Mitsubishi Heavy Industries SRR25ZS-W, Service Manual

Page 1: ...SM SERVICE MANUAL SRR25ZS W SRR35ZS W FDTC25VH1 FDTC35VH1 Split system air to air heat pump type INVERTER RESIDENTIAL AIR CONDITIONERS Ceiling concealed type 4 way ceiling cassette type 285 ...

Page 2: ...ation control function by the indoor control 21 1 2 2 Operation control function by the wired remote control 18 1 2 4 Operation control function by the outdoor control 40 4 Troubleshooting procedure If the air conditioner runs 2 1 SRR series 46 3 Troubleshooting procedure If the air conditioner does not run at all 46 1 Cautions 46 2 Items to check before troubleshooting 46 10 How to make sure of w...

Page 3: ...ol 74 6 Inverter checker for diagnosis of inverter output 76 7 Outdoor unit inspection points 77 80 2 Troubleshooting 79 1 List of troubles 2 2 2 Troubleshooting flow 4 Troubleshooting at the outdoor unit 73 79 3 ELECTRICAL WIRING 122 4 PIPING SYSTEM 125 67 2 2 FDTC series 2 2 1 Diagnosing of microcomputer circuit 67 1 Selfdiagnosis function 67 ...

Page 4: ... the relevant parts are shown Press to start operation press again to stop This button sets the room temperature This button changes the air flow up down direction This switch is for setting the time This button selects SLEEP operation This switch selects the CLEAN operation This button selects ON TIMER operation This buttions is used for setting the cur rent time and timer function Switch for res...

Page 5: ... light yellow Illuminates during TIMER operation HI PO Illuminates d This button c unit when re 1 sec Unit ON OFF button Function Operation mode Indoor temperature setting Fan speed Flap Louver Timer switch COOL About 24ºC Auto Auto Continuous DRY About 25ºC HEAT About 26ºC When two air conditioners are installed in the room use setting when the two air conditioners are not operated with one wirel...

Page 6: ...ill start from the set time d When the following operation are set HIGH POWER operation will be canceled When the HI POWER ECONO button is pressed again When the SILENT botton is pressed When the operation mode is changed When the NIGHT SETBACK botton is pressed When it has been 15 minutes since HIGH POWER operation has started e Not operable while the air conditioner is OFF f After HIGH POWER ope...

Page 7: ...ng SRR25ZS W SRR35ZS W 4th speed 37 rps 4th speed 46 rps 5th speed 46 rps 4th speed 56 rps 11 Outline of heating operation d Weekly timer operation Timer operation ON timer OFF timer can be set up to 4 times a day for each weekday ON OFF ON ON ON OFF few minutes ON ON ON HOT KEEP OFF OFF 3 minutes ON OFF OFF Thermostat ON Thermostat OFF Failure Heating Compressor Indoor fan motor Outdoor fan motor...

Page 8: ...5 minutes Accumulated compressor operation time 2 After end of defrost operation When it elapsed 35 minutes Accumulated compressor operation time 3 Outdoor heat exchanger temperature sensor TH2 When the temperature has been below 5ºC for 3 minutes continuously 4 The difference between the outdoor air sensor temperature and the outdoor heat exchanger temperature sensor The outdoor air temperature 0...

Page 9: ...humidity to the target condition Indoor outdoor unit control the operation condition to reduce the humidity and also prevent over cooling b Outline of control i Indoor unit fan speed and compressor are controlled by the area which is selected by the temperature difference ii The indoor unit check the current area by every 5 minutes and operate by the next checking c Other When the outside temperat...

Page 10: ...he automatic operation 27 5 25 5 19 5 18 A 30 Heating Dehumidifying Cooling Indoor air temperature C Outdoor air temperature C i ii iii When both the indoor and the outdoor air temperatures are in the range A cooling or heating is switched depending on the difference between the setting temperature and the indoor air temperature When the operation mode has been judged following the change of setti...

Page 11: ... 8 2 Cooling overload protective control a Operating conditions b Detail of operation Indoor fan Outdoor fan 4 way valve Outdoor air temperature Lower limit speed 1 2 i ii i ii c Reset conditions Depends on compressor speed The lower limit of compressor speed is set to 30 or 40 rps However when the thermo OFF the speed is reduced to 0 rps The outdoor fan is stepped up by 3 speed step Upper limit 8...

Page 12: ...temperature while the compressor is turned on ii Compressor speed is controlled according to the zones of indoor heat exchanger temperature as shown by the following table Thi R P1 P1 Thi R P2 P2 Thi R P3 P3 Thi R Protection control speed NP Normal Retention NP 4rps NP 8rps Sampling time s Normal 20 20 20 Thi R NP P1 P2 P3 NP 50 47 55 54 50 NP 92 47 5 55 57 92 NP 115 47 5 39 55 40 57 42 115 NP 39 ...

Page 13: ...e Fuzzy 90 Cooling Heating Lower limit speed 15 rps 20 rps Item Model 2 If the temperature of 110ºC is detected by the temperature sensor on the discharge pipe then the compressor will stop im mediately When the discharge pipe temperature drops and the time delay of 3 minutes is over the unit starts again within 1 hour but there is no start at the third time i Current safe i Purpose Current is con...

Page 14: ...fan motor has operated at 300 min 1 or under for more than 30 seconds the unit enters first in the stop mode and then stops the entire system n Rotor lock If the motor for the compressor does not turn after it has been started it is determined that a compressor lock has occurred and the compressor is stopped o Outdoor fan motor protection If the outdoor fan motor has operated at 75 min 1 or under ...

Page 15: ...intained during the drain detection ii Heating 1 Operating conditions When the outdoor air temperature TH3 is 0ºC or lower continues for 30 seconds while the compressor command speed is other than 0 rps 2 Detail of operation The outdoor fan is stepped up by 2 speed step at each 20 seconds Upper limit 8th speed 3 Reset conditions When either of the following conditions is satisfied a The outdoor ai...

Page 16: ...he backlight lighting can be changed If the backlight is ON setting when the screen is tapped while the backlight is turned off the backlight only is turned on Operations with switches and are excluded USB port USB connector mini B allows connecting to a personal computer For operating methods refer to the instruction manual attached to the software for personal computer remote control utility sof...

