Hitachi RAC-18GH5, Service Manual

Page 1: ...ITY DIMENSIONS mm NET WEIGHT SPECIFICATIONS 1030 295 207 12 RAS 18GH5 CONTENTS SPECIFICATIONS 5 HOW TO USE 9 CONSTRUCTION AND DIMENSIONAL DIAGRAM 30 MAIN PARTS COMPONENT 32 WIRING DIAGRAM 34 CIRCUIT DIAGRAM 35 PRINTED WIRING BOARD LOCATION DIAGRAM 37 BLOCK DIAGRAM 39 BASIC MODE 41 REFRIGERATING CYCLE DIAGRAM 47 DESCRIPTION OF MAIN CIRCUIT OPERATION 48 AUTO SWING FUNCTION 52 SERVICE CALL Q A 53 TRO...

Page 2: ...d be 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 m...

Page 3: ...of 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 al ways 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 b...

Page 4: ...the 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...

Page 5: ...and 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 t...

Page 6: ...HEAT PROTECTOR FUSE MICRO COMPUTER CIRCUIT POWER RELAY POWER SWITCH TEMPORARY SWITCH SERVICE SWITCH TRANSFORMER VARISTOR NOISE SUPPRESSOR THERMOSTAT REMOTE CONTROL SWITCH LIQUID CRYSTAL FUSE CAPACITY RAS 18GH5 30 W NO NO NO NO NO 3 15A G4A YES NO YES NO 450NR NO YES IC YES 20 A TIME DELAY FUSE 1450g UNIT PIPES MAX 15m REFRIGERANT CHARGING VOLUME Refrigerant R410A PIPES MIN 5m ADDITIONAL REFRIGERAN...

Page 7: ...ameter ø 16mm The connection of insulated drain hose Please use insulated drain hose for the indoor piping commercial product The difference in height between the indoor and outdoor unit should be kept max 10m The connecting pipe no matter big or small should all be insulated with insulation pipe and then warapped with vinyl tape The insulator will deteriorate if it is not wrapped with tape Figure...

Page 8: ...k your sales agent or qualified technician for the installation of your unit Water leakage short circuit or fire may occur if you install the unit by yourself Please use earth line Do not place the earth line near water or gas pipes lightning conductor or the earth line of telephone Improper installation of earth line may cause electric shock Be sure to use the specified piping set for R410A Other...

Page 9: ... deflector and drips down occasionally This will wet your furniture Therefore do not operate 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 Do not climb on the outdoor unit or put objects on it Pleas...

Page 10: ...orizontal deflector Vertical deflector Air Outlet Refer page 21 Remote controller Send out operation signal to the indoor unit So as to operate the whole unit Refer page 11 OUTDOOR UNIT Drain pipe Condensed water drain to outside Connecting cord and insulation pipe for piping Air inlet Back and Left side Air outlet WIDTH mm 1030 850 MODEL RAS 18GH5 RAC 18GH5 HEIGHT mm 295 650 DEPTH mm 207 298 MODE...

Page 11: ...o how to open or close the front panel OPERATION LAMP This lamp lights 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 ...

Page 12: ...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 AUTO HEAT DEHUMIDIFY COOL FAN FAN SPEED LOW MED HI SLEEPING STOP CANCEL START RESERVE START STOP TIME TIMER SET TIMER SELECTOR ON TIMER OFF TIMER AUTO SWING NAMES AND FUNCTIONS OF REMOTE CONTROL UNIT REMOTE ...

Page 13: ...ton Operation starts with a beep Press the button again to stop operation You can raise or lower the temperature setting as necessary by maximum of 3 C Press the temperature button and the temperature setting will change by 1 C each time The preset temperature and the actual room temperature may vary somewhat depending on conditions The display does not indicate the preset temperature in the AUTO ...

Page 14: ...ture has been reached HI Economical as the room will become warm quickly But you may feel a chill at the beginning MED Quiet LOW More quiet Set the desired room temperature with the TEMPERATURE buttons the display indicates the setting The range of 18 22 C is recommended as the room temperature for heating If the temperature setting is 20 C the room temperature will be controlled at around 20 C Th...

