DC INVERTER COOLING ONLY CONDENSING UNIT SERVICE MANUAL Capacity: 24000Btu/h~54000Btu/h Rate Frequency: 60Hz Operation Range: 39.2°F(4°C)~118.
Foreword Thank you for choosing MRCOOL Universal air conditioners. In order to correctly install and use our units,. and for the satisfactory operation effect, please read this manual carefully. This manual specifies safe operation requirements from perspectives of product introduction, control, troubleshooting and maintenance, as well as basic principles and implementation methods.
CONTENTS 1 Product Introduction ...................................................................................................... 3 1.1 Lists of Units .......................................................................................................................... 3 1.2 Electrical Parameters ............................................................................................................. 5 2 Control ..................................................................................
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Safety Notice on Maintenance PROHIBITED： (1) Do not pierce or burn. (2) Please note that refrigerant may be odorless. (3) The appliance shall be stored in a room without continuously operating ignition sources (For example: open flames, an operating gas appliance or an operating electric heater). (4) Indoor unit adopts special joints that can’t be detached. The installation method is the same with the common joints.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT high speed; Otherwise personal injury may occur. (5) Measure the insulation resistance after maintenance. The resistance must be 1M or higher. Bad insulation may lead to electric shock. (6) Welding and cutting work must be done in a well-ventilated place. (7) Gas appliances, heaters and other fire sources should be kept away from the installation and maintenance site. (8) Maintenance should be done according to suggestions of the manufacturer.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 1 Product Introduction 1.1 Lists of Units 1.1.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 1.1.2 List of Indoor Units Model Cooling Capacity (Btu/h) Power Supply V/Ph/Hz Finished Product Code Airhandler MDUI18024E 24000 208/230V-1Ph-60Hz EH010N0090 Airhandler MDUI18036E 36000 208/230V-1Ph-60Hz EH010N0070 Airhandler MDUI18048E 48000 208/230V-1Ph-60Hz EH010N0080 Airhandler MDUI18060E 54000 208/230V-1Ph-60Hz EH010N0060 NOTE: 1 Ton =12000Btu/h = 3.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 1.2 Electrical Parameters Model Circuit breaker capacity Power supply A MDUCO18024036 208/230V-1Ph-60Hz 35 MDUCO18048060 208/230V-1Ph-60Hz 45 Model Power supply Fuse capacity Circuit breaker capacity A A MDUI18024E 208/230V-1Ph-60Hz 3.15 15 MDUI18036E 208/230V-1Ph-60Hz 3.15 15 MDUI18048E 208/230V-1Ph-60Hz 3.15 15 MDUI18060E 208/230V-1Ph-60Hz 3.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 2 Control 2.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 2.2 Control Mode 2.2.1 Based Control 2.2.1.1 Compressor Control When cooling mode is turned on, indoor fan will run for a while before the compressor starts. Under different modes, the compressor can only be stopped after running for some time (special cases excluded). This is to protect the compressor from frequent start or stop. Once the compressor is stopped, it must not be restarted right away. Please wait for a few minutes. 2.2.1.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 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.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT temperature to quickly reach the set temperature. Energy saving mode is achieved by setting the condensing unit operating mode to operate the air conditioner within a small load range. Operating mode Outdoor unit dip switches Standard mode Strong mode Energy saving mode 2.3.3 Set Indoor Fan Speed Set the indoor fan speed through the eight dip switches of the indoor main control board. The higher level, the higher speed of the indoor unit fan.
