Equipment Operates But Does Not Provide Cooling - Daikin RZQ Series FCQ20EVA Service Manual

SiME281501E
2.6

Equipment Operates but does not Provide Cooling

Applicable All models of TopAir series
Models
 Wrong selection of model
Supposed
 Refrigerant shortage
Causes
 Insufficient airflow in the indoor unit
 Increase of high pressure
Troubleshooting
Caution Be sure to turn off the power switch before connecting or disconnecting connectors, or parts may be damaged.
Measure the temperature of suction
air and discharge air.
Temperature difference = Suction air
temp. – Discharge air temp.
Temperature
difference for cooling should
be between 8 and
18˚C.
NO
Does any frost
generate around inlet
port of indoor unit heat exchanger
or outlet port of electronic
expansion valve?
NO
Does indoor unit
airflow rate decrease?
NO
Is the level of
high pressure higher than
normal level?
NO
Service Diagnosis
 In addition, the following errors may be conceivable
• Insufficient compression of the compressor
• Insufficient circulation of refrigerant
• Defective electronic expansion valve
YES
load increase after installation
• Wrong selection of model
• Affection of direct sun
YES
operation current less than
YES
YES
Does the heat
YES
of the unit?
NO
Is the
YES
specified level?
NO
Symptom-based Troubleshooting
Normal.
Additional unit installation
should be considered.
Refrigerant shortage possibly
generates trouble.
After vacuum drying, charge
correct amount of refrigerant.
Check the each section.
• Clogged air filter
• Soiled heat exchanger
• Defective fan motor
(Refer to troubleshooting "
Check the each item.
• Refrigerant overcharge
• Air mixed in refrigerant system
• Soiled heat exchanger
• Short circuit of discharge air
• Disturbing item in airflow
• Defective fan motor of outdoor
unit
(Refer to troubleshooting "
Check the each item.
• Insufficient compression of
compressor
• Insufficient circulation of
refrigerant
• Defective electronic
expansion valve
A6
".)
E7
".)
80