SiUS041829E
Troubleshooting
Part 6 Service Diagnosis
79
4.7 Low-voltage Detection or Over-voltage Detection
Error Code
U2
Method of Error
Detection
Low-voltage detection:
An abnormal voltage drop is detected by the DC voltage detection circuit.
Over-voltage detection:
An abnormal voltage rise is detected by the over-voltage detection circuit.
Error Decision
Conditions
Low-voltage detection:
The voltage detected by the DC voltage detection circuit is below 180 ~ 196 V (depending on
the model).
The compressor stops if the error occurs, and restarts automatically after 3-minute standby.
Over-voltage detection:
An over-voltage signal is fed from the over-voltage detection circuit to the microcomputer (over
458 ~ 500 V, depending on the model).
The compressor stops if the error occurs, and restarts automatically after 3-minute standby.
Supposed
Causes
Power supply voltage out of specification
Defective DC voltage detection circuit
Defective over-voltage detection circuit
Defective PAM control part
Disconnection of compressor harness
Short circuit inside the fan motor winding
Noise
Momentary drop of voltage
Momentary power failure
Defective outdoor unit PCB
Summary of Contents for RX09RMVJU9
Page 17: ...SiUS041829E Part 2 Specifications 13 1 Specifications 14 Part 2 Specifications ...
Page 125: ...SiUS041829E Check Part 6 Service Diagnosis 121 18 class R25105 1 2 3 4 Multimeter ...
Page 127: ...SiUS041829E Check Part 6 Service Diagnosis 123 18 class R20704 W V U DC_P1 DC_N1 ...
Page 143: ...SiUS041829E Operation Limit Part 8 Appendix 139 4 Operation Limit RX09 12 18RMVJU9 3D092209E ...
