MrCool U-match MDUI18024 Service Manual Download Page 73

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MRCOOL

Universal Service Manual

Picture

Name

Function

Accumulator

Flash refrigerant from liquid to gas

Condenser

It is used to transfer partial heat of the hot flow to the cold flow so that the
flow temperature can reach the specified index. It is an energy exchanging
device.

Electronic

expansion valve

It is used to lower the pressure and temperature of liquefied refrigerant and
adjust the flow of refrigerant entering the evaporator.

Electromagnetic

Valve

Electromagnetic valve controls increased enthalpy switch.

Summary of Contents for U-match MDUI18024

Page 1: ...1 DC Inverter U match Series for R410A Unitary Split Air Conditioner SERVICE MANUAL Capacity 24kBtu h 60kBtu h Rate Frequency 60Hz Operation Range Cooling 5 F 15 C 129 2 54 Heating 22 F 30 C 75 2 F 24 C ...

Page 2: ...ng the air conditioner please first read the instruction manual Before installing the air conditioner please first read the instruction manual Before repairing the air conditioner please first read the technical service manual ...

Page 3: ...efrigerant Charging 57 4 4 Maintenance of Major Components 59 4 5 Removal of Major Components 69 4 6 Explosive View and Lists of Parts 103 Appendices 109 1 Resistance Temperature Lists of Temperature Sensors 109 1 1 Voltage List of 15 kΩ Temperature Sensors including ODU and IDU temperature sensors 109 1 2 Voltage List of 20 kΩ Pipeline Temperature Sensors including temperature sensors for defrost...

Page 4: ...ssary qualifications WARNING 1 If the working place is more than 2m s high please wear a safety helmet gloves and a safety belt 2 Never mix any other substances except the specified refrigerant into the refrigerant circuit 3 When re locating the appliance check whether the new location is strong enough to withstand the weight of the appliance 4 If there is refrigerant leak please fix the leak befo...

Page 5: ...d all be done according to applicable local rules and regulations Safety Notice on Operation PROHIBITED 1 Never try to modify the unit otherwise it may cause electric shock overheat or fire hazard 2 If the power cord or conducting wires are scratched please replace them 3 Never use connected or extended power cord or share the power socket with other appliances 4 Prepare a specialized power circui...

Page 6: ...MRCOOL Universal Service Manual 3 1 Product Introduction 1 1 Lists of Units 1 1 1 List of Outdoor Units Model Power Supply Appearance V Ph Hz MDUO1836 208 230V 1Ph 60Hz MDUO1860 208 230V 1Ph 60Hz ...

Page 7: ...g Capacity Btu h Power Supply Appearance V Ph Hz Airhandler MDUI18024 24000 24000 208 230V 1Ph 60Hz Airhandler MDUI18036 36000 36000 208 230V 1Ph 60Hz Airhandler MDUI18048 48000 48000 208 230V 1Ph 60Hz Airhandler MDUI18060 54000 54000 208 230V 1Ph 60Hz Note 1 Ton 12000Btu h 3 517kW ...

Page 8: ...breaker capacity V Ph Hz A MDUO1836 208 230V 1Ph 60Hz 35 MDUO1860 208 230V 1Ph 60Hz 45 Model Power Supply Fuse Capacity Circuit Breaker Capacity V Ph Hz A A MDUO1824 208 230V 1Ph 60Hz 15 15 MDUO1836 208 230V 1Ph 60Hz 15 15 MDUO1848 208 230V 1Ph 60Hz 15 15 MDUO1860 208 230V 1Ph 60Hz 15 15 ...

Page 9: ...MRCOOL Universal Service Manual 6 2 Control 2 1 Operation Mode 2 1 1 Cooling Mode ...

Page 10: ...MRCOOL Universal Service Manual 7 2 1 2 Heating Mode ...

Page 11: ...ns The outdoor fan can run at the highest level 10 and the lowest level 1 By controlling the speed of outdoor fan the unit can achieve cooling at low temperature and heating at high temperature In fan mode outdoor fan will not work 2 2 1 4 4 way Valve Control After heating mode is turned on for a while 4 way valve will be energized to change the direction of refrigerant flow so that the system can...

Page 12: ...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...

Page 13: ...acity Dial Code Set the capacity of the outdoor unit through the four digit dial codes of the outdoor unit main control board Specific dialing definition the first digit dial code distinguishes the capacity Capacity 24K 36K 48K 60K Dial Codes 2 3 2 Set Defrost Mode The second digit dial code are selecting the defrost mode The following table shows the 36K outdoor unit dial code for example Mode 1 ...

Page 14: ...ed by setting the condensing unit operating mode to operate the air conditioner within a small load range Operating mode Outdoor unit dial code Standard mode Default Forcible mode Energy saving mode 2 3 4 Set Indoor Fan Speed Set the indoor fan speed through the four digit dialing codes of the indoor main control board The higher level the higher speed of the indoor unit fan Capacity 24K indoor un...