MRCOOL Capacity DC INVERTER COOLING ONLY CONDENSING UNIT 24K indoor unit dip switches 36K indoor unit dip switches Level 5 Level 6 Level 7 Level 8 Capacity 48K indoor unit dip switches 60K indoor unit dip switches Level 1 Level 2 (Default) Level 3 Level 4 Level 5 10
MRCOOL Capacity DC INVERTER COOLING ONLY CONDENSING UNIT 48K indoor unit dip switches 60K indoor unit dip switches Level 1 Level 2 (Default) Level 6 Level 7 Level 8 2.3.4 Refrigerant Recovery Control Press and hold "SW1" for about 5s to enter the first level menu of the debugging mode, the outdoor unit mainboard LED displayer flashes. Under the first level menu, short press "SW1" to switch various functions.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 2.3.6 Thermostat Functions Please refer to the thermostat instruction manual for all functions. 3 Troubleshooting 3.1 Wiring Diagrams The following electric diagram is for reference only. Please refer to diagram sticked on the unit as the latest version. 3.1.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Model: MDUCO18048060 13
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 3.1.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 3.2 PCB Layout 3.2.1 Interface Indoor unit: Mainboard Model: MDUI18024E，MDUI18036E，MDUI18048E, MDUI18060E No. Printing Interface No.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Outdoor unit: Mainboard Model: MDUCO18024036, MDUCO18048060 No. Printing 1 AC-L 2 AC-N 3 4 5 DC_MOTOR 1 DC_MOTOR 2 COM-MAN UAL 6 CN6 7 COM7 Interface No.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT No. Printing 8 T_LAC Interface Low temperature cooling temperature sensing 2. Outdoor tube temperature sensor interface 9 T_SENSOR2 4. Outdoor ambient temperature sensor interface 6. Discharge temperature sensor interface No. Printing Interface - - - - - - - - - -- - - Drive Board: Model: MDUCO18024036 No. Printing Interface No.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT No. Printing Interface No. Printing Interface 8 DC-MOTOR1 DC fan terminal 17 JTAG1 Programming interface (for testing) 9 DC-BUS1 Power discharge terminal (for testing) - - - Model: MDUCO18048060 No. Printing Interface No.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Filtering Board: 2 Model: MDUCO18024036 ⑩ 1 5 ⑩ ⑩ 6 ⑩ 7 3 ⑩ ⑩ 4 ⑩ No. Printing Interface No.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 3.2.2 IPM, PFC Testing Method 3.2.2.1Method of Testing IPM Module (1) Preparation before test: prepare a universal meter and turn to its diode option, and then remove the wires U, V, W of the compressor after it is powered off for one minute. (2) Testing Steps Step 1: put the black probe on the place P and the red one on the wiring terminal U, V, W respectively as shown in the following figure to measure the voltage between UP, VP and WP.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT MDUCO18024036 MDUCO18048060 21
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 3.3 Error Code No.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT There are LED indicators on the main board of the indoor unit, which are used to display the operating status and malfunction information of the unit. LED indicator Color Function Power Indicator Red Indoor unit main board is powered on, Power Indicator is on. Green After detecting the indoor fan turn-on signal, the running indicator light is on, when detecting the indoor fan turning-off signal, the running indicator light is off.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Troubleshooting： 24
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 3.4.2 “E3” Compressor Low-pressure Protection, Refrigerant Shortage Protection, Refrigerant Recovery Mode Error display: ODU mainboard LED displayer Error judgment condition and method: It is judged through the action of low pressure switch. If the low pressure switch is cut off, it is judged that low pressure is too low and the system stops operation for protection.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Troubleshooting： 26
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 3.4.3 “E4” Compressor Air Discharge High-temperature Protection Error display: ODU mainboard LED displayer Error judgment condition and method: Test the compressor discharge temperature through compressor discharge pipe and shell top temperature sensor.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Troubleshooting： 3.4.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT the error.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Possible reason: ■Poor contact between ambient temperature sensor and terminal in mainboard interface ■Ambient temperature sensor is abnormal ■Detecting circuit is abnormal Troubleshooting： NOTE: Please refer to Appendix 1 for the relation between temperature and resistance of temperature sensor. 3.4.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Troubleshooting： Malfunction of discharge temperature sensor Check if the discharge temperature sensor on mainboard is inserted on the needle stand correctly No Correctly insert the temperature sensor on the needle stand Yes Disconnect the temperature sensor and measure if its resistance is normal No Replace the temperature sensor Yes Replace the outdoor mainboard NOTE: Please refer to Appendix 1 for the relation between temperature and resistance
