Hitachi Summit RAC-70YH5 Service Manual Download Page 54

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6. Room Temperature Thermistor Circuit

●

Fig. 6-1 shows the room temperature
thermistor circuit.

Room
temperature
thermistor

Fig. 6-1

R309

C302

Micro
computer

Room
temp. input

R310

Heat exchanger
temperature thermistor

Fig. 7-1

R307

C301

Micro computer

Heat
exchanger
temperature
input

R308

Fig. 6-2

oltage at

(V)
A

-10

Fig. 7-2

oltage at

(V)
A

7. Heat exchanger temperature thermistor circuit

●

The voltage at

depends on the room

temperature as shown in Fig. 6-2.

●

The circuit detects the indoor heat
exchanger temperature and controls
the following.

(1) Low-temperature defrosting during

cooling and dehumidifying
operation.

The voltage at

depends on the heat

exchanger temperature as shown in
Fig. 7-2.

0305E Pg 57-82

4/1/06, 10:59 AM

Summary of Contents for Summit RAC-70YH5

Page 1: ...PACITY DIMENSIONS mm NET WEIGHT SPECIFICATIONS 1030 295 191 12 RAS 70YH5 CONTENTS SPECIFICATIONS 4 HOW TO USE 6 CONSTRUCTION AND DIMENSIONAL DIAGRAM 28 MAIN PARTS COMPONENT 30 WIRING DIAGRAM 32 CIRCUIT DIAGRAM 33 PRINTED WIRING BOARD LOCATION DIAGRAM 39 BLOCK DIAGRAM 42 BASIC MODE 43 REFRIGERATING CYCLE DIAGRAM 57 AUTO SWING FUNCTION 58 DESCRIPTION OF MAIN CIRCUIT OPERATION 59 SERVICE CALL Q A 83 ...

Page 2: ...brated 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 as measured by a...

Page 3: ...ted 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 earth is being t...

Page 4: ...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 0305E Pg 01 05 4...

Page 5: ... 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 outside temper...

Page 6: ...PRESSOR THERMOSTAT REMOTE CONTROL SWITCH LIQUID CRYSTAL RAS 70YH5 PWM DC35V NO NO NO NO NO 3 15A NO NO YES NO NO 416NR 12D NO YES IC YES 40 W NO NO NO YES INTERNAL YES 3 0A G4A NO NO YES NO 450NR YES YES IC NO 1800g WITHOUT REFRIGERANT BECAUSE COUPLING IS FLARE TYPE UNIT PIPES MAX 30m REFRIGERANT CHARGING VOLUME Refrigerant R410A RAC 70YH5 JU1015D3 4 Chargeless upto 20m above 20m upto max 30m char...

Page 7: ...l should all be insulated with insulation pipe and then wrapped with vinyl tape The insulator will deteriorate if it is not wrapped with tape The connection of insulated drain hose Please use insulated drain hose for the indoor piping commercial product The indoor piping should be insulated with the enclosed insulation pipe If the insulator is insufficient please use commersial products Be sure to...

Page 8: ...a circuit breaker the danger 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 SHIFTING OR MAINTENANCE PRECAUTIONS DURING OPERATION Avoid an extended period of direct air flow for your health W A R N I N G Sho...

Page 9: ... 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 is not intended for use by young children or infirm persons unless they have been adequately supervised by a responsible person to ensure that they can use the appliance safely Young children should be sup...

Page 10: ...indoor unit Refer page 19 FRONT PANEL AIR INLET INDOOR UNIT INDICATORS Light indicator showing the operating condition Refer page 5 REMOTE CONTROL Send out operation signal to the indoor unit So as to operate the whole unit Refer page 6 1030 850 295 800 191 298 DRAIN PIPE Condensed water drain to outside CONNECTING CORD AIR INLET BACK LEFT SIDE AIR OUTLET 0305E Pg 06 15 4 1 06 10 48 AM 8 ...

