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Hitachi RAI-25NH5A, Service Manual

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Hitachi RAI-25NH5A Service Manual Download Page 32

Remote Control

CIRCUIT DIAGRAM

– 31 –

Key matrix table

Input

P28

P27

P26

P25

Output

Door open

Cancel

Reservation

On timer

Off timer

Door shut

–

–

–

Sleep

Door open

Hour down

Hour up

Time setting

Start/Stop

Door shut

Temperature down

Temperature up

Fan speed selection

Start/Stop

Door open

–

Auto swing

Fan speed selection

Operation mode select

Door shut

–

–

–

Auto swing

P21

P22

P23

Summary of Contents for RAI-25NH5A

Page 1: ...85 580 20 RAI ECPM RAI 25NH5A RAI 35NH5A RAI 50NH5A CONTENTS SPECIFICATIONS 4 HOW TO USE 6 CONSTRUCTION AND DIMENSIONAL DIAGRAM 27 MAIN PARTS COMPONENT 28 WIRING DIAGRAM 29 CIRCUIT DIAGRAM 31 BLOCK DIAGRAM 35 BASIC MODE 37 REFRIGERATING CYCLE DIAGRAM 51 AUTO SWING FUNCTION 53 DESCRIPTION OF MAIN CIRCUIT OPERATION 54 SERVICE CALL Q A 58 TROUBLE SHOOTING 62 PARTS LIST AND DIAGRAM 66 RAI 25NH5A RAI 3...

Page 2: ...e accurately calibrated in advance 7 In installing the unit having been repaired be careful to prevent the occurence of any accident such as electrical shock leak of current or bodily injury due to the drop of any part 8 To check the insulation of the unit measure the insulation resistance between the power cord plug and grounding terminal of the unit The insulation resistance should be 1M or more...

Page 3: ... parts Even rejected goods should be handled in the same way Fig 1 Conductive Container 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...

Page 4: ...e screwed part using a rag plate Soldering iron Grounding wire Fig 4 Grounding a soldering iron Use a high insulation mode 100V 10M or higher when ordinary iron is to be used 7 In checking circuits for maintenance inspection or some others be careful not to have the test probes of the measuring instrument shortcircuit a load circuit or the like Metal plate of aluminium stainless steel etc Staple 2...

Page 5: ...ion 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 outside temperature is below 10 C 50...

Page 6: ...r MICROPROCESSOR POWER RELAY POWER SWITCH TEMPORARY SWITCH SERVICE SWITCH TRANSFORMER VARISTOR NOISE SUPPRESSOR THERMOSTAT REMOTE CONTROL SWITCH LIQUID CRYSTAL RAI 25NH5A RAI 35NH5A RAI 50NH5A WITHOUT REFRIGERANT BECAUSE COUPLING IS FLARE TYPE UNIT PIPES REFRIGERANT CHARGING VOLUME Refrigerant 410A 4 25W NO NO NO NO NO NO NO NO YES NO NO NO NO YES IC YES ...

Page 7: ...D LEVEL INDOOR AIR FLOW VOLUME Hi SOUND LEVEL INDOOR AIR FLOW VOLUME Hi W H D INSTALLED W H D cu ft COOLING HEATING CEILING CASSETTE RAI 25NH5A RAI 35NH5A RAI 50NH5A 1ø 220 240V 50Hz 35 39 42 8 5 m3 min 10 8 m3 min 11 6 m3 min 36 40 44 8 5 m3 min 10 8 m3 min 11 9 m3 min YES YES YES 4 4 4 NOT PROVIDED POWER CORD SHOULD BE PREPARED AND CONNECTED TO OUTDOOR UNIT WHEN INSTALLED YES WIRELESS YES WIRELE...

Page 8: ...r of electric shock exists Do not install near location where there is flammable gas The outdoor unit may catch fire if flammable gas leaks around it Please ensure smooth flow of water when installing the drain hose CAUTION PRECAUTIONS DURING OPERATION Avoid an extended period of direct air flow for your health W A R N I N G Do not insert a finger a rod or other objects into the air outlet or inle...