Page 15: ...oor unit mainboard LED displayer flashes Under the first level menu short press SW1 to switch various functions After switching to 08 short press SW2 or SW3 to enter the refrigerant recovery control mode ON means open OF means close And then short press SW1 to save During debugging if no operation is performed within 10s the debugging mode interface will be exited 2 3 7 Forced Operation Control Pr...

Page 16: ...oling heating mode And then short press SW1 to save During debugging if no operation is performed within 10s the debugging mode interface will be exited 2 3 8 Thermostat Functions Thermostat model XE70 00 E1 please refer to the thermostat instruction manual for all functions ...

Page 17: ...Service Manual 14 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 1 Wiring Diagrams of ODUS Model MDUO1836 ...

Page 18: ...MRCOOL Universal Service Manual 15 Model MDUO1860 ...

Page 19: ...MRCOOL Universal Service Manual 16 3 1 2 Wiring Diagrams of IDUs Model MDUO18024036 Model MDUO18048060 ...

Page 20: ...ut 8 X9 G_SCAN Indoor motor check 2 AC L X1 Live wire input 9 X14 OFAN H OUT AC motor high speed output 3 CN3 Wired control communication interface 10 X11 OFAN H IN AC motor high speed input 4 CN1 DC motor output 11 X8 OFAN L IN AC motor low speed input 5 X7 Transformer Neutral wire input 12 X6 OFAN L OUT AC motor low speed output 6 X13 Transformer Live wire input 13 X3 C Transformer Neutral wire ...

Page 21: ... Universal Service Manual 18 7 X10 O_SCAN 4 Way check 14 X4 R Transformer Live wire output Pinboard No Printing Interface No Printing Interface 1 DC MOTOR1 DC motor output 2 COM2 DC motor control signal input ...

Page 22: ...e input 12 LPP System low pressure protection interface 3 HEAT_TI E_B Chassis electric heating belt 13 HPP System high pressure protection interface 4 HEAT_TI E_C Compressor electric heating belt 14 T_SENSOR2 2 Outdoor tube temperature sensor interface 4 Outdoor ambient temperature sensor interface 6 Discharge temperature sensor interface 5 4WAY 4 way valve 15 T_LAC Low temperature cooling tempera...

Page 23: ...on interface 19 DC_MOTOR1 DC_MOTOR2 DC motor output 10 L PRESS low pressure sensor interface 20 PWR1 310V DC power supply interface Drive Board Model MDUO1836 No Printing Interface No Printing Interface 1 L2 2 PFC induction wire blue 10 P OUT Reserved 2 AC L Live wire 11 L1 2 PFC induction wire white 3 L1 1 PFC induction wire brown 12 L2 1 PFC induction wire yellow 4 N Neutral wire 13 G OUT Reserv...

Page 24: ...UO1860 No Printing Interface No Printing Interface 1 L2 2 PFC induction wire blue 8 L1 2 PFC induction wire white 2 AC L Live wire 9 U Compressor U phase terminal 3 L1 1 PFC induction wire brown 10 V Compressor V phase terminal 4 N Neutral wire 11 W Compressor W phase terminal 5 JTAG1 Programming interface for testing 12 PWR Drive power supply terminal 6 COMM Communication terminal same with COMM ...

Page 25: ...inal 6 N OUT Power output neutral wire terminal 3 E1 Filtering board ground wire terminal 7 L OUT Power output live wire terminal 4 E2 Filtering board grounding hole reserved Model MDUO1860 No Printing Interface No Printing Interface 1 AC L Power input live wire terminal 6 N OUT1 Power output neutral wire terminal reserved 2 N Power input neutral wire terminal 7 N OUT Power output neutral wire ter...

Page 26: ... voltage between NU NV and NW 3 If the measured voltages between UP VP WP NU NV NV are all among 0 3V 0 7V then it indicates the IPM module is normal If any measured valve is 0 it indicates the IPM is damaged 3 2 2 2 Method of Testing PFC Module Short Circuit 1 Preparation before test prepare a universal meter and turn to its diode option and then remove the wires L1 2 L2 1 after it is powered off...

Page 27: ...MRCOOL Universal Service Manual 24 ...

Page 28: ...MRCOOL Universal Service Manual 25 MDUO1860 ...

Page 29: ...n 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 26 e1 High pressure sensor error 27 C4 ODU jumper cap error...

Page 30: ...ssure switch If the high pressure switch is cut off it is judged that high pressure is too high and the system stops operation for protection Possible reason Cut off valve of ODU is not fully opened High pressure switch is abnormal Outdoor or indoor fan is not working properly IDU filter or air duct is blocked heating mode Ambient temperature is too high Refrigerant charging amount is too much Sys...

Page 31: ...al Service Manual 28 Troubleshooting 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 ...

Page 32: ...e is too low and the system stops operation for protection Possible reason Cut off valve of ODU is not fully opened Low pressure sensor is abnormal Outdoor or indoor fan is not working properly IDU filter or air duct is blocked cooling mode Ambient temperature is too low Refrigerant charging amount is insufficient System pipeline is blocked Troubleshooting ...

