Panasonic U-8ME1E8E Service Manual page 169

4. 2WAY Alarm Codes
P20 Alarm
Alarm code
Alarm meaning
Alarm conditions
Probable cause
Check
Correction
Example
Notes
P22 Alarm
Alarm code
Alarm meaning
Alarm conditions
Probable cause
Check
Correction
Example
6
Notes
P20
High load alarm
The high pressure increase is not rapid but the alarm occurs when the horsepower down does
not meet the anticipated time.
(1) Forgot to open the valve.
(2) Operation failure of mechanical valve
(3) Idle away of outdoor fan
Check the valve, mechanical valve and outdoor fan.
—
—
—
P22
Fan motor trouble
Fan motor start failure, fan motor Hall IC input failure
Possible causes are a Hall IC input circuit failure and a fan HIC failure.
Check the fan motor wiring, the Hall IC wiring, and the connector connections.
If the wiring and connectors are normal, then check that the capacitor of the Hall IC input circuit
is securely soldered on the outdoor unit control PCB. Also use a tester and measure the
resistance between fan HIC power (HIC+) and ground (HIC–).
If there is a short-circuit, there is an HIC malfunction.
Fan PCB FAN-C0906DXH8
If the fan does not start, the below corrections may be effective.
(1) If there is a fan HIC failure or circuit failure, replace the PCB.
(2) If the fan motor is locked, replace the fan motor.
—
Turn OFF the power, and check the continuity of "+" and "–" on the fan circuit PCB.
(+)
(–)
(+)
Fan PCB FAN-C1806DXH8
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2WAY SYSTEM
Trouble Diagnosis
(–)
(–) (+)