Panasonic U-8ME1E81 Service Manual page 164

4. 2WAY Alarm Codes
H31 Alarm
Alarm code
Alarm meaning
Alarm conditions
Probable cause
Check
Correction
Example
6
Notes
L04 Alarm
Alarm code
Alarm meaning
Alarm conditions
Probable cause
Check
Correction
Example
Notes
H31
HIC trouble alarm
This alarm occurs when the microcomputer identifies a trouble signal (indicating abnormal HIC
temperature or other trouble) from the HIC.
The HIC judges the current and temperature, and outputs the trouble signal. In general this
indicates trouble with the HIC itself.
Overcurrent in HIC circuit, and the resultant abnormal heating, caused by HIC failure
Check the power wiring and connector wiring. If the wiring and connectors are normal, use a
tester to measure the resistance between the compressor HIC power (HIC+) and ground (HIC–).
If there is a short-circuit, there is an HIC malfunction.
HIC PCB for 8HP to 16HP
(A747038)
HIC -
(NV)
HIC +
(P)
HIC PCB for 18HP and 20HP
(A747036)
HIC -
(NV)
HIC +
(P)
If an HIC failure is found, replace the PCB.
—
Turn OFF the power, and check the continuity of HIC+ and HIC– on the HIC PCB.
L04
Outdoor system address duplication
Communication by inter-unit control wiring was received that contained the same address as
that unit 5 times or more within 3 minutes.
Incorrect outdoor system address settings
Check the system address settings again.
Correct the system address settings.
—
Recovery from this alarm occurs automatically (when communication that contains the same
address as that unit is not received for 3 minutes after detection).
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2WAY SYSTEM
Trouble Diagnosis