Panasonic U-8MF2E8 Service Manual page 137

4. 3WAY Alarm Codes
F17 Alarm
Alarm code F17
Alarm meaning Low-pressure sensor trouble
Alarm conditions (1) Sensor short circuit
(2) Sensor open circuit
Probable cause (1) Sensor malfunction (including connector)
(2) PCB malfunction
Check (1) Measure the sensor resistance. Check that the sensor is operating normally.
(2) Use a remote monitor or a PC monitor to check the temperature that is recognized
by the microcomputer.
Correction —
Example —
Notes —
F31 Alarm
Alarm code F31
Alarm meaning Outdoor unit non-volatile memory (EEPROM) trouble
Alarm conditions (1) Non-volatile memory is not present when power initialization occurs.
(2) Read values do not match after writing to non-volatile memory is complete.
Probable cause (1) Memory was not inserted after the PCB was replaced.
(2) The lifetime of the non-volatile memory has been reached.
(3) Non-volatile memory is installed incorrectly (wrong direction, bent pins, etc.).
Check (1) Check the non-volatile memory on the PCB.
Correction —
Example —
Notes —
H01 Alarm
Alarm code H01
Alarm meaning Compressor 1 Current trouble
Alarm conditions Compresor 1 (INV) primary current detected overcurrent higher than the values (overcurrent) listed
in the table below.
Horsepower of unit
Probable cause (1) Wiring failure
(2) Operating under extremely high-pressure status (over-loaded operation)
(3) Power source and voltage failure (sudden voltage decrease)
Check (1) Wiring failure
Check whether the connection between "HIC PCB" and " inverter
compressor" is wiring failure.
See the fugure at right.
(2) Operating under extremely high-pressure status
(over-loaded operation)
• Failure to open the service valve of the outdoor unit
Check open/closed status of the service valve of the outdoor unit.
• Difference of characteristics of high-pressure sensor (under-shift)
• Connect a gauge to the high-pressure outlet and check for
changes in the value dispalyed by the monitoring software, and for
large deviation of the gauge pressure.
(3) Check power source and voltage.
Correction (1) Wiring failure
Correct wiring disconnection and wiring failure.
(2) Operating under extremely high-pressure status (over-loaded operation)
• Open the service valve of the outdoor unit.
• Replacing high-pressure sensor
When replacing a high-pressure sensor, carry out after refrigerant recovering of the outdoor unit.
(3) Improving power source and voltage
Example —
Notes —
8HP 10HP
Current (A) 15.1 19.8
12HP 14HP 16HP
21.0 21.0 22.5
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3WAY SYSTEM
Trouble Diagnosis
U
V
W
HIC PCB
Inverter compressor
5