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Troubleshooting： Malfunction of discharge temperature sensor Check if the discharge temperature sensor on mainboard is inserted on the needle stand correctly No Correctly insert the temperature sensor on the needle stand Yes Disconnect the temperature sensor and measure if its resistance is normal No Replace the temperature sensor Yes Replace the outdoor mainboard NOTE: Please refer to Appendix 1 for the relation between temperature and resistance
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Troubleshooting: Malfunction of ODU memory chip error Replace the outdoor mainboard 3.4.9 “H4” Overload Error display: ODU mainboard LED displayer Error judgment condition and method: When condensing pressure is higher than the protection value, system will report overload protection. Possible reason: ■Cooling ODU heat exchanger is blocked or heat exchange is bad. ■Heating IDU heat exchanger is blocked or heat exchange is bad.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Troubleshooting： H4 Overload YES Outdoor heat exchanger is blocked Remove the obstacle NO YES Indoor heat exchanger is blocked. Remove the obstacle NO Ambient temperature is out of the operation range YES Normal protection. No need to handle it. YES Release a proper amount of refrigerant NO Too much charging quantity. NO Replace the drive board YES Error still exist? Replace the compressor 3.4.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT ■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. ■Drive board compressor current sampling circuit element is damaged or drive chip current sampling AD terminal is abnormal. ■Compressor is damaged. Troubleshooting： 3.4.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Possible reason: ■Outdoor fan wiring terminal is not correctly connected to the mainboard. ■Outdoor fan is damaged. ■If it is a new unit or a new motor has been replaced in the unit and the wire connection is correct, then probably it is the program that goes wrong.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT ■Drive board compressor current sampling circuit element is damaged or drive chip current sampling AD terminal is abnormal. ■Compressor is damaged.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 3.4.13 “HC” PFC Protection Error display: ODU mainboard LED displayer Error judgment condition and method: After power is connected, and drive chip received PFC lead F0 that is of low level, then it is PFC module malfunction. System will shut down for protection. Possible reason: ■Power grid voltage is abnormal. ■Drive board PFC module is damaged. ■Drive board PFC module’s 15V power supply is lower than 13.5V.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 3.4.14 “Lc” Startup Failure Error display: ODU mainboard LED displayer Error judgment condition and method: If the state of compressor stays at Startup for a long time and can’t switch to Running, then inverter compressor compressor startup failure.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 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.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT ■Drive board current sampling circuit element is damaged or drive chip current sampling AD terminal is abnormal. ■Compressor is damaged. Troubleshooting： 3.4.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Possible reason: ■Communication wire between master control and driver is not well connected, or has bad contact, or is broken. ■The switch power of drive board is abnormal, therefore, the 3.3V power voltage is abnormal. ■Communication circuit of the drive board or the master control board is abnormal. Troubleshooting： 3.4.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Troubleshooting： P7 Driver module sensor error Replace the drive board 3.4.19 “P8” Driver Module High Temperature Protection Error display: ODU mainboard LED displayer Error judgment condition and method: If IPM module temperature or PFC module temperature exceeds the set protection value, then it can be judged that driver module temperature is too high and system will shut down for protection.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 3.4.20 “PA” AC Current Protection Error display: ODU mainboard LED displayer Error judgment condition and method: If input current value exceeds the set protection value, then it can be judged that AC current protection occurs and system will shut down for protection. Possible reason: ■System is heavy-loaded and compressor current is too large. ■Grid voltage is abnormal. ■PFC module is damaged.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Troubleshooting： PC Current detection (or current sensor) circuit error Replace the drive board . 3.4.22 “PL” Bus Low-Voltage Protection Error display: ODU mainboard LED displayer Error judgment condition and method: When compressor is running and there is no other malfunction, if busbar voltage is lower than the set value for low voltage protection, then it can be judged that bus low-voltage protection occurs. System will shut down for protection.