Hitachi RAK-18QXB Service Manual Download Page 59

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[Connector circuit waveform while the motor runs]

Voltage waveforms of different phases as viewed from

the OV line while the motor rotor is turning counterclockwise

as viewed from the shaft side

4 terminal

3 terminal

2 terminal

1 terminal

5 ms. or 10 ms.

Fig. 12-2

Each stepping motor runs as excited in 1 or 2 phases at 100 PPS or 200 PPS.

The excitation pattern passes the microcomputer (IC601) and then the driver IC and excites the coil of each stepping motor.

Fig. 12-1

12. Stepping motor drive circuit

Some models not need to install the horizontal sweep motor.

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Summary of Contents for RAK-18QXB

Page 1: ...20 0 90 4 20 10 920 3 070 14 330 4 81 4 60 95 250 1 600 4 93 4 72 14 330 3 070 16 380 3 19 3 05 2 50 0 90 3 10 8 530 3 070 10 580 7 30 6 98 3 50 0 90 4 00 5 00 1 90 5 20 11 940 3 070 13 650 17 060 6 480 17 740 20 470 7 510 24 910 7 45 7 12 1 560 500 2 700 4 00 0 90 4 80 5 80 2 20 7 00 Hitachi Household Appliances Wuhu Co Ltd XB XB XB XB XB XB RAK 35RXB RAK 25RXB RAK 18QXB RAK 50RXB 295 210 11 750 ...

Page 2: ... DANGER 2 ...

Page 3: ... rejected goods should be handled in the same way 2 When any part is handled uncovered in counting packing and the like the handling person must always use himself as a body earth Make yourself a body earth by passing one M ohm earth resistance through a ring or bracelet 3 Be careful not to touch the parts with your clothing when you hold a part even if a body earth is being taken 4 Be sure to pla...

Page 4: ...rcuits for maintenance inspection or some others be careful not to have the test probes of the measuring instrument short circuit a load circuit or the like Bare copper wire for body earth Metal plate of Al stainless steel etc Working table Resistor 1MΩ 1 2W Earth wire Staple Fig 3 Grounding of the working table soldering iron Grounding wire Screw stop at the screwed part using a rag plate 4 ...

Page 5: ...d re start in a moment there is occasion that the cooling and heating operation does not start for 3 minutes it is not abnormal and this is the result of the operation of IC delay circuit This IC delay circuit ensures that there is no danger of blowing fuse or damaging parts even if operation is restarted accidentally 5 This room air conditioner should not be used at the cooling operation when the...

Page 6: ...CESSOR POWER RELAY POWER SWITCH TEMPORARY SWITCH SERVICE SWITCH TRANSFORMER VARISTOR NOISE SUPPRESSOR THERMOSTAT REMOTE CONTROL SWITCH LIQUID CRYSTAL WITHOUT REFRIGERANT BECAUSE COUPLING IS FLARE TYPE PIPES REFRIGERANT CHARGING VOLUME Refrigerant 410A NO NO NO NO NO NO YES NO NO YES IC YES YES RAK 18QXB RAK 25RXB RAK 35RXB RAK 50RXB 30W DC325V 3 15A 450NR R YES 6 ...

Page 7: ...The indoor piping should be insulated with the enclosed insulation pipe If the insulator is insufficient please use commercial products Be sure to completely seal any gap with putty 2300 mm or more Plug MODEL 45 RAK 35RXB RAK 25RXB RAK 18QXB RAK 50RXB Maximum pipe length 20m Maximum pipe length 30m Minimum pipe length 3m 50WXB 25 35WXB 7 ...

Page 8: ...ake sure to turn OFF power supply and then set the position of the switch otherwise will cause damage to the Main PCB 1 2kW 1 2kW 1 2kW 1 8kW 1 8kW 1 8kW SWITCH POSITION CAPACITY SELECTION NOTE FACTORY default setting is at 1 8kW capacity This setting is applicable for RAK 18QXB only 8 ...