Page 15: ... the temperature setting The function will stop the indoor unit will stop emitting air as soon as the room temperature becomes lower than the setting temperature 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 for dehumidifying Press the START STOP button Dehumidifying operation starts with a...

Page 16: ...hed HI Economical as the room will become cool quickly MED Quiet LOW More quiet Set the desired room temperature with the TEMPERATURE button the display indicates the setting The range of 25 28 C is recommended as the room temperature for cooling If the temperature setting is 27 C the room temperature will be controlled at around 27 C The temperature setting and the actual room temperature may var...

Page 17: ...etting temperature is large fan starts to run at HI speed When the room temperature reaches setting temperature fan speed changes to LOW automatically When the difference of room temperature and setting temperature is large fan starts to run at HI speed After room temperature reaches the preset temperature the cooling operation which changes the fan speed and room temperature to obtain optimum con...

Page 18: ...mote 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 signal window ...

Page 19: ... of the OFF timer ON timer and ON OFF timer ON Timer Time Day Month The device will turn on at the designated times TIME DAY MONTH current time day month OFF TIMER ON TIMER RESERVE CANCEL PM Start Stop PM AM PM 1 Press the ON TIMER button the ON mark blinks on the display 1 Press the ON OFF button so that the OFF mark blinks 2 Set the turn off time with the TIMER control button Press the RESERVE b...

Page 20: ...n off at 10 30 p m and then automatically turn on earlier so that the preset temperature can be reached at 7 00 a m The settings of the turn on off times are now complete 4 Press the TIME button again The time indication starts lighting instead of flashing PM PM AM PM PM PM AM AM AM AM PM PM 2Set the turn off time with the TIMER control button 3 Point the signal window of the remote controller tow...

Page 21: ...o LOW setting 30 minutes after the setting of the sleep timer Fan Heating The room temperature will be controlled 5 C below the temperature and the FAN SPEED will be set to LOW setting 30 minutes after the setting of the sleep timer Operation with the sleep timer If date or current time is not set sleep timer can not be set If you set the sleep timer after the off on off or off on timer has been s...

Page 22: ...oves and stops at the position where the air outlet closes When cooling dehumidifying When heating CAUTION In Cooling operation do not keep the horizontal air deflector swinging for a long time Some dew may form on the horizontal air deflector and dew may drop RESET Adjustment of the conditioned air in the upward and downward directions The horizontal air deflector is automatically set to the prop...

Page 23: ...e old batteries 2 Install the new batteries The direction of the batteries should match the marks in the case 1 Do not use new and old batteries or different kinds of batteries together 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 ...

Page 24: ...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 25: ...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 26: ... qualified service personal Before cleaning stop operation and switch off the power supply CAUTION CAUTION Do not bend the air cleansing and deodorizing filter as it may cause damage to the structure NOTE In case of removing the air cleansing and deodorizing filters please follow the above procedures The cooling capacity is slightly weakened and the cooling speed becomes slower when the air cleans...

Page 27: ...tly brush it with soft bristle brush Allow filters to dry in shade 3 Re insert the air purifying filter to the filter frame Set the filter with FRONT mark facing front and slot them into the original state After attaching the filters push the front panel at three arrow portions as shown in figure and close it CAUTION Do not wash with hot water at more than 40 C The filter may shrink When washing i...

Page 28: ... front panel with both hands to detach and attach it 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 the coating Removing the Front Panel Arm When the front panel is fully opened with both hands push the right arm to...

Page 29: ... BY QUALIFIED SERVICE PERSONAL EITHER EVERY HALF YEARLY OR YEARLY CONTACT YOUR SALES AGENT OR SERVICE SHOP Is the earth line disconnected or broken Is the mounting frame seriously affected by rust and is the outdoor unit tilted or unstable Is the plug of power line firmly plugged into the socket Please ensure no loose contact between them Cleaning and maintenance must be carried out only by qualif...

