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Hitachi RAM-18QH5E, Service Manual

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Hitachi RAM-18QH5E Service Manual Download Page 77

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MODEL   RAM-18QH5E

1

PMRAC-63CA1

902

1

2P TERMINAL

2

PMRAC-51CA1

901

1

CABINET

3

PMRAM-40QH5

907

1

COIL (REVERSING VALVE)

4

PMRAM-65QH4

901

1

COMPRESSOR

5

RAC-2226HV

805

3

COMPRESSOR RUBBER

6

PMRAM-40QH5

910

1

CONDENSER

7

PMRAC-09CHA1

903

1

D-GRILL

8

PMRAC-25NH4

903

1

ELECTRICAL EXPANSION COIL

9

PMRAM-40QH5

902

1

ELECTRICAL EXPANSION COIL

10

PMRAM-65QH4

903

2

EXPANSION VALVE

11

PMRAC-40CNH2

919

1

FAN MOTOR 40W

12

PMRAC-51CA1

908

1

NET

13

PMRAC-25NH4

909

1

OVERHEAT THERMISTOR SUPPORT

14

PMRAC-25NH4

910

1

OVERLOAD RELAY COVER

15

PMRAM-40QH5

901

1

P.W.B. (MAIN)

16

PMRAC-25CNH2

902

1

PROPELLER FAN

17

KPNT1

001

6

PUSH NUT

18

PMRAM-40QH5

915

1

PWB (POWER)

19

PMRAS-51CHA1

013

1

PWB (SW. POWER)

20

PMRAC-18SH4

901

1

REACTOR

21

PMRAC-19SH4

904

1

REVERSING VALVE

22

PMRAM-40QH5

903

1

SIDE PLATE (R)

23

PMRAM-40QH5

908

1

STRAINER (COND 1)

24

PMRAM-40QH5

909

1

STRAINER (COND 2)

25

PMRAM-40QH5

904

1

STRAINER (COND)

26

PMRAM-40QH5

912

1

STRAINER (PIPE)

27

PMRAM-40QH5

913

1

STRAINER (ST-PIPE-AS-1)

28

PMRAM-40QH5

914

1

STRAINER (ST-PIPE-AS-2)

29

PMRAC-25NH4

914

1

SUPPORT (FAN MOTOR)

30

PMRAM-40QH5

905

1

SV COVER

31

PMRAC-40CNH2

901

1

SYSTEM POWER MODULE

32

PMRAC-25NH4

913

1

TERMINAL BOARD (4P)

33

PMRAM-40QH5

911

1

THERMISTOR (DEFROST)

34

PMRAC-40CNH2

914

1

THERMISTOR (OH)

35

PMRAM-40QH5

906

1

THERMISTOR-V

36

PMRAC-19SH4

901

1

THERMISTOR (OUTSIDE TEMPERATURE)

37

PMRAC-51CA1

909

1

TOP COVER

38

PMRAM-65QH4

915

2

VALVE 2S

39

PMRAM-65QH4

916

2

VALVE 3S

PART N0. RAM-18QH5E

NO.

Q’TY / UNIT

PARTS NAME

Summary of Contents for RAM-18QH5E

Page 1: ...AL DIAGRAM 12 MAIN PARTS COMPONENT 13 CAPACITY DIAGRAM 15 WIRING DIAGRAM 20 CIRCUIT DIAGRAM 21 BLOCK DIAGRAM 25 BASIC MODE 27 REFRIGERATING CYCLE DIAGRAM 40 DESCRIPTION OF MAIN CIRCUIT OPERATION 42 TROUBLE SHOOTING 66 PARTS LIST AND DIAGRAM 82 RAM 18QH5E After installation 750 570 280 40 W A COOLING CAPACITY DC INVERTER DUAL SYSTEM MULTI TYPE MODEL POWER SOURCE TOTAL INPUT TOTAL AMPERES SPECIFICAT...

Page 2: ... 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 mo...

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 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 bo...

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 Stapl...

Page 5: ...casion 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...

