SiUS341802E
Troubleshooting by Error Code
Service Diagnosis
256
2.58 Power Supply Insufficient or Instantaneous Abnormality
Error Code
U2
Applicable
Models
All outdoor unit models
Method of Error
Detection
Detect the voltage of capacitor of the main circuit in the inverter PCB.
Error Decision
Conditions
When the voltage in the DC circuit (between diode module and power module) falls below 190 VDC
(for 208/230 V models), 380 VDC (for 460 V models) or 560 VDC (for 575 V models).
Supposed
Causes
Abnormal power supply voltage
Instantaneous power failure
Open phase
Defective inverter PCB
Defective outdoor unit main PCB
Defective compressor
Defective main circuit wiring
Defective fan motor
Defective connection of signal cable
Troubleshooting
There are
some defects in the
power supply conditions
aforementioned.
The insulation
resistance of the
compressor is not more
than 100 k
Ω
.
NO
YES
YES
Fix the defects.
Replace the compressor
(M1C).
Check for power supply
conditions.
(1) Power supply voltage falls
within ±10% of the rated
voltage?
(2) Any open phase in the
power supply wiring or any
wrong wiring?
(3) Imbalance in the power
supply voltage is
maintained within 12 V?
A
NO
Go to the next page.
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Summary of Contents for Aurora Series
Page 317: ...SiUS341802E Wiring Diagrams Appendix 304 RXLQ96 120TATJU 2D112581A ...
Page 318: ...Wiring Diagrams SiUS341802E 305 Appendix RXLQ72TAYDU 2D112582A ...
Page 319: ...SiUS341802E Wiring Diagrams Appendix 306 RXLQ96 120TAYDU 2D112583A ...
Page 331: ...SiUS341802E Wiring Diagrams Appendix 318 VAM1200GVJU 3D073270C ...
Page 332: ...Revision History Month Year Version Revised contents 04 2018 SiUS341802E First edition ...