Page 33: ...harge pipe and shell top temperature sensor If the tested temperature value is higher than 115 the unit will stop for protection Possible reason Cut off valve of ODU is not fully opened Electronic expansion valve is abnormal Outdoor or indoor fan is not working properly IDU filter or air duct is blocked cooling mode Ambient temperature exceeds allowable operation range Refrigerant charging amount ...

Page 34: ...ror display ODU mainboard LED displayer Error judgment condition and method Sample the AD value of temperature sensor through temperature sensor detecting circuit and judge the range of AD value If the sampling AD value exceeds upper limit and lower limit in 5 seconds continuously report the error ...

Page 35: ...5 F3 Outdoor Ambient Temperature Sensor Error Error display ODU mainboard LED displayer Error judgment condition and method Sample the AD value of temperature sensor through temperature sensor detecting circuit and judge the range of AD value If the sampling AD value exceeds upper limit and lower limit in 5 seconds continuously report the error Possible reason Poor contact between ambient temperat...

Page 36: ...rd LED displayer Error judgment condition and method Sample the AD value of temperature sensor through temperature sensor detecting circuit and judge the range of AD value If the sampling AD value exceeds upper limit and lower limit in 5 seconds continuously report the error Possible reason Poor contact between temperature sensor and terminal in mainboard interface Temperature sensor is abnormal D...

Page 37: ...d LED displayer Error judgment condition and method Sample the AD value of temperature sensor through temperature sensor detecting circuit and judge the range of AD value If the sampling AD value exceeds upper limit and lower limit in 5 seconds continuously report the error Possible reason Poor contact between temperature sensor and terminal in mainboard interface Temperature sensor is abnormal De...

Page 38: ...mory Chip Error Error display ODU mainboard LED displayer Error judgment condition and method If ODU mainboard cannot read the memory chip this error will be reported Possible reason Memory chip on the ODU mainboard is damaged Memory chip is weakly welded Memory chip lead is short circuited Troubleshooting Malfunction of ODU memory chip error Replace the outdoor mainboard ...

Page 39: ...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 Operating temperature is too high System charging quantity is too much ...

Page 40: ... 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 compr...

Page 41: ...display ODU mainboard LED displayer Error judgment condition and method Mainboard doesn t receive the signal of outdoor fan within 30s after the outdoor fan starts up 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 th...

Page 42: ...rs too much from the set running speed In each case compressor runs out of step and system stops for protection Possible reason Compressor 3 phase wire connection is lack of phase or phased reversed Compressor phase wire connection is bad System is blocked short of refrigerant or compressor oil Drive board IPM module is damaged Drive board compressor current sampling circuit element is damaged or ...

Page 43: ...MRCOOL Universal Service Manual 40 Troubleshooting ...

Page 44: ...n Possible reason Power grid voltage is abnormal Drive board PFC module is damaged Drive board IPM module s 15V power supply is lower than 13 5V Drive board PWM signal for PFC and the corresponding element are abnormal Drive board PFC current sampling circuit element is damaged or drive chip current sampling AD terminal is abnormal Troubleshooting HC PFC protection Normal protection Check whether ...

Page 45: ...isplayer Error judgment condition and method Check the error code on nixie tube of ODU main control board If PJ is displayed it indicates inverter compressor startup failure Possible reason Poor contact of compressor UVW wire Compressor is broken Compressor drive board is broken Troubleshooting ...

Page 46: ...ce the drive board Re arrange the wires Heavy current wires s hould avoid the drive board chip NO YES 3 4 16 P5 Over Current Protection Error display ODU mainboard LED displayer Error judgment condition and method If compressor s instant current value is higher than the set current protection value then it can be judged that compressor over current occurs and system will shut down for protection P...

Page 47: ...control and driver is cut off for 30s then it can be judged that the communication between master control and driver is faulted System will shut down for protection 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 o...

Page 48: ...s lower than the set protection value then it can be judged that driver module sensor error occurs and system will shut down for protection Possible reason Module temperature sensor is short circuited or broken circuited Drive board current sampling circuit element is damaged or drive chip current sampling AD terminal is abnormal Troubleshooting P7 Driver module sensor error Replace the drive boar...

Page 49: ...e module or there is other substance on the back of the module The module securing screws are not tightened up Drive board temperature sampling circuit element is damaged or drive chip temperature sampling AD terminal is abnormal Troubleshooting 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 prote...

Page 50: ...od After power charging if offset voltage average is detected to exceed 12 5 of 1 65V in 1s then it can be judged that current detection or current sensor circuit is faulted System will shut down for protection Possible reason Current detection or current sensor sampling circuit element is abnormal Drive chip compressor current sampling AD terminal is badly welded or short circuited Troubleshootin...

Page 51: ...d or drive board busbar voltage sampling AD terminal is abnormal Troubleshooting PL Bus low voltage protection Grid voltage is normal or not Normal protection Replace the dr ive board YES NO 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...