Page 6: ...R SWITCH TEMPORARY SWITCH SERVICE SWITCH TRANSFORMER VARISTOR NOISE SUPPRESSOR THERMOSTAT REMOTE CONTROL SWITCH LIQUID CRYSTAL 40 W NO NO NO YES YES 5 0A G4A NO NO YES NO 450NR YES YES IC NO 1600g WITHOUT REFRIGERANT BECAUSE COUPLING IS FLARE TYPE UNIT PIPES REFRIGERANT CHARGING VOLUME Refrigerant 410A RAM 18QH5E JU1013D2 MAX 35m RAM 18QH5E Additional charge of refrigerant is not required ...

Page 7: ...FACTOR MAXIMUM LENGTH OF PIPING STANDARD RAM 18QH5E 1ø 220 240V 50Hz 16 4 0 1 50 4 50 13 660 5 120 15 360 1 245 200 1 800 10 97 5 72 5 24 99 5 0 1 50 5 60 17 070 5 120 19 120 1 350 200 1 780 12 64 6 20 5 68 99 MAX 35m TWO UNIT TOTAL CE EMC LVD RAM 18QH5E MODEL W PACKING mm H D cu ft 905 633 394 8 27 43 GROSS WEIGHT kg 6 35D 9 52DX2 FLARE NUT SIZE SMALL LARGE INDOOR SUCTION TEMPERATURE C COOLING OP...

Page 8: ... UNIT 1 8 2 5 3 5 1 8 1 8 1 8 2 5 2 5 2 5 1 8 3 5 2 5 3 5 1 8 1 00 2 50 2 5 1 00 3 10 3 5 1 00 4 00 1 8 1 8 1 50 4 00 1 70 2 30 1 50 4 50 2 00 2 00 1 50 4 50 1 60 2 40 1 50 4 50 1 80 2 20 1 50 4 50 560 200 750 750 200 880 1090 200 1300 1190 200 1680 1245 200 1720 1245 200 1800 1245 200 1800 1245 200 1800 2 5 3 3 4 8 5 2 5 5 5 5 5 5 5 5 2 5 1 10 3 20 3 4 1 10 4 40 4 2 1 10 5 0 2 25 2 25 1 50 5 20 2...

Page 9: ... 8 ...

Page 10: ... 9 RAM 18QH5E MODEL RAM 18QH5E ...

Page 11: ... 10 ...

Page 12: ... 11 AC 220V 240V ONLY L N INDOOR 1 C1 D1 C2 D2 INDOOR 2 RAM 18QH5E ...

Page 13: ... 12 RAM 18QH5E ...

Page 14: ...ION MODEL POWER SOURCE OUTPUT BLU BLUE YEL YELLOW BRN BROWN WHT WHITE GRY GRAY ORN ORANGE GRN GREEN RED RED BLK BLACK PNK PINK VIO VIOLET RAM 18QH5E DC 360V 40W RESISTANCE VALUE 20 C 68 F 75 C 167 F M RED BLK WHT YEL BLU Control circuit built in 360V 15V 0V 0 6V 0 15V ...

Page 15: ...D VOLTAGE RATED FREQUENCY POLE NUMBER COMPRESSOR Compressor Motor Specifications CONNECTION 25 C 68 F 75 C 167 F RESISTANCE VALUE 2M 1 063 2M 1 268 RAM 18QH5E JU1013D2 SINGLE DC 280 330V 50Hz 4 U V W M M M WHITE YELLOW RED WHITE RED YELLOW ...

Page 16: ...NT TEMPERATURE MODEL RAM 18QH5E 7 6 5 3 8 4 01 4 12 RATING CAPACITY COOLING CAPACITY KW INPUT W 4 00 3 72 735 1050 1208 1245 1332 4 3 2 1 0 20 25 30 35 40 45 0 1000 2000 3000 COOLING CAPACITY ROOM TEMPERATURE 27 C WHEN TWO INDOOR UNITS OPERATE ...

