Service Manual
Table Of Contents
- Cover
- Table of contents
- Part 1 List of Functions
- Part 2 Specifications
- Part 3 Printed Circuit Board Connector Wiring Diagram
- Part 4 Refrigerant Circuit
- Part 5 Functions and Control
- Part 6 Test Operation and Field Settings
- Part 7 Remote Controller
- Part 8 Troubleshooting
- 1. Troubleshooting with LED
- 2. Service Diagnosis
- 3. Error Codes and Description
- 4. Troubleshooting for CTXG, CTXS, FTXS, CDXS, FDXS, FVXS Series
- 5. Troubleshooting for FFQ Series
- 6. Troubleshooting for Branch Provider (BP) Unit
- 7. Troubleshooting for Outdoor Unit
- 8. Thermistor Resistance/Temperature Characteristics
- 9. Pressure Sensor
- 10. Method of Replacing Inverter’s Power Transistors Modules
- Part 9 Appendix
Troubleshooting for Outdoor Unit SiUS181631EA
254 Troubleshooting
7.25 Power Supply Insufficient or Instantaneous Failure
Error Code
U2
Method of Error
Detection
Detection of voltage of main circuit capacitor built in the inverter and power supply voltage.
Error Decision
Conditions
When the abnormal voltage of main circuit capacitor built in the inverter and abnormal power supply
voltage are detected
Supposed
Causes
Power supply insufficient
Instantaneous power failure
Defective outdoor fan motor
Defective main PCB (A1P)
Troubleshooting
Check No.32
Refer to P.265
Is the power
supply voltage 200 ~
240V ±10%?
Check
No.32
Is the resistance
between each pin of the fan
motor above
standard
value?
Is the
measured voltage 220 -
240 VDC or
more?
Caution
Be sure to turn off the power switch before connecting or disconnecting
connectors, or parts may be damaged.
Is the P - N
resistance not less
than several hundred
of ohms?
Correct the power supply.
Field factors
Replace the main PCB
(A1P).
(R22105)
YES
YES
YES
NO
NO
Replace the fan motor.
NO
Monitor the voltage
(Instantaneous voltage
drop)
NO
YES
When the compressor is
running, measure the voltage
between + and – of
electrolytic capacitor (C+, C–).