Specifications
Table Of Contents
- Cover
- Table of Contents
- Part 1 General Information
- Part 2 Specifications
- Part 3 Refrigerant Circuit
- Part 4 Function
- Part 5 Test Operation
- Part 6 Troubleshooting
- Part 7 Appendix
- 1. Piping Diagrams
- 2. Wiring Diagrams for Reference
- 3. List of Electrical and Functional Parts
- 4. Option List
- 5. Piping Installation Point
- 6. Example of connection (R-410A Type)
- 7. Thermistor Resistance / Temperature Characteristics
- 8. Pressure Sensor
- 9. Method of Checking the Inverter’s Power Transistors and Diode Modules
- Part 8 Precautions for New Refrigerant (R-410A)
- Index
- Drawings & Flow Charts

Si34-704 Troubleshooting by Indication on the Remote Controller
Troubleshooting 275
3.48
“
U7
”
Outdoor Unit: Transmission Failure (Across Outdoor
Units)
Remote
Controller
Display
U7
Applicable
Models
All models of outdoor units
Method of
Malfunction
Detection
Microcomputer checks if transmission between outdoor units.
Malfunction
Decision
Conditions
When transmission is not carried out normally for a certain amount of time
Supposed
Causes
Connection error in connecting wires between outdoor unit and outdoor unit outside control
adapter
Connection error in connecting wires across outdoor units
Setting error in switching cooling/ heating
Integrated address setting error for cooling/ heating
(function unit, outdoor unit outside control adapter)
Defective outdoor unit PCB (A1P)
Defective outdoor unit outside control adapter