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
40
3.4.15 “P0” Driver Reset Protection
Error display:
ODU mainboard LED displayer
Error judgment condition and method:
Drive board chip resets and starts initialization. After the drive board is energized for 5s, it detects that the
chip resets again. In this case, it can be judged as drive chip reset protection.
Possible reason:
■3.3V drive chip supply voltage drop.
■TRST lead of JTAG programming is interrupted.
Troubleshooting
:
P0 Driver reset protection
3.3V drive board
voltage is normal or
not?
Replace the drive board
Re-arrange the wires. Heavy
current wires s hould avoid
the drive board chip.
NO
YES
3.4.16 “P5” Over-Current Protection
Error display:
ODU mainboard LED displayer
Error judgment condition and method:
If compressor’s instant current value is higher than the set current protection value, then it can be judged that
compressor over-current occurs and system will shut down for protection.
Possible reason:
■System load is too much and compressor current is too large.
■Compressor 3-phase wire connection is lack of phase or phase-reversed.
■Compressor phase wire is loose or has bad contact.