Page 9: ...r a long time take the batteries out The batteries will last for approximately 1 year However if the remote controller display begins to fade and degradation of reception performance occurs within a year replace both batteries with new size AAA LR03 alkaline The attached batteries are provided for the initial use of the system The usable period of the batteries may be short depending on the manufa...

Page 10: ...may be shorter This unit can be fi xed on a wall using the fi xture provided Before fi xing it make sure the indoor unit can be controlled from the remote controller Handle the remote controller with care Dropping it or getting it wet may compromise its signal transmission capability After new batteries are inserted into the remote controller the unit will initially require approximately 10 second...

Page 11: ...ation will change when the room temperature varies However the mode of operation will not change when indoor unit is connected to multi type outdoor unit VARIOUS FUNCTIONS Auto Restart Control If there is a power failure operation will be automatically restarted when the power is resumed with previous operation mode and airfl ow direction As the operation is not stopped by remote controller If you...

Page 12: ...peration the operation lamp blinks in a cycle of 3 seconds on and 0 5 second off The maximum time for defrosting is 20 minutes However if the indoor unit is connected to multi type outdoor unit the maximum time for defrosting is 15 minutes If the piping length used is longer than usual frost is likely to form 1 2 3 Defrosting 8 DEHUMIDIFYING OPERATION Dehumidifying Function When the room temperatu...

Page 13: ...does not start if the temperature setting is higher than the current room temperature even though the OPERATION lamp lights The cooling function will start as soon as user set the temperature below the current room temperature 10 FAN OPERATION AUTO SWING OPERATION User can use the device simply as an air circulator VERTICAL SWING HORIZONTAL SWING START STOP 1 2 Press the MODE selector so that the ...

Page 14: ...just before defrost operation when the air conditioner is running in HEATING operation After auto restart POWERFUL operation is cancelled and previous operation shall start For multi model connections POWERFUL operation may not function depending on operation conditions 12 SILENT OPERATION By pressing SILENT button during AUTO HEATING DEHUMIDIFYING COOLING or FAN operation the fan speed will chang...

Page 15: ...temperature automatically and by limiting the maximum power consumption value 14 ECO OPERATION By pressing the ECO button during AUTO HEATING DEHUMIDIFYING or COOLING operation the air conditioner performs the ECO operation 1 To start ECO operation To cancel ECO operation Press ECO button during operation is displayed on the LCD A beep sound is emitted from indoor unit and the ECO lamp on the indo...

Page 16: ...n the unit will operate in previous mode During Leave Home operation fan speed and horizontal air defl ector position cannot be changed By pressing Leave Home button implementation of Weekly Timer or Once Timer is cancelled In case of power supply shut down after autorestart all setting for number of days operation will be reset and unit shall be in continuous operation POWERFUL SILENT and ECO ope...

Page 17: ...ancel Reservation Point the signal window of the remote controller towards the indoor unit and press CANCEL button and ON or OFF set time goes out with a beep and the TIMER lamp on the indoor unit turns off NOTE User can set only one of the OFF timer ON timer or ON OFF timer If WEEKLY TIMER already set by setting the ONCE TIMER ONCE TIMER operation is prioritized When ONCE TIMER operation is compl...

Page 18: ...is possible to select Mode A or Mode B For each mode up to 6 programs can be set per day In total a maximum of 42 programs can be set for a week for each mode If calendar and clock are not set the reservation setting for WEEKLY TIMER cannot be set If calendar and clock are not set correctly WEEKLY TIMER will not operate correctly Reservation for calendar and clock shall be set fi rst before operat...

Page 19: ...e and program number 6 shall have the latest time If the setting time is the same Priority will be given to the latest reservation contents CAUTION If the remote controller is left idle and SEND button is not pressed within 3 minutes after reservations have been made all current reservations will be lost WEEKLY TIMER OPERATION 22 How to select Mode A or Mode B of WEEKLY TIMER setting 1 Press WEEKL...

Page 20: ...lamp lights up If TIMER lamp does not light up Press SEND button again Reservation data will not change if SEND button is not pressed Step 3 Copy and cancel the reservation schedule NOTE If there is no reservation data copying data from one day to another day cannot be done 1 2 3 4 5 6 8 WEEKLY TIMER OPERATION 24 Step 3 Copy and cancel the reservation schedule How to delete WEEKLY TIMER data Delet...

