Service Diagnosis
24
U4
Description
Communication Abnormality
Supposed Cause
1. Faulty outdoor unit PCB.
2. Faulty indoor unit PCB.
3. Indoor unit – outdoor unit signal transmission error due to wiring error.
4. Indoor unit – outdoor unit signal transmission error due to disturbed power supply waveform.
5. Indoor unit – Outdoor unit signal transmission error due to breaking of wire in the connection
wires between the indoor and outdoor units.
Troubleshooting
Is the
voltage fluctuation
within ±10% from the
rated value?
Yes
Yes
Rotate
the outdoor fan
by hand. Does the
outdoor fan rotate
smoothly?
Yes
Yes
Check the power supply voltage.
Check the indoor unit - outdoor
unit connection wires.
No
Check the LED A on the
outdoor unit PCB.
Check the power supply waveform.
Check the voltage of the
connection wires on the indoor
terminal board between No. 1 and
SIG, and between No. 2 and SIG.
Replace the connection wires
between the indoor unit and
outdoor unit.
Locate the cause of the
disturbance of the power
supply waveform, and correct it.
No
Correct the indoor unit -
outdoor unit connection wires.
Diagnose the outdoor unit
PCB.
Replace the outdoor fan motor
and the outdoor unit PCB.
Is there any
wiring error?
Properly insulated?
Is there any
disturbance?
Yes
Is LED A blinking?
Yes
No
No
Correct the power supply.
No
Replace the indoor unit PCB.
No
*Remark:
Refer to Appendix A for power supply waveform check procedures (Item 4, page 34).
Summary of Contents for SKYAIR
Page 1: ...R410A SERVICE MANUAL SKYAIR Inverter Single Split SM 5CKY CCY CEY EU A1...
Page 3: ...ii...
Page 29: ...Wiring Diagram 26 Wiring Diagram Model ABQ71 100 125 140AV1 Model ACQ71 100 125AV1...
Page 30: ...Wiring Diagram 27 Model AHQ71AV1 Model AHQ100 125AV1...
Page 31: ...Wiring Diagram 28 Model AHQ140AV1 Model ABQ140BV1...
Page 32: ...Wiring Diagram 29 Model ACQ100 125BV1 Model ABQ71 100CV1...
Page 33: ...Wiring Diagram 30 Model ABQ125 140CV1 Model ACQ71 100 125CV1...
Page 34: ...Wiring Diagram 31 Model AHQ71 100 125CV1 Model AHQ140CV1...
