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
36
Possible reason:
■Outdoor fan wiring terminal is not correctly connected to the mainboard.
■Outdoor fan is damaged.
■If it is a new unit or a new motor has been replaced in the unit and the wire connection is correct, then probably
it is the program that goes wrong.
Troubleshooting
：
Malfunction of
discharge
temperature
sensor
Check if the
control wire of outdoor fan motor is
connected on the outdoor
mainboard correctly
Replace the
outdoor fan motor and then
restart the unit to see if there still
is malfunction of outdoor fan
motor
Correctly connect the
control wire of fan motor
on the mainboard
Operate the unit with
the new motor
Replace the
outdoor
mainboard
Yes
No
No
Yes
3.4.12 “H7” Driver Out-of-Step Protection
Error display:
ODU mainboard LED displayer
Error judgment condition and method:
During operation, it can’t detect the rotor position and stops output. Or the actual running speed differs too
much from the set running speed. In each case, compressor runs out of step and system stops for protection.
Possible reason:
■Compressor 3-phase wire connection is lack of phase or phased-reversed.
■Compressor phase wire connection is bad.
■System is blocked, short of refrigerant or compressor oil.
■Drive board IPM module is damaged.