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 3.4.23 “PH” Bus High-Voltage Protection Error display: ODU mainboard LED displayer Error judgment condition and method: If there is no other malfunction and the busbar voltage is higher than the set value for high voltage protection, then it can be judged that bus high-voltage protection occurs. System will shut down for protection. Possible reason: ■Voltage of power grid is abnormal.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Troubleshooting： PU Charge loop error YES Grid voltage is too low ? Normal protection NO Replace the drive board 3.4.25 “ee” Drive Memory Chip Error Error display: ODU mainboard LED displayer Error judgment condition and method: If power is connected but the drive board with memory chip cannot detect the memory chip or read the memory chip data correctly, then it can be judged that drive memory chip error exists.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 3.5 Failures Not Caused by Errors (1) If your air conditioner fails to function normally, please first check the following items before maintenance: Problem Cause Corrective measure If you turn off the unit and then immediately turn it on, in order to protect the compressor and avoid system overload, compressor will delay running Please wait for a while. for 3min. The air conditioner can't run. Wire connection is wrong.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT (2) The following situations are not operation failures. Problem Mist comes from the air conditioner. Time of occurrence Cause If the unit is running under high humidity, the During operation. wet air in the room will be quickly cooled down. The air conditioner generates The air conditioner is buzzing at the beginning some noise. of operation. Thermostat will be buzzing when it starts working. The noise will become weak 1min later.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 4 Maintenance 4.1 System Diagram 4.2 Connection Pipe Vacuum Pumping NOTICE ① Make sure the outlet of vacuum pump is away from fire source and is well-ventilated. ② Before vacuum pumping, make sure the unit cut-off valves are closed. ③ When vacuum pumping, both the liquid pipe and the gas pipe must be pumped. (1) Remove the caps of the liquid valve, gas valve and also the service port.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT And verify if the pressure gauge at the low pressure side of the manifold valve assembly reads -0.1Mpa (-750mmHg), if not, it indicates there is leak somewhere. Then, close the switch fully and then stop the vacuum pump. (6) Wait for 10min to see if the system pressure can remain unchanged. If the pressure increase, there may be leakage.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 4.3 Refrigerant Charging Pre-charging Step 1: Connect the high pressure gauge line to the valve of liquid pipe and connect the low pressure gauge line to the valve of gas pipe. Connect the middle gauge line to the vacuum pump. Power on the vacuum pump and perform vacuum drying. Step 2: After vacuum drying, close the high and low pressure gauge valves. Then remove the middle gauge line from the connector of vacuum pump. Then connect to the refrigerant tank.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Refrigerant charging when unit is turned on: Step 1: Close the valve of refrigerant tank. First remove the pressure gauge lines and connect the outdoor unit to the indoor unit. Then reconnect the pressure gauge lines. Connect the low pressure gauge line to the other joint of gas valve and connect the high pressure gauge line to the liquid valve. Connect the middle gauge line to the vacuum pump. Power on the vacuum pump and perform vacuum drying.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 4.4 Maintenance of Major Components 4.4.1 Replacement of thermostat Please refer to the instruction manual of thermostat 4.4.2 How to replace the compressor 4.4.2.1 Diagnosis of compressor failure A. On condition that the unit can be started up Step 1: If the unit can be started up, then start it up to check the current of the faulted compressor. Use a pressure gauge to measure the pressure of the big and small valves.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Inverter compressor QXAS-F428zX450L Step 2: Judge whether the operating noise of the compressor is normal, and whether there is a sharp noise or obvious scraping. If there is a normal compressor working nearby, compare their operating noise. Step 3: Check the drive board of compressor, i.e. the IPM module. Please refer to the IPM checking method in the section of troubleshooting. Check the drive board of compressor, i.e. the IPM module.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Refer to the following table for the resistance between any two terminals: Compressor model UV Winding resistance VW Winding resistance WU Winding resistance QXAS-D32zX090FA 1.02±7%Ω 1.02±7%Ω 1.02±7%Ω QXAS-F428zX450L 0.54±7%Ω 0.54±7%Ω 0.54±7%Ω Measure the earth resistance of each wiring terminal. The resistance should be above 10 megohm. If not, we can judge that the compressor is faulted inside. Step 3: Check whether the IPM module is normal.