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Mini VRF SYSTEM
Trouble Diagnosis
6
3. Mini VRF Alarm Codes
P29 Alarm
Alarm code P29
Alarm meaning Compressor start failure. Compressor is missing phase or reverse phase.
Alarm conditions This alarm may occur at start, and occurs when open phase or lock alarm is detected or the
compressor is in reversed-phase, and when a DCCT failure occurs.
Probable cause (1) Power supply voltage malfunction
(2) Wiring failure (missing, connection failure, miswiring, reversed-phase)
*
Wiring between the HIC PCB and compressor
Check (1) Check the power supply and voltage.
Check whether the voltage between each of the phases is correct while the compressor is
running.
(It is necessary to check the compressor while running because the voltage may decrease
when the compressor starts running.)
(2) Check the wiring.
Check whether the following wiring is missing, connection failure or miswiring (position of U, V,
W is properly placed).
• Wiring between the HIC PCB and compressor
• HIC PCB side
• Compressor side
Correction (1) Correct the power supply voltage.
(2) Correct the wiring.
(3) Replace the HIC PCB.
(4) Replace the compressor.
Example —
Alarm code
Alarm meaning
Alarm conditions
Probable cause
P22
Outdoor unit fan motor has failure.
Fan motor start failure, fan motor Hall IC input failure
(1) Wiring failure
(2) Outdoor Unit Control PCB failure
(3) Fan failure
(4) Fan motor failure
Check
(1) Wiring check
1-1 Are the connectors "CN-FM_UP" and "CN-FM_LO" firmly connected to the Outdoor
Unit Control PCB
(lock engaged)?
If “Yes”, see “2-1”.
If “No”, correct the connector connections.
(2) Outdoor fan motor check
2-1 Disconnect the connectors "CN-FM_UP" and "CN-FM_LO" from the Outdoor Unit
Control PCB and rotate the outdoor fan by hand ; does it rotate freely?
(Check the outdoor fan motor lock)
If “Yes”, see “3-1”.
If “No”, replace the outdoor fan motor.
(3) Outdoor control PC board check
3-1 Turn the power on and run the unit again; is P22 triggered again? Or can you see or
hear anything that is obviously wrong in its rotation?
If “Yes”, see “3-2”.
If “No”, see “3-3”.
3-2 Replace the Outdoor Unit Control PCB.
3-3 If there is nothing particularly out of the ordinary, see what happens.
Correction
Example
(1) Correct the wiring.
(2) Remove the obstacles attached to the fan.
(3) Replace the fan motor.
(4) Replace the Outdoor Unit Control PCB.
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Turn OFF the power, and check the continuity of “+” and “–” on the Outdoor Unit Control PCB.
P20 Alarm
Alarm code P20
Alarm meaning
Alarm conditions
Probable cause
Check
Correction
Example
Notes
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.
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Mini VRF SYSTEM
Trouble Diagnosis
SM830289-00_Sec6.indd 22SM830289-00_Sec6.indd 22 2021/01/29 16:15:442021/01/29 16:15:44
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