Page 21: ... retrieved from indoor unit To check monthly power consumption Press INFO button Temperature will be displayed for 10 seconds Direct the remote controller towards the receiver of indoor unit within 2 meters in front of indoor unit and press INFO button Wait for 2 seconds for signal transmission Once received the current calendar and clock check whether they are correct or not by pressing CLOCK but...

Page 22: ...will remain This indicates that COOLING and DEHUMIDIFYING mode operation is locked When pressing MODE button or will be displayed Method to unlock COOLING and DEHUMIDIFYING modes including FAN operations Press ECO and SILENT buttons simultaneously for about 5 seconds when the remote controller is OFF All operation mode symbols will appear on the display for about 10 seconds After that operation mo...

Page 23: ...n The deflector s will start to swing up and down is displayed on the LCD Press AUTO SWING VERTICAL button again The deflector s will stop in the current position disappeared from the LCD CAUTION When operating the unit in cooling operation with the air deflector facing down and moving automatically for a long period of time water will be condensed on the air deflector and drips down occasionally ...

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Page 29: ...10 RAK 18 Q XB RAK 25 35RXB RAK 50RXB 12 7 MODEL More than 50mm More than 2300mm Service space More than 50mm More than 50mm 265 265 369 5 231 5 231 5 550 668 42 5 193 39 37 100 100 115 180 160 8 3 4 55 19 3 60 220 4 RAK 18QXB RAK 25RXB RAK 35RXB RAK 50RXB 29 ...

Page 30: ... R E W O P T U P T U O DC 325V W 0 3 Control circuit built in M WHT RED YEL 0 6 5V 0V V 15V BLU BLK 325 L E D O M THERMOSTAT MODEL IC OPERATION MODE T A E H L O O C ON 15 3 59 54 16 7 62 06 OFF 15 0 59 00 16 7 62 06 ON 23 3 73 94 24 7 76 46 OFF 23 0 73 40 24 7 76 46 ON 31 3 88 34 32 7 90 86 OFF 31 0 87 80 32 7 90 86 TEMPERATURE C F INDICATION 16 INDICATION 24 INDICATION 32 RAK 18QXB RAK 25RXB RAK ...

Page 31: ...WIRING DIAGRAM RAK 18QXB RAK 25RXB RAK 35RXB RAK 50RXB 31 ...

Page 32: ...WIRING DIAGRAM OF THE PRINTED WIRING BOARD Remote controller RAR 6N1 SWB SW10 Carbon SW Reset carbon SW 32 ...

Page 33: ...CIRCUIT DIAGRAM MODEL RAK 18QXB POWER FOR CLEANNESS 33 ...

Page 34: ...CIRCUIT DIAGRAM MODEL RAK 25RXB RAK 35RXB RAK 50RXB POWER FOR CLEANNESS 34 ...

Page 35: ...mputer Stepping motor drive circuit Wireless remote controller Wireless receive Reset circuit Control Power circuit Room temperature thermistor Heat exchanger thermistor Oscillator clock circuit Indoor Outdoor interface circuit Indoor DC fan motor send circuit MODEL Infrared sensor Vertical sweep motor 2 ECO Sensor RAK 18QXB RAK 25RXB RAK 35RXB RAK 50RXB Outdoor unit 1 2 3 35 ...

Page 36: ...ent regardless of the room temperature Runs at ultra Lo when thermo is off Operates at Med regardless of the room temperature Runs at ultra Lo when thermo is off 1 Runs at Hi until room temperature reaches to setting temperature SFTDSC after operation is started 2 Runs at ultra Lo when thermo is off button button button button button button button PDCIN2 PDCOF2 Med Lo Silent 108 Med Lo Silent Sett...

