Mitsubishi Electric MSZ-RW25VG Service Manual Download Page 1

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INDOOR UNIT

No. OBH902

REVISED EDITION-A

CONTENTS

1. TECHNICAL CHANGES ······························3

2. PART NAMES AND FUNCTIONS ··················4

3. SPECIFICATION ········································5

4. NOISE CRITERIA CURVE ····························6

5. OUTLINES AND DIMENSIONS ·····················7

6. WIRING DIAGRAM ·····································8

7. REFRIGERANT SYSTEM DIAGRAM ·············9

8. SERVICE FUNCTIONS ······························ 10

9. MICROPROCESSOR CONTROL ················· 18

10. TROUBLESHOOTING ······························· 30

11. DISASSEMBLY INSTRUCTIONS ················· 46

PARTS CATALOG (OBB902)

Outdoor unit service manual

MUZ-RW•VG Series (OBH903)

Models

MSZ-RW25VG

SC1

MSZ-RW35VG

SC1

MSZ-RW50VG

SC1

SERVICE MANUAL

OBH902 is void.

Revision A:

•Test point of 12 V DC has been corrected.

Summary of Contents for MSZ-RW25VG

Page 1: ...7 6 WIRING DIAGRAM 8 7 REFRIGERANT SYSTEM DIAGRAM 9 8 SERVICE FUNCTIONS 10 9 MICROPROCESSOR CONTROL 18 10 TROUBLESHOOTING 30 11 DISASSEMBLY INSTRUCTIONS 46 PARTS CATALOG OBB902 Outdoor unit service manual MUZ RW VG Series OBH903 Models MSZ RW25VG E1 SC1 MSZ RW35VG E1 SC1 MSZ RW50VG E1 SC1 SERVICE MANUAL OBH902 is void Revision A Test point of 12 V DC has been corrected ...

Page 2: ...erant may spurt out from the gap between the valve stem and the valve body resulting in injuries Preparation before the repair service Prepare the proper tools Prepare the proper protectors Provide adequate ventilation After stopping the operation of the air conditioner turn off the power supply breaker and pull the power plug Discharge the capacitor before the work involving the electric parts Pr...

Page 3: ...s to the MUZ RW VGHZ series outdoor units enables the low standby power control The following models may be connected to the MUZ RW VGHZ series after once connected to the MXZ series and operated for example because of relocation In that case the MUZ RW VGHZ series outdoor units will not operate without taking a step Follow the procedure Deleting the memorized abnormal condition described in 10 2 ...

Page 4: ...Air purifying device Wi Fi module Air outlet Operation indicator lamp Remote control receiving section Air purifying Power Model All models 1 Installation plate 1 2 Installation plate fixing screw 4 25 mm 5 3 Wireless remote controller 1 4 Felt tape For left or left rear piping 1 5 Battery AAA for remote controller 2 6 Air cleaning filter Deodorizing filter black 1 7 Air purifying device 1 MSZ RW2...

Page 5: ...4 30 Silent 19 26 Heating Super High dB A 41 42 46 High 36 41 Med 30 37 Low 25 32 Silent 19 25 Fan speed Cooling Super High rpm 900 920 1 020 High 790 870 Med 660 770 Low 530 550 690 Silent 450 600 Heating Super High rpm 920 940 1 120 High 800 950 Med 690 840 Low 600 750 Silent 450 600 Fan speed regulator 5 Remote controller model E SH21A SC SH21B Specifications and rating conditions of main elect...

Page 6: ... 125 250 500 1000 2000 4000 8000 NC 60 NC 50 NC 40 NC 30 NC 20 NC 70 OCTAVE BAND SOUND PRESSURE LEVEL dB re 0 0002 MICRO BAR BAND CENTER FREQUENCIES Hz NC 10 MSZ RW35VG COOLING FUNCTION SPL dB A LINE Super High FAN SPEED HEATING 45 46 90 80 70 60 50 40 30 20 10 63 125 250 500 1000 2000 4000 8000 NC 60 NC 50 NC 40 NC 30 NC 20 NC 70 OCTAVE BAND SOUND PRESSURE LEVEL dB re 0 0002 MICRO BAR BAND CENTER...