Page 30: ...ks 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 number date of installation Please also inform him regarding the fault Power supply shall be connected at the rated voltage oth...

Page 31: ...be within 10m 5 Power supply cord length is about 2m 6 Connecting cable 2 5mm dia x 3 AB Line 1 6mm dia x 2 CD Line is used for the connection 1019 Top air suction grille 47 47 28 147 380 About About 350 31 120 5 56 17 5 60 60 70 70 158 263 317 450 Drain outlet Connecting cable Power cord Hole on the wall for ø 65mm pipe Drain cap connection port Narrow pipe Wide pipe Drain Drain hose View from ba...

Page 32: ... 31 MODEL RAC 18GH5 Note 1 200mm or more servicing space is required above the outdoor unit ...

Page 33: ...MOSTAT MODEL IC OPERATION COOL HEAT ON 17 6 63 7 19 6 67 3 OFF 17 3 63 1 19 3 66 7 ON 25 6 78 1 27 6 81 7 OFF 25 3 77 5 27 3 81 1 ON 33 6 92 5 35 6 96 1 OFF 33 3 91 9 35 3 95 5 MODEL RAS 18GH5 RAC 18GH5 PHASE RATED VOLTAGE SINGLE RATED FREQUENCY DC35V 220 230V TEMPERATURE C OUTPUT POLE NUMBER 6 30 W 40 W 50 Hz 35V 5V RED YELLOW BLUE M RESISTANCE VALUE 20 C 75 C RM 122 4 RA 114 8 RM 161 6 RA 139 6 ...

Page 34: ...ANCE VALUE CAUTION When the Air Conditioner has been operated for a long time with the capillary tubes clogged or crushed or with too little refrigerant check the color of the refrigerant oil inside the compressor If the color has been changed conspicuously replace the compressor EXTERNAL OVERLOAD RELAY INTERNAL PROTECTOR NO YES ORANGE RM WHITE PROTECTOR RA RED CAPACITOR S RED C WHITE R ORANGE RAC...

Page 35: ...R WHT BRN RED P C B P C B RECEIVER 7 LINES IVO CN11 CN11 CN2 IVO BLK CN3 BLK BLK WHT CN12 RED BLK INDOOR UNIT OUTDOOR UNIT A COMPRESSOR B FAN MOTOR C POWER SWITCH D THERMAL FUSE FOR 2P TERMINAL 102 C E THERMAL FUSE FOR P C B 96 C F REVERSING VALVE G 50 μF CAPACITOR H 2 5 μF CAPACITOR BLU BLUE YEL YELLOW BRN BROWN WHT WHITE GRY GRAY ORN ORANGE GRN GREEN RED RED BLK BLACK PNK PINK VIO VIOLET IVO IVO...

Page 36: ... 35 CIRCUIT DIAGRAM Remote Control ...

Page 37: ...A A A A A A 1 6W 1 6W 1 6W 1 6W 1 6W 1 6W 1 6W A 1 6W A A 1 6W A A 1 6W 1 6W H A 1W 5 0 2 R610 R601 R603 R606 R607 R608 10K 10K 1K R609 1K 1 6W 10K 5 1K 10K R602 R604 R605 10K 1K 5 5 5 1 6W 1 6W A A 10K 1 6W A 5 1 6W A 1K R621 47 R622 A 5 R712 R713 1K 2K 1 6W 1 6W R303 R304 R305 R306 R307 390 390 390 5 1k 390 5 1K R302 R313 10k 10k 10k 10k 10k R314 R315 R316 R317 10k 10k R318 R319 R320 R331 R332 1...

Page 38: ... 39 BLOCK DIAGRAM MODEL RAS 18GH5 RAC 18GH5 ...

Page 39: ...own below according to the room temperature A shift is not accepted at the time of operation start There is no switching between modes after start of operation When the operation is started again within 20 min after stop with the start stop button operation will be executed in the previous mode The operation details are the same as for each operation mode The set temperature is set with the room t...