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Make sure the electric box cover of the compressor is in good condition. NOTICE: Before replacement, make sure the nameplates and models of the compressors are identical. NOTICE: Make sure the lubricant is sealed inside the compressors. (2) Prepare relevant tools 1) Prepare nitrogen. Please strictly follow the nitrogen welding standards during the welding process. Make sure there is sufficient nitrogen. The nitrogen pressure should be above 2.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Step 2: Disconnect power If the compressor needs to be replaced after judging as above, then switch off the outdoor unit and disconnect the power cable of the outdoor unit. Use insulating tape to wrap the power cable and put a notice board on the power switch to remind people to be cautious of electric shock.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT NOTE: Confirm whether the compressor needs to be replaced. The pipe mouths of the faulted compressor must be sealed by adhesive tape as soon as the compressor is detached. Make sure the compressor is well preserved for the ease of future analysis. Step 6: Check the components If the oil is contaminated, check the components of the unit, including the gas-liquid separator.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 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.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT below 36V, proceed with the next step. In case that a universal meter is not available, disconnect power for 20min and then continue with the next step. Step 3: Remove all the wires on the drive board of the compressor. Step 4: Remove the screws on the drive board of the compressor. The screws are located in the white circles as shown above in the picture. Step 5: Replace with a new compressor drive board.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 4.5 Removal of Major Components 4.5.1 Removal of ODU Major Components Picture Name Function Through compression, the low pressure refrigerant occupies a less space. Compressor As its pressure and temperature both rise, it becomes high pressure and high temperature refrigerant. It is the power drive of the system. The power drive of the fan.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Model: MDUCO18024036 Removal of front panel NOTE: Before removing the front panel, make sure power is cut off. Step Picture Work instruction 1. Remove the upper cover Unscrew the screws of the upper cover plate with a plate. screwdriver. 2. Remove the front side plate. Unscrew the screws of the upper and front side plate with a screwdriver. 3. Remove the front grill. Unscrew the screws of the front grill with a screwdriver.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Removal of front panel NOTE: Before removing the front panel, make sure power is cut off. Step Picture Work instruction Unscrew the screws that connect the right side plate 5. Remove the right side plate. to the electric box and the screws around the right side plate. Screw up the screws around the right side plate. Be 6. Install the right side plate careful to handle well the clasps at the bottom of the right side plate.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Removal of front panel NOTE: Before removing the front panel, make sure power is cut off. Step Picture Work instruction Fix the clasps on both sides 9. Install the front side plate. of the plate and tighten up the screws. Tighten up the screws 10. Install the upper cover plate. around the upper cover plate.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Removal of compressor/gas liquid separator NOTE: Before removing the compressor/gas liquid separator, make sure there is no refrigerant in the pipeline and power is cut off. Step Picture Work instruction Weld the pipes that are connected to the compressor/gas liquid 2. Break off the pipes that separator. connecting to the compressor/gas liquid Then remove the pipes. NOTE: When welding the separator.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Removal of compressor/gas liquid separator NOTE: Before removing the compressor/gas liquid separator, make sure there is no refrigerant in the pipeline and power is cut off. Step Picture Work instruction 5. Install the new Screws After replacing the compressor/gas liquid compressor/gas liquid separator, tighten up the separator onto the chassis. Nuts base screw nuts. Weld the connection pipes of compressor so as to 6.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Model: MDUCO18024036 Removal of fan and motor Note: Before removing the fan, make sure power is cut off. Step Picture Work instruction Use a screwdriver to unscrew the two screws 1. Remove the grill. on the upper left and lower right corners. Use a wrench to remove the specialized nut and gasket of the fan. NOTE: Please keep the 2. Remove the fan. nut and gasket safe after removing them from the fan.