Page 52: ...ertain period of time then it can be judged that charge loop error exists System will shut down for protection Possible reason Voltage of power grid is abnormal Voltage is too low Drive board charge loop element is abnormal Drive board busbar voltage sampling circuit element is damaged or drive chip busbar voltage sampling AD terminal is abnormal Troubleshooting PU Charge loop error Normal protect...

Page 53: ...ctor of memory chip is badly welded or short circuited Troubleshooting ee Drive memory chip error Drive board is installed with memory chip or not Install the memory chip Replace the drive board YES NO 3 4 26 e1 High Pressure Sensor Error Error display ODU mainboard LED displayer Sample the AD value of pressure sensor through pressure sensor detecting circuit and judge the range of AD value If the...

Page 54: ...ror Error display ODU mainboard LED displayer Error judgment condition and method If jumper cap model doesn t match with mainboard report the error Possible reason Jumper cap is not installed Jumper cap model is wrong Detecting circuit is abnormal Troubleshooting ...

Page 55: ...MRCOOL Universal Service Manual 52 ...

Page 56: ...ower is resumed Power plug is loose Re insert the power plug Thermostat has low battery Replace the batteries Bad cooling or heating effect Air inlet and outlet of the units have been blocked Clear the obstacles and keep the room for the units well ventilated Improper temperature setting Reset a proper temperature Fan speed is too low Reset a proper fan speed Air flow direction is not right Change...

Page 57: ... The sound will disappear after the valve changes its direction There is hissing sound when the unit is started or stopped and a slight hissing sound during and after operation It s the sound of gaseous refrigerant that stops flowing and the sound of drainage system There is a sound of crunching during and after operation Because of temperature change front panel and other components may be swelle...

Page 58: ...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 2 meanwhile the gas and liquid valves should be kept closed in case of refrigerant leak 3 Connect the hose used for evacuation to the vacuum pump 4 Open the switch at the lower pressure side of the ...

Page 59: ...uid valve can be opened fully only after the manifold valve assembly is removed 8 Place back the caps of the liquid valve gas valve and also the service port NOTICE For large size units there are maintenance ports for liquid valve and gas valve During evacuation you may connect the two hoses of the branch valve assembly to the maintenance ports to speed up the evacuation Refrigerant should be recl...

Page 60: ...n tighten up the connector again and completely open the valve of refrigerant tank at the same time Step 4 Keep the refrigerant tank erect and put it on an electronic scale Record the current weight as m1 Step 5 Open the high pressure gauge valve Keep the low pressure gauge valve closed Then charge refrigerant into the system Meanwhile record the weight of refrigerant tank as m2 Step 6 m1 m2 m If ...

Page 61: ...onditioner and let it run for a while Step 5 Open the low pressure gauge valve Keep the high pressure gauge valve closed Then charge in the remaining charging quantity m Step 6 After all required refrigerant is charged in close the valve of refrigerant tank Step 7 Remove the pressure gauge to finish the refrigerant charging work Procedure of refrigerant charging Following is the supplementary requ...

Page 62: ...lectric current of an inverter compressor will be different under different rotation speed or different working conditions If the compressor is working at 60Hz the working current corresponding to different condensing temperature and evaporating temperature is shown below Inverter compressor QXFT F310zN450 Step 2 Judge whether the operating noise of the compressor is normal and whether there is a ...

Page 63: ... valve and you can feel its move as it is reset upon startup b Make sure the coil is fixed firmly 2 4 way valve During normal operation the 4 copper tubes that connect to the valve will have different temperature When the 4 way valve is working it will generate some noise and vibration This is the position of the 4 way valve Do not touch it directly with your hands There is hot refrigerant at the ...

Page 64: ...o the exhaust side it is with high pressure and high temperature regardless of the operating mode When the unit is powered on in defrosting or oil return mode the 4 way valve will produce some noise Do not touch the pipes directly with your hands and be cautious of the hot temperature Step 4 Check the drive board of compressor i e the IPM module Please refer to the IPM checking method in the secti...

Page 65: ...ing the electronic expansion valve The checking method is the same as instructed above Step 4 Check whether the IPM module is normal Please refer to the IPM checking method in the section of troubleshooting 4 4 2 2 Replacement of compressor Step 1 Preparation 1 Prepare the components for replacement When carrying the old and new compressors do not place the compressors horizontally or upside down ...

Page 66: ...ssors 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 0MPa Make sure the rubber seals of the suction and exhaust openings of the compressor are in good condition Make sure the electric box cover of the compressor is in good condition ...

Page 67: ...compressor wires temperature sensors and electric heaters mark them correspondingly for the convenience of reconnecting them Step 4 Discharge refrigerant Discharge refrigerant from the system Discharge simultaneously from the high pressure side and low pressure side Do not discharge too fast It should take more than 12h to completely discharge the refrigerant otherwise large quantity of lubricant ...

Page 68: ...nt smell b If the oil is contaminated replace the compressor and the gas liquid separator 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 c...

Page 69: ...eplace 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...

