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Hitachi RAC-08PH1, Service Manual, Page: 70 / 114

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Hitachi RAC-08PH1 Service Manual Download Page 70

3. Indoor/Outdoor Interface Circuit

The interface circuit superimposes an interface signal on the DC 35V line to perform communications 
between indoor and outdoor units. This circuit consists of a transmitting circuit which superimposes an 
interface signal transmit from the microcomputer on the DC 35V line and a circuit which detects the 
interface signal on the DC 35V line.
Communications are performed alternatively transmitting and receiving.

3-1 Communication signal from outdoor microcomputer to indoor microcomputer.
At first outdoor microcomputer will send a request signal (SDO) to indoor microcomputer.
38 KHz  of carrier signal is generated and modulated by

 the request signal (SDO)  from the outdoor 

microcomputer pin 44 .  
This signal is superimposed to DC 35V line via C801 and L801.
To prevent erroneous reception, the outdoor microcomputer is designed so that it cannot receive a 
signal while it is outputting a request signal.
The receiving circuit in the indoor unit consists of a comparator and transistor. The interface signal 
from the outdoor unit on the DC 35V line is supplied to C321, where DC components are eliminated, 
and isthen shaped by the comparator. The shaped signal is detected by diode, amplified by amp, and 
output to pin 51  of the indoor microcomputer.
Fig. 3-2 shows the waveforms at each component when data is transferred from the outdoor 
microcomputer to the indoor microcomputer.

3-2 Communication signal from indoor microcomputer to outdoor microcomputer.
The request signal (SDO) generates by indoor microcomputer is output to pin 52 , and amplifies by 
Q331.
I/F signal approx. 38 kHz is generated by pin 88  of indoor microprocessor.
This I/F signal is then amplified and superimposed to DC 35V line via L301 and C332 of indoor 
interface circuit.
Fig. 3-3 shows the waveforms at each component when data is transferred from indoor microcomputer 
to outdoor microcomputer.
The circuit operation of the outdoor receiving circuit is same as indoor receiving circuit.

70

Summary of Contents for RAC-08PH1

Page 1: ...DOOR UNIT OUTDOOR UNIT 1 PHASE 50 Hz 220 230V 1 PHASE 50 Hz 220 230V 2 50 0 90 3 10 15 01 0 505 27 780 280 218 548 1 PHASE 50 Hz 220 230V 13 65 0 13 648 3 070 17 060 After installation RAS 14PH1 RAC 14PH1 BLOCK DIAGRAM 26 BASIC MODE 27 REFRIGERATING CYCLE DIAGRAM 36 DESCRIPTION OF MAIN CIRCUIT OPERATION 37 SERVICE CALL Q A 79 TROUBLE SHOOTING 82 Procedure for Disassembly and Reassembly 105 PARTS L...

Page 2: ...d measuring instruments for use in repairs or inspection should 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 te...

Page 3: ... parts Even rejected goods should be handled in the same way Fig 1 Conductive Container IC A conductive polyvinyl bag IC Conductive sponge 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 wit...

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

Page 5: ...sion 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 1...

Page 6: ...VARISTOR NOISE SUPPRESSOR THERMOSTAT REMOTE CONTROL SWITCH LIQUID CRYSTAL NO NO NO YES YES 3 0A G4A NO NO YES NO 450NR YES YES IC NO WITHOUT REFRIGERANT BECAUSE COUPLING IS FLARE TYPE UNIT PIPES MAX 20m REFRIGERANT CHARGING VOLUME Refrigerant 410A RAC 08PH1 RAC 14 H 820g RAS 10PH1 RAS 14PH1 NO NO NO NO NO NO NO YES NO NO NO NO YES IC YES 5RS102ZBC21 P 1 DC35V 25W DC120 380V 40W 1000g ASD084SF A7JK...

Page 7: ...ation or fire PROHIBITION Do not put objects like thin rods into the panel of blower and suction side because the high speed fan inside may cause danger Do not bundle the power cable pull it put something on it heat it process it or put it between things Breakage of the power cable may result Use of a damaged cable may cause an electrical shock or a fire PROHIBITION PROHIBITION 3 WARNING PRECAUTIO...

Page 8: ...2 RAS 08PH1 RAS 10PH1 RAS 14PH1 RAS 18PH1 RAC 14PH1 RAC 18PH1 RAC 08PH1 RAC 10PH1 7 0325 5 6 7 RAC 08PH1 RAC 10PH1 RAC 14PH1 RAC 18PH1 8 600 9 9 5 NAMES AND FUNCTIONS OF EACH PART INDOOR UNIT INDICATIONS TIMER LAMP Orange This lamp lights when the timer is working OPERATION LAMP Yellow This lamp lights during operation The OPERATION LAMP flashes in the following cases during heating 1 During prehe...

Page 9: ... stops it will not restart for about 3 minutes unless you turn the power switch off and on or unplug the power cord and plug it in again This is to protect the device and does not indicate a failure If you press the FUNCTION selector button during operation the device may stop for about 3 minutes for protection 7 VARIOUS FUNCTIONS Auto Restart Control If there is a power failure operation will be ...