Page 11: ... to clean the filter The lamp goes out when the POWER SWITCH set to OFF and ON again TEMPORARY SWITCH Use this switch to start and stop when the remote controller does not work By pressing the temporary switch the operation is done in automatic mode OPERATION INDICATOR This figure shows the opening condition of front panel Refer to page 18 in relation to how to open or close the front panel TEMPOR...

Page 12: ...Use these buttons to raise or lower the temperature setting Keep pressed and the value will change more quickly TIME button Use this button to set and check the time and date RESET buttons FUNCTION selector Use this button to select the operating mode Every time you press it the mode will change from AUTO to HEAT to DEHUMIDIFY to COOL and to FAN cyclically FAN SPEED selector This determines the fa...

Page 13: ...ton 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 mode If you change the setting the indoor unit...

Page 14: ...s to MED or LOW automatically when the preset temperature has been reached HI Economical as the room will become warm quickly But you may feel a chill at the beginning MED Fan speed slow LOW Fan speed slower 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 condition...

Page 15: ...ng 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 beep Press the button...

Page 16: ... LOW Fan speed 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 setting is higher than t...

Page 17: ...ure 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 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 ...

Page 18: ...ERVED sign goes out with a beep and the TIMER lamp turns off on the indoor unit 1 Set the current month and day with the TIMER control 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 that the OFF mark ligh...

Page 19: ...rol 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 and ...

Page 20: ...mp 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 of the remote controller tow...

Page 21: ...t the sleep timer to turn off after 1 2 3 or 7 hours 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 set the sleep timer becomes effective instead of the off on off or off on timer set You can not set other timer during sleep timer operation NOTE 0305E Pg 16 27 4 1 06 10 49 AM 19 ...

Page 22: ...he 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 folks who have difficulty in...

Page 23: ... 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 Inverter type fluorescent lamp To prevent inter...

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

Page 25: ...h soft bristle brush Allow filters to dry in shade 3 Re insert the air cleansing 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 it shake off mois...

Page 26: ...coating Removing the Front Panel When 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 slightly pull it out forward Attaching the Front Panel Move the projections of the left and right arms into the Flanges in the unit and securely insert them into the holes Projection Hole Flange 3 MAINTENANCE AT BEGINNING OF LONG OFF...

Page 27: ...llows The wire which is coloured green and yellow must be connected to the terminal in the plug which is marked with the letter E or by the earth symbol or coloured green or green and yellow The wire which is coloured blue must be connected to the terminal which is marked with the letter N or coloured black The wire which is coloured brown must be connected to the terminal which is marked with the...

Page 28: ... rubbing noise from the fan casing which is cooled and then gradually warmed as operation stops The odor will possibly be emitted from the room air conditioner because the various odor emitted by smoke foodstuffs cosmetics and so on sticks to it So please clean the air filter and the evaporator regularly to reduce the odor Please contact your sales agent immediately if the air conditioner still fa...

Page 29: ...light is dimmed a slight brightness fluctuation may occur This is of no consequence The conditions of the local Power Supply Companies are to be observed Minimum Maximum Indoor Dry bulb C 21 32 Wet bulb C 15 23 Outdoor Dry bulb C 21 43 Wet bulb C 15 26 Note Avoid to use the room air conditioner for cooling operation when the outside temperature is below 21 C 70 F The recommended maximum and minimu...

Page 30: ...on the wall for ø 65mm pipe Drain cap connection port Narrow pipe Wide pipe Drain Drain hose View from back Pipe lead out When piping is drawn horizontally exchange the drain hose for the drain cap Top air suction grille 1019 6 5 60 Front cover 47 295 Vertical deflector P Horizontal deflector Discharge grille 1030 183 191 6 5 60 47 0305E Pg 28 32 4 1 06 10 50 AM 28 ...

Page 31: ... 74 26 850 957 81 800 96 169 5 788 10 10 10 320 340 Air outlet 340 20 22 298 201 Handle Holes for anchor bolt 2 ø12 Fixing hole 507 198 57 12 37 Notch for anchor bolt 2 ø12 Notchs More than More than More than 100 More than 700 100 100 Service space 0305E Pg 28 32 4 1 06 10 50 AM 29 ...