Page 17: ... 16 CAPACITY DIAGRAM RELATED TO THE AMBIENT TEMPERATURE MODEL RAM 18QH5E HEATING CAPACITY ROOM TEMPERATURE 20 C WHEN TWO INDOOR UNITS OPERATE ...

Page 18: ...LATED TO THE PIPING LENGTH MODEL RAM 18QH5E 1 0 0 9 0 8 0 7 0 6 0 5 10 20 30 25 35 15 PIPING LENGTH m CHANGE RATIO OF CAPACITY HEATING 1 0 0 9 0 8 0 7 0 6 0 5 10 20 30 25 35 15 PIPING LENGTH m CHANGE RATIO OF CAPACITY COOLING ...

Page 19: ...ODEL RAM 18QH5E Heating 90 NC 70 NC 60 NC 50 NC 40 NC 30 NC 20 80 70 60 50 40 Sound pressure Level dB 30 20 10 63 Octave band Main wavelength Hz 125 250 500 1000 2000 4000 8000 APPROXIMATE THRESHOLD HEARING FOR CONTINUROUS NOISE ...

Page 20: ...ODEL RAM 18QH5E Cooling 90 NC 70 NC 60 NC 50 NC 40 NC 30 NC 20 80 70 60 50 40 Sound pressure Level dB 30 20 10 63 APPROXIMATE THRESHOLD HEARING FOR CONTINUROUS NOISE Octave band Main wavelength Hz 125 250 500 1000 2000 4000 8000 ...

Page 21: ... 20 MODEL RAM 18QH5E WIRING DIAGRAM OUTDOOR UNIT ...

Page 22: ...SEG1 SEG0 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 504FP 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 2SC2...

Page 23: ...PRINTED WIRING BOARD LOCATION DIAGRAM MODEL RAM 18QH5E 23 MOUNTING PCB SET TYPE ...

Page 24: ... Indoor and outdoor P W B Clock circuit Over heat thermistor Defrost thermistor Reversing valve coil DC35V C2 D2 Indoor Unit 2 Indoor Outdoor interface circuit 1 Indoor Outdoor interface circuit 2 Outdoor temperature thermistor PAM Power circuit Outdoor fan motor Power module Trip signal synthesis circuit Upper arm drive circuit Lower arm drive circuit Relay drive circuit Relay circuit Electric Ex...

Page 25: ... 27 heating ff BASIC MODE MODEL RAM 18QH5E ...

Page 26: ...ey is pressed 2 30 minutes after the sleep key is set the sleep shift of temperature starts and upper shift is made at least 5 times If 25 C is not reached after 6 shifts shifts repeat unit 25 C is reached 3 The sleep shift upper value of set temperature is 28 C 4 After 6 hours a shift down to the initial set temperature is made at a rate of 0 33 C 5 min 5 If the operation mode is changed during s...

Page 27: ...minutes and ON for 1 minule at high humidity or OFF for 6 minutes and ON for 1 minute at low humidity repeatedly acoording to the humidity judgement when the thermostat is turned OFF 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...

Page 28: ... 33 Table 6 Table 7 ...

Page 29: ... 35 ...

Page 30: ...rned to initial condition ASTUS 0 Released by condition 1 or 2 during reversing cycle period Shifted to balancing period 3 Outputs during defrost Indoor defrost request Transmitted to all units being operated in heating mode Compressor Balancing period for TDF414 seconds Starting of reversing cycle period by SDRCT2 min 1 for TSKTM2 seconds Accelerating by DFCTEP min 1 TDFSPT seconds in remaining r...

Page 31: ... 37 ...

Page 32: ...of defrost MAX time has elapsed 3 Failure occurred 4 Either unit 1 or unit 2 started operation Released during start of balancing period Stopped or started after remaining balancing period has elapsed Released during reverse cycle period Stopped or started after balancing for 3 minutes 3 Outputs during auto fresh Indoor unit defrost request Transmitted only to unit to which auto fresh is applied i...