Page 37: ...N_M 900min 1 900min 1 900min 1 900min 1 900min 1 463 PKOU_M 400min 1 400min 1 400min 1 400min 1 400min 1 465 FZZY_GN_M 1 1 1 1 1 467 FZZYTM_M 2min 2min 2min 2min 2min 468 DWNRATEW_M 80 80 80 80 80 469 DWNRATEC_M 60 60 60 60 70 480 SHIFTW_M 0 0 0 0 0 481 SFTSZW_M 0 0 0 0 0 488 SHIFTC_M 0 0 0 0 0 48C SHIFTD_M 0 0 0 0 0 44A CLMXTP_M 33 33 33 33 33 4B4 YNEOF_M 24 24 24 25 25 4DF SFTDSW_M 0 66 0 66 0 6...

Page 38: ...DASUPHH 45 00 45 00 DASDNHH 41 00 41 00 DASUPH 40 00 40 00 DASDNH 35 33 35 33 DASUPL 35 00 35 00 DASDNL 28 00 28 00 DASUPS 28 00 28 00 DASDNS 27 00 27 00 NORUPH 44 00 44 00 NORDNH 40 00 40 00 NORUPL 39 00 39 00 NORDNL 35 00 35 00 NORUPS 35 00 35 00 NORDNS 34 00 34 00 PDCIN2 50 00 54 00 PDCOF2 45 00 48 00 DNZKON 15 00 15 00 DNZKOF 13 00 13 00 FNUPPW C 5500 min 1 5500 min 1 5500 min 1 5500 min 1 30 ...

Page 39: ...ode and v change operation mode 3 During Cool Dashed operation thermo off temperature is set temperature with shift value 3 C After thermo off operation continue in Fuzzy control mode 4 Compressor minimum ON time and OFF time is 3 minutes 5 During normal cooling mode compressor maximum rpm CMAX will maintain for 60 minutes if indoor temperature is lower than CLMXTP No time constrain if indoor tem ...

Page 40: ...cancel the powerful operation 5 If the sleep timer is set during powerful operation the powerful operation will be canceled 6 When the powerful operation is set the fan speed will be set to HIGH and the compressor s maximum speed will be set to CMAX2 during powerful operation The compressor s lower limit speed is CKYMIN_PW 7 The fan speed increases by FNUPPW_C 8 After the powerful operation is end...

Page 41: ...r fan is operated in the Lo mode During thermo OFF indoor fan will be OFF for 5 minutes and ON for 1 minute 3 When the operation is started by the themostat turning ON the start of the indoor fan is delayed 32 seconds after the start of compressor operation 4 The compressor is operated forcedly for 3 minutes after operation is started 5 The minimum ON time and OFF time of the compressor are 3 minu...

Page 42: ...led 6 If the differential the room temperature the temperature setting is the differential 3 after powerful setting the compressor s maximum speed during powerful operation will be set to SDMAX Then the differential reduce the differential 2 33 during powerful operation the compressor s speed will be set to SDRPM If the differential the room temperature the temperature setting is the differential ...

Page 43: ...in for 120 minutes No time limit constrain if room temperature is 18 or less and outdoor temperature is 2 or less 6 During preheating or defrosting or auto fresh defrosting mode indoor unit operation lamp will blink at interval of 2 seconds ON and 1 second OFF 7 When heating mode starts it will enter into preheating mode if indoor heat exchanger temperature is less than YNEOF 0 33 8 When fan is se...

Page 44: ...FCLN_WAM_P FCLN_SDF_P CLNCMP Silent button WSZMAX CSZMAX Compresson speed Indoor fan Outdoor fan 8 WUD L L 0HG RZ RZ 6LOHQW 6 8OWUD R SILENT Notes Can t set POWERFUL and SILENT at the same time 44 ...

Page 45: ...AX2 during powerful operation The compressor s lower limit 8 After the powerful operation is ended the system automatically operates with the previous settings speed is WKYMIN_PW used before the powerful operation the powerful operation Setting Defrosting Inhibit Period DFTIM_OT P5 DFTIM_OT P0 DFTIM_OTP 10 Time Outdoor temperature 1 0 5 C 0 C Notes 1 The first inhibit time after operation start is...