Page 7: ... FLARED CONNECTION ø6 35 GAS LINE ø9 52 0 45m FLARED CONNECTION ø9 52 DRAIN HOSE INSULATION ø29 CONNECTED PART ø16 O D PIPING INSULATION ø37 O D LIQUID LINE ø6 35 0 64m FLARED CONNECTION ø6 35 GAS LINE ø9 52 0 59m FLARED CONNECTION ø12 7 DRAIN HOSE INSULATION ø29 CONNECTED PART ø16 O D MSZ RW25VG MSZ RW35VG MSZ RW50VG OBH902A ...

Page 8: ...8 WIRING DIAGRAM 6 MSZ RW25VG MSZ RW35VG MSZ RW50VG OBH902A ...

Page 9: ...r RT12 main Indoor coil thermistor RT13 sub Refrigerant flow in cooling Refrigerant flow in heating MSZ RW25VG MSZ RW35VG Indoor heat exchanger Flared connection Room temperature thermistor RT11 Flared connection Refrigerant pipe ø9 52 with heat insulator Refrigerant pipe ø6 35 with heat insulator Indoor coil thermistor RT12 main Indoor coil thermistor RT13 sub Refrigerant flow in cooling Refriger...

Page 10: ...number in the following order 1 2 3 4 3 Press button to complete the pairing setting After you turn the breaker ON the remote controller that first sends a signal to an indoor unit will be regarded as the remote controller for the indoor unit Once they are set the indoor unit will only receive the signal from the assigned remote controller afterwards 8 3 SETTING THE INSTALLATION POSITION Be sure t...

Page 11: ...onds have passed after the indoor unit was operated with the remote controller If main power is turned OFF or a power failure occurs while AUTO START STOP timer is active the timer setting is can celled If the unit has been turned OFF with the remote controller before power failure the auto restart function does not work as the power button of the remote controller is OFF To prevent the breaker fr...

Page 12: ...ompleted The WPS PUSH mode will return to initial state if WPS button is not pressed for 2 minutes 3 1 1 Connect the router to the air conditioner NOTE If the indication LED Air purifying lamp of the indoor unit does not change or blinks 5 times connection fails Please reset connection and setup the Wi Fi module and the router again Main causes that WPS failed are as follows Communication distance...

Page 13: ...Submit button NOTE It may take several minutes to show the indication above The LED Air purifying lamp of the indoor unit indication does not change or blinks 5 times if connection fails In that case reset connection and set up the Wi Fi module and the router again NOTE If you want to use Static select Static in DHCP 1 and enter the information of router and network then tap the Submit button 3 2 ...

Page 14: ...router does not exceed the limit Make sure that DHCP is enabled or check IP address setting of the Wi Fi module Check DNS settings of the router or check DNS address of the Wi Fi module Check if the router is connected to Internet Set up the Wi Fi module after operating the air conditioner using the wirelessremote controller at least once If the connection fails even after checking the above set u...

Page 15: ... will be warmer if you set the correction value of the room temperature to 5 C 8 6 CHANGING THE CORRECTION VALUE OF THE ROOM TEMPERATURE THE INLET TEMPERATURE CIRCULATOR CIRCULATOR CIRCULATOR CIRCULATOR CIRCULATOR TEMP TEMP TEMP TEMP TEMP TEMP Figure 1 Figure 2 1 How to change the correction value of the room temperature 1 Press OFF ON button on the remote controller to turn the indoor unit off Fi...

Page 16: ... electronic control P C board is replaced in servicing the correction value is reset The numerical value any of 3 4 or 5 described on the wiring diagram will be needed when a service man sets the correction value again after replacing the P C board NOTE 3 The instruction for setting the correction value again is attached to the indoor electronic control P C board of the service part as well JR24 C...

