Panasonic U-72MF2U9 Service Manual page 176

4. 2WAY Alarm Codes
3. 3WAY Alarm Codes
F17 Alarm
Alarm code
Alarm meaning
Alarm conditions
Probable cause
Check
Correction
Example
Notes
F31 Alarm
1
Alarm code
Alarm meaning
Alarm conditions
Probable cause
2
Check
Correction
Example
Notes
3
H01, H11 Alarm
Alarm code
Alarm meaning
4
Alarm conditions
Probable cause
5
Check
6
Correction
7
Example
8
Notes
9
F17
Low pressure sensor of the outdoor unit has failure. (LPS)
(1) Sensor short circuit
(2) Sensor open circuit
(1) Sensor malfunction (including connector)
(2) The Outdoor Unit Control PCB malfunction
(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.
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F31
EEPROM on outdoor unit PCB has failure.
(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.
(1) Memory was not inserted after the Outdoor Unit Control 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.).
(1) Check the non-volatile memory on the Outdoor Unit Control PCB.
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H01, H11
H01 : Overcurrent in 1st compressor.
H11 : Overcurrent in 2nd compressor.
1st compressor, 2nd compressor primary current detected overcurrent higher than the values
(overcurrent) listed in the table below.
Type of outdoor unit 72
Current (A) 30.0
(1) Wiring failure
(2) Operating under extremely high-pressure status (over-loaded operation)
(3) Power source and voltage failure (sudden voltage decrease)
(1) Wiring failure
Check whether the connection between "HIC PCB" and "inverter compressor" is wiring failure.
(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.
• Connect a gauge to the high-pressure outlet and check for changes in the value displayed
by the monitoring software, and for large deviation of the gauge pressure.
(3) Check power source and voltage.
(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
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96 120 144
43.0 30.0 30.0
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2WAY SYSTEM
3WAY VRF SYSTEM
Trouble Diagnosis
Trouble Diagnosis