Page 9: ...te under such condition for a long time If the amount of heat in the room is above the cooling or heating capability of the unit for example more people entering the room using heating equipments and etc the preset room temperature cannot be achieved This appliance is not intended for use by young children or infirm persons unless they have been adequately supervised by a responsible person to ens...

Page 10: ...te while the lamp lights To re start an indoor unit which was operated later stop the indoor unit which was operated first or later and reset the type of operation then perform operation again One unit Heating Other unit Cooling Dehumidifying Circulating fan Adjusting the Number of Indoor Units Decrease the number of indoor units to be operated especially when it is very hot or cold or when you wa...

Page 11: ...during operation The OPERATION LAMP flashes in the following cases during heating 1 During preheating For about 2 3 minutes after starting up 2 During defrosting Defrosting will be performed about once an hour when frost forms on the heat exchanger of the outdoor unit for 5 10 minutes each time TIMER LAMP This lamp lights when the timer is working FILTER LAMP When the device is operated for a tota...

Page 12: ... Controls the angle of the horizontal air deflector TIMER control Use this button to set the timer OFF TIMER button Select the turn OFF time ON TIMER button Select the turn ON time RESERVE button Time setting reservation CANCEL button Cancel time reservation Precautions for Use Do not put the remote controller in the following places Under direct sunlight In the vicinity of a heater Handle the rem...

Page 13: ...Timer mode is set As the settings are stored in memory in the remote controller you only have to press the START STOP button next time Press the FUNCTION selector so that the display indicates the AUTO mode of operation When AUTO has been selected the device will automatically determine the mode of operation HEAT COOL or DEHUMIDIFY depending on the current room temperature However the mode of oper...

Page 14: ...wer Set the desired room temperature with the TEMPERATURE buttons the display indicates the setting The temperature setting and the actual room temperature may vary somewhat depending on conditions Press the START STOP button Heating operation starts with a beep Press the button again to stop operation As the settings are stored in memory in the remote controller you only have to press the START S...

Page 15: ...top the indoor unit will stop emitting air as soon as the room temperature becomes lower than the setting temperature The preset room temperature may not be reached depending on the number of people present in the room or other room conditions Set the desired room temperature with the TEMPERATURE button the display indicates the setting The range of 20 26 C is recommended as the room temperature f...

Page 16: ...an speed slower SILENT Fan speed ultra slower Set the desired room temperature with the TEMPERATURE button the display indicates the setting The temperature setting and the actual room temperature may vary some how depending on conditions Press the START STOP button Cooling operation starts with a beep Press the button again to stop operation The cooling function does not start if the temperature ...

Page 17: ...un at HI speed After room temperature reaches the preset temperature the cooling operation which changes the fan speed and room temperature to obtain optimum conditions for natural healthful cooling will be performed For the cooling operation FAN OPERATION You can use the device simply as an air circulator Use this function to dry the interior of the indoor unit at the end of summer Press the FUNC...

Page 18: ...ler toward the indoor unit and press the CANCEL button The RESERVED sign goes out with a beep and the TIMER lamp turns off on the indoor unit 1 Set the TIME button 1 Press the OFF TIMER button The OFF mark blinks on the display 1 Press the ON TIMER button the ON mark blinks on the display 2 Set the turn off time with the TIMER control button Press the RESERVE button 3 Press the ON TIMER button so ...

Page 19: ...ntrol button The setting of turn off time is now complete Example The device will turn off at 11 00p m Example The device will turn on at 7 00 a m The setting of the turn on time is now complete 4Set the turn on time with the TIMER control button 5 Point the signal window of the remote controller toward the indoor unit and press the RESERVE button The ON mark starts lighting instead of flashing an...

Page 20: ...yed on the remote controller The TIMER lamp lights with a beep from the indoor unit When the sleep timer has been set the display indicates the turn off time Example If you set 3 hours sleep time at 11 38 p m the turn off time is 2 38 a m 2 Press the SLEEP button and set the sleep timer The device will be turned off by the sleep timer and turned on by on timer How to Cancel Reservation Point the s...

