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
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Note: When pouring the liquid from the separator, make sure the discharge pipe is at the lower position.Slant at
an angle not larger than 20°
Use a transparent container to collect the content inside the separator. Check its color, seal it well and return
it to the factory for inspection.
Note: If the compressor is damaged and needs to be replaced, the gas-liquid separator should also be replaced,
whether or not there are impurities in the separator or other abnormal conditions.
Confirm which parts of the system should be replaced. Make sure the pipe mouths of the damaged parts or
components are sealed by adhesive tape as soon as they are detached. Keep them in the original condition for
future analysis.
Step 7: Clear the pipeline
After confirming which parts of the system should be replaced, check the pipeline of the system. Blow
through the main pipeline with nitrogen. After clearing the pipeline, if the components are not replaced
immediately, seal the pipeline with adhesive tape to prevent the system from being contaminated by water and
impurities in the air.
Step 8: Replace the compressor
For the removal of compressor, please refer to the section: Removal of Major Components.
Step 9: Check/Replace the gas-liquid separator
Note: If a compressor is damaged and needs to be replaced, its gas-liquid separator should also be replaced.
This is to avoid the abnormal condition of the separator from affecting the safe and reliable operation of the
system.
For the removal of gas-liquid separator, please refer to the section: Removal of Major Components.
Step 10: Check the system for leaks
(1) First of all, check each welding point. Check whether the welding points are smooth and whether there is
any obvious welding hole or other abnormal condition.
(2) Next, fill high-pressure nitrogen into the system for leak detection. If it is only the outdoor unit that needs
to be repaired and the indoor unit is confirmed normal, then it’s OK to charge high-pressure nitrogen into
the outdoor unit only. Fill in the nitrogen simultaneously from the high pressure side and low pressure
side. We recommend charging the nitrogen from the big and small valves at the same time. The
pressure of nitrogen should be above 20kgf. Then use soapy water to check for leaks. Check the
welding points particularly.
(3) Finally, retain the pressure of the system. Fill high-pressure nitrogen into the system and maintain the