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
8
2.2.3.2 Low Pressure Protection Control
System will enable low pressure protection control if the low pressure switch is detected open for
continuously a little time. Under low pressure protection, system will be shut down and display error code E3.
When low pressure protection occurs, system will restore operation if the low pressure switch is detected to be
reclosed within a few minutes after shutdown. If low pressure protection occurs for several times in a period of
time, system will not restore operation automatically. You need to manually turn off the unit before restarting up
the unit. (If low pressure protection occurs frequently, please send for professional personnel to repair.)
2.2.3.3 Discharge High Temperature Protection Control
System will enable discharge temperature protection control if the discharge high temperature sensor is
detected open for continuously a little time. Under discharge high temperature protection, system will be shut
down and display error code E4. When discharge high temperature protection occurs, system will restore
operation if the discharge high temperature sensor is detected to be reclosed within a few minutes after shutdown.
If discharge high temperature protection occurs for several times in a period of time, system will not restore
operation automatically. You need to manually turn off the unit before restarting up the unit.
2.3 Functions
2.3.1 Set Capacity Dip Switch
Set the capacity of the outdoor unit through the four dip switches of the outdoor unit main control board.
Specific dip switch definition, the first dip switch distinguishes the capacity. The second dip switch is meaningless.
Capacity
24K
36K
48K
60K
Dip Switches
2.3.2 Set Operating Mode
The third dip switch and the fourth dip switch are selecting the operating mode. Standard mode is the
conventional mode.
By setting the strong mode dip switches of the condensing unit, the air conditioner can quickly increase the
capacity output and ensure reliable operation in a short time, so as to meet the user's demand for the indoor