Page 32: ...0 1 20 0 68 0 OFF 15 3 59 5 20 7 69 3 ON 23 6 74 5 28 0 82 4 OFF 23 3 73 9 28 7 83 7 ON 31 6 88 9 36 0 96 8 OFF 31 3 88 3 36 7 98 1 M RED BLK WHT YEL BLU 100 322V 15V 0V 0 6 5V FG MODEL RAS 70YH5 POWER SOURCE DC 100 322V DC350V OUTPUT 30W 100W 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 RED 360V BLK 0V WHT 15V...

Page 33: ... the color of the refrigerant oil inside the compressor If the color has been changed conspicuously replace the compressor V R YELLOW W S RED U C WHITE MODEL COMPRESSOR MODEL PHASE SINGLE RATED VOLTAGE AC 220 240 V RATED FREQUENCY 50 Hz POLE NUMBER 4 CONNECTION 20 C 68 F 75 C 167 F RESISTANCE VALUE 2M 1 05 2M 1 268 U V W WHITE M M M YELLOW RED RAC 70YH5 JU1015D3 0305E Pg 28 32 4 1 06 10 50 AM 31 ...

Page 34: ... 32 INDOOR UNIT OUTDOOR UNIT WIRING DIAGRAM MODEL RAS 70YH5 RAC 70YH5 0305E Pg 28 32 4 1 06 10 50 AM 32 ...

Page 35: ...EG0 SEG43 SEG42 SEG41 SEG40 P40 P41 P42 P43 P00 P01 P02 P03 P10 P11 P12 P13 D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 BEEP P20 P30 P31 NCVL C1 VL C2 VL C3 XC IN XC OUT VDD X OUT X IN RESET CARR P23 P22 P21 VSS IC 1 M3455OM6A 530FP LCD 1 C8 50v 1u K 1 D3 RB425D 1 2 K2K3 K4 K5 P10 P11 P12 K6 K7 K8 K8 K10 K11K12 K18 K17 K15 K16 K13 K14 D0 D1 D2 D3 R1 100k SW1 R2 P 100k R3 100k R4 100k R5 Q1 2SC3443 or 2SC2982 R6...

Page 36: ... 35 CIRCUIT DIAGRAM MODEL RAS 70YH5 0305E Pg 35 4 1 06 10 52 AM 1 ...

Page 37: ... 37 CIRCUIT DIAGRAM MODEL RAC 70YH5 0305E Pg 37 4 1 06 10 53 AM 1 ...

Page 38: ... 39 PRINTED WIRING BOARD LOCATION DIAGRAM MODEL RAS 70YH5 MAIN P W B Marking on P W B COMPONENT SIDE SOLDERING SIDE RECEIVING P W B Marking on P W B 0305E Pg 39 42 4 1 06 10 53 AM 39 ...

Page 39: ... 40 MODEL RAC 70YH5 MAIN P W B 0305E Pg 39 42 4 1 06 10 53 AM 40 ...

Page 40: ... 41 MAIN P W B NF P W B CAPA P W B 0305E Pg 39 42 4 1 06 10 53 AM 41 ...

Page 41: ...temperature thermistor Reset circuit Initial setting circuit Temporary switch Electric Expansion valve drive circuit Electric Expansion valve Outdoor microcomputer AX 6S00 Trip signal synthesis circuit L N SPM2 Outdoor unit Terminal board Power Circuit Power Circuit Noise Filter Magnetic relay Indoor microcomputer AX 7S31 A A B B A A B B 0305E Pg 39 42 4 1 06 10 53 AM 42 ...

Page 42: ... 43 51 53 53 55 57 49 29 66 22 0305E Pg 43 4 1 06 10 54 AM 1 ...