Page 70: ... cables compressor wires and the electric heating belt according to the signs marked before and the wiring diagram on the cover of the electric box 4 4 3 How to replace the drive module of compressor Step 1 First make sure that power is cut off Set the universal meter at the AC voltage and measure the voltage between L1 L2 L3 and N If each time the voltage is 0V Errors may occur to the universal m...

Page 71: ... compressor The screws are located in the white circles as shown above in the picture Step 5 Replace with a new compressor drive board Before replacement apply some silica gel on the IPM module Step 6 Install the new compressor drive board Fix the screws and connect the wires correctly ...

Page 72: ...oling heating Motor The power drive of the fan It enables the fan to run so as to provide smooth currents of air for forced convection and heat exchange of condenser and evaporator Fan It is used to provide smooth currents of air for forced convection and heat exchange of condenser and evaporator Gas liquid separator Installed at the suction side of compressor it can separate the liquefied refrige...

Page 73: ...e hot flow to the cold flow so that the flow temperature can reach the specified index It is an energy exchanging device Electronic expansion valve It is used to lower the pressure and temperature of liquefied refrigerant and adjust the flow of refrigerant entering the evaporator Electromagnetic Valve Electromagnetic valve controls increased enthalpy switch ...

Page 74: ...r plate Unscrew the screws of the upper cover plate with a 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 4 Remove the front panel Unscrew the screws that connect the front panel to the middle insulating board and screws around the front panel ...

Page 75: ...he electric box and the screws around the right side plate 6 Install the right side plate Screw up the screws around the right side plate Be careful to handle well the clasps at the bottom of the right side plate 7 Install the front panel Install the front panel by mounting on 6 clasps on its both sides Please note that there is one screw on the lower right side 8 Install the grill Attach the gril...

Page 76: ...er plate Tighten up the screws around the upper cover plate Model MDUO1836 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 1 Remove wires Loosen the securing screws of the wires with a screwdriver Remove the wires Note When removing the wires mark...

Page 77: ...nnected to the compressor gas liquid separator Then remove the pipes Note When welding the pipes do not let the flame burn the other components 3 Loosen the compressor s base connectors gas liquid separator s base nuts Screws Use a wrench to twist off the compressor gas liquid separator s base nuts 4 Remove the compressor gas liquid separator from the chassis Take away the compressor gas liquid se...

Page 78: ...g interfaces of compressor gas liquid separator to the pipeline Weld the connection pipes of compressor so as to connect them to the compressor Note When replacing the compressor avoid touching the nearby pipeline and components 7 Connect the compressor wires Connect the compressor wires to the wire terminals on the top of compressor Note When connecting the wires be sure to match the colors with ...

Page 79: ...rom the 4 way valve Use a soldering gun to loosen the 4 joints on the 4 way valve and then remove the connection pipes Note When welding the pipes the 4 way valve should be wrapped with wet cloth for cooling Do not let the flame burn the other components 3 Replace the 4 way valve and connect it to the connection pipes Replace the 4 way valve and then use a soldering gun to weld the 4 joints of the...

Page 80: ... the screws of the coil of 4 way valve with a screwdriver Model MDUO1836 Removal of fan and motor Note Before removing the fan make sure power is cut off Step Picture Work instruction 1 Remove the grill Use a screwdriver to unscrew the two screws on the upper left and lower right corners 2 Remove the fan Use a wrench to remove the specialized nut and gasket of the fan Note Please keep the nut and ...

Page 81: ...stall the fan Install the fan in place Put on the gasket and use a wrench to secure the screw nut Note After installing the fan turn the fan by hand to see if it can run normally If not please check for the reason 6 Install the grill After replacing the motor use a screwdriver to tighten up the screw bolt that secures the motor Arrange the wires according to the wiring diagram Model MDUO1836 Remov...

Page 82: ...tric box Unscrew the screws of electric box The connection wires inside and outside the electric box should be removed 3 Remove motor support When removing the motor support be careful to protect the components 4 Remove the condenser Welding interface 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 burn t...

Page 83: ...denser Welding interface 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 Weld the connection pipes Nitrogen welding the pressure of nitrogen is 0 5 0 1kgf c relative pressure Note When welding the pipes do not let the flame burn the other components 7 Secure the electric box and arran...

Page 84: ...upper left and right side panels Model MDUO1836 Removal of electronic expansion valve Note Before removing the electronic expansion valve make sure there is no refrigerant in the pipeline and power is cut off Step Picture Work instruction 1 Remove the electric box Remove the upper lower and front panels Loosen the wire clamp at the bottom of the electric box Unscrew the screws of electric box The ...

Page 85: ... the fixed block Remove the fixed block between the electronic expansion valve and the pipe 3 Remove the electronic expansion valve Take off the coil of electronic expansion valve Loosen the connection pipe of electronic expansion valve by welding Then remove the connection pipe Note When welding the pipe do not let the flame bunt the other components 4 Take out the electronic expansion valve Take...