Page 17: ...ane angle 1 horizontal position press buttons or buttons on the remote controller to move the positions angle of the left vanes need for adjustment Pressing buttons moves the upper left vane and pressing buttons moves the lower left vane Align the positions of the left vanes with those of the right vanes respectively 5 After the adjustment work is complete pressing OFF ON button on the remote cont...

Page 18: ... ECONO COOL button DRIVE button Battery replacement indicator CLOCK button Lid Slide the lid down to open the remote controller Slide it down further to get to the weekly timer buttons WEEKLY TIMER set buttons TIME TIMER set buttons forward button backward button RESET button i save button NIGHT MODE button SENSOR i see button VANE control button WIDE VANE button INDOOR UNIT DISPLAY SECTION Operat...

Page 19: ...35VG SC1 MSZ RW50VG SC1 CIRCULATOR Signal transmitting section Operation display section Temperature buttons OFF ON stop operate button Indication of remote controller model is on back Distance of signal About 6 m Beep s is are heard from the indoor unit when the signal is received FAN speed control button PURIFIER button DIRECTION button Operation select button CIRCULATOR button DRIVE button CLOC...

Page 20: ...outdoor heat exchanger becomes too low The compressor stops once the indoor outdoor fans stop the 4 way valve reverses and the compressor re starts This mode continues until the temperature of outdoor heat exchanger rises or the fixed time passes 9 5 AUTO CHANGE OVER AUTO MODE OPERATION Once desired temperature is set unit operation is switched automatically between COOL and HEAT operation Mode se...

Page 21: ...pping motors for the horizontal vanes The rotating direction speed and angle of the motor are controlled by pulse signals approximately 12 V transmitted from indoor microprocessor 2 The horizontal vane angle and mode change as follows by pressing VANE CONTROL button Horizontal position 4 In COOL and DRY operation Vane angle is fixed to Horizontal position In HEAT operation Vane angle is fixed to A...

Page 22: ... is higher the air conditioner can keep comfort As a result energy can be saved To cancel this operation select a different mode or press one of the following buttons in ECONO COOL operation ECONO COOL or VANE control button 2 Vertical vane 1 Vane motor drive These models are equipped with a stepping motor for the vertical vane The rotating direction speed and angle of the motor are controlled by ...

Page 23: ...mer setting a Press OFF TIMER button during operation b Set the time of the timer using TIME set buttons and Each time forward button is pressed the set time increases by 10 minutes each time backward button is pressed the set time decreases by 10 minutes 2 To release the timer To release ON timer press ON TIMER button To release OFF timer press OFF TIMER button TIMER is cancelled and the display ...

Page 24: ...sing adjusts the tem perature Hold down the button to change the time quickly The temperature can be set between 16 C and 31 C at COOL operation The temperature can be set between 10 C and 31 C at HEAT operation blinks Pressing selects the day of the week to be set Pressing selects the setting number E g Mon Tue Sun and 1 are selected All days can be selected NOTE The simple ON OFF timer setting i...

Page 25: ... air conditioner starts to operate in summer When occupants are in blanket or wear heavily When there is an object whose temperature changes rapidly in a short time When windows and doors are small or they are far from the air conditioner When the sensor cannot detect the heat source such as of small kids or pets When using a floor heating or an electric carpet When occupants do not move after the...

Page 26: ...ncy energy saving mode or No occupancy Auto OFF mode when nobody is in the room 9 10 AIRFLOW CONTROL MODE AIRFLOW CONTROL mode offers air conditioning according to a location of an occupant in a room detected by i see SENSOR 1 Press DIRECTION button during COOL DRY HEAT or AUTO mode to activate the AIRFLOW CONTROL mode This mode is only available when the i see control mode is effective 2 Each pre...

Page 27: ...the next time with a single press of i save button 9 11 NIGHT MODE OPERATION NIGHT MODE changes the brightness of the operation indicator disables the beep sound and limits the noise level of the outdoor unit 1 Press NIGHT MODE button during operation to activate NIGHT mode The operation indicator lamp dims The beep sound will be disabled except that emitted when the operation is started or stoppe...