Page 21: ...ops in its current position Several seconds about 6 seconds may be required before the deflector starts to move Use the horizontal air deflector within the adjusting range shown on the right When the AUTO SWING button is pressed while the operation is stopped the horizontal air deflector moves and stops at the position where the air outlet closes When the auto swing operation is performed if the h...

Page 22: ...her 2 Take out the batteries when you do not use the remote controller for 2 or 3 months CAUTION Push and pull to the direction of arrow CIRCUIT BREAKER When you do not use the room air conditioner set the circuit breaker to OFF TEMPORARY SWITCH If the remote controller does not work due to battery failure press this switch to start and stop operation This temporary operation will be at the settin...

Page 23: ...with your wake up time in the morning This will enable you to enjoy a comfortable room temperature Please use the timer effectively Dusty air filter will reduce the air volume and the cooling efficiency To prevent from wasting electric energy please clean the filter every 2 weeks Please pay attention to the room temperature and air flow direction when operating the unit for baby children and old f...

Page 24: ...e used for a long period of time please switch off the power from the mains If the power from mains remains ON the indoor unit still consumes about 8W in the operation control circuit even if it is in OFF mode Warning To protect the whole unit during lightning please stop operating the unit and remove the plug from the socket OFF Interference From Electrical Products Caution To avoid noise interfe...

Page 25: ...er Set it with UP SIDE mark facing front Slot the filter to suction grille and close as original state Press the mark PUSH at the left and right sides of the suction grille to fix it securely CAUTION Do not wash with hot water at more than 40 C The filter may shrink When washing it shake off moisture completely and dry it in the shade do not expose it directly to the sun The filter may shrink Do n...

Page 26: ...pe it with a soft dry cloth When it is excessively dirty wipe with soft cloth soaked in lukewarm water or neutral detergent Then wipe thoroughly with a soft dry cloth CAUTION Do not splash or direct water to the body of the unit when cleaning it as this may cause short circuit Never use hot water above 40 C benzine gasoline acid thinner or a brush because they will damage the plastic surface and t...

Page 27: ... possibly be emitted from the room air conditioner because the various odor emitted by smoke foodstuffs cosmetics and so on sticks to it So the air filter and the evaporator regularly must be cleaned to reduce the odor Please contact your sales agent immediately if the air conditioner still fails to operate normally after the above inspections Inform your agent of the model of your unit production...

Page 28: ... 26 MEMO ...

Page 29: ... 10m 4 An F cable 1 6mm or 2 0mm dia X 3 control side is used for the connection cable Unit mm Wireless remote controller 147 56 18 650 Panel 600 Opening on ceiling 580 Indoor unit 400 Suspension bolt 64 42 393 Electric box 580 Indoor unit 600 Opening on ceiling 610 Suspension bolt 650 Panel 285 110 Above 300 32 Ceiling Panel Optional part RAI ECPM Narrow pipe fl6 35 97 Drain Drain outlet 42 65 Wi...

Page 30: ...5V OUTPUT 25W Control circuit built in BLU BLUE YEL YELLOW BRN BROWN WHT WHITE GRY GRAY ORN ORANGE GRN GREEN RED RED BLK BLACK PNK PINK VIO VIOLET IC COOL HEAT RAI 25NH5A RAI 35NH5A RAI 50NH5A RAI 50NH5A RAI 35NH5A RAI 25NH5A ON OFF ON OFF ON OFF 15 0 59 0 14 7 58 5 23 0 73 4 22 7 72 9 31 0 87 8 30 7 87 3 13 0 55 4 12 7 54 9 21 0 69 8 20 7 69 3 29 0 84 2 28 7 83 7 20 0 68 0 20 3 68 5 28 0 82 4 28 ...

Page 31: ... 29 Wired Remote Control Weekly Timer MODEL RAI 25NH5A RAI 35NH5A RAI 50NH5A WIRING DIAGRAM INDOOR UNIT ...