Page 10: ... will be performed about once an hour when frost forms on the heat exchange of the outdoor unit for 5 10 minutes each time During defrosting operation the operation lamp blinks in cycle of 3 seconds on and 0 5 second off The maximum time for defrosting is 20 minutes If the piping length used is longer than usual frost will likely to form 9 DEHUMIDIFYING OPERATION Use the device for dehumidifying w...

Page 11: ...MPERATURE buttons the display indicates the setting The temperature setting and the actual room temperature may vary somewhat depending on conditions 3 As the settings are stored in memory in the remote controller you only have to press the START STOP button next time 11 Press the START STOP button Fan operation starts with a beep Press the button again to stop operation START STOP FAN OPERATION Y...

Page 12: ...nd the RESERVED sign lights A beep occurs and the TIMER lamp lights on the indoor unit PM Example The device will turn off at 11 00p m The setting of turn off time is now complete 2 Set the turn on time with the TIMER control button AM 3 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 and the RESER...

Page 13: ...eep timer Start The device will be turned off by the sleep timer and turned on by on timer 1 Set the ON timer 2 Press the SLEEP button and set the sleep timer AM AM For heating In this case the device will turn off in 2 hours at 1 38 a m and turn on early so that the preset temperature will be almost reached at 6 00 next morning How to Cancel Reservation Point the signal window of the remote contr...

Page 14: ...EL Remove the front panel and wash with clean water Wash it with a soft sponge After using neutral detergent wash thoroughly with clean water When front panel is not removed wipe it with a soft dry cloth Wipe the remote controller thoroughly with a soft dry cloth Wipe the water thoroughly If water remains at indicators or signal receiver of indoor unit it causes trouble Method of removing the fron...

Page 15: ...riority s During sleep timer operation the fan speed sets to SILENT regardless of the preset speed The remote controller display indication will remain unchanged even with the SILENT setting TIMER PROGRAMMING SLEEP TIMER OPERATION 18 19 REGULAR INSPECTION PLEASE CHECK THE FOLLOWING POINTS EVERY EITHER HALF YEARLY OR YEARLY CONTACT YOUR SALES AGENT SHOULD YOU NEED ANY HELP 1 2 3 WARNING WARNING Che...

Page 16: ...to room temperature changes Mist is generated as the air within the room is suddenly cooled by conditioned air Water generated during defrosting operation evaporates and steam is emitted Caused as the smells and particles of smoke food cosmetics etc present in room air become attached the unit and blown off into the room again Defrosting is underway as the heating operation is stopped the microcom...

Page 17: ...CONSTRUCTION AND DIMENSIONAL DIAGRAM MODEL RAS 08PH1 RAS 10PH1 RAS 14PH1 INDOOR UNIT RAS_AW_015 018e 17 218 ...

Page 18: ...CONSTRUCTION AND DIMENSIONAL DIAGRAM OUTDOOR UNIT MODEL RAC 08PH1 RAC 10PH1 18 ...

Page 19: ...ill Air outlet Handle Holes for anchor bolt 2 ø12 x 6 slots for ø8 0 bolt for 2 ø8 0 bolt Notch for anchor bolt Fixing hole Drain hole Drain hole OUTDOOR UNIT More than 50 More than 100 More than 200 More than 300 Rear side Service space MODEL RAC 14 H P 1 19 ...

Page 20: ...32 7 90 9 34 7 94 5 OFF 32 0 89 6 35 3 95 5 M RED BLK WHT YEL BLU 35V 5V 0V 0 5V FG MODEL S L E D O M E L B A C I L P P A G N I T A R E M A N REVERSING VALVE COIL 135 20 C REACTOR L1 13 mH 0 224 RAC 08PH1 10PH1 14PH1 RAC 08PH1 10PH1 14PH1 5 4 嘕 RAC 08PH1 10PH1 14PH1 F DC 35V E C R U O S R E W O P DC 120 380V W 5 2 T U P T U O 40W Control circuit built in BLU BLUE YEL YELLOW BRN BROWN WHT WHITE GRY...

Page 21: ...erating cycle has been operated for a long time with the capillary tubes clogged or crushed or with too little refrigerant check the color of the refrigerating machine oil inside the compressor If the color has been changed conspicuously replace the compressor 2M 1 15 2M 1 40 U V W M M M WHITE YELLOW RED RAC 08PH1 RAC 10PH 5RS102ZBC21 DC 220 350 V 710W RAS_AW_015 018e RAC H ASD084SF A7JK 14P 1 1 7...

Page 22: ...WIRING DIAGRAM RAS 08PH1 RAC 08PH1 RAS 10PH1 RAC 10PH1 RAS 14PH1 RAC 14PH1 RAC 08PH1 RAC 10PH1 RAC 14PH1 22 ...

Page 23: ...CIRCUIT DIAGRAM MODEL RAS 08PH1 RAS 10PH1 RAS 14PH1 23 ...

Page 24: ...1 H P 0 1 C A R 1 H P 8 0 C A R L E D O M 24 ...

Page 25: ...RAC 14PH1 MODEL Ｌ Ｎ 25 ...

Page 26: ...RAS_AW_022_A3e 22 RAS 08PH1 RAC 08PH1 RAS 10PH1 RAC 10PH1 RAS 14PH1 RAC 14PH1 26 ...