Page 86: ...connection pipe of electronic expansion valve When welding the electronic expansion valve the valve should be wrapped with wet cloth Nitrogen welding the pressure of nitrogen is 0 5 0 1kgf c relative pressure Note When welding the pipes do not let the flame burn the other components Install the coil of electronic expansion valve 6 Secure the electric box and arrange the wires as required Put the e...

Page 87: ... panels Check whether each component and connection wire is well connected If everything is OK install the upper left and right panels Tighten up the screws Model MDUO1860 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 plate Unscrew the screws of the upper cover plate with a screwdriver 2 Remove the fron...

Page 88: ...the front grill with a screwdriver 4 Remove the front panel Unscrew the screws that connect the front panel to the middle insulating board and screws around the front panel 5 Install the front panel Install the front panel by mounting on 6 clasps on its both sides Please note that there is one screw on the lower right side 6 Install the grill Attach the grill back in place and tighten up the screw...

Page 89: ...lve cover with a screwdriver 8 Remove the right side plate Unscrew the screws that connect the right side plate to the electric box and the screws around the right side plate 9 Install the right side plate Screw up the screws around the right side plate Be careful to handle well the clasps at the bottom of the right side plate 10 Install the grill Attach the grill back in place and tighten up the ...

Page 90: ...Service Manual 87 Removal of front panel Note Before removing the front panel make sure power is cut off Step Picture Work instruction 11 Install the upper cover plate Tighten up the screws around the upper cover plate ...

Page 91: ...th a screwdriver Remove the wires Note When removing the wires mark the wire terminals corresponding to their color so as to avoid misconnection 2 Loosen the securing screws at the foot of compressor Use a wrench to twist off the screw nuts at the foot of compressor 3 Break off the pipes that connecting to the compressor Weld the pipes that are connected to the compressor Then remove the pipes Not...

Page 92: ...essor and replace it Note When replacing the compressor avoid touching the nearby pipeline and components 5 Fix the new compressor back onto the chassis After replacing the compressor tighten up the screws at the foot of compressor 6 Connect the compressor suction port and exhause port with the pipes Weld the compressor connection pipes and connect them to the compressor Note When replacing the co...

Page 93: ...essor wires to the wire terminals on the top of compressor Note When connecting the wires be sure to match the colors with the corresponding wire terminals Model MDUO1860 Removal of 4 way valve Note Before removing the 4 way valve make sure refrigerant is fully discharged from the unit and power is cut off Step Picture Work instruction 1 Take off the coil of the 4 way valve Carefully unscrew the s...

Page 94: ...nection pipes Note When welding the pipes the 4 way valve should be wrapped with wet cloth for cooling Do not let the flame burn the other components 3 Replace the 4 way valve and connect it to the connection pipes Replace the 4 way valve and then use a soldering gun to weld the 4 joints of the 4 way valve Note When welding the pipes the 4 way valve should be wrapped with wet cloth for cooling Do ...

Page 95: ...e grill Use a screwdriver to unscrew the two screws on the upper left and lower right corners 2 Remove the fan Use a wrench to remove the specialized nut and gasket of the fan Note Please keep the nut and gasket safe after removing them from the fan 3 Remove motor Use a screwdriver to unscrew the bolt of motor Note Motor wire should be first removed from the electric box ...

Page 96: ...h a new motor Then tighten up the screw bolt 5 Install the fan Install the fan in place Put on the gasket and use a wrench to secure the screw nut Note After installing the fan turn the fan by hand to see if it can run normally If not please check for the reason 6 Install the grill After replacing the motor use a screwdriver to tighten up the screw bolt that secures the motor ...

Page 97: ... upper lower and front panels Loosen the wire clamp at the bottom of the electric box Unscrew the screws of electric box 2 Remove the electric box The connection wires inside and outside the electric box should be removed When removing the electric box be careful to protect the components 3 Remove the compressor gas liquid separator from the chassis Take away the compressor gas liquid separator an...

Page 98: ...2 welding interfaces Nitrogen welding the pressure of nitrogen is 0 5 0 1kgf c relative pressure Note When welding the pipes do not let the flame burn the other components Tighten the screws of gas liquid separator 5 Secure the electric box and arrange the wires as required Put the electric box back in place and tighten up the screws Arrange the wires as original 6 Check and open the upper and sid...

Page 99: ...r lower and front panels Loosen the wire clamp at the bottom of the electric box Unscrew the screws of electric box 2 Remove the electric box The connection wires inside and outside the electric box should be removed When removing the electric box be careful to protect the components 3 Remove the electronic expansion valve Take off the coil of electronic expansion valve Loosen the connection pipe ...

Page 100: ... new electronic expansion valve Weld the connection pipe of electronic expansion valve When welding the electronic expansion valve the valve should be wrapped with wet cloth Nitrogen welding the pressure of nitrogen is 0 5 0 1kgf c relative pressure Note When welding the pipes do not let the flame burn the other components Install the coil of electronic expansion valve 6 Secure the electric box an...