Page 43: ...min 1 CMAX2 5800 min 1 CSTD 5300 min 1 CKYMAX 4000 min 1 CJKMAX 4000 min 1 CBEMAX 3000 min 1 WMIN 1200 min 1 CMIN 1200 min 1 STARTMC 60 Seconds DWNRATEW 100 DWNRATEC 100 SHIFTW 2 00 C SHIFTC 1 00 C CLMXTP 30 00 C YNEOF 25 00 C TEION 2 00 C TEIOF 9 00 C SFTDSW 0 66 C DFTIM1 50 Minutes DFTIM2 50 Minutes 0305E Pg 45 4 1 06 10 55 AM 45 ...

Page 44: ...rpm CMAX will maintain for 60 minutes 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 temper...

Page 45: ...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 or sleep key all data...

Page 46: ...he 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 the compressor ar...

Page 47: ... control mode 4 Compressor minimum ON time and OFF time is 3 minutes 5 During normal heating mode compressor maximum rpm WMAX will maintain for 120 minutes if indoor temperature is higher than 18 C No time limit constrain if indoor temperature is lower than 18 C and outdoor temperature is lower than 2 C 6 During Hotkeep or Defrost mode indoor operation lamp will blink at interval of 3 seconds ON a...

Page 48: ...ation mode is set and sleep control starts 6 The indoor fan speed does not change even when the fan speed mode is changed Lo 7 When defrosting is to be set during sleep operation 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 ch...

Page 49: ...OR UNIT HEATING OUTDOOR UNIT INDOOR UNIT INDOOR UNIT COMP S TANK REV VALVE 5S VALVE 2S VALVE STRAINER EXPANSION VALVE STRAINER COND HIGH PRESSURE LOW PRESSURE COMP S TANK REV VALVE 5S VALVE 2S VALVE STRAINER EXPANSION VALVE STRAINER COND HIGH PRESSURE LOW PRESSURE 0305E Pg 57 82 4 1 06 10 59 AM 57 ...

Page 50: ...G 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 DURING SWINGING S...

Page 51: ...of Q201 s base rises and Q202 is turned ON Since Q202 s collector is set to LO at this time Q202 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 turned OFF the voltage of the DC 12V line decreases When it becomes about 7V ZD202 is turned OFF then Q201 is turned O...

Page 52: ...put 4kHz sound 3 Initial setting IC301 The pre heating operation start value ratings of the compressor maximum rotation speed etc are preset in the micro computer 4 Receive circuit Infrared signals from the wireless remote controller are received by the light receiving unit and output after being amplified and shaped 8 7 IC401 E 2PROM 6 5 Micro computer 26 27 R404 R403 1 2 4 3 5V 0V 5V D401 4 5 2 ...

Page 53: ...ins of the micro computer Micro computer pins Step width Horizontal air deflectors 10ms 1 2 3 4 5 6 7 8 Horizontal air deflectors 15 16 17 18 Fig 5 2 Micro computer Output Signals As the micro computer s outputs change as shown in Fig 5 2 the core of the auto sweep motor is excited to turn the rotor Table 5 1 shows the rotation angle of horizontal air deflectors Rotation angle per step 0 0879 Time...

Page 54: ...put R308 5 4 3 2 1 0 0 10 Fig 6 2 20 30 40 Voltage at V A 5 4 3 2 1 0 0 10 10 Fig 7 2 20 30 40 Voltage at V A 64 63 7 Heat exchanger temperature thermistor circuit The voltage at A depends on the room temperature as shown in Fig 6 2 The circuit detects the indoor heat exchanger temperature and controls the following 1 Low temperature defrosting during cooling and dehumidifying operation The voltag...

Page 55: ...n motor WCC return the FG sinal under frequency RPM The circuit produces fan motor drive from 340V DC supplied from the indoor unit and controls the fan motor speed CAUTION 1 Indoor fan motor circuit will be connected with primary power source line and please take care of the electrical shock I O G 0V 20V 5V 5V 15V 0V VDC FM GND VCC VS FG JOINT CONNECTOR 1 3 4 5 6 340V R501 ZD201 IC201 Q503 Q502 Q...

Page 56: ...ctive module faulty or defective connection Although the compressor continues to operate normally the power factor will decrease the operation current will increase and the overcurrent breaker of the household power board will probably activate Reference If diode stack 1 is faulty the compressor may stop due to lp anbormally low speed etc immediately after it starts or it may not operate at all be...

