Operation Shutdown Due To High-Pressure Control Or Freeze-Up Protection (Thermistor Activation) - Daikin FTK25JVE9 Service Manual

Si04-115
5.2 Operation Shutdown Due to High-Pressure Control or
Freeze-Up Protection (Thermistor Activation)
A5 A5 A5 A5
Remote
Controller
Display
Indoor unit LED
Display
"
Method of
Malfunction
Detection
"
"
Malfunction
Decision
Conditions
"
"
Supposed
"
Causes
"
"
"
Troubleshooting
Check No.5
Refer to P.88
Service Diagnosis
High pressure control
During heating operations, the temperature detected by the indoor heat exchanger
thermistor is used for the high pressure control (stop, outdoor fan stop, etc.)
The freeze protection control (operation halt) is activated during cooling operation according
to the temperature detected by the indoor unit heat exchanger thermistor.
High pressure control
During heating operations, the temperature detected by the indoor heat exchanger
thermistor is above 67°C
Freeze protection
When the indoor unit heat exchanger temperature is below 0°C during cooling operation.
Operation halt due to clogged air filter of the indoor unit.
Operation halt due to dust accumulation on the indoor unit heat exchanger.
Operation halt due to short-circuit.
Detection error due to faulty indoor unit heat exchanger thermistor.
Detection error due to faulty indoor unit PCB.
Be sure to turn off power switch before connect or disconnect connector,
Caution
or parts damage may be occurred.
Check the air passage.
Is there any short-circuit?
NO
Check the intake air filter.
Is it very dirty?
NO
Check the dust accumulation on
the indoor unit heat exchanger.
Is it very dirty?
NO
Check No. 5
Indoor unit heat exchanger
thermistor check
Does it conform to the
thermistor characteristic
chart?
NO
YES
YES
YES
YES
Trouble shooting
Provide sufficient air passage.
Clean the air filter.
Clean the heat exchanger.
Replace the indoor unit PCB.
Replace the thermistor (replace
the indoor unit PCB).
(R1945)
67