Page 17: ...peration This button is also used to reset the FILTER CLEANING display Press it after cleaning the air filter 1 Wired remote control Model RC E5 The figure below shows the remote control with the cover opened Note that all the items that may be displayed in the liquid crystal display area are shown in the figure for the sake of explanation Characters displayed with dots in the liquid crystal displ...

Page 18: ...tton Every time this button is pressed displays switch as below AUTO COOL HEAT FAN DRY TEMP button Change the set temperature by pressing or button FAN SPEED button The fan speed is switched in the following order 1 speed 2 speed 3 speed 4 speed AUTO 1 speed U D button Used to determine the up down louver position ON TIMER button Used to set the ON TIMER OFF TIMER button Used to set the OFF TIMER ...

Page 19: ...or temperatures 2 CPU reset Reset CPU from the remote control as follows TOP screen Menu Service setting Service Maintenance Service password The selected screen is displayed The selected screen is displayed Service Maintenance 2 Special settings CPU reset Microcomputers of indoor unit and outdoor unit connected are reset State of restoration after power failure 3 Power failure compensation functi...

Page 20: ...function items are saved in the memory of indoor unit g Weekly timer peak cut timer or silent mode timer settings h Remote control function setting Please check the I U Set clock first on the initializing screen set the timer Other thanA C is connected 4 Alert displays If the following a to c appear check and repair as follows Communication check screen This appears if communications cannot be est...

Page 21: ...tate of stop is memorized Although the timer mode is cancelled at the recovery from power failure the setting of weekly timer is changed to the holiday setting for all weekdays b Operation mode c Air flow volume mode d Room temperature setting e Louver auto swing stop However the stop position 4 position is cancelled so that it returns to Position 1 f Remote control function items which have been ...

Page 22: ... the temperature shown at right 3 3 Cooling operation Heating operation Room temperature detected with Thi A C 59 56 Heating operation stopped cooling Heating OK Indoor heat exchanger temperature C b The following automatic controls are performed other than a above i Cooling or heating operation mode is judged according to the conditions of the Judgment based on Setting temperature Cooling select ...

Page 23: ...alve Outdoor unit fan Indoor unit fan Drain pump 3 2 2 Thermostat ON Thermostat OFF 2 2 Notes 1 Operation Stop Turned ON OFF by the control other than the room temperature control 2 ON during the drain pump motor delay control 3 Drain pump ON setting may be selected with the indoor unit function setting of the wired remote control 3 Dehumidifying DRY operation Indoor ambient temperatures and humid...

Page 24: ...or a week Up to 8 patterns can be set for a day The day off setting is provided for holidays and non business days Note 1 It is necessary to set the clock to use the weekly timer vii Combination of patterns which can be set for the timer operations Note 1 Allowed Not Sleep timer Sleep timer Set OFF timer by hour Weekly timer Set ON timer by hour Set OFF timer by clock Set ON timer by clock Set OFF...

Page 25: ...cts 35 C or higher the fan operates with the set air flow volume c If the fan control at heating thermostat OFF is set at the Set air flow volume from the remote control the fan operates with the set air flow volume regardless of the thermostat ON OFF 2 Once the fan motor is changed from OFF to ON during the thermostat ON the indoor fan motor is not turned OFF even if the heat exchanger thermistor...

Page 26: ... Press the LOUVER button to operate the swing louver when the air conditioner is operating SWING is displayed for 3 seconds and then the swing louver moves up and down continuously 2 To fix the swing louver at a position press one time the LOUVER button while the swing louver is moving so that four stop positions are displayed one after another per second When a desired stop position is displayed ...

Page 27: ...r fan if the heat exchanger thermistors both Thi R1 and R2 detect 25 C or lower 2 Indoor fan OFF is fixed for 5 minutes After the 5 minutes the indoor fan is operated at ULo for 2 minutes In the meantime the louver is controlled at level 3 After operating at ULo for 2 minutes the indoor fan moves to the state of 1 above 4 If the thermostat is turned ON it moves to the hot start control 5 When the ...

Page 28: ...the indoor unit of which the thermostat has been turned OFF is turned OFF The same occurs also when the remote control sensor is effective 9 Filter sign As the operation time Total ON time of ON OFF switch accumulates to 180 hours 1 FILTER CLEANING is displayed on the remote control This is displayed when the unit is in trouble and under the centralized control regardless of ON OFF Notes 1 Time se...

Page 29: ...itch OFF releases the forced drain pump ON condition Normal state 1 2 Normal state Drain detection switch ON Stop 1 Indoor unit operation mode Control A Control B Compressor ON Compressor OFF Cooling Dry Heating Fan 2 Notes 1 Including the stop from the cooling dehumidifying fan and heating and the anomalous stop 2 Including the Fan operation according to the mismatch of operation modes i Control ...

Page 30: ...n fan motor stops with the anomalous stop E16 b If the fan motor fails to reach at 50 min 1 less than the required speed it stops with the anomalous stop E20 Compressor forced off temperature Hs 50 Hs 50 Item Symbol Low High Item Symbol Low High A 1 0 2 5 A 0 5 1 0 b Selection of indoor fan speed If it enters the frost prevention control during cooling operation including dehumidifying the indoor ...

Page 31: ...or unit address If button is pressed at the next it is displayed orderly starting from the unit of smallest No d In case of anomaly If any anomaly occurs on a unit in a group a protective function operates that unit stops with the anomalous stop but any other normal units continue to run as they are e Signal wiring procedure Signal wiring between indoor and outdoor units should be made on each uni...

Page 32: ...TA CnT CnT CnTA CnT CnTA Operation stop pulse CnT CnT CnT CnTA CnT CnT CnTA CnT CnTA Operationpermission prohibitionlevel CnT CnTA CnT CnTA CnT CnTA CnT CnT CnTA CnT CnTA Operation permission prohibition pulse CnT CnT CnT CnTA CnT CnT CnTA CnT CnTA Cooling heating selection level CnT CnTA CnT CnTA CnT CnTA CnT CnTA CnT CnT Cooling heating selection pulse CnT CnTA CnT CnTA CnT CnTA CnT CnTA CnT CnT...