Page 27: ...or stopped forcibly for 3 minutes Start stop swith Operation lamp Fan speeds Hi Hi Med Med Lo Lo Set to Ultra Lo Lo or Stop depending on the room temperature and time Set to Stop if the room temperature is 18 in the Ultra Lo mode other than during preheating cooling is recovered at 18 33 The fan speed is controlled by the heat exchanger temperature the overload control is executed as in the follow...

Page 28: ...RTDF1 TDF411 TDF412 STARCPDH TDF413 FWSS FWSOY FWS FWKAF FWL Hi Set fan speed Hi FWAH Ultra Hi FWAHH Ultra Hi FWH Hi Set fan speed AUTO FWHH FCSOY FCS FCL FCAH FCH FCHH FDSOY FDS1 FDS2 Table 2 Room temperature shift value Shift value Fan speed AUTO Hi Med SHIFTW Fan speed Lo Silent Sleep SFTSZW SHIFTC Dehumidifying operation SHIFTD Operation mode Mode data file RAS 08PH1 LABEL NAME Fan speed mode ...

Page 29: ...412 STARCPDH TDF413 FWSS FWSOY FWS FWKAF FWL Hi Set fan speed Hi FWAH Ultra Hi FWAHH Ultra Hi FWH Hi Set fan speed AUTO FWHH FCSOY FCS FCL FCAH FCH FCHH FDSOY FDS1 FDS2 Table 2 Room temperature shift value Shift value Fan speed AUTO Hi Med SHIFTW Fan speed Lo Silent Sleep SFTSZW SHIFTC Dehumidifying operation SHIFTD Operation mode Mode data file RAS 10PH1 LABEL NAME Fan speed mode Operation mode H...

Page 30: ...PDH TDF413 FWSS FWSOY FWS FWKAF FWL Hi Set fan speed Hi FWAH Ultra Hi FWAHH Ultra Hi FWH Hi Set fan speed AUTO FWHH FCSOY FCS FCL FCAH FCH FCHH FDSOY FDS1 FDS2 Table 2 Room temperature shift value Shift value Fan speed AUTO Hi Med SHIFTW Fan speed Lo Silent Sleep SFTSZW SHIFTC Dehumidifying operation SHIFTD Operation mode Mode data file RAS 14PH1 LABEL NAME Fan speed mode Operation mode Heating op...

Page 31: ...ave elapsed after cool dash was started when the room temperature reaches the cooling set temperature 1 C including cooling shift and then becomes lower than the preset temperature by 0 66 C after the steady speed period when thermo is OFF if cool dash finished in the above the compressor does not go through the steady speed period but it starts fuzzy control 3 The thermo OFF temperature during co...

Page 32: ... the fan speed mode is changed 5 When operation is stopped during sleep operation the set temperature when stopped as well as the time continue to be counted 6 If the set time is changed during sleep operation all data including set temperature time etc is cleared and restarted 7 If sleep operation is canceled by the cancel key or sleep key all data is cleared 8 The indoor fan is stopped while the...

Page 33: ...flector Outdoor fan Indoor fan Timer lamp Sleep key Operation lamp SLEEP on the remote controller is lit Hi Med Lo Sleep Silent Facing up Horizontal Shut Set to 2 hours Lo S 1 h r 2 h r 0 5 h r Dehumidifying Notes 1 The sleep operation starts when the sleep key is pressed 2 When the sleep key is set the indoor fan is set to Sleep Silent FDOY 3 If the operation mode is changed during sleep operatio...

Page 34: ...2 6 The operation indicator blinks every second during initial cycle operation preheating defrosting including balance time after defrosting is finished or auto fresh defrosting 7 For preheating judgment preheating starts if the heat exchange temperature is lower than YNEOFC and is cancelled if the heat exchange temperature is YNEOF plus 0 33 or higher at the start of operation using the START STOP...

Page 35: ...no preset temperature shift due to time elapse Heating Sleep Operation 1 min WMIN DFMAX Compressor speed TDF 411 TDF 412 TDF 413 TDF421 WMAX TDF 431 STARCPL STARCPL 4000min 4000min TDF 422 Notes 1 The defrosting inhibit period is set as shown in the diagram below When defrosting has finished once the inhibit period is newly set based on the outdoor temperature when the compressor was started Durin...

Page 36: ...MODEL RAS 08PH1 RAC 08PH1 MODEL RAS 14PH1 RAC 14PH1 RAS 10PH1 RAC 10PH1 36 ...

Page 37: ...F MAIN CIRCUIT OPERATION MODEL RAS 08PH 1 Reset Circuit The reset circuit initializes the microcomputer program when power is ON or OFF Low voltage at pin resets the microcomputer and Hi activates the microcomputer When power ON 5V voltage rises and reaches 4 4V pin of IC521 is set to Hi At this time the microcomputer starts operation When power OFF voltage drops and reaches 4 2V pin of IC521 is s...

Page 38: ... 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 IC711 it is applied to the buzzer The piezoelectric element in the buzzer oscillates to generate the buzzer s sound Fig 2 1 Fig 3 1 Buzzer circuit Sound wave Metal diaphragm V Pizoelectric element V Fig 3 2 Buzzer Operation 38 ...