Page 32: ...oor open Cancel Reservation On timer Off timer Door shut Sleep Door open Hour down Hour up Time setting Start Stop Door shut Temperature down Temperature up Fan speed selection Start Stop Door open Auto swing Fan speed selection Operation mode select Door shut Auto swing P21 P22 P23 ...

Page 33: ...CIRCUIT DIAGRAM MODEL RAI 25NH5A RAI 35NH5A RAI 50NH5A 33 ...

Page 34: ...to sweep motor for Air deflector LCD wireless Heat exchanger thermistor Room temperature thermistor Wired remote control receive circuit Wired remote control H LINK Optional parts Weekly Timer Reset circuit Initial setting circuit Temporary switch Indoor microcomputer AX 7X20 INDOOR UNIT ...

Page 35: ... 37 47 RAI 25NH5A RAI 35NH5A RAI 50NH5A ...

Page 36: ...0 min 1 3500 min 1 CJKMAX 1800 min 1 2500 min 1 2700 min 1 CBEMAX 1600 min 1 2200 min 1 2000 min 1 WMIN 1500 min 1 1200 min 1 1800 min 1 CMIN 1500 min 1 1500 min 1 1800 min 1 STARTMC 60 Seconds 60 Seconds 60 Seconds DWNRATEW 80 80 80 DWNRATEC 80 80 80 SHIFTW 4 00 C 4 00 C 4 00 C SHIFTC 1 00 C 1 00 C 2 99 C CLMXTP 30 00 C 30 00 C 30 00 C YNEOF 21 00 C 21 00 C 21 00 C TEION 2 00 C 2 00 C 2 00 C TEIO...

Page 37: ...if indoor temperature is lower than CLMXTP No time constrain if indoor temperature is higher than CLMXTP 6 When fan is set to Hi compressor rpm will be limited to CKYMAX 7 When fan is set to Med compressor rpm will be limited to CJKMAX 8 When fan is set to Lo compressor rpm will be limited to CBEMAX 9 During Cool Dashed when room temperature reaches set temperature 1 C compressor rpm is actual rpm...

Page 38: ...hen switching is made 7 The indoor fan speed does not change even when the fan speed mode is changed 8 When operation is stopped during sleep operation the set temperature when stopped as well as the time continue to be counted 9 If the set lime is changed during sleep operation all data including set temperature time etc is cleared and restarted 10 If sleep operation is canceled by the cancel key...

Page 39: ...he time 2 C 2 The indoor 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 th...

Page 40: ... 10sec Preheat released WMIN WSTD WMAX NOTE 11 WMAX2 Notes 1 Condition for entering into Hot Dashed mode When fan set to Hi or Auto mode and i Indoor temperature is lower than 18 C and ii outdoor temperature is lower than 10 C and iii Temperature difference between indoor temperature and set temperature has a corresponding compressor rpm larger than WMAX 2 Hot Dashed will release when i Room tempe...

Page 41: ...eration defrosting is engaged and sleep operation is restored after defrosting 8 When operation is stopped during sleep operation the set temperature when stopped as well as the time continue to be counted 9 If the set time is changed during sleep operation all data including set temperature time etc is cleared and restarted 10 If sleep operation is canceled by the cancel key or sleep key all data...

Page 42: ...3 8 Single ended union 3 8 Single ended union 3 8 Single ended union 1 4 Indoor heat exchanger Air Flow Air Flow Indoor heat exchanger Single ended union 1 4 Charge port 1 2 Charge port 1 2 Service valve 1 4 Electric expansion 1 valve Electric expansion 2 valve Strainer Strainer Strainer Silencer Compressor REFRIGERATING CYCLE DIAGRAM RAI 25NH5A RAI 35NH5A RAI 50NH5A ...

Page 43: ...ce valve 1 4 Service valve 3 8 Service valve 3 8 Single ended union 3 8 Single ended union 3 8 Single ended union 1 4 Indoor heat exchanger Air Flow Air Flow Indoor heat exchanger Single ended union 1 4 Charge port 1 2 Charge port 1 2 Service valve 1 4 Electric expansion 1 valve Electric expansion 2 valve Strainer Strainer Strainer Silencer Scroll Compressor ...

