Discharge Pipe Temperature Control - Daikin B-Series Service Manual

Troubleshooting
5.15

Discharge Pipe Temperature Control

F3
Remote
Controller
Display
Outdoor Unit LED A
Display
Method of The discharge pipe temperature control (stop, frequency drooping, etc.) is checked with the
temperature being detected by the discharge pipe thermistor.
Malfunction
Detection
Malfunction 2YC45, 2YC63
If the temperature being detected by the discharge pipe thermistor rises above 120°C, the
Decision
compressor will stop. (The error is cleared when the temperature has dropped below 107°C.)
Conditions
2YC32
The temperature at which the compressor halts varies according to the frequency.
(1) 110°C when the frequency is above 45 Hz on ascending or above 40 Hz on descending.
(2) 102°C when the frequency is between 30 Hz and 45 Hz on ascending or between 40Hz and
(3) 98°C when the frequency is below 30 Hz on ascending or below 25 Hz on descending.
Supposed
Causes
Troubleshooting
Check No.04
Refer to P.217
Check No.06
Refer to P.219
Check No.11
Refer to P.222
198
5 1 4 2 1 3 4 4
25Hz on descending.
If the compressor stops 6 times straight due to abnormal discharge pipe temperature, the
system will be shut down.
The error counter will reset itself if this or any other error does not occur during the following
60-minute compressor running time (total time).
Refrigerant shortage
Four way valve malfunctioning
Discharge pipe thermistor defective
(heat exchanger or outdoor temperature thermistor defective)
Outdoor unit PCB defective
Water mixed in the local piping
Electronic expansion valve defective
Stop valve defective
Be sure to turn off power switch before connect or disconnect connector,
Caution or parts damage may be occurred.
Check No. 06
Check the thermistors.
Functioning
Check No. 04
Check the electronic expansion
valve.
Functioning
Check No. 11
Check the refrigerant line.
Functioning
1
Malfunctioning
Discharge pipe thermistor
Outdoor unit heat exchanger thermistor
Outdoor temperature thermistor
Malfunctioning
Malfunctioning
Refrigerant shortage
Four way valve malfunctioning
Water mixed
Stop valve defective
Si12-714
Replace a defective
thermistor.
Replace the valve itself or
the coil.
Refer to the refrigerant line
check procedure.
Replace the outdoor unit
PCB.
(R4700)
Service Diagnosis