Page 39: ...izontal air defectors Fig 4 1 Rotation angle per step Time per step ms 0 0882 10 Horizontal air deflectors 4 Auto Sweep Motor Circuit Fig 4 1 shows the Auto sweep motor drive circuit the signals shown in Fig 4 2 are output from pin E E E E E H H H H H of microcomputer As the microcomputer s outputs change as shown in Fig 4 2 the coils of the auto sweep motor is excite to turn the rotor Table 4 1 s...

Page 40: ...C DC converter and the 35 V power supply from the outdoor unit to generate 12 V control power which drives the stepping motor during the operation In addition use the regulator IC 121 to generate 5 V power required for driving the micro computer and controlling fan motor If the terminal block was overheated due to a connecting cable improper connection the thermal fuse built in the terminal block ...

Page 41: ... shows the relation between the voltage at the point B and the speed Some differences will occur due to the condition of the unit s The fan motor outputs the feedback pulse of the speed which is input into the pin on the micro computer This pulse is equivalent to a frequency of 12 60 speed Example 1000 min 1 x 12 60 200 Hz The micro computer monitors the frequency and adjusts the output pulse rang...

Page 42: ...sary 2 DB3 L1 C023 and L2 The DB3 L1 C023 and L2 shape waveform of the input current When the current runs through the L1 is taken for I1 and the current runs through the L2 is taken for I2 as shown in Fig 1 2 I1 becomes an input current to the capacitor which peak value was crushed by the L1 and I2 becomes a resonance current which causes the LC resonance using the L2 and C023 By combining the I1...

Page 43: ...sorb electrical noise generated during operation of compressor and also absorb external noise entering from power line to protect electronic parts Be sure to connect the earth cable between the indoor unit and the outdoor unit Otherwise the noise filter circuit won t operate properly 6 SA1 and VS1 to VS3 These surge absorber and varistors absorb external power surge such as induced thunder Be sure...

Page 44: ...signal The receiving circuit in the indoor unit consists of a comparator and transistor The interface signal from the outdoor unit on the DC 35V line is supplied to C821 where DC components are eliminated and is then shaped by the comparator The shaped signal is detected by diode amplified by amp and output to pin i i i i i of the indoor microcomputer Fig 2 2 shows the waveforms at each component ...

Page 45: ...V 5V R256 R214 R257 D206 IC5 1 2 4 6 R260 R261 R258 R259 R262 0V 5V 0V R263 Q204 R268 5V 6 5V 0V R803 Q801 R801 R802 C802 C801 L801 I F0V NF COIL 2 C808 L802 0V 12V Communications from indoor microcomputer to outdoor microcomputer Communications from outdoor microcomputer to indoor microcomputer Fig 2 1 Indoor Outdoor interface circuit CONTROL P W B C807 C806 35V 28 27 5 7 51 45 ...

Page 46: ...or to Outdoor Communications Outdoor microcomputer Pin 48 Pin 51 Indoor microcomputer Pin 50 Pin 49 48 5 50 49 33ms 1 frame 100ms Leader 5V 5V 0V 5V 35V DC line 0V 5V 0V 0V 35V Outdoor microcomputer Pin 48 Pin 51 Indoor microcomputer Pin 50 Pin 49 Fig 2 2 Voltages Waveforms of Indoor Outdoor Microcomputers Outdoor to Indoor Communications 48 5 50 49 46 ...

Page 47: ... all 1s 3 Communications waveforms Leader 100ms Leader 100ms When reset approx 100ms When reset approx 10ms 35 V 34 V 36 V 0 7 0 7 7 7 0 33 3ms 3 2 1 NO 0 Bit No 0 7 0 7 0 7 0 7 Bit No 0 3 2 1 33 3ms 33 3ms 33 3ms Transmit receive switching time 4 95ms 33 3ms 33 3ms Outdoor message Indoor message 33 3ms 33 3ms 0 Character No 2 In n door microcomputer to outdoor microcomputer HIC 47 ...

Page 48: ... LSB Actual compressor rotation speed 0 LSB Compressor command speed 0 LSB Compressor minimum rotation speed 0 LSB Compressor minimum rotation speed 1 Compressor minimum rotation speed 2 Compressor minimum rotation speed 3 Compressor minimum rotation speed 4 MSB Compressor command speed 1 Compressor command speed 2 Compressor command speed 3 Compressor command speed 4 Compressor command speed 5 Co...

Page 49: ... module circuit U is ON V is ON 3 Intelligent power module circuit IPM circuit Fig 3 1 shows peripheral circuits of intelligent power module IPM In the diagram U V and W are called the upper arm U V and W the lower arm 49 ...

Page 50: ...lled to ON OFF by 2 5kHz 5kHz chopper signal Rotation speed of the compressor is proportional to duty ratio ON time ON time OFF time of this chopper signal Time T in Fig 3 2 shows the switching period and relation with rotation speed N of the compressor is shown by formula below N 60 2 X 1 T Fig 3 3 shows voltage waveform at each point shown in Figs 3 1 and 3 4 First half of upper arm is chopper s...

