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17

2. Indoor unit failure recall mode table

Upper lamp of OP-
ERATION INDICA-

TOR lamp

Abnormal point 

(Failure mode) 

Condition Remedy 

Not lighted 

Normal 

1-time 

fl

 ash every 

0.5-second 

Room temperature 
thermistor 

The room temperature thermistor short or 
open circuit is detected every 8 seconds dur-
ing operation. 

Refer to the characteristics of the room temperature 
thermistor (10-7.). 

2-time 

fl

 ash 

2.5-second OFF 

Indoor coil 
thermistor 

The indoor coil thermistor short or open circuit 
is detected every 8 seconds during operation. 

Refer to the characteristics of the main indoor coil ther-
mistor, the sub indoor coil thermistor (10-7.). 

3-time 

fl

 ash 

2.5-second OFF 

Serial signal 

The serial signal from outdoor unit is not re-
ceived for a maximum of 6 minutes. 

Refer to 10-6.  "How to check miswiring and serial 
signal error". 

11-time 

fl

 ash 

2.5-second OFF 

Indoor fan motor 

The rotational frequency feedback signal is not 
emitted for the 12 seconds after the indoor fan 
motor is operated. 

Refer to 10-6.  "Check of indoor fan motor". 

12-time 

fl

 ash 

2.5-second OFF 

Indoor control 
system 

It cannot properly read data in the nonvolatile 
memory of the indoor electronic control P.C. 
board. 

Replace the indoor electronic control P.C. board.

NOTE

: Blinking patterns of this mode differ from the ones of 

TROUBLESHOOTING CHECK TABLE (10-4.). 

OBH764

Summary of Contents for MSZ-WN25VA - E1

Page 1: ...G 15 11 DISASSEMBLY INSTRUCTIONS 27 Outdoor unit service manual MUZ WN VA Series OBH765 MSZ WN25VA MSZ WN35VA INDOOR UNIT Models MSZ WN25VA E1 MSZ WN35VA E1 SERVICE MANUAL NOTE RoHS compliant products have G mark on the spec name plate No OBH764 PARTS CATALOG OBB764 Questo manuale d istruzione è fornito da trovaprezzi it Scopri tutte le offerte per Mitsubishi Condizionatore MSZ WN25 o cerca il tuo...

Page 2: ...h the refrigerant Do not touch the hot or cold areas in the refrigeration cycle When the repair or the inspection of the circuit needs to be done without turning off the power exercise great caution not to touch the live parts Use the specified refrigerant only Never use any refrigerant other than that specified Doing so may cause a burst an explosion or fire when the unit is being used serviced o...

Page 3: ...3 1 TECHNICAL CHANGES MSZ WN25VA E1 MSZ WN35VA E1 1 New model OBH764 ...

Page 4: ... for remote controller 2 Air cleaning filter Silver ionized air purifier filter 1 2 PART NAMES AND FUNCTIONS Operation indicator lamp Remote control receiving section Horizontal vane Air inlet Air lter Air purifying filter Front panel Air outlet Heat exchanger Emergency operation switch Remote controller Air cleaning lter Silver ionized air purifier filter Display section OBH764 ...

Page 5: ...Med 330 Low 210 Sound level Cooling Super High dB A 43 46 High 37 38 Med 30 31 Low 22 Heating Super High dB A 43 44 High 37 Med 30 Low 23 Fan speed Cooling Super High rpm 1 080 1 240 High 880 930 Med 710 730 Low 550 Heating Super High rpm 1 120 1 150 High 900 Med 710 Low 520 Fan speed regulator 4 Remote controller model SG17A NOTE Test conditions are based on ISO 5151 Cooling Indoor Dry bulb tempe...

Page 6: ...10 MSZ WN25VA INDOOR UNIT WALL MICROPHONE 0 8m 1m 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 FREQUENCIES Hz COOLING FUNCTION SPL dB A LINE Super High FAN SPEED HEATING Test conditions Cooling Dry bulb temperature 27 C Wet bulb temperature 19 C Heating Dry bulb temperature 20 C...