Page 40: ... Heating 16 19 6 C 24 27 6 32 35 6 Differential C 0 33 Low temperature T1 ON C 1 0 defrosting Reset C 12 0 Preheating Reset C 17 0 ON C 15 0 Pd cut 1 T3 ON C 56 0 T4 Reset C 52 0 Pd cut 2 T6 ON C 66 0 T7 Reset C 57 0 T5 Fan Relay H Original C 58 0 Pd cut 3 T8 ON C 62 0 T9 Reset C 57 0 Table 1 Specifications Table 2 Sensor operation values Other detailed specifications 1 When the room temperature r...

Page 41: ... min 00 60 min OT 00 60 min 00 60 min HT 60 60 min 60 60 min Obtain OT moved up time depending on the temperature difference from the table below 10 NICE TEMPERA TURE reservation Heating Cooling Setting temp Room temp Time min Setting temp Room temp Time min 00 01 00 00 00 00 02 00 00 01 25 03 00 10 02 25 05 00 15 03 25 07 00 20 05 25 08 00 30 07 25 10 00 30 08 25 11 00 45 10 25 13 00 40 11 25 60 ...

Page 42: ... 47 REFRIGERATING CYCLE DIAGRAM MODEL RAS 18GH5 RAC 18GH5 ...

Page 43: ... 48 DESCRIPTION OF MAIN CIRCUIT OPERATION 1 ON OFF The ON OFF and Timer reserve button and Sleeping function independently Their operations are shown in Fig 1 1 Fig 1 1 Timer operation ...

Page 44: ...and DC 5V lines are increased When the voltage of DC 12V lines reaches about 7V ZD511 is turned ON the potential of Q511 s base rises and Q511 is turned ON Since Q511 s collector is set to LO at this time Q512 is turned OFF and the reset input of the micro computer is set to Lo The DC 5V line voltage has already become 5V at this time and the micro computer starts operation When the power is turne...

Page 45: ...ltage is applied to the buzzer and the diaphragm of the buzzer vibrates to output 4kHz sound 4 Initial setting IC301 The pre heating operation start value ratings of the compressor maximum rotation speed etc are preset in the micro computer 5 Receive circuit Infrared signals from the wireless remote controller are received by the light receiving unit and output after being amplified and shaped ...

Page 46: ...oom temperature control To control the room temperature turn on and off the disconnect switch To protect the compressor wait at least 3 minutes before turning on again The fan speed is MED Does not operate is 12V is not generated in the control circuit When the service switch is used for operation each change switch is overridden Setting the service switch to Cooling turns on the Power relay ...

Page 47: ...MODE ONE SWING CLOSING 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 DURI...

Page 48: ... dehumidifying operation the actual room temperature is compared with the room temperature setting when starting the operation and the operation is as follows 1 When actual room temper ature room temperature setting The operation is according to the room temperature setting on the remote con troller 2 When actual room tem perature room tempera ture setting Regardless of the room temperature settin...

Page 49: ... speed followed by MED fan speed for 30 seconds and then by HI fan speed A8 Q7 The operation stops during a heating operation while the room temperature is set at 30 Q9 If a heating operation is performed when the exterior temperature is high the operation may stop to protect the equipment A9 The outdoor fan does not move at a heating operation by the service switch It is not a trouble When heatin...

Page 50: ...perature cannot be controlled at an automatic operation Q14 It is automatically set as follows At cooling Set at 27 C At dehumidifying S e t s l i g h t l y lower than room temperature The room temperature setting can be raised 3 C by or lowered 3 C by V A14 When changing the room temperature setting in an automatic operation the next automatic operation mode is determined by new room temperature ...

Page 51: ...after changing the time setting A16 In the Automatic fan speed mode the indoor fan changes to MED and LO fan speed Q17 It is not a trouble The cold wind preventive function operates A17 Set the temporary switch normal In case of ON timer the operation does not start at a preprogrammed time but a little earlier Q18 Nice temperature reservation The Nice temperature reservation functions The operatio...

