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
37
Troubleshooting：
Outdoor heat exchanger is blocked
Indoor heat exchanger is blocked.
Ambient temperature is out of the
operation range
H
4 Overload
Too much charging quantity.
Error still exists?
Remove the obstacle
Remove the obstacle
Normal protection. No
need to handle it.
Release a proper amount
of refrigerant
Replace the drive board
Replace the compressor
YES
YES
YES
YES
YES
NO
NO
NO
NO
3.4.10 “H5” IPM Protection
Error display: ODU mainboard LED displayer
Error judgment condition and method:
When power is connected and drive chip received IPM lead F0 that is of low level, than it is IPM module
malfunction. System will shut down for protection.
Possible reason:
■Compressor 3-phase wire connection is lack of phase or phase-reversed.
■System is overloaded and compressor current is too large.
■Drive board IPM module is damaged.
■Drive board IPM module’s 15V power supply is lower than 13.5V.
■Drive board 6-line PWM signal and the corresponding element are abnormal.