Page 33: ...ooling heating 6 Forced thermo OFF Unit goes thermo off 7 Temporary stop Refer to 22 Temporary stop input 8 Silent mode Outdoor unit silent mode is activated ii In case of Pulse input setting Local setting It is effective only when the input signal to CnT 6 or CnTA is changed OFF ON and at that time unit operation ON OFF is inverted ON ON OFF OFF OFF ON ON ON ON Remote control OFF Remote control O...

Page 34: ...OFF Operation Stop Operation permission 1 Operation prohibition Unit stops 1 Only the LEVEL INPUT is acceptable for external input however when the indoor function setting of Level input Factory default or Pulse input is selected by the function for External input of the wired remote control operation status will be changed as follows In case of Level input setting In case of Pulse input setting U...

Page 35: ...peration Remote control CnT Operation stop pulse CnTA Operation permission prohibition level Operation permission prohibition zone Actual operation Remote control Remote control ON Remote control OFF Remote control ON Remote control ON Remote control OFF Remote control ON ON ON ON ON ON ON ON OFF OFF OFF OFF OFF OFF OFF ON ON OFF ON ON ON ON ON OFF OFF OFF OFF OFF OFF Operation Operation Operation...

Page 36: ...es are inverted Cooling Heating or Heating Cooling d If the cooling heating selection signal is given by the external input the operation mode is transmitted to the remote control Selection of cooling heating external input function External input selection External input selection Cooling heating selection External input method Level External terminal input CnT or CnTA Cooling heating Cooling hea...

Page 37: ...n temperature by the return air temperature sensor and the measured temperature after installing the unit a It is adjustable in the unit of 0 5 C with the wired remote control indoor unit function RETURN AIR TEMP 1 0 C 1 5 C 2 0 C 1 0 C 1 5 C 2 0 C b Compensated temperature is transmitted to the remote control and the compressor to control them Note 1 The detection temperature compensation is effe...

Page 38: ...m the return air temperature According to temperature difference between setting temperature and return air temperature indoor fan tap are controlled automalically Auto 1 Changes the indoor fan tap within the range of Hi Me Lo Auto 2 Changes the indoor fan tap within the range of P Hi Hi Me Lo 35 Indoor unit overload alarm RC EX3A only If the following condition is satisfied at 30 minutes after st...

Page 39: ...of main IU IU back up function Infrared sensor setting Previous Back Select the item Infrared motion sensor setting Select the item Infrared sensor setting Disable Enable Back Menu Direction Cooling 16 14 Mon F1 High power F2 Energy saving Timer Now stopping Set temp TOP screen Menu Energy saving setting or Motion sensor control Infrared sensor control Set button The Infrared sensor control screen...

Page 40: ...hours unit stops Compressor keeps stopped regardless of the setting temperature Notes 1 When the following operations are set power saving control will be canceled Energy saving Home leave mode Warm up control Cooling operation check When the operation mode is changed DRY or FAN 2 Not operable while the air conditioner is OFF Low When the extent of human activity is low High When the extent of hum...

Page 41: ... b Ending conditions Operation returns to the heating cycle when either one of the following is satisfied 1 Outdoor heat exchanger sensor TH2 temperature 13ºC or higher 2 Continued defrost operation time For more than 15 minutes Max 15 minutes Heating operation Defrost operation Depends on an operation condition the time can be longer than 7 minutes 2 7 minutes Hot keep operation 1 2 4 Operation c...

Page 42: ...ON Upper 3 Lower 3 ON Upper 1 Lower 1 C A OFF E D B F Compressor speed Upper lower limit rps Upper 2 Lower 3 Upper 3 Lower 2 Lower 1 Upper 1 Range A Range B 50 50 50 44 60 30 Release 26 24 Indoor air temperature Range A Range B 4 Cooling low outdoor temperature protective control a Operating conditions When the outdoor air temperature TH3 is 22ºC or lower continues for 20 seconds while the compres...

Page 43: ...de 1 Operating conditions 2 Detail of operation 3 Reset conditions Protective control ON 21 22 Normal operation Protective control Outdoor air temperature C Model SRK50 Models SRK20 35 Model SRK50 A B C D RPSmin 40 40 RPSmin 80 80 RPSmin 90 90 RPSmin 102 102 RPSmin 49 53 41 53 47 47 41 53 57 45 57 51 51 45 55 59 47 59 53 53 47 58 62 51 58 51 When the outdoor air temperature TH2 is 22ºC or higher c...

Page 44: ... 4 rps 4 rps 1 0 rps 100 110 Example Fuzzy 90 Cooling Heating Lower limit speed 15 rps 20 rps Item Model 2 If the temperature of 110ºC is detected by the sensor on the discharge pipe then the compressor will stop immediately When the discharge pipe temperature drops and the time delay of 3 minutes is over the unit starts again within 1 hour but there is no start at the third time 9 Current safe a ...

Page 45: ...tion If the outdoor fan motor has operated at 75 min 1 or under for more than 30 seconds the compressor and fan motor are stopped 15 Outdoor fan control at low outdoor air temperature a Cooling 1 Operating conditions When the outdoor air temperature TH3 is 22ºC or lower continues for 30 seconds while the compressor com mand speed is other than 0 rps 2 Detail of operation After the outdoor fan oper...

Page 46: ...ON or the completion of the defrost control Other than the defrost control b Contents of control 1 c Reset condition When the compressor has been turned OFF 2 When the conditions of i above are satified the compressor stops Error stop occurs when the compressor has stopped 3 times within 60 minutes 3 When after satisfying the conditions of 1 and 2 above the compressor speed room temperature Thi A ...

Page 47: ...OUBLESHOOTING PROCEDURES FOR ELECTRICAL EQUIPMENT 1 Cautions 2 Items to check before troubleshooting 3 Troubleshooting procedure If the air conditioner does not run at all Important YES YES YES NO NO NO NO YES Reference Reference AC proced wireless source source satisfied ...

