Panasonic U-4LE2E5 Service Manual & Test Run Service Manual page 145

4. 2WAY Alarm Codes
3. Mini VRF Alarm Codes
P03 Alarm
Alarm code P03
Alarm meaning Compressor discharge temperature is too high.
Alarm conditions Compressor : Pre-trip stops when the temperature exceeds 106°C.
* The alarm occurs when pre-trip stop occurs more than once. However, the pre-trip counter is cleared
if the compressor operates continuously for a specified length of time (more than 2.5 minuites).
Probable cause (1) Insufficient amount of refrigerant
(including trouble resulting from an insufficient initial charge and from gas leakage)
(2) Blocking of low-pressure parts caused by intrusion of foreign objects (moisture, scale, etc.)
(3) Malfunction of expansion valves (MOV1)
(4) Compressor discharge sensor failure
(5) Outdoor Unit Control PCB failure
(6) Failure to open the service valve of the outdoor unit
(7) Electrical noise
Check (1) Insufficient refrigerant
Trouble: Liquid effectiveness is poor.
Check:
(2) Sensor failure
Check:
(3) Failure to open the service valve of the outdoor unit
Check open/closed status of the outdoor unit service valve.
(4) If the cause is still unknown after checking the above, there is possibility that electrical noise is the
cause of the trouble.
Correction (1) Replace the sensor.
(2) Replace the Outdoor Unit Control PCB.
(3) Correct the problem locations.
Example All of the probable causes
Check whether or not the superheating temperature is declining if the expansion valves
(MOV1) are opened to 300 pulses or more (after checking for foreign object intrusion).
• This alarm is likely to occur when wiring is partially cut. (It is difficult to identify, even
when continuity is checked.) The detected discharge temperature is high.
• Replace the sensor with another discharge sensor and compare the temperature conditions.
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2WAY SYSTEM
Mini VRF SYSTEM
Trouble Diagnosis
Trouble Diagnosis
6