Page 101: ...thing is OK install the upper left and right panels Tighten up the screws 4 5 2 Removal of IDU Major Components 4 5 2 1 Airhandler Unit Disassembly and Assembly of the Electric Box Step Picture Work instruction 1 Remove the upper panel Loosen screws around the upper panel with a screwdriver Remove the upper panel away from the unit 2 Remove the electric box Disconnect the power cord and control li...

Page 102: ...he screws around the electric element with a screwdriver Wire the electric element to the wiring terminal 5 Reinstall the electric box Place the electric box at the proper position Tighten screws around 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 1 Remove t...

Page 103: ...rew bolts fixing the bracket Remove the motor rightward from the fan 4 Reinstall the fan Place the motor at the proper position Tighten screws fixing the motor and fan blades Tighten screw bolts fixing the motor bracket After the installation reassemble the unit as before Disassembly and Assembly of the Evaporator and Drain Pan Step Picture Work instruction 1 Remove the upper panel Loosen screws r...

Page 104: ...ve the enhanced frame if applicable Remove the screws from enhanced frame Disassemble the enhanced frame from the unit 4 Remove the mounting plate of the drain pan Loosen screws at both side of the mounting plate with a screwdriver Remove the mounting plate from the unit 5 Remove the primary drain pan Remove the primary drain pan from the unit ...

Page 105: ...n Reassemble the unit as before Disassembly and Assembly of the Filter Step Picture Work instruction 1 Remove the mounting plate Loosen screws fixing the mounting plate with a screwdriver Remove the mounting plate away from the unit 2 Remove the filter screen Remove the filter screen away from the unit After replacing the filter screen reassemble the unit as before ...

Page 106: ...ts of Parts MDUO1836 1 2 3 4 5 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 29 30 31 32 28 34 35 36 37 39 41 42 43 44 45 46 47 49 50 51 52 54 55 56 57 6 40 38 33 53 48 No Material name 1 Coping 2 Electric Box Assy 3 PFC Inductance 4 Filter Board 5 Reactor Sub Assy 6 Power Switch 7 Main Board ...

Page 107: ...6 Handle 27 Chassis Assy 28 Foot 29 Cut Off Valve 30 Fusible Plug 31 Gas liquid Separator 32 Accumulator 33 4 Way Valve Coil 34 Drainage Hole Cap 35 Temperature Sensor 36 Temperature Sensor 37 Electrical Heater Compressor 38 Electrical Heater Chassis 39 Electric Expansion Valve Sub Assy 40 Drainage Joint 41 Cut Off Valve 3 8 N 42 Strainer 43 Electric Expand Valve Fitting 44 One Way Valve 45 Electr...

Page 108: ...or 57 Rear Grill MDUO1860 1 3 4 5 6 7 8 9 10 11 13 15 14 17 18 20 24 26 25 23 16 27 28 29 34 30 31 33 35 38 39 42 43 49 50 2 22 19 32 21 47 48 45 46 36 37 12 44 41 40 No Material name 1 Coping 2 Rear Grill 3 Left Side Plate 4 Electric Box Assy 5 Drive Board 6 Radiator 7 Main Board 8 Filter Board ...

Page 109: ...mpressor and Fittings 25 Accumulator 26 Foot 27 Chassis Sub Assy 28 Cut Off Valve Sub Assy 29 Strainer 30 Magnet Coil Electromagnetic Valve 31 Electric Expand Valve Fitting 32 One Way Valve 33 Cut off Valve 34 Electronic Expansion Valve 35 4 Way Valve Assy 36 Pressure Sensor 37 Strainer 38 Cut Off Valve 3 8 39 Pressure Protect Switch 40 Electrical Heater Compressor 41 Electrical Heater Compressor ...

Page 110: ...ts of Parts MDUO1836 1 2 3 6 4 7 9 11 12 13 14 15 17 18 20 22 23 25 26 27 29 28 10 16 8 5 19 21 24 No Material name 1 Coping 2 Left Side Plate 3 Electric Box Assy 4 Terminal Board 5 Transformer 6 Terminal Board 7 Main Board 8 Terminal Board 9 Pinboard 10 Rear Side Plate ...

Page 111: ... Top Cover Board Sub Assy 15 Bottom Cover Plate Assy 16 Right Side Plate 17 Bottom Cover Plate Assy 18 Water Tray 19 Strainer 20 Cut Off Valve 3 8 N 21 Thermal Expansion Valve 22 Cut Off Valve 23 Evaporator Assy 24 Evaporator Assy 25 Evaporator Assy 26 Water Tray Assy 27 Choke Plug 28 Water Tray 29 Filter Sub Assy ...

Page 112: ...33 2 923 11 87 35 0 484 80 1 871 2 934 10 82 75 0 506 81 1 811 2 945 9 78 43 0 53 82 1 754 2 955 8 74 35 0 554 83 1 699 2 964 7 70 5 0 579 84 1 645 2 974 6 66 88 0 605 85 1 594 2 983 5 63 46 0 631 86 1 544 2 992 4 60 23 0 658 87 1 497 3 001 3 57 18 0 686 88 1 451 3 009 2 54 31 0 714 89 1 408 3 017 1 51 59 0 743 90 1 363 3 025 0 49 02 0 773 91 1 322 3 033 1 46 8 0 801 92 1 282 3 04 2 44 31 0 835 93...