Page 57: ... protect electronic parts 6 Surge absorber Varistor 1 2 3 absorbs external power surge 7 Inrush protective resistor R002 R003 This works to protect from overcurrent when power is turned on Reference When inrush protective resistor is defective diode stack may malfunction As a result DC voltage is not generated and no operation can be done Be careful to avoid an electric shock as a high voltage is ...

Page 58: ...ting circuit modulates this signal by approx 38kHz high frequency This high frequency signal is amplified by a transistor superimposed on the DC 35V line via C801 or C811 C821 and L801 or L802 L803 and supplied to the indoor unit To prevent erroneous reception the outdoor microcomputer is designed so that it cannot receive a signal while is is outputting a request signal The receiving circuit in t...

Page 59: ...o computer 5V 5V 5V 12V 5V 5V IC8 R283 Q201 5V 5V 5V HIC 5V R813 R812 C802 Q803 C804 R811 R810 SDO1 SDI1 73 68 0V L801 L811 C801 R802 Q801 5V R801 R803 D210 0V 0V 0V 0V 0V 0V 0V C805 NF COIL2 C802 C216 R263 R262 R261 R260 D206 C214 Q206 R254 R255 R258 R257 R256 R259 C803 C804 Interface relay 35V Communications from indoor micro computer to outdoor micro computer Communications from outdoor micro c...

Page 60: ...35V DC line Base of outdoor P W B Q801 Q802 Outdoor micro computer 69 11 Pin 68 Pin Pin SDI Pin 35V DC line 100ms Leader 33ms 1 frame 5 7 5ms Transmit receive switching time 33ms 1 frame Fig 2 2 Voltages Waveforms of indoor Outdoor Micro computers Outdoor to Indoor Communications Fig 2 3 Voltages Waveforms of indoor Outdoor Micro computers Indoor to Outdoor Communications 0305E Pg 57 82 4 1 06 10 ...

Page 61: ...side are called the upper arm and the three transistors on the negative d side the lower arm W U V W W V V U U A DC Compressor motor U coil V coil W coil System Power module 2 C501 C502 C503 R24 0 35 m H Power relay Coil R007 R008 Inrush current protection relay C006 R001 Noise filter coil L N Terminal board FUSE 25A Fig 3 1 Power module circuit U is ON V is ON 0305E Pg 57 82 4 1 06 10 59 AM 69 ...

Page 62: ...ching order of power module N 60 2 X 1 T Fig 3 3 shows voltage current waveform at each point shown in Figs 3 1 and 3 4 First half of upper arm is chopper second half is ON and first half of lower arm is chopper second half is ON Fig 3 3 Voltage waveform at each point When power is supplied U U because of that U is chopped current flows as shown below 1 When U transistor is ON U transistor U coil ...

Page 63: ...imple inspection inspection mode when operated with compressor lead disconnected LD310 blinks four times about 2 seconds later Unit has not entered the normal operation Fig 3 4 System Power module circuit U is OFF V is ON Self diagnosis Self diagnosis lamp and mode lp peak current cut LD301 Abnormal low speed rotation LD301 Switching incomplete LD301 Blinks 2 times Blinks 3 times Blinks 4 times Ta...

Page 64: ...is power current flows to pin 4 of IC1 via R701 and IC1 starts to turn ON Since voltage in the direction of arrow generates at point c at the same time current passing through R708 and D702 is positive fed back to IC1 2 During ON The drain current at IC1 increases linearly During this period the gate voltage and current become constant because of the saturation characteristics of the transformer 3...

Page 65: ... 2 When only the 5V output is low REG 1 regulator faulty 5V 0V shorted output is too high or REG 1 is abnormal 3 When 12V and 5V are abnormal The following defects can be considered 1 Fan operation power rush prevention relay shorting in relay etc 2 REG 1 regulator is abnormal etc Shorting on primary circuits When shorting occurs in the secondary circuits there is no abnormality in the primary cir...

