Troubleshooting Guide
Table Of Contents
- Foreword
- Safety Notice
- CONTENTS
- Safety Notice on Maintenance
- Safety Notice on Operation
- 1. Product Introduction
- 2. Control
- 2.1 Operation Mode
- 2.2 Control Mode
- 2.3 Functions
- 2.3.1 Set Capacity Dial Code
- Set the capacity of the outdoor unit through the f
- Capacity
- 24K
- 36K
- 48K
- 60K
- Dial Codes
- 2.3.2 Set Defrost Mode
- The second digit dial code are selecting the defro
- 2.3.3 Set Operating Mode
- The third digit dial code and the fourth digit dia
- By setting the Forcible mode dial codes of the con
- Energy saving mode is achieved by setting the cond
- 2.3.4 Set Indoor Fan Speed
- Set the indoor fan speed through the four-digit di
- Capacity
- 24K indoor unit dial code
- 36K indoor unit dial code
- Level 1 (Default)
- Level 2
- Level 3
- Capacity
- 48K indoor unit dial code
- 60K indoor unit dial code
- Level 1 (Default)
- Level 2
- Level 3
- 2.3.5 Forced Defrost Control
- Press and hold "SW1" for about 5s to enter the fir
- 2.3.6 Refrigerant Recovery Control
- Press and hold "SW1" for about 5s to enter the fir
- 2.3.7 Forced Operation Control
- Press and hold "SW1" for about 5s to enter the fir
- 2.3.8 Thermostat Functions
- Thermostat model: XE70-00/E1, please refer to the
- 3.1 Wiring Diagrams
- 3.2 PCB Layout
- 3.2.2 IPM, PFC Testing Method
- 3.3 Error Code
- 3.4 Troubleshooting
- 3.4.1 “E1” Compressor High Pressure Protection
- 3.4.2 “E3” Compressor Low-pressure Protection, Ref
- 3.4.3 “E4” Compressor Air Discharge High-temperatu
- 3.4.4 “F2” Condenser Temperature Sensor Error
- 3.4.5 “F3” Outdoor Ambient Temperature Sensor Erro
- 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 Communicatio
- 3.4.18 “P7” Driver Module Sensor Error
- 3.4.19 “P8” Driver Module High Temperature Protec
- 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
- 3.4.26 “e1” High Pressure Sensor Error
- 3.4.27 “C4” ODU Jumper Cap Error
- 3.5 Failures Not Caused by Errors
- 4. Maintenance
- Appendices
- 1. Resistance/Temperature Lists of Temperature Sen
- 2. Temperature/Pressure List of Refrigerant
- 3. Operation Tools
MRCOOL Universal Service Manual
9
and outdoor and indoor fan will both stop. When the temperature sensed by outdoor tube temperature sensor
reaches the preset value of defrosting stop, system will quit defrosting. The 4-way valve will switch back to the
heating condition, compressor and outdoor unit fan restart.
2.2.2.2 Oil Return Control
If the unit is running at low frequency for a long time, system will enable oil return control. This is to lead oil in
the pipeline back to the compressor so that the compressor will not be lack of oil. Generally, the oil return takes
about 5min. The compressor running frequency will be raised to the preset oil return frequency.
2.2.3 Protection Control
2.2.3.1 High Pressure Protection Control
System will enable high pressure protection control if the high pressure switch is detected open for
continuously a little time. Under high pressure protection, system will be shut down and display error code E1.
When high pressure protection occurs for the first time, system will restore operation if the high pressure
switch is detected to be reclosed for continuously a little time. When high pressure protection occurs for the
second time in a certain time period, system will not restore operation. You need to manually turn off the unit and
clear the error before restarting up the unit. (If high pressure protection occurs frequently, please send for
professional personnel to repair.)
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.
2.2.3.3 High Temperature Prevention Control
Under heating mode, system will enable high temperature prevention control if the temperature sensed by
indoor tube temperature sensor reaches a certain value. When high temperature prevention control is enabled,
outdoor fan will slow down.
2.2.3.4 Discharge High Temperature Protection Control
System will enable discharge temperature protection control if the discharge high temperature sensor is