Page 7: ...8 41 42 249 248 21 5 3 167 157 207 5 206 5 172 14 46 60 193 19 PIPING INSULATION Ø35 O D LIQUID LINE Ø7 0 0 39m FLARED CONNECTION Ø6 35 GAS LINE Ø9 52 0 34m FLARED CONNECTION Ø9 52 DRAIN HOSE INSULATION Ø28 CONNECTED PART Ø16 O D AIR IN INSTALLATION PLATE PIPING DRAIN HOSE AIR OUT 11 26 OBLONG HOLE 11 20 OBLONG HOLE INSTALLATION PLATE INDOOR UNIT WALL HOLE Ø65 OBH764 ...

Page 8: ...8 MSZ WN25VA MSZ WN35VA 6 WIRING DIAGRAM OBH764 ...

Page 9: ...ure thermistor RT11 Flared connection Refrigerant flow in cooling Refrigerant flow in heating Refrigerant pipe ø9 52 with heat insulator Refrigerant pipe ø6 35 with heat insulator Indoor coil thermistor RT12 Indoor coil thermistor RT13 Unit mm 7 REFRIGERANT SYSTEM DIAGRAM OBH764 ...

Page 10: ... 8 3 AUTO RESTART FUNCTION When the indoor unit is controlled with the remote controller the operation mode the set temperature and the fan speed are memorized by the indoor electronic control P C board AUTO RESTART FUNCTION automatically starts operation in the same mode just before the shutoff of the main power Operation If the main power has been cut the operation settings remain After the powe...

Page 11: ...of the indoor unit turns on with a beep tone 2 Select COOL mode with OPERATION SELECT button 3 Press TEMPERATURE buttons TOO WARM or TOO COOL button to select the desired temperature The setting range is 16 31 C 1 Coil frost prevention The compressor operational frequency is controlled by the temperature of the indoor heat exchanger to prevent the coil from frosting When the temperature of indoor ...

Page 12: ...rol This mode continues until the temperature of indoor heat exchanger falls 3 Defrosting Defrosting starts when the temperature of 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 3 Positioning To conf...

Page 13: ...t 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 9 5 TIMER OPERATION ON OFF TIMER 1 How to set the time 1 Check that the current time is set correctly NOTE Timer operation will not work without setting the current time Initially 0 00 blinks at the current time display of TIME MONIT...

Page 14: ...rom the remote controller In the latter case normal operation will start NOTE Do not press EMERGENCY OPERATION switch during normal operation Operation mode COOL HEAT Set temperature 24 C 24 C Fan speed Med Med Horizontal vane Auto Auto The operation mode is indicated by the Operation Indicator lamp as follows Operation Indicator lamp EMERGENCY COOL EMERGENCY HEAT STOP Lighted Not lighted 9 7 3 MI...

Page 15: ... drop caused by the battery replacement 3 Do not use the leaking batteries Press RESET button with a thin instrument and then use the remote controller Remove the back lid and insert batteries Then reattach the back lid 10 1 CAUTIONS ON TROUBLESHOOTING 1 Before troubleshooting check the following 1 Check the power supply voltage 2 Check the indoor outdoor connecting wire for miswiring 2 Take care ...

Page 16: ...ck the blinking pattern and identify the abnormal point by referring to the indoor unit failure recall mode table Refer to 10 2 2 Make sure to check at least 2 consecutive blinking cycles 2 Releasing the failure mode recall function Release the failure mode recall function by the following procedures Turn OFF the power supply and turn it ON again Press RESET button of the remote controller The out...

Page 17: ...of the main indoor coil ther mistor the sub indoor coil thermistor 10 7 3 time flash 2 5 second OFF Serial signal The serial signal from outdoor unit is not re ceived for a maximum of 6 minutes Refer to 10 6 How to check miswiring and serial signal error 11 time flash 2 5 second OFF Indoor fan motor The rotational frequency feedback signal is not emitted for the 12 seconds after the indoor fan mot...

Page 18: ...peration means the operation within 30 minutes after EMERGENCY OPERA TION switch is pressed Refer to outdoor unit service manual Upper lamp Flash on and off at 0 5 sec ond intervals Cause Indoor Outdoor unit Miswiring or trouble of se rial signal Upper lamp 2 time flash Cause Indoor unit Trouble of room temperature indoor coil thermistor Upper lamp 3 time flash Cause Indoor unit Trouble of indoor ...