Page 48: ... 20 SR SM 285 47 09 SRK DB 087D 4 Troubleshooting procedure If the air conditioner runs NO NO NO NO YES YES YES YES 48 49 55 49 55 s s ...

Page 49: ...essor is stopped Broken compressor wire Compressor blockage Trouble of outdoor unit When the value of the discharge pipe sensor exceeds the set value The air conditioner stops Gas shortage defective discharge pipe sensor service valve is closed Over heat of compressor When there is no signal between the indoor PCB and outdoor PCB for 10 seconds or longer when the power is turned on or when there i...

Page 50: ...ta are recorded for up to 5 previous occurrences Data which are older than the 5th previous occurrence are erased In addition data on the temperature of each sensor room temperature indoor heat exchanger outdoor heat exchanger outdoor air temperature discharge pipe remote control information operation switching fan speed switching are recorded when trouble occurs so more detailed information can b...

Page 51: ... Fan speed mode mode mode 21ºC 22ºC 23ºC 24ºC 25ºC 1 time previous previous time 2 times previous 3 times previous 4 times previous 5 times previous Only for indoor heat exchanger sensor 2 Indicates the number of occasions previous to the present the error display data are from Temperature setting 26ºC 27ºC 28ºC 29ºC 30ºC 1 time previous previous time 2 times previous 3 times previous 4 times prev...

Page 52: ...the stop stop code 2 times previous when the air conditioner was stopped by protective stop control Displays the reason for the stop stop code 3 times previous when the air conditioner was stopped by protective stop control Displays the reason for the stop stop code 4 times previous when the air conditioner was stopped by protective stop control Displays the reason for the stop stop code 5 times p...

Page 53: ...inuously within 20 seconds after power ON 25 C or lower is detected for 5 seconds continuously 3 times within 40 minutes after intial detection of this anomalous temperature When the discharge pipe sensor s value exceeds the set value When the outdoor heat exchanger sensor s value exceeds the set value Service valve is closed Refrigerant is insufficient Refrigerant is overcharge Compressor lock Ov...

Page 54: ...N HEAT TIMER light 1 s digit Display pattern when in service mode Fan speed mode when there is an abnormal stop 2 time flash 3 time flash 4 time flash AUTO HI MED LO 5 time flash ULO 6 time flash 7 time flash operation mode and fan speed mode becomes as follows HI POWER ECONO Mode Operation mode Fan speed mode 0 5 sec 1 5 sec RUN light 10 s digit TIMER light 1 s digit 11 second interval 0 5 sec OF...

Page 55: ...55 45 35 25 15 5 5 15 25 35 45 55 65 75 85 95 56 46 36 26 16 6 6 16 26 36 46 56 66 76 86 96 57 47 37 27 17 7 7 17 27 37 47 57 67 77 87 97 58 48 38 28 18 8 8 18 28 38 48 58 68 78 88 98 59 49 39 29 19 9 9 19 29 39 49 59 69 79 89 99 No does not sound Sensor name Room temperature sensor Indoor heat exchanger temperature sensor Outdoor air temperature sensor Outdoor heat exchanger temperature sensor 64...

Page 56: ...48 28 8 8 28 48 68 88 108 128 148 50 30 10 10 30 50 70 90 110 130 150 52 32 12 12 32 52 72 92 112 132 54 34 14 14 34 54 74 94 114 134 56 36 16 16 36 56 76 96 116 136 58 38 18 18 38 58 78 98 118 138 No does not sound Sensor value displayed when the error code is normal 64ºC 0 5 sec 0 1 sec 1 5 sec 11 second interval 0 5 sec OFF ON OFF ON OFF ON temperature information data Buzzer sound If the tempe...

Page 57: ... 20 SR SM 285 56 09 SRK DB 087D Service data record form 50 Operation mode Fan speed mode Wireless r Wireless r Wireless r Wireless r Wireless r wireless Wireless r ...

Page 58: ...ge pipe temperature sensor characteristics Indoor fan motor error Broken sensor wire connector poor connection 0 0 20 40 60 80 100 120 135 20 40 60 80 100 120 140 160 180 Temperature C Resistance k Defective fan motor connector poor connection defective indoor unit PCB unit Power source reset Is it normalized Malfunction by temporary noise Replace fan motor If the error persists after replacing th...

Page 59: ...unit PCB is faulty Service valve is closed EEV is faulty Compressor faulty Current safe stop Overload operation compressor lock overcharge 66 4 428Ω U V V W U W or more at 20ºC short circuit unit Defective outdoor unit PCB Defective outdoor unit PCB between terminals Inspect outdoor air temperature sensor Defective outdoor unit PCB ...

Page 60: ...at of compressor Gas shortage defective discharge pipe temperature sensor Error of signal transmission Wiring error including power cable defective indoor outdoor unit PCB 57 temperature temperature Defective outdoor unit PCB unit unit unit ...

Page 61: ...B See page 66 for the fan motor and outdoor unit PCB check After making sure the fan motor and outdoor unit PCB are Power source reset Is it normalized Malfunction by temporary noise Replace fan motor If the error persists after replacing the fan motor replace the outdoor unit PCB the fan motor and outdoor unit ourdoor unit PCB outdoor unit Replace outdoor fan motor AC AC AC AC AC AC 2 Check resis...

Page 62: ...efective outdoor unit PCB Replace Defective outdoor unit PCB Replace NO YES Is the space for installation of indoor and or outdoor unit enough Is there any short circuit of air on indoor and or outdoor unit At heating does the indoor fan motor run Is the filter clogged Is there any liquid flooding Is there any anomalous sound on the compressor After resetting power for several times does it become...

Page 63: ...uring point Resistance when normal Measuring point Resistance when normal Defrost operation is performed for 10 minutes at approx 35 minutes Defrost operation is performed for 10 minutes at approx 35 minutes Compressor stop The compressor cannot pick up its speed owing to the current safe so that the designed capacity is not achieved The compressor cannot pick up its speed owing to the heating ove...