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Removal of fan and motor Note: Before removing the fan, make sure power is cut off. Step Picture Work instruction Install the fan in place. Put on the gasket and use a wrench to secure the screw nut. NOTE: After installing the 5. Install the fan. fan, turn the fan by hand to see if it can run normally. If not, please check for the reason. After replacing the motor, use a screwdriver to tighten up the screw bolt 6. Install the grill.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Removal of condenser NOTE:Before removing the condenser, make sure there is no refrigerant in the pipeline and power is cut off. Step Picture Work instruction 3. Remove motor support. When removing the motor support, be careful to protect the components. Heat up the welding points of connection pipes through gas welding until the pipes break off. NOTE: When welding the pipes, do not let the flame 4. Remove the condenser. burn the other components.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Removal of condenser NOTE:Before removing the condenser, make sure there is no refrigerant in the pipeline and power is cut off. Step Picture Work instruction Secure the screws of condenser and support. Then fix them together on the chassis. Install the condenser by referring to the positions of entering and leaving pipes. 6. Install the new condenser. Weld the connection pipes. Nitrogen welding: the pressure of nitrogen is 0.5±0.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Model: MDUCO18048060 Removal of front panel NOTE: Before removing the front panel, make sure power is cut off. Step Picture Work instruction 1. Remove the upper cover Unscrew the screws of the upper cover plate with a plate. screwdriver. Loose the screw fixing the frontside plate with 2. Remove front side plate screwdriver. sub-assy. Hold the front side plate upwards and then put it on the floor flatly.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Removal of front panel NOTE: Before removing the front panel, make sure power is cut off. Step Picture Work instruction 4. Remove left side plate and Loose screws fixing left side plate and rear side plate with rear side plate. screwdriver. 73 Remove the rear side plate.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Model: MDUCO18048060 Disassembly of compressor NOTE:Before removing the compressor, make sure there is no refrigerant in the pipeline and power is cut off. Step Picture Work instruction 1. Remove the small side Loosen the securing screws of the small side panel. panel. Remove the small side panel. 2. Loosen the securing screws Use a wrench to twist off the screw nuts at the foot of at the foot of compressor. compressor.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Disassembly of compressor NOTE:Before removing the compressor, make sure there is no refrigerant in the pipeline and power is cut off. Step Picture Work instruction Take out the compressor and replace it. NOTE:When replacing the 4. Remove the compressor from the chassis. compressor, avoid touching the nearby pipeline and components. 5. Fix the new compressor back After replacing the compressor, tighten up the onto the chassis.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Disassembly of compressor NOTE:Before removing the compressor, make sure there is no refrigerant in the pipeline and power is cut off. Step Picture Work instruction Connect the compressor wires to the wire terminals on the top of compressor. NOTE: When connecting 7. Connect the compressor wires. the wires, be sure to match the colors with the corresponding wire terminals.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Removal of fan and motor NOTE: Before removing the fan, make sure power is cut off. Step Picture Work instruction Use a screwdriver to unscrew the bolt of motor. NOTE: Motor wire should 3. Remove motor. be first removed from the electric box. 4. Install the motor. Replace with a new motor. Then tighten up the screw bolt. Install the fan in place. Put on the gasket and use a wrench to secure the screw nut. NOTE:After installing the 5.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Removal of fan and motor NOTE: Before removing the fan, make sure power is cut off. Step Picture Work instruction After replacing the motor, use a screwdriver to tighten 6. Install the grill. up the screw bolt that secures the motor. Model: MDUCO18048060 Removal of gas liquid separator NOTE: Before removing the gas liquid separator, make sure there is no refrigerant in the pipeline and power is cut off.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Removal of gas liquid separator NOTE: Before removing the gas liquid separator, make sure there is no refrigerant in the pipeline and power is cut off. Step Picture Work instruction Install the gas liquid separator by referring to the positions of entering and leaving pipes. Welding interface Weld the 2 welding interfaces. 3. Install the new gas liquid Nitrogen welding: the pressure of nitrogen is separator 0.5±0.1kgf/ cm²(relative pressure).