Page 113: ... 121 0 561 3 181 31 11 57 1 863 122 0 547 3 184 32 11 09 1 897 123 0 532 3 187 33 10 63 1 931 124 0 519 3 19 34 10 2 1 964 125 0 505 3 192 35 9 779 1 998 126 0 492 3 195 36 9 382 2 03 127 0 48 3 198 37 9 003 2 062 128 0 467 3 2 38 8 642 2 094 129 0 456 3 203 39 5 997 2 125 130 0 444 3 205 41 7 653 2 185 131 0 433 3 207 42 7 352 2 215 132 0 422 3 21 43 7 065 2 243 133 0 412 3 212 44 6 791 2 272 134...

Page 114: ...ge V Temperature Resistance kΩ Voltage V 30 361 8 0 173 66 3 998 2 75 29 339 8 0 183 67 3 861 2 766 28 319 2 0 195 68 3 729 2 781 27 300 0 206 69 3 603 2 796 26 282 2 0 218 70 3 481 2 811 25 265 5 0 231 71 3 364 2 825 24 249 9 0 245 72 3 252 2 838 23 235 3 0 259 73 3 144 2 852 22 221 6 0 273 74 3 04 2 865 21 208 9 0 288 75 2 94 2 877 20 196 9 0 304 76 2 844 2 889 19 181 4 0 328 77 2 752 2 901 18 1...

Page 115: ... 110 1 01 3 141 15 31 47 1 282 111 0 9825 3 145 16 30 04 1 319 112 0 9556 3 15 17 28 68 1 356 113 0 9295 3 153 18 27 39 1 393 114 0 9043 3 157 19 26 17 1 429 115 0 8799 3 161 20 25 01 1 466 116 0 8562 3 165 21 23 9 1 503 117 0 8333 3 168 22 22 85 1 54 118 0 8111 3 171 23 21 85 1 577 119 0 7895 3 175 24 20 9 1 614 120 0 7687 3 178 25 20 1 65 121 0 7485 3 181 26 19 14 1 686 122 0 7289 3 184 27 18 32...

Page 116: ...3 0 3389 3 245 58 5 32 2 607 154 0 3312 3 246 59 5 13 2 626 155 0 3237 3 247 60 4 948 2 646 156 0 3164 3 249 61 4 773 2 664 157 0 3093 3 25 62 4 605 2 682 158 0 3024 3 251 63 4 443 2 7 159 0 2956 3 252 64 4 289 2 717 160 0 2891 3 253 65 4 14 2 734 1 3 Voltage List of 50 KΩ Discharge Temperature Sensors including discharge air temperature sensor Temperature Resistance kΩ Voltage V Temperature Resis...

Page 117: ... 0 193 91 4 3345 2 302 1 153 0 202 92 4 2044 2 323 2 145 42 0 212 93 4 0789 2 344 3 135 96 0 223 94 3 9579 2 364 4 131 5 0 233 95 3 841 2 384 5 126 17 0 242 96 3 7283 2 404 6 119 08 0 256 97 3 6194 2 423 7 113 37 0 267 98 3 5143 2 442 8 107 96 0 28 99 3 4128 2 46 9 102 85 0 292 100 3 3147 2 478 10 98 006 0 306 101 3 22 2 496 11 93 42 0 319 102 3 1285 2 514 12 89 075 0 333 103 3 0401 2 531 13 84 95...

Page 118: ...864 39 27 227 0 886 130 1 485 2 873 40 26 147 0 913 131 1 449 2 882 41 25 114 0 94 132 1 4141 2 891 42 24 128 0 967 133 1 3803 2 9 43 23 186 0 994 134 1 3474 2 908 44 22 286 1 022 135 1 3155 2 916 45 21 425 1 05 136 1 2846 2 924 46 20 601 1 078 137 1 2545 2 932 47 19 814 1 107 138 1 2233 2 94 48 19 061 1 136 139 1 1969 2 947 49 18 34 1 164 140 1 1694 2 955 50 17 651 1 193 141 1 1476 2 96 51 16 99 ...

Page 119: ...0 43 2580 16 468 14 1220 44 2650 15 483 15 1250 45 2710 14 504 16 1280 46 2770 13 520 17 1320 47 2840 12 538 18 1350 48 2910 11 556 19 1400 49 2980 10 579 20 1440 50 3050 9 598 21 1470 51 3100 8 618 22 1520 52 3180 7 639 23 1560 53 3250 6 660 24 1600 54 3320 5 682 25 1640 55 3400 4 705 26 1680 56 3480 3 728 27 1730 57 3540 2 752 28 1780 58 3630 1 777 29 1820 59 3720 3 Operation Tools The following...

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