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
252 Troubleshooting
7.24 Low Pressure Drop due to Refrigerant Shortage or
Electronic Expansion Valve Abnormality
Error Code
U0
Method of Error
Detection
Refrigerant shortage is detected by discharge pipe thermistor and low pressure saturation
temperature.
Error Decision
Conditions
Microcomputer judge and detect if the system is short of refrigerant.
★
The error is not decided while the operation continues.
Supposed
Causes
Refrigerant shortage or refrigerant system clogging (incorrect piping)
Defective low pressure sensor
Defective main PCB (A1P)
Defective thermistor (R3T)