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 4.5.2 Removal of IDU Major Components 4.5.2.1 Air Handler Unit Disassembly and Assembly of the Electric Box Step Picture Work instruction ● Loosen screws around the upper panel with a screwdriver. 1. Remove the upper panel ● Remove the upper panel away from the unit. ● Disconnect the power cord and control line from the wiring terminals, and then draw them out. 2. Remove the electric box. ● Loosen screws around the electric box with a screwdriver.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Disassembly and Assembly of the Electric Box Step Picture Work instruction ● Place the electric box at the proper position. ● Tighten screws around the electric box 5. Reinstall the electric box. with a screwdriver. ● Connect the power cord and control line properly. ● Reassemble the unit as before. Disassembly and Assembly of the Fan Motor Step Picture Work instruction ● Loosen screws round the upper panel 1. Remove the upper panel.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Disassembly and Assembly of the Fan Motor Step Picture Work instruction ● Place the motor at the proper position. ● Tighten screws fixing the motor and fan blades. ● Tighten screw bolts fixing the motor 4. Reinstall the fan. bracket. ● After the installation, reassemble the unit as before. Disassembly and Assembly of the Evaporator and Drain Pan Step Picture Work instruction ● Loosen screws round the upper panel 1. Remove the upper panel.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Disassembly and Assembly of the Evaporator and Drain Pan Step Picture Work instruction ● Loosen screws at both side of the 4. Remove the mounting plate of mounting plate with a screwdriver. the drain pan. ● Remove the mounting plate from the unit. 5. Remove the primary drain ● Remove the primary drain pan from the pan. unit. 6. Remove the secondary drain ● Remove the secondary drain pan from pan. the unit.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Disassembly and Assembly of the Filter Step Picture Work instruction ● Loosen screws fixing the mounting plate with a screwdriver. 1. Remove the mounting plate. ● Remove the mounting plate away from the unit. ● Remove the filter screen away from the unit. 2. Remove the filter screen. ● After replacing the filter screen, reassemble the unit as before.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 4.6 Explosive View and Lists of Parts 4.6.1 ODU Explosive View and Lists of Parts MDUCO18024036 1 2 3 4 5 6 7 8 9 10 11 12 42 41 40 13 14 15 16 39 17 18 19 38 20 36 37 21 No.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT No.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT MDUCO18048060 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 No.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT No.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 4.6.2 IDU Explosive View and Lists of Parts MDUI18036E MDUI18060E 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 No.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT No.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Appendices 1 Resistance/Temperature Lists of Temperature Sensors 1.1 Voltage List of 15 KΩ Temperature Sensors (including ODU temperature sensors) Temperature (℃) Resistance (kΩ) Voltage (V) Temperature (℃) Resistance (kΩ) Voltage (V) -20 144 0.311 71 2.523 2.825 -19 138.1 0.323 72 2.439 2.838 -18 128.6 0.345 73 2.358 2.852 -17 121.6 0.362 74 2.28 2.865 -16 115 0.381 75 2.205 2.877 -15 108.7 0.4 76 2.133 2.