Use and Care Manual
Table Of Contents
- Foreword
- Safety Notice
- CONTENTS
- Safety Notice on Maintenance
- Safety Notice on Operation
- 1 Product Introduction
- NOTE: 1 Ton =12000Btu/h = 3.517kW 1.2 Electrical Parameters
- 2 Control
- 3 Troubleshooting
- 3.1 Wiring Diagrams
- 3.2 PCB Layout
- 3.3 Error Code
- 3.4 Troubleshooting
- 3.4.1 “E1” Compressor High Pressure Protection
- 3.4.2 “E3” Compressor Low-pressure Protection, Refrigerant Shortage Protection, Refrigerant Recovery Mode
- 3.4.3 “E4” Compressor Air Discharge High-temperature Protection
- 3.4.4 “F2” Condenser Temperature Sensor Error
- 3.4.5 “F3” Outdoor Ambient Temperature Sensor Error
- 3.4.6 “F4” Discharge Temperature Sensor Error
- 3.4.7 “F6” ODU Tube Temperature Sensor Error
- 3.4.8“EE” ODU Memory Chip Error
- 3.4.9 “H4” Overload
- 3.4.10 “H5” IPM Protection
- 3.4.11 “H6” DC Fan Error
- 3.4.12 “H7” Driver Out-of-Step Protection
- 3.4.13 “HC” PFC Protection
- 3.4.14 “Lc” Startup Failure
- 3.4.15 “P0” Driver Reset Protection
- 3.4.16 “P5” Over-Current Protection
- 3.4.17 “P6” Master Control and Driver Communication Error
- 3.4.18 “P7” Driver Module Sensor Error
- 3.4.19 “P8” Driver Module High Temperature Protection
- 3.4.20 “PA” AC Current Protection
- 3.4.21 “Pc” Driver Current Error
- 3.4.22 “PL” Bus Low-Voltage Protection
- 3.4.23 “PH” Bus High-Voltage Protection
- 3.4.24 “PU” Charge Loop Error
- 3.4.25 “ee” Drive Memory Chip Error
- 3.5 Failures Not Caused by Errors
- 4 Maintenance
- Appendices
- 1 Resistance/Temperature Lists of Temperature Sensors
- 1.1 Voltage List of 15 KΩ Temperature Sensors (including ODU temperature sensors)
- 1.2 Voltage List of 20 KΩ Pipeline Temperature Sensors (including temperature sensors for defroster, IDU and ODU pipes)
- 1.3 Voltage List of 50 KΩ Discharge Temperature Sensors (including discharge air temperature sensor)
- 2 Temperature/Pressure List of Refrigerant
- 3 Operation Tools
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT
52
4.3 Refrigerant Charging
Pre-charging
Step 1: Connect the high pressure gauge line to the valve of liquid pipe and connect the low pressure gauge
line to the valve of gas pipe. Connect the middle gauge line to the vacuum pump. Power on the vacuum pump
and perform vacuum drying.
Step 2: After vacuum drying, close the high and low pressure gauge valves. Then remove the middle gauge
line from the connector of vacuum pump. Then connect to the refrigerant tank.
Step 3: Loosen the middle gauge line from the connector of pressure gauge to a proper extent and slightly
open the valve of refrigerant tank. Evacuate the middle gauge line. Then tighten up the connector again and
completely open the valve of refrigerant tank at the same time.
Step 4: Keep the refrigerant tank erect and put it on an electronic scale. Record the current weight as m1.
Step 5: Open the high pressure gauge valve (Keep the low pressure gauge valve closed). Then charge
refrigerant into the system. Meanwhile, record the weight of refrigerant tank as m2.
Step 6: m1-m2=m. If m equals to the required charging quantity M, close the valve of refrigerant tank at once.
Then move to step 8.
Step 7: If you can’t continue to charge refrigerant into the system and the quantity of charged refrigerant is
less than the required charging quantity, then record the current quantity of charged refrigerant:
m=m1-m2
m`=M-m
The remaining charging quantity is: m`=M-m
Step 8: After charging, remove the pressure gauge.










