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 
22 
3.3 Error Code 
No. 
Error code 
Error 
1 
E1 
Compressor high pressure protection 
2 
E3 
Compressor low pressure protection 
3 
E4 
Compressor air discharge high-temperature protection 
4 
F2 
Condenser temperature sensor error 
5 
F3 
Outdoor ambient temperature sensor error 
6 
F4 
Discharge temperature sensor error 
7 
F6 
ODU tube temperature sensor error 
8 
EE 
ODU memory chip error 
9 
H4 
Overload 
10 
H5 
IPM protection 
11 
H6 
DC fan error 
12 
H7 
Driver out-of-step protection 
13 
HC 
Pfc protection 
14 
Lc 
Startup failure 
15 
P0 
Driver reset protection 
16 
P5 
Over-current protection 
17 
P6 
Master control and driver communication error 
18 
P7 
Driver module sensor error 
19 
P8 
Driver module high temperature protection 
20 
PA 
AC current protection 
21 
Pc 
Driver current error 
22 
PL 
Bus low-voltage protection 
23 
PH 
Bus high-voltage protection 
24 
PU 
Charge loop error 
25 
ee 
Drive memory chip error 
If malfunction occurs during operation, LCD temperature display zone will show the failure information. If 
several  malfunctions  occur  at  the  same  time,  their  corresponding  error  codes  will  be  shown  in  turn.  When 
malfunction occurs, please shut off the unit and send for professional personnel to repair. For example, E1 (as 
shown below) indicates high pressure protection.   