Page 64: ... DC 0 and 20V Replace indoor unit PCB NO YES NO b Indoor fan motor check procedure 1 Indoor unit PCB output check 2 Fan motor resistance check FMi DC15V Indoor unit PCB DC 308 336V DC several V 4 6 V CNU GND Blue Yellow White Black Red Measuring point Resistance when normal Measuring point Voltage range when normal k M ...

Page 65: ...tor Check then the operation Faulty part other than fan motor YES Fan motor is faulty YES YES YES NO NO NO Replace the faulty part and the fuse Test run then the unit for checking Is there any damage on the internal circuit of fan motor Check the resistance value to judge See pages 63 to 66 Is the fuse blown on the indoor and outdoor unit PCB Is there any faulty part fan motor etc See pages 63 to ...

Page 66: ...sistor Remove the faston terminal and test output voltage Inspection of outdoor fan motor See page 66 Check point of outdoor unit Color Color symbol OR Mark Brown BR Yellow Green Y G Black BK Blue BL White WH Yellow YE Red RD Orange Display Voltage range Voltage check in PCB The normal range is as follows DC280V DC230V DC310V DC220V DC218V DC222V DC213V DC212V DC214V DC215V DC214V DC216V DC225V DC...

Page 67: ...a separate unit Measuring point Resistance when normal b Outdoor fan motor check procedure Measuring point Voltage range when normal DC15V DC several 4 7V Outdoor unit PCB GND DC308 336V CNFAN Red Black White Yellow Blae FM0 1 2 3 i ii iii DC iv i Fan motor resistance check Measuring point Resistance when normal k ii Black Black source unit unit unit unit unit ...

Page 68: ...r of temperature sensor 97 Indoor unit control PCB Defective indoor unit control PCB Defective temperature sensor input cir cuit Replacement of PCB 1 time flash Keeps flashing Indoor return air temperature sensor Defective indoor return air temperature sensor defective element broken wire short circuit Poor contact of temperature sensor connector Replacement repair of temperature sensor 98 Indoor ...

Page 69: ...nsor 111 Outdoor unit control PCB Defective outdoor unit control PCB Defective temperature sensor input circuit Replacement of PCB Stays OFF Keeps flashing Installation operation status Service valve gas side closing operation Replacement 112 Stays OFF Keeps flashing Outdoor unit control PCB compressor Current cut Anomalous compressor over current Replacement of PCB 113 114 Installation operation ...

Page 70: ...after initial communication was established Excessive number of connected indoor units by controlling with one remote control Whenever excessively connected indoor units is detected after power ON Return air temperature sensor anomaly 50 C or lower is detected for 5 seconds continuously within 60 minutes after initial detection of this anomalous temperature Indoor heat exchanger temperature sensor...

Page 71: ...and fuse Note 1 With regard to parts of high voltage circuits and refrigeration cycle judge it according to ordinary inspection methods ii Instruction of how to replace indoor unit control PCB Read the SAFETY PRECAUTIONS carefully first of all and then strictly follow it during the replacement in order to protect yourself The precautionary items mentioned below are distinguished into two levels WA...

Page 72: ...ved in iv Control PCB Parts mounting are different by the kind of PCB 〇 ON OFF Part number SW2 Blue Address setting SW5 Master Slave setting SW7 Function setting CNT Blue External switch CNJ White Louver motor CNN Yellow Thermistor Heat exchanger CNI Blue Float SW CNH Black Thermistor Return air CNW3 Red Power PCB CNB White Remote control CNG Blue CNZ White HA CNE White RAM checker CNW4 Blue Power...

Page 73: ...e Reserved Reserved Reserved Keep OFF Test run drain pump motor Normal Test run Normal Model selection As per model See table 1 Remark Address No setting at plural indoor units control by 1 R C 0 F Switch Description Default setting Table 1 Indoor unit model selection with SW6 1 SW6 4 25VH 35VH SW6 4 SW6 1 SW6 2 SW6 3 Default setting OFF OFF OFF ON ON OFF OFF OFF Switch Keep OFF ...

Page 74: ...another error mode which has a higher priority than the previous error saved in memory occurs it is overwritten in memory and is displayed Reset of power source Be sure to avoid electrical shock when replacing or checking the outdoor unit control PCB because some voltage is still retained in the electrolytic capacitor on the PCB even after shutting down the power source to the outdoor unit Be sure...

Page 75: ...uper Heat Discharge Pipe Super Heat Protection State No of The Compressor Outdoor Unit Fan Speed 63H1 On Off Defrost Control On Off Total Running Hours of The Compressor Pulse of The Outdoor Unit Expansion Valve EEVC Pulse of The Outdoor Unit Expansion Valve EEVH 13 Supply Air Temperature ە Number 33 details of compressor protection status No Contents of display 0 Normal 1 Discharge pipe temperatu...

Page 76: ...mperature anomaly 3 Current safe control of inverter primary current 4 High pressure protection control 5 High pressure anomaly 6 Low pressure protection control 7 Low pressure anomaly 8 Anti frost prevention control 9 Current cut 10 Power transistor protection control 11 Power transistor anomaly Overheat 12 Compression ratio control 13 Spare 14 Dewing prevention control 15 Current safe control of...

Page 77: ...starting check operation 6 Inverter checker for diagnosis of inverter output Checking method LED U V W LED1 LED3 LED5 LED2 LED4 LED6 LED1 LED3 LED5 LED2 LED4 LED6 LED1 LED3 LED5 LED2 LED4 LED6 LED1 LED3 LED5 LED2 LED4 LED6 LED1 LED3 LED5 LED2 LED4 LED6 LED1 LED3 LED5 LED2 LED4 LED6 ON OFF status of LED If all of LED are ON OFF according to following pattern If all of LED stay OFF or some of LED ar...

Page 78: ... Remove the faston terminal and test output voltage Inspection of outdoor fan motor See page 66 Check point of outdoor unit Color Color symbol OR Mark Brown BR Yellow Green Y G Black BK Blue BL White WH Yellow YE Red RD Orange Display Voltage range Voltage check in PCB The normal range is as follows DC280V DC230V DC310V DC220V DC218V DC222V DC213V DC212V DC214V DC215V DC214V DC216V DC225V DC224V D...

Page 79: ... 20 SR SM 285 78 ...