Page 46: ...Reverse cycle period 3 MAX Preheating Preheating released Stop 15 or more Auto fresh defrosting Hi or Lo Reversing valve defrosting 暖房通電 Over defrosting inhibit period Start Stop button Fan speed set to Hi Defrost signal Preheating judgment Preheating released Indoor fan Hi Med Lo Ultra Lo Outdoor fan Operation lamp Reversing valve heating on mode Hi or Lo Deceleration period Reverse cycle period ...

Page 47: ...MODEL COOLING CYCLE HEATING CYCLE RAK 18QXB RAK 25RXB RAK 35RXB Outdoor unit Outdoor unit 47 OUTDOOR UNIT INDOOR UNIT OUTDOOR UNIT INDOOR UNIT ...

Page 48: ...COOLING CYCLE HEATING CYCLE RAK 50RXB MODEL Outdoor unit Outdoor unit 48 OUTDOOR UNIT INDOOR UNIT OUTDOOR UNIT INDOOR UNIT ...

Page 49: ...n the front panel is fully opened with both hands push the right arm to the inside to release it and while closing the front panel Shaft Hole 2 1 slightly put it out forward After removing two screws pull the center of the front cover and release the claws Pull the side faces lower sections of the front cover as shown in the figure and remove the CAUTION Remove and attach the front cover to the di...

Page 50: ...removethe drain pan 2 Remove the screws from the upper and lower bearing covers 3 Remove the locking hook of the lower bearing cover from the Cabinet Remove two lock screws from the fan motorholder 5 Pull up the evaporator by holding it at the lowerside Insert a screwdriver through the spacebetween the evaporator and drain chute and loosen the fan lock screw to remove the fanand fan motor 1 4 50 ...

Page 51: ...ectively The primary 18 5 V is supplied to the drive circuit of the indoor fan motor the 12 V is supplied to each vane motor and to the drive circuits of the cleaning unit driving motor and other equipment and the 8 5 V is adjusted to a stable 5 V by the 3 terminal regulator IC IC101 IC103 and supplied to the microcomputer peripheral circuit If a failure in a part or circuit has produced an abnorm...

Page 52: ...t is Lo for resetting and Hi for heating Waveform of each part when switching ON the power and when shutting down is shown in the Fig 2 2 After switching ON the power 㽲 pin of IC501 supply voltage and 㽼 pin of microcomputer becomes Hi when DC5V line rises and reaches approximately 4 4V or higher Then resetting will be cancelled and microcomputer starts operating After shutting down the power 㽲 pin...

Page 53: ...eform Voltage at pin 5 of microcomputer between 0 V and pin 5 FG voltage of fan motor between pins 㽵 and 㽸 of CN2 When slow 700min 1 1 7ms When fast 1200min 1 1 7ms 5V 5V When slow 700min 1 7 1ms When fast 1200min 1 15V 15V 4 2ms 1300min 1 2 1V 5 4V Fig 3 1 Fig 3 2 0 9 1 Indoor fan motor 9 96 9 9 5 5 5 5 5 5 4 3 5 9 9 5 5 5 5 5 4 4 3 3 1 9 Primary 325V Primary 18 5V Power siganl of indoor fan from...

Page 54: ...R OUTPUT PIN OF THE MICRO computer After the amplitude of this signal has been set to 12Vp p by a transistor IT IS APPLIED TO THE BUZZEr 4HE PIEZOELECTRIC ELEMENT IN THE BUZZER OSCILLATES TO GENERATE THE BUZZERgS SOUND R640 C632 The indoor fan motor and drive circuit are connected to the primary power supply They therefore have voltage to ground Guard against electric shocks 7HILE THE PRODUCT IS E...

Page 55: ... stored in IC531 data will not be erased even when power is turned off Fig 6 1 6 Initial Setting Circuit IC531 1 2 1 8 1 8 1 2 531 Fig 6 2 Initial Setting Circuit IC531 and IC532 For RAK 18Q X B only When power is supplied the microcomputer reads the data in IC531 and IC532 E PROM and sets the 2 preheating activation value and the rating and maximum speed of the compressor etc to their initial val...