Page 51: ...ely proportional to the input current of the air conditioner input current is controlled by using DC current Id detection resistor Reference If power module is defected self diagnosis lamps on the MAIN P W B may indicate as shown below LD303 LD302 LD301 MAIN P W B SERVICE SWITCH HIC IPM Fig 3 5 Table 3 1 RA H1 RAC 10PH1 08 C RAC 14PH1 DC VOLTAGE CHECKPOINT IPM 33 PIN DC VOLTAGE CHECKPOINT IPM 25 P...

Page 52: ...52 ...

Page 53: ...53 ...

Page 54: ...ply for microcomputer peripheral circuits and IPM driver circuit and as well as DC 35V are produced by switching power circuit Switching power circuit performs voltage conversion effectively by switching transistor IC1 to convert DC 330V voltage to high frequency of about 20kHz to 200kHz Fig 5 1 AC220 230V 54 ...

Page 55: ...55 ...

Page 56: ...56 ...

Page 57: ...57 ...

Page 58: ... of this room air conditioner system through the current sensor CT1 in order to keep the maximum rating of components by reading total operating current ID OVL is watching and limits the compressor current through the detection resistor which is built in IPM in order to control the compressor reliability Since the compressor reliability is related with its speed the ID OVL value is also linked wit...

Page 59: ...59 ...

Page 60: ...rrent R247 R248 R249 are provided to perform the same overload judgement even when the voltage varies 3 Start current control It is required to maintain the start current DC current constant to smooth the start of the DC motor of the compressor RAC 18YH6 RAC 25YH6 uses software to control the start current The start current varies when the supply voltage varies This control method copes with varia...

Page 61: ...reset circuit initializes the microcomputer program when Power is ON from OFF Low voltage at pin 7 resets the microcomputer and HI activates the microcomputer Fig 6 10 shows the reset circuit and Fig 6 11 shows waveform at each point when power is turned on and off When power is turned on 12V line and 5V line voltages rise and 12V line voltage reaches 10 9V an reset voltage input to pin 7 of micro...

Page 62: ... forms on the outdoor heat exchanger the temperature at the exchanger drops abruptly Therefore the resistance of the Defrost thermistor becomes high and the voltage at pin w of microcomputer drops If this voltage becomes lower than the set value stored inside the microcomputer starts defrosting control During defrosting operation the microcomputer transfers the defrosting condition command to the ...

Page 63: ...ally ON close Table 6 3 shows the circuit operation of each operation mode If the following result is not obtained reversing valve control circuit may be defective Table 6 3 Point Operation mode Cooling In normal cooling operation In normal heating operation In defrosting operation approx 35 V approx 35 V 0V Hi 0V Hi 12V Lo 0V not fixed Heating Between Pin 29 of microcomputer and 0V Between Pin 32...

Page 64: ...en close direction is as shown below When the power is turned on approx 0 9 V is applied to CN15 pins 1 to 4 when no power is supplied approx 12 V is applied When the power is reset expansion valve performs initial operation for 5 to 10 seconds During initial operation measure pins 1 to 4 of CN15 using multimeter If no change is found around 0 9 V or 12V expansion valve or microcomputer is defecti...

Page 65: ...width FG feedback Slower Instruction Faster Increase pulse width FG pulse is also used for Fan Motor failure detection Microcomputer will monitor FG pulse 30 seconds after start the fan motor If there is no signal detected it will consider that the Fan Motor was malfunction and stop the operation In this case LD302 on main R107 and IC4 are used for Fan Motor over current Vsp high Faster Vsp low sl...

Page 66: ...owing inside of outdoor unit by snowing It may make Fan Lock Stop by strong wind ex 17m sec or above against the Fan rotation In this case unit will be restart again after a while In case of Fan Lock Stop even though the DC Fan Motor is rotating correctly the possible cause in Fan Motor problem or control board problem Stop after the Fan motor runs 2 minutes Fan Motor may be broken Caution Please ...

Page 67: ...circuit rectifies the 230 V AC voltage applied between terminals L and N of the terminal board to produce a DC voltage However the DC voltage rises to approximately 280 to 350 V at the time of compressor operation Fig 1 1 2 5 1 4PH1 67 ...

Page 68: ...oltage Together with suppressing the electrical noise generated at the time of compressor operation the external noise entering via the power supply line is absorbed as well protecting the electronic parts of the system 5 SA1 VS1 VS2 VS5 This operates to suppress external surges from indirect lightning etc This smoothes the voltage rectified for operating the compressor When the input voltage is t...

Page 69: ...is found in this step the power circuit is normal Check the removed loads If any error is found in this step the power circuit has any failure Replace the power circuit for P W B A short circuited load may cause an output error not only in the load but also in the others Be sure to check all outputs of the loads Be sure to wait 15 minutes or more in order to discharge all the remaining voltage in ...

Page 70: ...l while it is outputting a request signal The receiving circuit in the indoor unit consists of a comparator and transistor The interface signal from the outdoor unit on the DC 35V line is supplied to C321 where DC components are eliminated and isthen shaped by the comparator The shaped signal is detected by diode amplified by amp and output to pin 51 of the indoor microcomputer Fig 3 2 shows the w...