Page 80: ...e sensor anomaly 97 E7 Return air temperature sensor anomaly 98 E8 Heating overload operation 99 E9 Drain trouble 100 E10 Excessive number of connected indoor units more than 17 units by controlling with one remote control 101 E11 Address setting error of indoor units 102 E16 Indoor fan motor anomaly 103 E19 Indoor unit operation check drain pump motor check setting error 104 E20 Indoor fan motor ...

Page 81: ...or operating NO YES NO Note 1 Outdoor 35 C Indoor 27 C 1 WAIT It is normal This unit is designed to start in the soft start mode by detecting the under dome temperature of compressor when it restart after power reset It is necessary to replace to higher capacity one or two install additional unit Compressor refrigerant oil protection control at starting is activated For the contents of control ref...

Page 82: ...Note 1 Outdoor 7 C Indoor 20 C 1 WAIT It is normal This unit is designed to start in the soft start mode by detecting the under dome temperature of compressor when it restart after power reset It is necessary to replace to higher capacity one or two install additional unit Compressor refrigerant oil protection control at starting is activated For the contents of control refer to the compressor sta...

Page 83: ... for long time without power source the insulation resistance may drop to a few MΩ because of refrigerant migrated in the compressor When the earth breaker is activated at lower insulation resistance check the following points When power ON crankcase heater heat up compressor and evaporate the refrigerant migrated in the compressor Check if the earth leakage breaker is conformed to higher harmonic...

Page 84: ...o the gap if necessary Prevent the vibration from transmitting to wall and etc by fixing pipes on the wall or wrapping rubber cushion around the pipe which goes through the hole in the wall or applying other appropriate means Strength of ceiling wall floor etc may be insufficient Review the installing position or reinforce it Check for leaning of installed unit or anomalous mounting of fan louver ...

Page 85: ... of piping of air conditioner It is likely to occur particularly during cooling or defrost operation in the heating mode It is normal The noise vibration occurs when the refrigerant starts or stops flowing It is normal When the defrost operation starts or stops during heating the refrigerant flow is reversed due to switching 4 way valve This causes a large change in pressure which produces a blowi...

Page 86: ...ion of air nitrogen etc In such occasion it is necessary to recover refrigerant vacuum dry and recharge refrigerant Since there could be many causes of noise vibration the above do not cover all In such case check the conditions when where how the noise vibration occurs according to following check point Indoor outdoor unit Cooling heating fan mode Startup stop during operation Operating condition...

Page 87: ...t the indoor unit side LM louver motor Is the louver operable with the remote control YES NO Does the louver operate at the power on YES NO YES NO Operate after waiting for more than 1 minute Repair wiring Defective indoor unit control PCB Replace Replace LM Normal Adjust LM lever and then check again 2 Error detection method 3 Condition of error displayed 4 Presumable cause Defective LM LM wire b...

Page 88: ...nit NO YES NO Is AC380 415V for 3 phase unit detected between ձ ղ and ճ on the teminal block of outdoor unit or isAC220 240V for 1 phase unit detected between ձ and ղ on the terminal block of outdoor unit YES Defective outdoor unit control PCB Noise filter Replace Misconnection or breakage of connecting wires Defective indoor unit control PCB Replace Replace FM LM etc Replace fuse Defective indoor...

Page 89: ...or terminal block exceed 15 VDC YES NO YES NO NO YES Does the voltage between X and Y in the indoor terminal block exceed 15 VDC Remove wire for the remote control Power source reset YES Correct Insert connector securely Remote control wire breakage Replace remote control Malfunction by temporary noise Defective indoor unit control PCB Replace Remote control wire breakage Replace remote control 2 ...

Page 90: ...etween the indoor and outdoor unit Power source reset NO YES YES NO NO NO NO NO YES YES YES Set one remote control for Master and the other for Slave YES Set SW1 on remote control PCB at Master Normal Set address again SW2 on indoor unit control PCB Separate remote control wires from high voltage wires Defective indoor unit control PCB Replace Defective remote control Change 2 Error detection meth...

Page 91: ...on with remote control 3 Condition of error displayed Same as above 4 Presumable cause Improper setting Surrounding environment Defective remote control communication circuit Faulty indoor unit control PCB Faulty outdoor unit control PCB Note If any error is detected 30 minutes after displaying WAIT on the remote control the display changes to INSPECT I U NO NO NO NO NO Are more than 3 units of re...

Page 92: ...n on the indoor unit terminal block NO YES WAIT See next page YES Normal Defective indoor unit control PCB Replace Correct connection wires between indoor and outdoor units Defective outdoor unit PCB Replace Defective connection wire broken wire Noise Defective indoor unit control PCB Replace 2 Error detection method 3 Condition of error displayed 4 Presumable cause Blown fuse Faulty outdoor unit ...

Page 93: ...replacing the power source fuse Diagnosis Countermeasure Replace the outdoor unit PCB NO YES NO Replace the outdoor unit PCB YES Replace the reactor Is there a short circuit between phases of outdoor unit PCB Are there cracks or burning on the power transistor module or diode stack Is reactor the anomalous NO YES Replace fuse 2 Error detection method 3 Condition of error displayed 4 Presumable cau...

Page 94: ...mote control side after disconnecting the remote control YES NO Are wires connected properly between the indoor and the outdoor units Is approx DC20V detected between on the outdoor unit terminal block NO Is approx DC20V detected between on the indoor unit terminal block NO 2 N YES YES YES Replace fuse Short circuit on remote control wire Defective remote control Correct wires Defective outdoor un...

Page 95: ...on terminals Is DC10V or higher detected on remote control wires if the remote control is removed Are wires connected properly between the indoor outdoor units NO YES Defective remote control Defective remote control Defective connecting wire Defective remote control wire Short circuit etc Defective indoor unit control PCB Replace 2 Error detection method 3 Condition of error displayed 4 Presumabl...

Page 96: ...r source reset NO Malfunction by noise Check peripheral environment Defective indoor unit control PCB Replace Move to E5 Communication error during operation Check 2 Error detection method When normal communication between the remote control and the indoor unit is interrupted for more than 2 minutes Detectable only with the remote control 3 Condition of error displayed Same as above 4 Presumable c...

