Indoor Unit Fan Operates, But Compressor Does Not Operate - Daikin RZQ Series FCQ20EVA Service Manual

SiME281501E
2.3 Indoor Unit Fan Operates, but Compressor does not
Operate
Applicable Model All models of TopAir series
 Fuse blown or disorder of contact in operation circuit
Supposed
 Defective thermistor
Causes
 Defective indoor/outdoor unit PCB
 Defective magnetic switch
 Defective power transistor
 Defective compressor
Troubleshooting
Caution
Be sure to turn off the power switch before connecting or disconnecting connectors, or parts may be damaged.
· Indoor unit fan runs at setting airflow rate.
· (In cooling)
When suction air temperature is higher than set temperature
· (In heating)
When suction air temperature is lower than set temperature
switch OFF or the fuse for power
switch turned ON at outdoor
applied at the compressor
output from the magnetic switch
or power transistor?
Is rated voltage output
Suction air
thermistor
Indoor unit
PCB
Input to
PCB
Service Diagnosis
Is the power
YES
switch blown?
NO
Is the heating
YES
air temperature >
32˚C
NO
(1)
Is rated voltage
YES
terminals?
NO
(2)
Is rated voltage
YES
NO
(3)
YES
from the PCB?
NO
Outdoor unit
PCB
Relay
Output
Input to
from
PCB
PCB
Magnetic
switch or
power
transistor
COMP
(3) (2)
Output from Output from
relay or magnetic
micro- switch or SW
computer circuit of
power
transistor
Symptom-based Troubleshooting
Turn ON the power switch or
replace the fuse.
Normal.
(Thermostat OFF by outdoor air
temperature)
Replace the compressor.
Replace the magnetic switch or
power transistor.
Replace the PCB.
Check the thermistor.
(1)
Output from
Compressor
76