Page 71: ...door microcomputers to communicate with each other Indoor P W B Outdoor P W B Terminal board Terminal board Control P W B Terminal board D C D C 0V 35V L101 52 51 88 R323 R322 R325 R328 C650 R650 Microcomputer 0V R324 0V R322 0V C323 5V Q331 Q332 Q333 R326 R330 R327 D321 R320 IC301 2 2 IC301 1 2 R328 R329 5V R336 R334 C324 6 5 7 3 8 4 2 1 R321 C321 C332 L301 CJ301 C333 C334 C335 0V R335 5V R332 R3...

Page 72: ...tdoor Microcomputers Outdoor to Indoor Communications Fig 3 3 Voltages Waveforms of indoor Outdoor Microcomputers Indoor to Outdoor Communications Pin Indoor microcomputer Pin Pin 35V DC line Outdoor microcomputer Pin Pin Indoor microcomputer Pin Pin 35V DC line 0V 5V 0V 0V 35V 44 44 62 52 51 62 52 51 72 ...

Page 73: ...ages rise and 12V line voltage reaches 10 9V an reset voltage input to pin of microcomputer is set to Hi Reset voltage will be hold Hi until the 12V line voltage drops to 9 90V even though the power shuts down Fig 4 1 Fig 4 2 12V line Power is ON Voltage V Power is OFF Voltage V 5V line 10 9V Time Time 9 9V Reset voltage Reset voltage 12V line 5V line 12 6 0 12 6 0 䋱䋲䌖 䌃䋲䋸䋱 䋰䌖 䌉 䌃䋵 䋨 䋲 䋯䋲 䋩 䌒䋲䋸䋵 䌒...

Page 74: ...uter transfers the defrosting condition command to the indoor microcomputer via the circuit interface The microcomputer always reads the outdoor temperature via a thermistor microcomputer pin an transfers it to the indoor unit thus controlling the compressor rotation speed according to the value set at the EEPROM in the indoor unit and switching the operation status outdoor fan on off etc in the d...

Page 75: ...on is approximately as shown in Table 6 1 when measured by multimeter Operation condition Collector voltage of D401 Cooling General operation of Cooling In normal heating operation Defrosting Sensor dry MAX rotation speed instructed by indoor microcomputer after defrost is completed Heating Dehumidifying About 35V About 35V About 35V About 0V About 0V Table 6 1 䌒䌌䋵 䋴 䋳 䋲 䋱 REVERSING VALVE 䌄䋴䋰䋱 䌃䌎䋲...

Page 76: ...ration measure each pin of the CN15 㽲 to 㽵 with a multimeter If no change is found around 0 9 V or 12V in this step the expansion valve or the microcomputer has failure The logic waveform during the operating of the expansion valve is shown in Fig 7 2 7 Electric expansion valve control circuit 㽵 㽴 㽳 㽲 1 2 3 4 5 6 7 8 VALVE CLOSE 8 7 6 5 4 3 2 1 VALVE OPEN 㽵 㽴 㽳 㽲 12V 0 9V 50ms 75ms 200ms 1 ON OFF ...

Page 77: ...al fan motor is controlled by the outdoor microcomputer This outdoor fan motor estimates the actual speed based on the DC current flowing to R741 it then adjusts this value as necessary so that it becomes the speed corresponding to the operation command transmitted from the indoor unit In addition overcurrent detection and other fault detection is performed based on the DC current Fig 8 1 77 ...

Page 78: ...ng inside of outdoor unit by snowing It may make Fan Lock Stop by strong wind ex 17m sec or above against the Fan rotation In this case unit will be restart again after a while In case of Fan Lock Stop even though the DC Fan Motor is rotating correctly the possible cause in Fan Motor problem or control board problem Stop after the Fan motor runs 2 minutes Fan Motor may be broken Caution Please tak...

Page 79: ...SERVICE CALL Q A Model RAS 08PH1 RAC 08PH1 RAS 10 10PH1 RAC PH1 RAS 14PH1 RAC 14 H P 1 E G E HJ E HJ K K E Q X G Z E 79 ...

Page 80: ... JQ J E G J JQ _ G Z E q q z q z E KQ K _ E KQ K J Z KQ K E E G G 80 ...

Page 81: ... E E G G E E E Z E E H E Z E Q E E G G G E E 81 ...

Page 82: ... as noted in the figure above may apply to the oscilloscope Remember that voltage of 175 V is applied to the 0V line on the P W B or the like as shown in the right diagram Voltage at point A Ground voltage 350V Point B 0V line t forget that high t install RAC 08PH1 RAC 10PH1 RAC 14PH1 82 Indoor Controller Outdoor Controller Point 375 F M P I Compressor motor Point line Control P W B Main P W B Pow...

Page 83: ...ply plug 2 After power is turned off wait for 10 minutes or more Then remove electrical parts cover and apply soldering iron of 30 to 75 W for 15 seconds or more to TAB05 and R001 terminals on the main P W B as shown in the figure below in order to discharge voltage in smoothing capacitor RAC 08PH1 RAC 10PH1 LEAD WIRE RAS_AW_063 082e RAC 08PH RAC 14PH1 1 RAC 10PH1 83 LEAD WIRE and apply soldering ...

Page 84: ...y code between the part and cabinet Removing electrical parts 1 Remove the electrical parts cover 2 Remove the connectors from the CN1 heat exchange thermistor CN4 stepping motor and CN10 fan motor 3 Remove two lock screws 4 Remove the electrical parts in the direction of arrow Removing control P W B 1 Remove the connectors from the CN16 2 Remove the P W B from the P W B support STRUCTURE OF AN IN...