Page 44: ...LOSING AIR DEFLECTOR 1 DOWNWARD 2 UPWARD INITIALIZE 1 DOWNWARD INITIALIZE 1 DOWNWARD 2 UPWARD STOP AT THE MOMENT START SWINGING 1 DOWNWARD 2 UPWARD 3 DOWNWARD STOP AT THE MOMENT START SWINGING 1 DOWNWARD 2 UPWARD 3 DOWNWARD STOP AT THE MOMENT ONE SWING CLOSING AIR DEFLECTOR 1 DOWNWARD 2 UPWARD INITIALIZE AT NEXT OPERATION INITIALIZE AT NEXT OPERATION STOP DURING ONE SWING STOP DURING SWINGING STOP...

Page 45: ...BZ 12V 0V R722 Q722 30 BZ When the buzzer sounds an approx 3 9kHz square signal is output from buzzer output pin of the microcomputer After the amplitude of this signal has been set to 12Vp p by a transistor it is applied to the buzzer The piezoelectric element in the buzzer oscillates to generate the buzzer s sound DESCRIPTION OF MAIN CIRCUIT OPERATION MODEL RAI 25NH5A RAI 35NH5A RAI 50NH5A Fig 2...

Page 46: ... 4 1 Microcomputer 22 21 20 19 18 17 16 15 R711 R712 C712 0V Q712 Q711 IC711 C711 9 7 10 11 12 13 15 16 P W B MAIN 14 6 5 4 3 2 1 8 0V CN8 M M M 12V D712 CN7 Rotor Auto sweep motor for horizontal air deflector 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 11 AUTO SWEEP MOTOR AUTO SWEEP MOTOR AUTO SWEEP MOTOR The air deflectors are driven by the stepping motors which are instructed by the microcomputer...

Page 47: ...erature input R302 A 5 4 3 2 1 0 0 10 10 Heat exchanger temperature C Fig 6 2 20 30 40 Voltage at V A 5 Heat exchanger temperature thermistor circuit The voltage at depends on the room temperature as shown in Fig 5 2 The circuit detects the indoor heat exchanger temperature and controls the following 1 Preheating 2 Low temperature defrosting during cooling and dehumidifying operation 3 Detection o...

Page 48: ...e preheating activation value and the rating and maximum speed of the compressor etc to their initial values Data of self diagnosis mode is stored in IC401 data will not be erased even when power is turned off Fig 7 1 Microcomputer External ROM SCL SDA 0V 0V 0V 5V 5V 5V C401 IC401 E2 PROM R404 R403 27 26 1 2 3 4 8 7 6 5 ...

Page 49: ...t for 3 4 minutes until it is defrosted If the air conditioner operates in cooling mode when it is cold the evaporator may get frosted Normal sound when refrigerant flows in pipe Compressor may not operate when room temperature is 10 C or less It also stops when the humidity is preset humidity or less It occurs during defrost ing Wait for 5 10 minutes until the condenser is defrosted At the beginn...

Page 50: ...y before stopping operation At this point fan speed is automatic This is because Nice temperature reservation function is operating This function starts operation earlier so the preset temperature is reached at the preset time Operation may start maximum 60 minutes before the preset time It does not work It works only during cooling and heating This is because Nice temperature reservation function...

Page 51: ...ling capability so noise becomes slightly louder This does not indicate a fault Noise from the outdoor unit occasionally changes The compressor rotation speed changes according to the difference between the thermostat set temperature and room temperature This does not indicate a fault There is a difference between the set temperature and room temperature There may be a difference between the set t...

Page 52: ...it or short circuit DC fan motor overcurrent detection Overcurrent in indoor DC fan motor has been detected IC401 data reading fault There was error in the data read from IC401 1 Four way valve faulty 2 Disconnection in heat exchange thermistor only during heating Service SW in outdoor electrical parts turned ON 1 Indoor interface circuit 2 Outdoor interface circuit Please check at the outdoor ele...