Page 28: ...t Although received sound will be heard from the indoor unit and mark is displayed on remote controller when is pushed CIRCULATOR operation doesn t work in multi connection FAN operation may make you feel cold wind Reduce the FAN speed or adjust the airflow direction to avoid the wind 9 16 DRIVE MODE SELECTOR 1 How to set DRIVE mode selector 1 Select a desired mode from WIDE ROOM ECO or QUIET 2 Pr...

Page 29: ...to Med The coil frost prevention works even in the test run or the emergency operation In the test run or emergency operation the horizontal vane operates in VANE AUTO mode Emergency operation continues until the emergency operation switch is pressed once or twice or the unit receives any signal from the remote controller In the latter case normal operation will start NOTE Do not press the emergen...

Page 30: ...ting ser vice work 2 Before servicing verify that all connectors and terminals are connected properly 3 When the electronic control P C board seems to be defective check for disconnection of the copper foil pattern and burnt or discolored components 4 When troubleshooting Refer to 10 2 10 3 and 10 4 4 How to replace batteries Weak batteries may cause the remote controller malfunction In this case ...

Page 31: ...switch so that the memorized abnormal condition is deleted 4 Release the failure mode recall function according to Releasing the failure mode recall function men tioned above Yes Blinks No OFF NOTE 1 Make sure to release the failure mode recall function after it is set up otherwise the unit cannot operate properly 2 If the abnormal condition is not deleted from the memory the last abnormal conditi...

Page 32: ... set to the failure mode recall function The air purifying device or i see SENSOR might be abnormal Check if the air purifying device or i see SENSOR is abnormal according to the following procedures ON OFF Beeps Repeated cycle Repeated cycle 2 5 second OFF Blinking at 0 5 second interval Beeps Repeated cycle 2 5 second OFF Blinking at 0 5 second interval Beeps After repairing the unit recall the ...

Page 33: ...etween CN1T1 and GND on the electronic P C board falls significantly 0 4V 0 5ms 3 time blink Refer to 10 6 Check of AIR PURIFYING power Abnormal electric discharge error 1 When the voltage between CN1T1 and GND on the electronic P C board falls by 1 2V below the normal voltage value 2 5V 2 time blink Electrode Spark discharge Electrode Electrode 1 time blink AIR PURIFYING power control When the vo...

Page 34: ... Trouble of thermistor in outdoor unit POWER lamp 7 time blink Cause Outdoor unit Trouble of outdoor con trol system POWER lamp 14 time blink or more Cause Outdoor unit Other ab normality Indoor Outdoor unit Trouble of thermistors Start Refer to 10 6 How to check mis wiring and serial signal error Check room temperature thermistor and indoor coil thermis tor Refer to 10 7 Test point diagram and vo...

Page 35: ...that the number of the connected devices to the router does not exceed the limit Make sure that DHCP setting is enabled Make sure that DNS setting of the router and DNS address of the Wi Fi module are correct Make sure that the router is connected to the internet Make sure that the communication is not limited with security of the router If the problem persist even after you check above follow the...

Page 36: ... Outdoor thermistors POWER lamp blinks 6 time blink 2 5 second OFF The outdoor thermistors short or open circuit during the compressor operation Refer to Check of outdoor thermistor Refer to outdoor unit service manual 7 Outdoor control sys tem POWER lamp blinks 7 time blink 2 5 second OFF It cannot properly read data in the nonvolatile memory of the inverter P C board or the out door electronic c...

Page 37: ... PURIFYING power Check 10 6 OPERATION INDICATOR POWER AIR PURIFYING No Abnormal point Operation indicator lamp Symptom Condition Remedy 1 MXZ type Operation mode setting AIR PURIFYING lamp blinks 2 5 second OFF POWER lamp is lit Outdoor unit operates but indoor unit does not operate The operation mode of the each indoor unit is differently set to COOL includes DRY FAN and HEAT at the same time the...