Page 56: ...r Voltage of point V 㷄 Room temperature Room temperature input Fig 8 1 Fig 8 2 䃢 A 0V 0V 5V 2 0 1 0 10 20 30 40 3 4 5 10 R402 C403 R407 91 9 Heat Exchanger Thermistor Circuit Heat exchanger temperature is noticed inside the room 1 Preheating 2 Low temperature defrosts at cooling and dehumidification operation time 3 Not working of reversing valve or detection of opening of heat exchanger thermisto...

Page 57: ...10 10 10 10 10 R901 R904 R641 R907 R908 R694 R902 R695 R741 R740 R642 DSW1 DSW1 R903 R905 R906 57 ...

Page 58: ...l demodulated at 30 kHz Typical communication waveform Signal between F cables 1 and 2 Enlarged waveform Fig 11 2 Fig 11 1 F E D G H D Signal sent by indoor microcomputer １Ｖ DIV 9 G Signal sent by outdoor microcomputer ˍ ˋ 9 9 H E Signals sent by indoor and outdoor microcomputers ˍ ˋ 9 9 F Signal between F cables and 5ms DIV 5ms DIV ˍ ˋ 9 9 The unit is receiving a signal that it sent it is not use...

Page 59: ...the shaft side 4 terminal 3 terminal 2 terminal 1 terminal 5 ms or 10 ms Fig 12 2 Each stepping motor runs as excited in 1 or 2 phases at 100 PPS or 200 PPS The excitation pattern passes the microcomputer IC601 and then the driver IC and excites the coil of each stepping motor Fig 12 1 12 Stepping motor drive circuit Some models not need to install the horizontal sweep motor 59 ...

Page 60: ...nal to microcomputer IC601 The infrared sensor output is Hi when the activity level is not detected On the contrary output is Lo 13 Infrared human presence sensor circuit With the infrared sensor the air conditioner can detect the activity level in a room and adjust the temperature and humidity automatically thus achieving the purpose of energy saving Fig 13 1 Sensor P W B Indoor main P W B Microc...

Page 61: ...ture higher than room temperature on the remote controller To improve the dehumidification efficiency performs quiet fan operation Therefore the air is cold and it is not a malfunction It sets to perform dehumidifying operation by setting the temperature slightly lower than remote controller setting 3 3 MODEL RAK 18QXB RAK 25RXB RAK 35RXB RAK 50RXB frost During an automatic run switching the fan s...

Page 62: ...r may cause a gap between the room temperature setting and actual room temperature If there is any difference between the setting and the room temperature adjust the temperature setting to match the living space to a comfortable temperature A4 The difference between the thermometer temperature setting and room temperature will change the rotation speed of the compressor This is not a sign of a bre...

Page 63: ... time The timer cannot be set unless it is set to the current time A1 When set to the current time setting the reading blinks for about 3 minutes Wireless remote control I set the sleep timer during operation But the indoor fan will not run it will not produce wind wind intensity will not change Q5 I tried to change the setting with the room temperature button of the remote control unit in vain Q6...

Page 64: ...move the electrical parts cover 2 Remove the connectors from the CN4 heat exchange 3 Remove t lock screws Removing control P W B 1 Remove the connectors from the CN3 2 Remove the P W B from the P W B support STRUCTURE OF AN INDOOR UNIT ELECTRIC PARTS CN16 FIXTURE SCREW hree ELECTRICA L COVER RAK 18QXB RAK 25RXB RAK 35RXB RAK 50RXB 64 thermistor CN9 stepping motor CN2 fan motor and CN16 CN15 CN19 P...

Page 65: ...ll destroy it Be on guard When reconnecting it insert it securely all the way home All the receptacles for connecting tab terminals are with a locking mechanism Forcibly pulling any such receptacle without unlocking it will destroy it Be on guard When reconnecting it insert it securely all the way home Pinch the locking mechanism with your fingers and pull it out unlocked Other instructions 1 Deta...

Page 66: ...oor or outdoor communications is in a failure The product stores 5 last stored failure modes There is a function for deleting memory Once you clear the memory and run the product for several days you can read the failure modes and check them thereby detecting the less frequent failure phenomena Failure modes can be checked by both the blinking of the lamp of the indoor unit and the display of the ...