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Temperature (℃) Resistance (kΩ) Voltage (V) Temperature (℃) Resistance (kΩ) Voltage (V) 15 23.6 1.282 106 0.848 3.123 16 22.53 1.319 107 0.825 3.128 17 21.51 1.356 108 0.802 3.133 18 20.54 1.393 109 0.779 3.137 19 19.63 1.429 110 0.758 3.141 20 18.75 1.467 111 0.737 3.145 21 17.93 1.503 112 0.717 3.15 22 17.14 1.54 113 0.697 3.153 23 16.39 1.577 114 0.678 3.157 24 15.68 1.613 115 0.66 3.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Temperature (℃) Resistance (kΩ) Voltage (V) Temperature (℃) Resistance (kΩ) Voltage (V) 61 3.579 2.664 151 0.266 3.242 62 3.454 2.682 152 0.261 3.244 63 3.333 2.7 153 0.254 3.245 64 3.217 2.717 154 0.248 3.246 65 3.105 2.734 155 0.243 3.247 66 2.998 2.75 156 0.237 3.249 67 2.898 2.766 157 0.232 3.25 68 2.797 2.781 158 0.227 3.251 69 2.702 2.796 159 0.222 3.252 70 2.611 2.811 160 0.217 3.253 1.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Temperature (℃) Resistance (kΩ) Voltage (V) Temperature (℃) Resistance (kΩ) Voltage (V) -1 68.79 0.743 95 1.561 3.061 0 65.37 0.773 96 1.515 3.068 1 62.13 0.804 97 1.47 3.074 2 59.08 0.835 98 1.427 3.08 3 56.19 0.866 99 1.386 3.086 4 53.46 0.898 100 1.346 3.092 5 50.87 0.931 101 1.307 3.098 6 48.42 0.965 102 1.269 3.103 7 46.11 0.998 103 1.233 3.108 8 43.92 1.033 104 1.198 3.114 9 41.84 1.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Temperature (℃) Resistance (kΩ) Voltage (V) Temperature (℃) Resistance (kΩ) Voltage (V) 43 9.42 2.243 139 0.4727 3.224 44 9.054 2.272 140 0.4613 3.226 45 8.705 2.299 141 0.4502 3.227 46 8.37 2.326 142 0.4394 3.229 47 8.051 2.353 143 0.4289 3.231 48 7.745 2.379 144 0.4187 3.232 49 7.453 2.404 145 0.4088 3.234 50 7.173 2.429 146 0.3992 3.235 51 6.905 2.453 147 0.3899 3.237 52 6.648 2.477 148 0.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Temperature (℃) Resistance (kΩ) Voltage (V) Temperature (℃) Resistance (kΩ) Voltage (V) -15 362.99 0.088 76 6.9882 1.943 -14 342.83 0.094 77 6.7608 1.969 -13 323.94 0.099 78 6.542 1.995 -12 306.23 0.104 79 6.3315 2.021 -11 289.61 0.11 80 6.1288 2.046 -10 274.02 0.116 81 5.9336 2.071 -9 259.37 0.123 82 5.7457 2.096 -8 245.61 0.129 83 5.5647 2.12 -7 232.67 0.136 84 5.3903 2.144 -6 220.5 0.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT Temperature (℃) Resistance (kΩ) Voltage (V) Temperature (℃) Resistance (kΩ) Voltage (V) 29 41.313 0.643 120 1.9123 2.77 30 39.61 0.665 121 1.8652 2.781 31 37.958 0.688 122 1.8158 2.793 32 36.384 0.711 123 1.7698 2.804 33 34.883 0.735 124 1.7253 2.814 34 33.453 0.759 125 1.6821 2.825 35 32.088 0.784 126 1.6402 2.835 36 30.787 0.809 127 1.5996 2.845 37 29.544 0.835 128 1.5602 2.855 38 28.359 0.
MRCOOL DC INVERTER COOLING ONLY CONDENSING UNIT 2 Temperature/Pressure List of Refrigerant R410A Temperature Pressure Temperature Pressure Temperature Pressure ℃ kPa ℃ kPa ℃ kPa -30 275 0 803 30 1880 -29 286 1 823 31 1910 -28 298 2 851 32 1960 -27 311 3 879 33 2030 -26 324 4 903 34 2080 -25 334 5 937 35 2130 -24 348 6 962 36 2180 -23 363 7 994 37 2240 -22 375 8 1020 38 2290 -21 391 9 1050 39 2350 -20 404 10 1090 40 2410 -19 424