Page 38: ... pressed the voltage measured at 2 above goes 0 V DC although the indoor P C board is normal Does the voltage between CN211 and on the power P C board rise to the range of 3 to 6 V DC within 12 seconds after the emergency operation switch is pressed Replace the indoor fan motor Yes No The indoor fan motor error has occurred and the indoor fan repeats 12 second ON and 30 second OFF 3 times and then...

Page 39: ...remote controller Refer to 8 2 Check if the unit operates with the remote controller Does the unit operate with the remote controller Yes No OK Measure the voltage between receiver P C board connector CN302 No 3 and No 2 when the remote controller button is pressed Is the voltage approximately 4 V DC 5 V DC No Yes Replace the indoor electronic control P C board 1 Look at the image of the signal tr...

Page 40: ...n motor Replace the indoor electronic control P C board Measure the resistance of the vane motor coil Refer to 10 5 Short circuit Replace the vane motor and the indoor electronic control P C board 1 The fan motor connector s lead wire is red whereas is black 2 Connect of the tester to fan motor connector s lead wire and to lead wire otherwise the resistance cannot be measured properly 3 Please rep...

Page 41: ...emergency operation starts No Does the outdoor LED light up Replace the indoor electronic control P C board Replace the indoor power P C board Yes Yes Yes Does the outdoor LED blink 6 times Yes Confirm that the thermostat is OFF and wiring is not loose No Does DC 6 V or more occur between indoor terminal block S2 and S3 Yes Replace the outdoor inverter P C board 1 No Turn the power supply OFF Repl...

Page 42: ...ply and then turn ON again Press the emergency operation switch Turn OFF the power supply Check once more if the indoor outdoor connecting wire is not miswiring Remove the indoor outdoor connecting wire from outdoor terminal block S3 Short circuit outdoor terminal block S2 and S3 1 1 Miswiring may damage indoor electronic control P C board during the operation Be sure to confirm the wiring is corr...

Page 43: ... control P C board High voltage approximately 5 8kV is generated during AIR PURIFYING power operation Pay careful attention and never touch the air purifying device and the high voltage lead part Yes No OFF Continuously blinking OFF Continuously blinking Does AIR PURIFYING lamp blink 2 time with unit stopping Turn ON the power supply Replace the indoor electronic control P C board Remove the air p...

Page 44: ...he installation condition combination of specific conditions such as antennas or wiring Check the following before asking for service 1 Devices affected by the electromagnetic noise TV sets radios FM AM broadcast shortwave 2 Channel frequency broadcast station affected by the electromagnetic noise 3 Channel frequency broadcast station unaffected by the electromagnetic noise 4 Layout of indoor outd...

Page 45: ...tion turns to 0 C Refer to 8 6 Emergency operation switch E O SW SW1 Connector to indoor power P C board CN102 Room temperature thermistor RT11 CN111 Indoor coil thermistor RT12 RT13 CN112 Indoor power P C board Indoor electronic control P C board Display and receiver P C board Switch buzzer P C board 10 7 TEST POINT DIAGRAM AND VOLTAGE 5 V DC 12 V DC CN2T1 pin Interlock switch CN2T1 Air purifying...

Page 46: ...Screw of the left side of the panel U Screw of the right side of the panel U Front panel Catch Photo 2 Indicates the visible parts in the photos figures Indicates the invisible parts in the photos figures MSZ RW25VG MSZ RW35VG MSZ RW50VG Photo 3 1 Slide the sleeve and check if there is a locking lever or not Slide the sleeve Pull the terminal while pushing the locking lever Hold the sleeve and pul...

Page 47: ...3 Remove the 3 screws of the panel R and pull the top of the panel R toward you to remove How to install the panel R Photo 4 1 Install the panel R from the bottom to the top 2 Install the 3 screws in the panel R Removing the panel L Photos 1 2 3 4 1 Remove the front panel the horizontal vanes upper R L lower R L and the corner boxes R L 2 Remove the panel U 3 Remove the screw of the panel L and pu...