Page 67: ...nit is blinking troubleshoot the product while referring to the table below 2 If you wish to try another operation while the lamp is blinking operate the START STOP button on the remote control unit twice The first push will reset the indoor microcomputer while the second will activate the product Self diagnosis display function indoor side display An example of 5 time blinking 2 second intermissi...

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Page 69: ...gle only 9 times sigle only 012 00 12 times Indoor interface circuit broken communication error between indoor and outdoor units 1 Indoor interface circuit Outdoor interface circuit broken 1 Outdoor interface circuit ...

Page 70: ... stopped Temporary operation SW How to stop the operation Press and hold the Temporary operation SW again Or stop the operation using the remote controller During the forced cooling operation the Timer indicator blinks twice When performing the forced cooling operation turn the power off once If you press and hold the switch for 5 sec or longer the forced cooling operation starts To stop the force...

Page 71: ...3 and page 38 7 71 ...

Page 72: ...Please set the DIP switch No 6 to ON accordingly Refe to page r 57 RAR 6N1 RAR 6N2 RAR 6N3 RAR 6N4 RAR 6N5 72 ...

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Page 75: ...dicated then release START STOP button and Mon Sun button Remote controller now enters Intermittent Fan Control Change Mode Default Pattern 1 HOW TO CHANGE THE INTERMITTENT FAN CONTROL SETTING 2 Press ROOM TEMPERATURE setting UP Ｖ DOWN buttons The intermittent pattern changed with indoor unit beep sound Transmission sign lights up with beep from indoor unit simultaneously Pattern 1 Pattern 2 Patte...

Page 76: ...p with beep from indoor unit simultaneously Beep sound pattern 1 Default setting Short beep Beep sound pattern 2 Changed setting Double beep HOW TO CHANGE THE FAN SPEED IN COOLING MODE DURING THERMO OFF Beep sound pattern 2 Changed setting Double beep NOTE 1 The selected fan speed will remain unchanged after the unit is turned off 2 If Timer reservation has been set it will be canceled 3 During ti...

Page 77: ...e sunshine operating hours and other factors of the day so that the phenomenon may not be able to be identified at the time of a repair service visit In that case too use the self diagnosis memory function Ć2 The outdoor self diagnosis display overload lower limit cut and OH thermistor heat up can be identified only when you are using the self diagnosis lamp of the outdoor unit and the self diagno...

Page 78: ...Check 3 Is the compressor of the outdoor unit running Yes No If you responded No to Check 2 ǂǂǂCheck 4 Does the emergency operation switch work Yes No First check the failure phenomenon and status and then move on to elaborate diagnosis Initiating troubleshooting No Yes Turn off the power wait at least 5 seconds turn it back on and observe the way the horizontal vanes move for about 30 seconds ǂǂǂ...

Page 79: ...le phase 3 wire power supply If the 3 15 A fuse has blown out eliminate the cause of the fuse blowout Otherwise there will occur another fuse blowout If the 3 15 A fuse has blown out due to an abnormally high voltage to the power supply the varistor VA001 will deteriorate and become destroyed as well On a repair service visit due to the failure phenomenon of The power will not become turned on tak...

Page 80: ...ls Instruct your users to use new alkaline batteries Does the remote control unit have a sufficient battery capacity If the liquid crystal display becomes extremely faded when a remote control signal is sent replace the batteries No Press the reset switch of the remote control unit then conduct another operation check Has the product worked Yes Instruct your users to be sure to press the reset swi...

Page 81: ...it output usually shows a noise waveform as shown in ǂthe right hand figure In the case of slight jamming this kind of waveform ǂwill not cause practical problems However intense degrees of jamming ǂwill disable the reception of remote control signals When the fluorescent lamp is old and is flickering it may cause disorders ǂin the reception of remote control signals Actions proposed 1 Make it har...

Page 82: ...s coming from other electrical products Turn on and off the electrical products turn off the power and turn on the power and check their effects on the reception of remote control signals For products whose operating states change check the effects of each state Actions proposed Change the location relationship between the air conditioner and the target products Use a different wall outlet for the...

