Service Manual

8. Troubleshooting
189
SMGB0079 rev.0 - 01/2013
8
Phenomenon Cause Check item
Action
(Turn OFF the main switch)
Insufcient cooling
process
Excessively high dis-
charge pressure
Insufcient air ow to
the outdoor unit heat
exchanger
Clogging of the outdoor unit
heat exchanger?
Remove the clogging
Obstacles at the inlet or the
outlet of the outdoor unit heat
exchanger
Remove the obstacles
Is the service area for the out-
door unit sufcient?
Secure the service area
Correct fan speed? Replace the fan motor
Excessively high air
temp. to the outdoor
unit heat exchanger
Short-circuited air to the out-
door unit?
Remove the cause of the short-
circuited air
Any other heat load near the
outdoor unit?
Remove the heat source
Excessively charged
refrigerant
Expansion valve opening Correctly charge the refrigerant
Non-condensate gas
in cycle
Check each temp. and each
pressure
Charge the refrigerant after the
vacuum pumping
Clogging of the dis-
charge piping
Check for clogging Remove the clogging
Failure or malfunction
of the expansion valve
Check for clogging Remove the clogging
Check the connection cord and
the connector
Replace the connector
Is there an operation sound
from the coil?
Replace the coil
Is the thermistor on the com-
pressor normal?
Replace the thermistor
Is the thermistor installed cor-
rectly on the compressor?
Correctly install the thermistor
Malfunction or internal leakage of the 4-way valve
Check the temp. difference at
the inlet and the outlet of the
4-way valve
Replace the 4-way valve
Excessively low suction
pressure
Malfunction or internal
leakage of the 4-way
valve
Check the Temp. Difference be-
tween the Inlet and the Outlet
of 4-Way Valve
Replace the 4-way valve
Failure of solenoid
valve for bypass
Check refrigerant leakage of
solenoid valve
Replace solenoid valve
Discharge temp. of the indoor unit is unstable
Check the expansion valve
of the indoor unit in the same
system
Replace the failed expansion
valve of the indoor unit