Panasonic R410A Service Manual page 88

4. Mini VRF Alarm Codes
F31 alarm
Alarm code
Alarm meaning
Alarm conditions
Probable cause
Check
Correction
Example
Notes
H03 alarm
Alarm code
Alarm meaning
Alarm conditions
Probable cause
1
Check
2
3
Correction
4
Example
Notes
5
6
F31
Outdoor unit non-volatile memory (EEPROM) trouble
(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 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 PCB.
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H03
Compressor CT sensor disconnected or short-circuit
Alarm occurs if the current value is 1.5 A or less when 2 seconds or longer have elapsed after
output from that compressor started.
* No current is detected even though the compressor is operating.
(1) CT circuit failure (including cut wiring, etc.)
(2) Disconnected CT circuit connector
(3) This CT circuit is connected to the connector of the other CT circuit.
(4) PCB failure
(5) Noise
(1) CT circuit failure, PCB failure
Trouble: • Current value during compressor operation is below the threshold value.
Check: • Check that the connector is not disconnected.
• Check the continuity of the CT circuit.
Install a normal CT in place of this CT and check. If current is detected, then the
PCB can be judged OK.
CT circuit failure
• Check that current is flowing in the phase where the CT circuit is connected.
Check voltage and current.
(2) Crossed wiring or installation error
Trouble: When the compressor is stopped, the current value at the other compressor is high.
(3) If the cause is still unknown after checking the above, then it is possible that noise is the
cause of the trouble. It is necessary to connect a PC or other instrument.
(1) Replace the CT circuit.
(2) Replace the outdoor unit PCB.
(3) Correct the problem.
(1) The connector was not inserted after the PCB was replaced.
Use a normal CT as a tool to determine whether the trouble is a PCB failure or CT failure.
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Mini VRF SYSTEM
Trouble Diagnosis