Page 66: ...erse electromotive force according to number of rotations This reverse electromotive force is voltage divided by R503 R505 and R608 R610 and appears as point A voltage IC3 compares and digitalizes point A voltage with point B voltage in which DC voltage Vd is voltage divided by R501 R502 and R611 and inputs this to microcomputer as position detection signals for points C D and E Microcomputer swit...

Page 67: ...eral circuit of microcomputer AX 6500 Table 7 1 Circuit block Basic operation Peak current cutoff circuit Overload external judgment circuit Voltage amplifier circuit Reset circuit This circuit detects DC current flowing power module When over current instantaneous value flows it stops upper and lower arm drive circuit and also produces lp signal to stop microcomputer This circuit detects DC curre...

Page 68: ...puter Fig 8 1 Overload Control System Configuration Fig 8 2 Overload control is to decrease the speed of the compressor and reduce the load when the load on the air conditioner increases to an overload state in order to protect the compressor electronic components and power breaker Overloads are judged by comparing the DC current level and set value Fig 8 1 shows the overload control system config...

Page 69: ...hes 7 2V Zener voltage of ZD201 ZD201 turns ON and Q211 and Q205 turn on and reset voltage becomes Hi Reset voltage is not set to Hi until VDD of microcomputer rises to 5V enabling operation due to ZD201 After power turns off when 12V line voltage drops ZD201 also turns OFF 12V line 12V line 5V line 5V line Reset voltage Reset voltage 12 6 0 Voltage when power is turned ON 12 6 0 Voltage when powe...

Page 70: ...rheat thermistor and electric expansion valve thermistor so that they detect the temperatures of the unit and control the system The circuit of the thermistors is shown as Fig 10 1 for model RAS 70YHA and their roles and temperature measuring points are shown as Table 10 1 Fig 10 1 Temperature Detection Circuit 0305E Pg 57 82 4 1 06 10 59 AM 78 ...

Page 71: ...ratures are used to decide how much the expansion valve is opened Outdoor temperature is used to decide the various operations of the air conditioner CN5 DEF thermistor Heat exchanger CN6 Outdoor temperature thermistor Outside temperature CN7 Electric expansion valve thermistor NARROW PIPE Indoor unit NARROW PIPE CN8 Electric expansion valve thermistor WIDE PIPE Indoor unit WIDE PIPE Table 10 2 sh...

Page 72: ... are checked out they are replaced If you can see two or more troubled thermistors a small number of blink takes precedence of others The electric expansions valve thermistor is put togrther with 3 pieces when replacing the thermistor replace one set of 3 pieces as taking care of positioning If you don t do so the unit may not operate normally and its cooling performance may drop Be ware that only...

Page 73: ... has not changed from around 0 9V or 12V expansion valve or microcomputer is defective Fig 11 2 shows logic waveform when expansion valve is operating 11 Electric expansion valve Pin Drive status Lear wire 1 ON OFF OFF OFF Pin No 12V 0 9V 200ms 75ms 50ms 42 38 41 37 40 36 39 35 ON ON OFF OFF ON OFF OFF ON OFF ON OFF OFF OFF ON ON OFF OFF OFF ON OFF OFF OFF ON ON OFF OFF OFF ON 2 3 4 5 6 7 8 White ...

Page 74: ...waveform of input voltage I input current V input voltage input voltage input current Effective voltage area Effective voltage area Invalid power area Even if voltage is applied current does not flow Assuming the same current capacity 20A power can be used about 10 effective comparing with curent use power factor of 90 and maximum capacity is thereby improved 0305E Pg 57 82 4 1 06 10 59 AM 82 ...

Page 75: ...ted 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 beginning of heating the fan speed remains...

Page 76: ... 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 is operating The...

Page 77: ...o 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 temperature and ro...

Page 78: ...kes about 10 minutes until the voltage fall after the power switch is turned off DANGER Across a b 0V line Across a ground Across b 0V line ground approx 260 360V approx 155 170V approx 155 170V When using an oscilloscope never ground it Don t forget that high voltages as noted above may apply to the oscilloscope DANGER Always keep your hands and metallic things away from the enclosure of the osci...