Page 19: ...ctronic control P C board 5 Outdoor power sys tem Upper lamp flashes 5 time flash 2 5 second OFF It consecutively occurs 3 times that the com pressor stops for overcurrent protection or start up failure protection within 1 minute after start up Refer to How to check of in verter compressor Refer to outdoor unit service manual Check the stop valve 6 Outdoor thermistors Upper lamp flashes 6 time fla...

Page 20: ...th a tester Refer to 10 7 Test point diagram and voltage 2 Indoor electronic control P C board for the chart of thermistor Indoor coil thermistor RT12 RT13 Indoor fan motor MF Check 10 6 Vane motor MV Measure the resistance between the terminals with a tester Part temperature 10 30 C Color of the lead wire Normal RED BLK 235 255 Ω BLK BLK RED BLK BLK ROTOR OBH764 ...

Page 21: ...is pressed the voltage measured at 2 above goes 0 VDC 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 VDC within 12 seconds after 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 sto...

Page 22: ...tart type within the range of 1 m 2 Yes No Reinstall the unit away from lights Attach a filter on receiving part Replace the indoor electronic control P C board Including the receiver 1 Look at the image of the signal transmitting section of the remote controller through the monitor of a digital camera or a camera phone It is normal if the LED of the signal transmitting section lights up when the ...

Page 23: ...d and the indoor fan 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 pr...

Page 24: ...inverter P C board in the outdoor unit repeat 3 6 second OFF and 0 8 second ON quick blinking for 3 minutes after the outdoor unit is energized Check the blinking pattern within 3 minutes after LED is turned on Af ter 3 minutes LED will blink 6 times whether the inverter P C board in the outdoor unit is normal or not No Replace the inverter P C board in the outdoor unit 2 Yes A 2 Be careful of 140...

Page 25: ...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 26: ...1 3 6 VDC 15 VDC GND High voltage DC 325 VDC 0 or 15 VDC Indoor terminal block connecting TAB2 Timer short mode point Refer to 8 1 Room temperature thermistor RT11 CN111 Connector to Indoor coil thermistor RT12 RT13 CN112 Vane motor CN151 Connector to indoor power P C board CN10A 12V DC 5V DC To disable Auto restart function cut the Jumper wire to JR77 Refer to 8 3 Emergency operation switch E O S...

Page 27: ...erminal with this connector has the locking mechanism Slide the sleeve Pull the terminal while pushing the locking lever Hold the sleeve and pull out the terminal slowly Connector Sleeve Locking lever Terminal with locking mechanism Detaching points The terminal which has the locking mechanism can be detached as shown below There are 2 types refer to 1 and 2 of the terminal with locking mechanism ...

Page 28: ...rical cover and remove the electrical cover 8 Disconnect the following connectors Indoor power P C board CN211 Indoor fan motor CN201 TAB1 TAB2 Terminal block CN20A To the indoor electronic control P C board 9 Remove the upper catch of the electrical box and pull out the electrical box To attach the electrical box pass the wires connecting the indoor power P C board and the indoor electronic contr...

Page 29: ...e back side of the control P C board holder 5 Unhook the catches of the control P C board holder and open the control P C board holder 6 Remove the indoor electronic control P C board from the control P C board holder 4 Removing the vane motor 1 Remove the panel Refer to 1 Remove the corner box 2 Remove the control P C board holder and the electrical box Refer to 2 3 Pull out the drain hose from t...

Page 30: ...lead wire of the fan motor from the motor band 10 Disengage the hooks of the motor band and remove the motor band Pull out the indoor fan motor 11 Remove the indoor coil thermistor from the heat exchanger Install the indoor coil thermistor in its former position when assembling it 12 Remove the screws fixing the left side of the heat exchanger 13 Lift the heat exchanger and pull out the line flow ...

Page 31: ...ked position Do not pull the lead wire when removing the indoor coil thermistor Holder shape Clip shape When fixing the indoor coil thermistor to the clip shape holder shape part the lead wire should point down 1 Set the indoor coil thermistor 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 par...

Page 32: ...ht 2016 MITSUBISHI ELECTRIC CORPORATION Published Dec 2016 No OBH764 Made in Japan Specifications are subject to change without notice HEAD OFFICE TOKYO BUILDING 2 7 3 MARUNOUCHI CHIYODA KU TOKYO 100 8310 JAPAN ...

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