Specifications
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 Function and Control
- Part 5 Operation Manual
- Part 6 Service Diagnosis
- 1. Caution for Diagnosis
- 2. Problem Symptoms and Measures
- 3. Service Check Function
- 4. Code Indication on the Remote Controller
- 5. Troubleshooting
- 5.1 Indoor Units
- 5.2 Outdoor Units
- 5.3 Indoor Unit PCB Abnormality A1
- 5.4 Freeze-up Protection Control or High Pressure Control A5
- 5.5 Fan Motor or Related Abnormality A6
- 5.6 Thermistor or Related Abnormality (Indoor Unit) C4,C9
- 5.7 Front Panel Open / Close Fault C7
- 5.8 Signal Transmission Error (between Indoor and OutdoorUnit) U4
- 5.9 Unspecified Voltage (between Indoor and Outdoor Units) UA
- 5.10 Freeze-up Protection Control A5
- 5.11 Outdoor Unit PCB Abnormality E1
- 5.12 OL Activation (Compressor Overload) E5
- 5.13 Compressor Lock E6
- 5.14 DC Fan Lock E7
- 5.15 Input Over Current Detection E8
- 5.16 Discharge Pipe Temperature Control F3
- 5.17 High Pressure Control in Cooling F6
- 5.18 Compressor Sensor System Abnormality H0
- 5.19 Position Sensor Abnormality H6
- 5.20 CT or Related Abnormality H8
- 5.21 Thermistor or Related Abnormality (Outdoor Unit) P4,J3,J6,J8,J9,H9
- 5.22 Electrical Box Temperature Rise L3
- 5.23 Radiation Fin Temperature Rise L4
- 5.24 Output Over Current Detection L5
- 5.25 Insufficient Gas U0
- 5.26 Low-voltage Detection or Over-voltage Detection U2
- 5.27 Signal Transmission Error (on Outdoor Unit PCB) U7
- 5.28 Anti-icing Function in Other Rooms / UnspecifiedVoltage (between Indoor and Outdoor Units) UA,UH
- 6. Check
- Part 7 Removal Procedure
- Part 8 Others
- Part 9 Appendix
- Index
- Drawings & Flow Charts
Function of Main Structural Parts SiBE12-713
78 Function and Control
2.2 Function of Thermistor
2.2.1 Heat Pump Model
A Outdoor Heat
Exchanger
Thermistor
1. The outdoor heat exchanger thermistor is used for controlling target discharge temperature.
The system sets a target discharge temperature according to the outdoor and indoor heat
exchanger temperature, and controls the electronic expansion valve opening so that the
target discharge temperature can be obtained.
2. The outdoor heat exchanger thermistor is used for detecting disconnection of the discharge
thermistor when cooling.
When the discharge pipe temperature becomes lower than the outdoor heat exchanger
temperature, the discharge pipe thermistor is judged as disconnected.
B Discharge
Pipe Thermistor
1. The discharge pipe thermistor is used for controlling temperature of the discharge pipe.
If the temperature of discharge pipe (used in place of the inner temperature of the
compressor) rises abnormally, the operating frequency drops or the operation halts.
2. The discharge pipe thermistor is used for detecting disconnection of the discharge
thermistor.
C Gas Pipe
Thermistor
1. In cooling, the gas pipe thermistors are used for gas pipe isothermal control.
The system controls electronic expansion valve opening so that gas pipe temperature in
each room becomes equal.
Four way valve
Compressor
EVB
EVC
EVD
EVA
Expansion valve
A
B
C
D
E
(R5067)