Panasonic U-8MF2E8 Service Manual page 147

4. 3WAY Alarm Codes
P22 Alarm
Alarm code P22
Alarm meaning Fan motor trouble
Alarm conditions Fan motor start failure, fan motor Hall IC input failure
Probable cause Possible causes are a Hall IC input circuit failure and a fan HIC failure.
Check 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.
HIC PCB for 8HP to 16HP
(A747038)
Correction 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.
Example —
Notes Turn OFF the power, and check the continuity of "+" and "–" on the fan circuit PCB.
P29 Alarm
Alarm code P29
Alarm meaning Inverter compressor missing phase or lock alarm
Alarm conditions This alarm may occur at start, and occurs when missing phase or lock is detected, and when a
DCCT failure occurs.
Probable cause Generally this alarm occurs when the refrigerant pressure balance is uneven at start, or when
inverter compressor lock occurs, there is a missing phase in the inverter compressor wiring, or a
DCCT failure occurs. This can be judged to be starting trouble which is not caused by HIC.
Check Check the power wiring and connector wiring.
Correction DCCT failure (replace PCB) or compressor failure
Example —
Notes Use a tester to measure the voltage between the DCCT output terminal on the rear of the PCB
and the ground. If the voltage is not within 2 – 3 V, then the DCCT has malfunctioned.
HIC -
(NV)
HIC +
(P)
5 - 25
3WAY SYSTEM
Trouble Diagnosis
5