Page 97: ...oor unit terminal block Power source reset Note 2 Check for faulty connection or breakage of signal wires between indoor outdoor units YES NO YES NO YES NO In case that the outdoor unit red LED flashes 2 time Repair signal wires Repair signal wires To the diagnosis of WAIT Unit is normal Malfunction by temporary noise etc 2 Error detection method When normal communication between indoor and outdoo...

Page 98: ...nger temperature sensor Replace Defective indoor unit control PCB Replace Defective indoor heat exchanger temperature sensor input circuit 2 Error detection method Anomalously low temperature or high temperature resistance is detected on the indoor heat exchanger temperature sensor Thi R1 R2 or R3 3 Condition of error displayed When the temperature sensor detects 50 C or lower for 5 seconds contin...

Page 99: ...ect connector Defective return air temperature sensor Replace Defective indoor unit control PCB Replace Defective return air temperature sensor input circuit 2 Error detection method Anomalously low temperature or high temperature resistance is detected by indoor return air temperature sensor Thi A 3 Condition of error displayed When the temperature sensor detects 50 C or lower for 5 seconds conti...

Page 100: ...For characteristics of indoor heat exchanger temperature sensor see the error display E6 YES NO YES NO Error stop Reset Indoor heat exchanger temperature C 56 63 Wash Defective indoor heat exchanger temperature sensor connector Correct Defective indoor heat exchanger temperature sensor Replace Check refrigerant system Adjust 2 Error detection method Indoor heat exchanger temperature sensor Thi R1 ...

Page 101: ... NO YES NO Check float switch Defective indoor unit control PCB Replace Defective indoor unit control PCB Replace Check option equipment Correct setting to Humidifier drain pump motor interlock Defective indoor unit control PCB Replace Check wiring of drain motor Correct Check drain pump motor 2 Error detection method Float switch is activated 3 Condition of error displayed If the float switch OPE...

Page 102: ... 5 Troubleshooting All models Diagnosis Countermeasure Are more than 17 indoor units connected to one remote control NO YES Defective remote control Replace Reduce to 16 or less units 2 Error detection method When it detects more than 17 of indoor units connected to one remote contorl 3 Condition of error displayed Same as above 4 Presumable cause Excessive number of indoor units connected Defecti...

Page 103: ...DIP switch SW2 on indoor unit control PCB 2 Error detection method IU address has been set using the Master IU address set function of remote control 3 Condition of error displayed Same as above 4 Presumable cause Mistake of address setting method Address setting from remote control can t be done Note Is Master IU address set function of remote control used E11 occurs YES IU IU IU R C In case the ...

Page 104: ...lace faulty fan motor and indoor unit control PCB Replace fan motor If the error persists after replacing the fan motor replace the indoor unit control PCB Malfunction by temporary noise 2 Error detection method Detected by rotation speed of indoor fan motor 3 Condition of error displayed When actual rotation speed of indoor fan motor drops to lower than 200min 1 for 30 seconds continuously the co...

Page 105: ...ol PCB ON E19 occurs when the power ON NO YES Defective indoor unit control PCB Defective SW7 Replace Turn SW7 1 on the indoor unit control PCB OFF and reset the power 2 Error detection method After indoor operation check when the communication between indoor and outdoor unit is established and SW7 1 is still kept ON 3 Condition of error displayed Same as above 4 Presumable cause Mistake in SW7 1 ...

Page 106: ...otor Check power voltage Replace faulty fan motor and indoor unit control PCB Replace fan motor If the error persists after replacing the fan motor replace the indoor unit control PCB Malfunction by temporary noise 2 Error detection method Detected by rotation speed of indoor fan motor 3 Condition of error displayed When the actual fan rotation speed does not reach to the speed of required speed 5...

Page 107: ...minute delay the compressor starts again automatically but if this error occurs again within 60 minutes after the initial detection 4 Presumable cause Faulty connection of remote control temperature sensor Defective remote control temperature sensor Defective remote control PCB Note After 10 seconds has passed since remote control temperature sensor was switched from invalid to valid E28 will not ...

Page 108: ...ensor Check unit side Isn t the air circulation of outdoor unit short circuited Are installation spaces adequate Isn t there any fouling or clogging on heat exchanger Control operation check Defective outdoor unit control PCB Replace Excessive refrigerant amount Recharge refrigerant by weighing proper amount on a scale 2 Error detection method Anomalous stop Reset 53 51 63 56 Outdoor heat exchange...

Page 109: ...perature sensor Insufficient refrigerant amount Recharge refrigerant by weighing proper amount on a scale Control operation check Defective outdoor unit PCB Replace Check unit side Isn t filter clogged Are indoor outdoor unit installation spaces adequate Isn t there any short circuit of air Isn t there any fouling clogging on indoor heat exchanger 2 Error detection method For the error detection m...

Page 110: ...fective outdoor heat exchanger temperature sensor Replace Defective outdoor unit PCB Replace Defective outdoor heat exchanger temperature sensor input circuit 2 Error detection method Detection of anomalously low temperature resistance on the outdoor heat exchanger temperature sensor 3 Condition of error displayed When the temperature sensor detects 55 C or lower for 5 seconds continuously within ...

Page 111: ...tdoor air temperature sensor Replace Defective outdoor unit PCB Replace Defective outdoor air temperature sensor input circuit 2 Error detection method Detection of anomalously low temperature resistance on outdoor air temperature sensor 3 Condition of error displayed When the temperature sensor detects 55 C or lower for 5 seconds continuously within 2 minutes to 2 minutes 20 seconds after the com...

Page 112: ...ire Short circuit Correct connector Defective discharge pipe temperature sensor Replace Defective outdoor unit PCB Replace Defective discharge pipe temperature sensor input circuit 2 Error detection method Detection of anomalously low temperature resistance on the discharge pipe temperature sensor 3 Condition of error displayed When the temperature sensor detects 25 C or lower for 5 seconds contin...