Page 85: ...ngers to unlock and remove the connector 3 When checking the voltage and waveform do not connect the probes to the forbidden areas show below Touching them may cause the ICP1 blowout and Q111 failure The Q111 is a MOS FET and its gate terminal is a high impedance When a probe such as a multimeter is contacted with the gate G the Q111 may have the continuous ON state to supply overcurrent in the ci...

Page 86: ...een performed several times Note In some failure modes only the retry operation is repeated without lamp indication Failure modes that will repeat a retry operation without the indoor unit lamp indication are as follows OH thermistor temperature rise Outdoor unit communication error Power voltage abnormal Less frequent defects The LD301 indicates a mode of failure detected on the outdoor unit side...

Page 87: ...nterface circuit is faulty when power is supplied the self diagnosis display will not be displayed 2 If the indoor unit does not operate at all check if the connecting cable is connected to the outdoor unit 3 To check operation again when the timer lamp is blinking you can use the remote control for operation except for mode mark 1 Lights for 0 35 sec at interval of 0 35 sec 2 Interface voltage er...

Page 88: ...SELF DIAGNOSIS LIGHTING MODE MODEL RAC 08 10 SELF DIAGNOSIS LIGHTING MODE MODEL RAC E10H2 RAS_AW_063 082e PH1 RAC PH1 88 ...

Page 89: ...SELF DIAGNOSIS LIGHTING MODE 1 H P 4 1 C A R L E D O M 89 ...

Page 90: ...ails wait 3 minutes for the unit to re start and check the self diagnosis lamp status again Check outdoor electrical parts Check the refrigerating cycle Normal No Yes Check the drive circuit IMP using the PRD checker Check the position sensor circuit With the unit set in the operating state press the start stop button Does the unit operate for approximately 2 seconds the LD303 coming on and then s...

Page 91: ...r unit and observe the self diagnosis lamp LD301 Count how many times the lamp blinks Blinks other than 1 time Blinks 1 time Can the unit be operated using the outdoor unit service switch See the nameplate on the outdoor unit for operating instructions Check the outdoor electrical parts Check the indoor electrical parts Check the refrigerating cycle In the event of overload limit cut or OH thermis...

Page 92: ...between terminals L and N on the outdoor unit terminal board Is DC35V or 20V being generated between terminals C and D on the indoor unit terminal board Is the microcomputer reset input pin7 Hi Is the microcomputer clock signal 10MHz at pins 0 and A being generated normally Is DC35V is being generated between terminals C and D on the outdoor unit terminal board Are C and D connection cables revers...

Page 93: ...ter Perform final operation check 3 Air deflector does not move others are normal Are pulse signals output at microcomputer pins when auto swing is turned on in the fan mode Replace the microcomputer Is a voltage over 15 or below 10V being generated on the 12V line Replace IC111 Yes Yes Yes Yes No No No No Check IC711 If it is normal replace the air deflector motor Perform final operation check 24...

Page 94: ...terminal board Insert the connection cable securely Replace IC121 Check if a short occurs in the 5V line If the 5V line is shorted ICP1 will be open again Check to see if the connection cables are disconnected or reversed If normal check the outdoor unit P W B Has the terminal board thermal fuse blown open Replace Q111 and IC111 Is DC5V being generated Perform final operation check When the unit i...

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Page 96: ...o be defective Replace defective parts Is the power circuit normal See the description on power circuit for details Is the switching power circuit OK Has the 3A fuse blown Check to see if C and D cables are connected correctly If reversed or incompletely inserted correct the cable connection Replace any defective parts If the 3A fuse has blown the varistor 2 etc may also be defective With the pipi...

Page 97: ...after the fan operates for 2 minutes Is the voltage between 4 and 6 at CN24 normal Normally the voltage is above approx DC1 7V Connect the connector Remove any obstructions Replace the fan motor and main P W B Is the voltage between 4 and 7 at CN24 normal Check to see if the voltage is within 2 5V 0 5V using a tester In effect the output voltage is alternately switched between 5V and 0V Replace th...

Page 98: ...erminals L and N on the terminal board Apply AC220 230V Check the interior wiring TAB05 TAB11 reactor and C023 yellow green connected properly Connect properly Replace the main P W B Possible causes include Power relay malfunction Defective microcomputer terminal Yes Yes Yes No No No 98 ...

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Page 102: ... W B LD301 blinks 1 time Reset stop However the unit always resets and stops just after power is supplied this does not indicate a fault Is the reset circuit normal Normally pin 7 of CN18 is approx 5V Replace the main P W B Make sure again that connectors are connected securely Perform final operation check Yes Yes Yes No No 102 ...

Page 103: ...Replace it and seal refrigerant If the compressor checker for an inverter type air conditioner is available re check using it JUDGING BETWEEN GAS LEAKAGE AND COMPRESSOR DEFECTIVE Blinking off Time until the lamp lights Approx 10 seconds Approx 10 seconds Approx 10 seconds Within Approx 30 seconds Compressor Compressor Gas leakage Possible malfunctioning part LD301 Self diagnosis lamp Lighting mode...