Page 53: ...ng generated between terminals C and D on the terminal board Are control voltages 12V 5V being generated normally Check according to the proper method for checking the power circuit No No No No Yes Yes Do the air deflectors perform initial operation when the power supply is turned on and off Check the indication P W B connection cord and light receiving unit No No Is the microcomputer reset input ...

Page 54: ... of CN10 Is there 1 or less between L901 and L902 Replace indoor fan motor Check disconnection etc of lead wires Replace Q901 Replace L901 Replace Q903 Replace micro computer Perform final operation check Replace micro computer Replace Q903 Replace Q901 Replace micro computer Replace micro computer Replace the air deflector motor Replace IC111 Perform final operation check Perform final operation ...

Page 55: ... 5 10 seconds Disconnect CN10 and set to the fan mode again The operation lamp lights once and goes out in 5 10 seconds Check to see if shorting etc has occurred in the P W B pattern Can the indoor fan be lightly turned by hand Set the power switch to off to check Replace the indoor fan motor Yes Yes Check to see if the indoor fan is touching the chassis etc If it does repair No Yes No ...

Page 56: ... 65 CHECKING THE REMOTE CONTROLLER ...

Page 57: ... 66 PARTS LIST AND DIAGRAM INDOOR UNIT MODEL RAI 25NH5A RAI 35NH5A RAI 50NH5A 17 18 13 2 4 8 14 3 1 5 12 6 7 15 ...

Page 58: ...04 1 TURBO FAN 6 PMRAI 32CNH2 R05 1 DRAIN PAN ASSEMBLY 7 PMRAK 18NH6A R02 1 REMOTE CONTROL ASSEMBLY 8 PMRAS 10C3M 003 1 REMOTE CONTROL SUPPORT 12 PMRAI 32CNH2 010 1 DRAIN CAP 13 PMRAI 25NH4 R04 1 DRAIN PUMP ASSEMBLY 14 PMRAI 25NH4 R03 1 CYCLE ASSEMBLY 15 PMRAI 25NH4 007 4 SUSP CLAMP 17 PMRAC 07CV1 R06 1 TERMINAL BOARD 2P 18 PMRAI 25NH5A R01 1 P W B MAIN PART N0 RAI 25NH5A NO Q TY UNIT PARTS NAME ...

Page 59: ...04 1 TURBO FAN 6 PMRAI 32CNH2 R05 1 DRAIN PAN ASSEMBLY 7 PMRAK 18NH6A R02 1 REMOTE CONTROL ASSEMBLY 8 PMRAS 10C3M 003 1 REMOTE CONTROL SUPPORT 12 PMRAI 32CNH2 010 1 DRAIN CAP 13 PMRAI 25NH4 R04 1 DRAIN PUMP ASSEMBLY 14 PMRAI 25NH4 R03 1 CYCLE ASSEMBLY 15 PMRAI 25NH4 007 4 SUSP CLAMP 17 PMRAC 07CV1 R06 1 TERMINAL BOARD 2P 18 PMRAI 35NH5A R01 1 P W B MAIN PART N0 RAI 35NH5A NO Q TY UNIT PARTS NAME ...

Page 60: ...04 1 TURBO FAN 6 PMRAI 32CNH2 R05 1 DRAIN PAN ASSEMBLY 7 PMRAK 18NH6A R02 1 REMOTE CONTROL ASSEMBLY 8 PMRAS 10C3M 003 1 REMOTE CONTROL SUPPORT 12 PMRAI 32CNH2 010 1 DRAIN CAP 13 PMRAI 25NH4 R04 1 DRAIN PUMP ASSEMBLY 14 PMRAI 50NH5 R02 1 CYCLE ASSEMBLY 15 PMRAI 25NH4 007 4 SUSP CLAMP 17 PMRAC 07VC1 R06 1 TERMINAL BOARD 2P 18 PMRAI 50NH5A R01 1 P W B MAIN PART N0 RAI 50NH5A NO Q TY UNIT PARTS NAME ...

Page 61: ...HITACHI PM NO 0401E Printed in Malaysia RAI 25NH5A RAI 35NH5A RAI 50NH5A ...

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