Page 48: ...ard CN1J1 DISPLAY AND i see SENSOR ASSEMBLY 6 Remove the DISPLAY AND i see SENSOR ASSEMBLY Photo 7 7 Disconnect the following connector Photo 8 Indoor electronic control P C board CN110 Wi Fi assembly CN2T1 Interlock switch Air purifying device CN161 Switch buzzer P C board CN211 Indoor fan motor CN151 Vane motors CN112 Indoor coil thermistor CN1T1 Air purifying device 8 Remove the electrical box ...

Page 49: ...tronic control P C board and the indoor power P C board Photo 8 2 Disconnect all the connectors on the indoor electronic control P C board and the indoor power P C board 3 Remove the indoor electronic control P C board and the indoor power P C board Removing the room temperature thermistor Photo 8 2 Disconnect the following connector CN111 Room temperature thermistor 3 Remove the room temperature ...

Page 50: ...hoto 9 2 4 Disengage the 2 catches of the display cover and remove the display cover Photo 9 1 2 5 Remove the display and receiver P C board Photo 9 3 Photo 9 Details of the display DISPLAY AND i see SENSOR ASSEMBLY and board in the display cover 50 Exploded view of display cover and DISPLAY AND i see SENSOR ASSEMBLY Display P C board receiver P C board Back side view of DISPLAY AND i see SENSOR A...

Page 51: ...Wi Fi assembly How to install the Wi Fi assembly Photo 10 11 1 Install the panel F 2 Attach the Wi Fi assembly 3 Hook the cable of Wi Fi assembly to the PANEL F 4 Connect the connector of CN110 Wi Fi assembly CN2T1 Interlock switch Air purifying device and CN161 Switch buzzer P C board to the indoor electronic control P C board 5 Install the electrical cover and install the screw in the electrical...

Page 52: ...ght side of the nozzle assembly Photo 13 Removing horizontal vane motors R Photo 13 6 Loosen the lead wires and disconnect the connector of the horizontal vane motors R 7 Remove the 2 screws of the horizontal vane motors R 8 Remove the horizontal vane motors R Removing horizontal vane motors L Photo 14 9 Loosen the lead wires and disconnect the connector of the horizontal vane motors L 10 Remove t...

Page 53: ...he right side of the nozzle assembly Photo 15 Removing the horizontal vane motor unit R and the ver tical vane motor R Photo 15 16 5 Remove the 3 screws of the horizontal motor unit R indicated in Photo15 and remove the lead wires of the vane motors R 6 Disengage the catch of the horizontal vane motor unit R and remove the horizontal vane motor unit R Photo15 7 Disengage the link of the vertical v...

Page 54: ...tical vane motor unit L Photo18 1 12 Disengage the catch of the vertical vane motor unit L and remove the vertical vane motor L from the verti cal vane motor unit L Photo18 1 54 Photo 17 Vertical vane motor unit L Link Photo 18 Catch of the horizontal vane motor unit 3 screws of the horizontal motor unit L Vertical vane motor unit L Detach the horizontal vane motor units L Then move them to the di...

Page 55: ...motor assembly slightly toward you and remove it by pulling to the right Photo 21 4 Remove the indoor coil thermistor from the heat exchanger 5 Remove the 2 screws of the hairpin holder on the left side of the heat exchanger Raise the left side of the heat exchanger and pull the line flow fan to the lower left to remove Photo 22 6 Disengage the 2 catches on the right side of the heat exchanger and...

Page 56: ...hermistor in the center of the clip shape part 2 Check the marked mounting position 3 Mount the clip shape part Position and procedure for mounting the clip shape part When fixing the indoor coil thermistor to the clip shape holder shape part the lead wire should point down About the same length Copyright 2021 MITSUBISHI ELECTRIC CORPORATION Issued Sep 2021 No OBH902 REVISED EDITION A Published Ju...

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