Page 104: ...ATE THE OUTDOOR UNIT INDEPENDENTLY 1 Connect the large dia pipe side and small dia pipe side service valve using a pipe Parts to be prepared 1 Reducing union 2 8 6 35 mm 3 8 9 52 mm 2 Copper pipe 2 8 and 3 8 Connect the small diameter service value and the large diameter service valve using the reducing union and copper pipe as shown on the right Charge refrigerant of 300g after vacuuming 1 The op...

Page 105: ...e each connector from the lead wire 2 Remove the four P W B supports from the control P W B 3 Pull the support hook at the upper side of the indication lamp of the indicating P W B and pull out the P W B forward Fig 4 Procedure for Disassembly and Reassembly INDOOR UNIT RAS 08PH1 RAS 10PH1 RAS 14PH1 7 0325 5 6 7 105 securely Then push the center of the front cover to lock the claws 1 Check that th...

Page 106: ...ns and radiation fin fixing screws 5 locations and remove the P W B from the support 1 Electrical Parts 1 Remove the upper cover fixing screws and lift the cover to remove it 2 Remove the service valve cover 3 Remove the terminal plate cover 4 Remove the right side cover 3 Remove the screws from the upper and lowerbearing covers 4 Remove the locking hook of the lower bearingcover from the Cabinet ...

Page 107: ...er and pull it forward Then remove the cover from the hook 5 Pull the right side of the front cover a little and pull up the left side to remove it from the hook Fig 13 6 Remove each connector and earth cable from the lead wire Remove four lock screws from the main P W B 7 8 Fig 14 Support hooks Support hooks Main P W B and pull two support hooks at the front side to remove the P W B Pull three su...

Page 108: ...PARTS LIST AND DIAGRAM INDOOR UNIT MODEL RAS 08PH1 RAS 10PH1 RAS 14PH1 30 108 ...

Page 109: ...50 1 2 5 3 5 6 7 50 6725 66 5 6 29 5 75 5 6 3 3 0 1 5 6 3 3 0 1 5 6 3 3 0 1 5 6 29 5 5 6 29 5 5 5 6 3 1 7 21 12 3 576 12 4 7 8 1 7 3 576 1 0 5 6 29 5 5 6 8 5 6 3 3 29 5 5 6 3 5 1 3 1 66 5 6 5 1 3 5 6 2 3 3 5 6 5 1 3 3 5 6 67 33 1 02725 5 6 725 6833257 5 6 3 25 217 5 725 5 6 5 7 5 5 6 5217 3 1 6 5 6 5 027 21752 66 5 6 3 5217 29 5 5 6 7 29 5 66 5 6 3 5 6 3 5 6 6 29 5 5 5 6 6 29 5 5 6 02817 1 3 7 109...

Page 110: ...UNIT MODEL RAC 08 H RAC 10 H 2 19 18 45 4 3 6 17 12 16 15 13 14 8 32 33 36 24 28 37 35 32 27 41 49 33 43 41 34 25 42 30 29 44 39 10 5 9 40 1 23 22 21 20 26 31 RAS_AW_083 093e 38 36 7 11 46 47 48 P 1 P 1 110 50 ...

Page 111: ...H4 A24 1 NUT PROPELLER FAN 24 HWRAC E10H2 A16 1 SIDE COVER L 25 HWRAC 10EH4 A08 1 FRONT COVER 26 RAC E10CYK 005 1 DISCHARGE GRILL 27 HWRAC 10EH4 A09 1 ELECTRIC PARTS PLATE 28 HWRAC 10EH4 A10 1 ELECTRIC PARTS COVER 29 HWRAC E10H2 A21 1 TERMINAL PLATE 30 HWRAC 25YH4 A32 2 TERMINAL BOARD 2P 31 HWRAC 10EH4 A11 1 HEAT SINK REGURATOR 1 32 HWRAC E08H A11 1 FUSE 15A 33 HWRAC D10EX2 A09 1 FUSE 3A 34 HWRAC ...

Page 112: ...OUTDOOR UNIT MODEL RAC 14 25 24 27 26 22 21 23 20 19 17 42 45 44 40 41 19 30 43 39 31 29 28 9 11 18 32 PH1 112 ...

Page 113: ...AW PARTS NO Q TY UNI T PARTS NAME 22 HWRAC 14EH4 A09 1 PROPELLER FAN 23 HWRAC 25YH4 A24 1 NUT PROPELLER FAN 24 HWRAC 25YH4 A25 1 SIDE COVER L 25 HWRAC 25YH4 A26 1 HANDLE 26 HWRAC 14EH4 A10 1 FRONT COVER 27 HWRAC 14PH1 A01 1 DISCHARGE GRILL 28 HWRAC 14EH4 A11 1 COVER CAPACITOR 29 HWRAC 14EH4 A12 1 ELECTRIC PARTS PLATE 30 HWRAC 14EH4 A13 1 ELECTRIC PARTS COVER 31 HWRAC 25YH4 A32 2 TERMINAL BOARD 2P ...

Page 114: ...HITACHI RAS 08PH1 RAC 08PH1 RAS 10PH1 RAC 10PH1 83 HHAW NO 00 E RAS 14PH1 RAC 14PH1 114 ...

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