Page 83: ...e of the indoor unit blinking Yes Yes Yes No No No Check for failures according to the self diagnosis display Did the self diagnosis lamp LD301 of the outdoor unit blink once or become turned off Check for failures according to the self diagnosis display Remove the connector CN4 of the room temperature thermistor and heat exchanger thermistor and measure the thermistor resistance Did the reading r...

Page 84: ...timated failure locations Indoor fan motor Fan motor drive circuit Diagnosis flow Initiating troubleshooting Yes Replace the indoor fan motor No Replace the indoor electrical parts Run the product by remote control and then stop it Reproduce the failure phenomenon Is the voltage between pins ĺ and ļ of the fan motor connector CN2 below 1 5 V Take measurements while the failure phenomenon is presen...

Page 85: ...used the self diagnosis way to check out there is no fault but low sensitivity false action is also occur please check as follows Structure confirm Is the structure and appearance of frensnel lens ok Please confirm whether there any dirt or nick on it Please confirm whether frensnel lens is loose Does the structure of the sensor P W B have any problem Note Ć The infrared sensor detects changes to ...

Page 86: ...nt before inserting it into the terminal board securely Detach the connector CN3 from the terminal board temperature fuse and check the temperature fuse for continuity Is the resistance almost 0 No Yes Initiating troubleshooting Replace the indoor electrical parts Replace the terminal board Estimated failure locations Outdoor unit error Please confirm the times of the LD301 blinking and then Situa...

Page 87: ...nks 9 times and the product will not run Estimated failure location 䊶 Loose connector wire break or short circuit in the room temperature thermistor heat exchanger thermistor Cautions 䊶 Starting the product by remote control will initiate failure detection Merely turning on the power will not activate the failure detection function Diagnosis flow Initiating troubleshooting Yes Yes No No Correct th...

Page 88: ... the indoor fan motor Indoor fan motor mechanically locked Indoor fan motor Indoor fan motor drive circuit Diagnosis flow Initiating troubleshooting No No No No No No No Yes Yes Yes Remove the cause of the mechanical lock Is the indoor fan motor connector CN2 securely inserted Is it free of wire breaks Correct the connector and wiring For 2 to 3 seconds after startup by remote control did a voltag...

Page 89: ...om errors Yes Yes Yes Yes No No No No Correct the F cable connection Is the CN securely inserted into the outdoor board Correct the connector Press the START STOP button on the remote control unit and start the product Are terminals 1 and 2of the terminal board of the electrical parts of the outdoor unit subjected to 㶎Take measurements within 3 minutes after remote control operation Check the elec...

Page 90: ...DIAGRAM INDOOR UNIT HITACHI 6 14 22 35 20 21 40 43 31 36 41 34 7 5 18 27 25 24 26 19 12 13 32 16 17 15 42 39 44 3 2 11 4 8 10 33 38 37 29 28 30 46 47 23 48 1 9 45 49 50 MODEL RAK 18QXB RAK 25RXB RAK 35RXB RAK 50RXB 90 ...

Page 91: ...2 48 1 K PANEL 49 1 CABI PLATE 50 1 SUPPORT P W B HWRAK 25PXB 922 HWRAK 25PXB 923 HWRAK 25PXB 924 HWRAK 25PXB 925 HWRAK 25PXB 926 HWRAK 35PPB 929 HWRAK 18QXB 903 HWRAK 35PPB 920 HWRAK 25PXB 916 HWRAK 25PXB 917 HWRAK 25PXB 918 HWRAK 35PPB 924 HWRAK 25PXB 920 HWRAK 25PXB 921 HWRAK 18PPB 902 HWRAK 35PPB 927 HWRAK 35PPB 928 HWRAK 25PXB 914 HWRAK 35PPB 913 HWRAK 25PXB 909 HWRAS 25YH4 A30 HWRAS 25YH4 A3...

Page 92: ...RAK 18QXB RAK 25RxXB HHAW NO 0088E 1 RAK 35RXB RAK 50RXB 92 ...

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