly
sight glass).
Light load.
Defective LP switch
Expansion valve stuck in
open position (abnormally
cold suction line).
Broken compressor valve.
Worn or scarred compressor
bearings (excessive
knocking).
Excessive head pressure
(compressor knocks).
Flash gas in liquid refrigerant
line (bubbly sight glass).
Expansion valve stuck or
possibly obstructed (short
cycling or continuous
running).
Clogged drier-strainer (feels
cold).
Ice or dirt on evaporator coil
(excessively warm air from
evaporator blower). See
Evaporator coil ices section
above.
CORRECTIVE ACTION
Check power source for
cause of variation of line
voltage.
Defrost and/or clean.
Repair leak and recharge
system.
Configure controller for light
load.
Check and/or replace.
Ensure feeler bulb is tight on
suction line. Check operation
and superheat.
Replace compressor.
Replace compressor.
Reduce head pressure.
Repair leak and recharge.
Replace valve.
Replace with new drier-
strainer.
Defrost and/or clean.