Page 113: ...e any anoumalous sound on the compressor YES YES YES Are the service valve gas side opened Open the service valve Defective outdoor unit PCB Replace Defective outdoor unit PCB Replace 2 Error detection method If the inverter output current value exceeds the setting value within 80 seconds after the compressor ON in the heating mode the compressor stops 3 Condition of error displayed If the output ...

Page 114: ...the valves Check refrigerant amount and refrigerant circuit In case of transitional increase of high pressure and or test run several times restarting may recover it because liquid refrigerant migrated in the compressor is discharged from the compressor Replace compressor 2 Error detection method In order to prevent from overcurrent of inverter if the current exceeds the specifications it makes th...

Page 115: ... the service valves fully opened Is the filter clogged Is there any liquid flooding Is the superheat within normal range Is the low pressure sensor and suction pipe temperature sensor normal Is there any anoumalous sound on the compressor YES YES From previous page Defective outdoor unit PCB Replace Defective outdoor unit PCB Replace 2 Error detection method In order to prevent from overcurrent of...

Page 116: ...ive outdoor unit PCB Replace 2 Error detection method Error is displayed if the converter voltage exceeds target voltage 3 times within 20 minutes Remote control may be set after 3 minute delay Error is displayed if the converter voltage is lower than DC210V 1 time within 5 seconds after power ON 3 Condition of error displayed Same as above 4 Presumable cause Defective outdoor unit PCB Dust on out...

Page 117: ...ary noise 2 Error detection method Detected by rotation speed of outdoor fan motor 3 Condition of error displayed When actual rotation speed of outdoor fan motor drops to 75min 1 or lower for 30 seconds continuously the compressor and the outdoor fan motor stop After 3 minute delay it starts again automatically but if this anomaly occurs 3 times within 60 minutes after the initial detection 4 Pres...

Page 118: ...on method 3 Condition of error displayed 4 Presumable cause Note If the power transistor primary current exceeds the setting value for 3 seconds the compressor stops Power transistor primary current Outdoor unit PCB anomaly Dust on outdoor unit PCB Blown F2 fuse Check soldered surfaces on the outdoor unit PCB for foreign matter like dust fouling etc Is F2 fuse 250V 20A blown Remove foreign matter ...

Page 119: ...r temperature sensor Replace Charge refrigerant Defective indoor unit control PCB Replace Defective indoor heat exchanger return air temperature sensor input circuits 2 Error detection method Judge insufficient refrigerant amount by detecting the temperature differnce between indoor heat exchanger Thi R and indoor return air Thi A 3 Condition of error displayed When the insufficient refrigerant am...

Page 120: ... installation spaces Faulty compressor Defective outdoor air temperature sensor Defective outdoor unit PCB Diagnosis Countermeasure 2 Error detection method 3 Condition of error displayed 4 Presumable cause Note Is outdoor ventilation condition good Inspect outdoor air temperature sensor Is it normal Is the refrigerant amount nomal Adjust the refrigerant amount properly Secure space for inlet and ...

Page 121: ...lace Defective outdoor unit PCB Replace Repalce compressor 2 Error detection method If it fails to change over to the rotor detection operation of compressor motor 3 Condition of error displayed If compressor fails to startup for 42 times 4 Presumable cause Outdoor fan motor anomaly Outdoor unit PCB anomaly Anomalous power source voltage Improper refrigerant amount and refrigerant circuit Faulty c...

Page 122: ...ondition of error displayed If it fails again to detect the rotor position after shifting to the compressor rotor position detection operation the compressor stops 4 Presumable cause Defective outdoor fan motor Defective outdoor unit PCB Anomalous power source voltage Improper refrigerant amount and refrigerant circuit Defective compressor motor bearing Note Insulation resistance The unit is left ...

Page 123: ...rk Heat exchanger temperature sensor Fan motor Room temperature sensor Th1 Th2 Diode stack DS Fuse F Connector CNE FM i Terminal block TB 1 2 Description Item Drain motor DM CNG CNS CNU CNW CNY DS Va Th1 Th2 1 Th2 2 FM i 250V Yellow Green Y G Float switch FS Varistor Va 1 2 2 1 F L F L INTERFACE KIT TO OUTDOOR UNIT POWER CABLE SIGNAL WIRE 1 2 N 3 EARTH WIRE POWER SOURCE 1 PHASE 220 240V 50Hz Meani...

Page 124: ...H 12 12 2 0A YE GN １ BK BK RD WH LM4 LM1 LM2 LM3 M M 1 M M 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 M M 1 M M BK 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 BK BK BK BK BK BK BK BK BK WH WH WH WH WH WH WH WH WH WH BL BL BL BL BL BL BL BL BL BL RD RD RD RD RD RD RD RD RD RD E1 F1 CNWO WH 1 3 5 YE GN RD 3 15A WH Power circuit Indoor unit PCB CNL BK 3 1 2 BK BK BK Option 1 2 volt free contact HS BK BK Remote ...

Page 125: ... Discharge pipe temperature sensor TH3 Outdoor air temperature sensor TH2 Heat exchanger temperature sensor L Reactor FMo Fan motor EEV Electric expansion valve coil CM Compressor motor CNTH CNFAN CNEEV CN20S Connector 20S 4 way valve coil Item Description BK Black Mark Color RD Red WH White OR Orange YE Yellow YG Yellow Green BK WH RD V W U PCB ASSY PCB1 M MS TRANSISTOR POWER POWER T 1A L 250V W ...

Page 126: ...25ZS S temperature Model SRK35ZS S Humidity sensor HD Humidity sensor HS pipe pipe 4 way valve 4 way valve Thi R2 temperature Th21 Thi R1 temperature Th1 Thi A Heat exchanger temperature sensor Th22 Thi R3 4 3 2 4 PIPING SYSTEM Models SRR25ZS W 35ZS W FDTC25VH1 35VH1 ...

Page 127: ...policy of continuous improvement we reserve the right to make changes in all specifications without notice C MITSUBISHI HEAVY INDUSTRIES THERMAL SYSTEMS LTD 2 3 Marunouchi 3 chome Chiyoda ku Tokyo 100 8332 Japan http www mhi mth co jp en INVERTER RESIDENTIAL AIR CONDITIONERS ...