Service Manual
Service Manual
PART 1 Product instructions
PART 2 System Instruction ………………………………………………….……………………………………… 3
2.1 Refrigerant Circuit ……………………………………………………………….………………………………… 3
2.2 Functional Parts Layout ………………………………………………….……………………………………… 4
2.3 Refrigerant Flow ……………………………………………………………..…………………………………… … 6
PART 3 Function and Control ………………….……………………………………………………………… 7
3.1 Function General …………………………………………………………………………..……………………… 8
3.1.1 Unit Shutdown Control ………………………………………..…………………………………….…….… 9
3.1.2 Unit Standby Control ………………………………………………………………..……………….…….… 9
3.1.3 Unit Normal Operation …………………………………………………………….…………….……….…… 10
3.1.4 Unit Special Control ……………………………………………………………………..………………..…… 10
3.1.5 Unit Protection Control or Restart……………………….……………………………..…….…………… 11
3.1.6 Fault of Main Board ………………………………….……………………………….………..………………… 12
3.1.7 Unit Fault Control or Restart ………………………………………………………..……….………. …. 13
PART 4 Field settings ……………………………………………………………………………….…………….…… 15
4.1 Test Operation ……………………………………………………………………………….…….……………… 16
4.1.1 Checks before Test Operation ……………………………………………………………….…….………… 16
4.1.2 Turn Power on …………………………………………………………………………………….……..………… 17
4.1.3 Manual Defrost …………………………………………………………………………….……………..………… 18
4.2 Setting by DIP Switches …………………………………………………………….……………..………..… 19
4.3 Thermostat ……………………..……………………………………………………….……………...…………… 20
PART 5 Intelligent Troubleshooting …………….…………………………………………..……………… 21
5.1 Diagnosis System Introduction ………………………….……………………………………..……..… 22
5.2 Symptom-based Troubleshooting ……………………….……………………………………..…… … 23
5.3 Troubleshooting by Main board Fault code……………….…………………………………………… 26
PART 6 Check ………………………………………………………………………………………………....………… 29
6.1 Check for Causes of Rise in High Pressure ……………………………………………….……..…… 30
6.2 Check for Causes of Dropping Low Pressure in Cooling …………….………….….………… 31
6.3 Check for Causes of Dropping Low Pressure in Heating ………………………….….……… 32
6.4 Check for Causes of Refrigeration cycling Blocked …………………………………..………… 33
6.5 Check for Temperature Sensor (T3/T4) …………………………………………..……….…………… 34
6.6 Check for High Pressure Switch (HPS) …………………………………………….….….………… … 35
6.7 Check for Low Pressure Switch (LPS) ……………………………………….…….…….………… … 36
6.8 Check for Discharge Temperature Switch (T5) ………………….…………………….…………… 37
6.9 Check for Compressor Check ……………………………………..……………………………………… 38
PART 7 Appendix…………………………………………………………………………………….……………….. 39
7.1 Wiring Diagrams ……………………………………………………………………………………………………… 40
7.2 Temperature and Resistance Relationship Tables …………………………………………………… 44
1