Page 79: ...n indoor unit electrical parts disconnect red gray lead wire connected from diode stack to system power module SPM2 to prevent secondary trouble Be sure to discharge smoothing capacitor Do not use a soldering iron with transformer If one is used thermal fuse inside transformer will be blown DISCHARGE PROCEDURE AND POWER SHUT OFF METHOD FOR POWER CIRCUIT WARNING As shown above apply soldering iron ...

Page 80: ...ice switch for 1 sec Does the compressor operate After checking be sure to press the service switch to stop the operation Check the refrigerating cycle Check the outdoor electrical parts Check the indoor electrical parts Check to see whether the F cable is connected incorrectly or disconnected See Out door unit self diagnosis lamp lighting mode See Troubleshooting when the timer lamp blinks Is app...

Page 81: ...1 Reversing valve defective 2 Heat exchanger thermistor dis connected only in the heating mode Note The malfunction mode is entered the 3rd time this abnormal indication appears read every 3 minutes Electrical parts in the outdoor unit 1 Indoor interface circuit 2 Outdoor interface circuit Please check at the outdoor electrical led lamp blinking LD301 and refer to self diagnosis lighting mode for ...

Page 82: ... MEASURING POSITION OF DC VOL TAGE P1 ve MEASURING POSITION OF DC VOL TAGE N1 ve SCREW DANGER OF ELECTRIC SHOCK SYSTEM POWER MODULE SPM2 LD301 LD302 LD303 LD304 SERVICE SWITCH MAIN P W B POWER P W B 0305E Pg 90 109 4 1 06 11 01 AM 90 ...

Page 83: ...n 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 pin 7 Hi Replace th...

Page 84: ... 92 2 Outdoor unit does not operate but receives remote infrared signal LD301 LD302 LD303 LD304 0305E Pg 90 109 4 1 06 11 01 AM 92 ...

Page 85: ...al the control P W B the control P W B the control P W B 4 Air deflector does not move others are normal 5 All systems stop from several seconds to several minutes after operation is started all indicators are also off 0305E Pg 90 109 4 1 06 11 01 AM 93 ...

Page 86: ... 94 6 Check the main P W B power circuit 0305E Pg 90 109 4 1 06 11 01 AM 94 ...

Page 87: ... 95 CHECKING THE REMOTE CONTROLLER 0305E Pg 90 109 4 1 06 11 01 AM 95 ...

Page 88: ...escription on power circuit for details Is 5V being generated between Pin 4 0V and pin 3 5V at CN 19 test pin Operate the outdoor unit according to the instruction How to operate the outdoor unit independently How did the self diagnosis lamp LD301 light Is the switching power circuit OK Has the 5A fuse blown See the self diagnosis lamp lighting mode Check to see whether the connected C and D cable...

Page 89: ... the control side coil terminal of interface relay Is a voltage at least 10V being generated between the contact terminals of interface relay Check the interface curcuit Yes Yes No No Yes D707 and C710 may be defective There is a defective section between the 12V output of switching power supply on the main P W B and interface relay also check for contact with solder etc Repalce the interface rela...

Page 90: ...ed The problem may be forgetting to connect after servicing Is the continuity of thermistor normal Is the thermistor circuit normal Replace the power module Replace any defective parts Connect the thermistor Replace the thermistor Replace parts in the thermistor circuit Check continuity of pattern and lead wires according to the P W B and schematic diagrams Check continuity of pattern and lead wir...

Page 91: ...ck continuity of new parts Check continuity of pattern and lead wires according to the P W B and schematic diagrams Yes Yes Replace system power module or defective parts Replace the system power module Replace any defective parts Is the thermistor circuit normal Are R503 and peripheral circuits of system power module normal Replace the main P W B Is the system power module normal Is the drive cir...

Page 92: ... 100 0305E Pg 90 109 4 1 06 11 01 AM 100 ...