Page 52: ... r settting indication takes a precedence A23 When setting the current time its indication blinks for approximately 3 minutes 1 When the operation mode is Automatic the fan speed is automatically fixed to Automatic 2 A t a n A u t o m a t i c operation the room temperature setting is not displayed The room temperature is automatically set as follows At cooling Set at 27 C At dehumidifying Set to a...

Page 53: ... the time over the pre programmed time As soon as the preprogrammed time is reached the time setting disappears A24 After selecting a Dehumidifying operation mode the fan speed mode remains LO fan speed Q25 At a Dehumidifying operation the LO fan speed is forcibly selected A25 ...

Page 54: ...tor 102 C Continuity across If there is no continuity check the electric parts and replace if abnormal 5 Thermal fuse for Terminal board 2 Before checking the varistor detach a terminal NO Operates by setting the service switch to forced cooling Return the service switch to Normal Set the remote controller to an operation status and press the ON OFF button Is the level LO approx 0 5V between drive...

Page 55: ...ing carry out a self diagnosis by indoor indicator lamp Fan Speed HI MED LO 3 Replace faulty part 4 Wait for 3 minutes before forced re operation by the service switch CN6 BLUE RED V RAS 18GH5 Cooling Heating 30 0 26 0 22 0 30 0 24 0 21 5 Is voltage normal approx 280 300V at out put side of the DB201 ...

Page 56: ...me Force cooling operation Unit is under forcible operation or under balancing after forcible operation Check force cooling switch at indoor electrical IC 401 Data read wrongly In case that data read from IC401 is wrong IC401 data is not in order Heat exchanger thermistor error Heat exchanger thermistor open or short circuit detected 1 Thermistor 2 Indoor control circuit board Room thermistor erro...

Page 57: ... 62 2 9 1 7 8 6 5 4 3 20 19 11 12 13 15 14 17 16 24 23 25 21 22 18 26 27 10 PARTS LIST AND DIAGRAM INDOOR UNIT MODEL RAS 18GH5 ...

Page 58: ... 1 P W B LED 13 PMRAS 60YH5 001 1 FRONT COVER ASSY 14 PMRAS 60YH5 002 1 FRONT PANEL 15 PMRAS 10C7M 008 3 CAP 16 PMRAS 51CHA1 010 2 FILTER 17 PMRAS 51CHA1 011 1 REMOTE CONTROL ASSY 18 PMRAS 10C3M 003 1 REMOTE CONTROL SUPPORT 19 PMRAS 51CHA1 015 1 THERMISTOR SUPPORT 20 PMRAS 18C9G 007 1 THERMISTOR 21 PMRAS 18CP2R 002 1 POWER SWITCH 22 PMRAS 18GH4 001 1 P W B MAIN 23 PMRAS 51CHA1 013 1 P W B POWER SW...

Page 59: ... 64 5 4 8 9 15 7 6 18 17 14 16 13 10 11 12 22 3 23 24 20 21 2 1 PARTS LIST AND DIAGRAM OUTDOOR UNIT MODEL RAC 18GH5 ...

Page 60: ...903 1 TERMINAL BOARD 4P 11 PMRAC 63CHA2 907 1 COMPRESSOR CAPACITOR 12 PMRAC 63CHA2 908 1 FAN MOTOR CAPACITOR 2 5μF 13 PMRAC 40CNH2 926 1 SIDE PLATE L 14 PMRAC 18CH1 903 1 CABINET 15 PMRAC 51CHA1 907 1 GRILL ASSY 16 PMRAC 40CNH2 923 1 SIDE PLATE R 17 PMRAC 24CP5 904 1 NET 18 PMRAC 40CNH2 922 1 TOP COVER 20 PMRAC 18GH4 906 1 REVERSING VALVE COIL 21 PMRAC 18GH5 901 1 REVERSING VALVE 22 PMRAC 51CHA1 9...

Page 61: ...PM NO 0479E Printed in Malaysia RAS 18GH5 RAC 18GH5 ...