Page 93: ...lamp is lit it does not indicate fault but the unit is overload status Recheck cord etc of the system power module If they are disconnected connect them securely If abnormality continues replace the system power module Overvoltage defect system power module faulty 15 times blinking Yes No 0305E Pg 90 109 4 1 06 11 01 AM 101 ...

Page 94: ...on as above The compressor is defective 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...

Page 95: ...r since built in battery is set in reverse direction and terminals are reversed CAUTION If inner circuit of system power module is disconnected open the indicator of tester will not swing and this may assumed as normal In this case if indicator swings when and terminals are connected in reverse of diagram below it is normal Furthermore compare how indicator swings at U V and W phases If indicator ...

Page 96: ...top the forced cool operation HOW TO OPERATE THE OUTDOOR UNIT INDEPENDENTLY The operation method is the same as How to operate using the connector to servicing the outdoor unit 1 The charging amount of 300g is equivalent to the load in normal operation Charge refrigerant of 300g after vacuuming 1 Do not operate for more than 5 minutes Parts to be prepared 1 Reducing union 2 8 6 35mm 1 2 12 7mm 2 C...

Page 97: ...r PGU PGV PGW NGU NGV NGW U V W P1 P2 U N1 L2 L1 W V Circuit diagram of the device excepting the reflux diode Circuit diagram of the module Terminals symbol mark of the module See next page for measuring value using tester 0305E Pg 90 109 4 1 06 11 01 AM 105 ...

Page 98: ... 106 PARTS LIST AND DIAGRAM INDOOR UNIT MODEL RAS 70YH5 22 2 9 1 7 8 6 4 5 3 19 20 11 12 10 13 15 14 16 17 18 24 23 21 0305E Pg 90 109 4 1 06 11 01 AM 106 ...

Page 99: ...AUTO SWEEP MOTOR 12 PMRAS 70YHA 007 1 P W B LED 13 PMRAS 60YH5 001 1 FRONT COVER ASSEMBLY 14 PMRAS 60YH5 002 1 FRONT PANEL 15 PMRAS 10C7M 008 3 CAP 16 PMRAS 51CHA1 010 2 AIR FILTER 17 PMRAS 51CHA1 011 1 REMOTE CONTROL ASSEMBLY 18 PMRAS 10C3M 003 1 REMOTE CONTROL SUPPORT 19 PMRAS 10C8M 003 1 THERMISTOR SUPPORT 20 PMRAS 70YHA 012 1 THERMISTOR 21 PMRAS 70YHA 009 1 P W B MAIN 22 PMRAS 70YHA 008 1 P W ...

Page 100: ... 108 PARTS LIST AND DIAGRAM OUTDOOR UNIT MODEL RAC 70YH5 18 23 24 32 28 12 11 6 10 1 27 9 30 26 13 5 14 4 20 19 15 21 22 29 7 3 8 2 25 31 33 17 35 36 34 16 0305E Pg 90 109 4 1 06 11 01 AM 108 ...

Page 101: ...MRAS 25NH4 913 1 TERMINAL BOARD 4P 18 PMRAM 65QH4 910 1 THERMISTOR OUTSIDE TEMPERATURE 19 PMRAC 70YHA 907 1 PROPELLER FAN 20 PMRAC 70YHA 912 1 SUPPORT FAN MOTOR 21 PMRAC 70YHA 904 1 FAN MOTOR 22 PMRAC 70YHA 901 1 CABINET 23 PMRAC 70YHA 906 1 NET 24 PMRAC 24CP5 905 1 TOP COVER 25 PMRAC 70YHA 909 1 SIDE PLATE R 26 PMRAC 70YHA 911 1 STRAINER COND 27 PMRAC 70YHA 910 1 STRAINER PIPE 28 PMRAC 70YHA 908 ...

Page 102: ...HITACHI PM NO 0305E Printed in Malaysia RAS 70YH5 RAC 70YH5 0305E cover 4 1 06 12 03 PM 2 ...

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Hitachi Summit RAC-70YH5, Service Manual

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