Page 33: ...performed Always operation status of indoor unit are monitored and forced cooling is inhibited when operation of any unit is detected Operation status Outdoor unit fan Fixed in LO Compressor rotation speed Fixed in 3900min 1 Note During forced cooling if failure occurs in outdoor unit thermostat is turned off However it is not counted Since rotation speed of compressor is fixed in 3900min 1 during...

Page 34: ...vice valve 3 8 Single ended union 3 8 Single ended union 3 8 Single ended union 1 4 Indoor heat exchanger Air Flow Air Flow Indoor heat exchanger Single ended union 1 4 Charge port 1 2 Charge port 1 2 Service valve 1 4 Electric expansion 1 valve Electric expansion 2 valve Strainer Strainer Strainer Silencer Compressor REFRIGERATING CYCLE DIAGRAM RAM 18QH5E ...

Page 35: ...4 Service valve 3 8 Service valve 3 8 Single ended union 3 8 Single ended union 3 8 Single ended union 1 4 Indoor heat exchanger Air Flow Air Flow Indoor heat exchanger Single ended union 1 4 Charge port 1 2 Charge port 1 2 Service valve 1 4 Electric expansion 1 valve Electric expansion 2 valve Strainer Strainer Strainer Silencer Scroll Compressor ...

Page 36: ...tive connection Immediately after the compressor starts it may stop due to abnormally low speed active error etc The compressor may continue to operate normally but the power factor will decrease the operation current will increase and the overcurrent breaker of the household power board will probably activate In case of active module faulty or defective contact Although the compressor continues t...

Page 37: ...out 330V Vd DC voltage Fig 1 2 Fig 1 3 C501 L a b a b OV OV N C502 C503 Vd DC voltage Approx 330 or 360V during operation Be careful to avoid an electric shock as a high voltage is generated Also take care not to cause a short circuit through incorrect connection of test equipment terminals The circuit board could be damaged SPM2 Smoothing Capacitors C501 C502 C503 Reactor Diode stack D25 VB60 Swi...

Page 38: ... From outdoor microcomputer to indoor microcomputer The request signal output from microcomputer pins X is input to the transmitting circuit The transmitting circuit outputs an approx 38kHz high frequency signal via pin and continues the output intermittently according to the request signal This high frequency signal is amplified by a transistor superimposed on the DC 35V line via C801 C811 and L8...

Page 39: ...or the indoor and outdoor micro computers to communicate with each other Communications from indoor micro computer to outdoor microcomputer Communications from outdoor micro computer to indoor microcomputer Fig 2 1 Indoor outdoor interface Circuit ...

Page 40: ...r Communications Base of outdoor P W B Q801 Q802 Outdoor micro computer pin 70 72 Indoor micro computer pin 35V DC line 48 Pin 49 100ms Leader 33ms 1 frame 0 7V 0V 5V 0V 5V 0V 5V 0V 35V 5 7 5ms Transmit receive switching time 33ms 1 frame 0V 5V 0V 5V 0V 5V 0V 35V Base of outdoor P W B Q801 Q802 Outdoor micro computer pin 69 71 Indoor micro computer pin 35V DC line 48 Pin 49 ...

Page 41: ...he positive e side are called the upper arm and the three transistors on the negative d side the lower arm Fig 3 1 System power module circuit U is ON V is ON W U V W W V V U U A DC Compressor motor U coil V coil W coil System Power module 2 R24 INVERTER 0 35 m H Power relay Coil R003 R002 Inrush current protection relay C006 R004 Noise filter coil L N Terminal board FUSE 25A ACT MODULE ...

Page 42: ...oportional 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 Fig 3 2 Switching 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 ...

Page 43: ...control P W B may indicate as shown below From results of power module simple 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 Power module circuit U is ON V is ON Self diagnosis Self diagnosis lamp and mode lp peak current cut LD301 Abnormal low speed rotation LD301 Switching ...

Page 44: ...ansistor IC1 to convert DC330V voltage to high frequency of about 20kHz to 200kHz Transistor IC1 operates as follows 1 Shifting from OFF to ON DC about 330V is applied from smoothing capacitors C020 Œ and C021 œ in the control power circuit With this power current flows to pin 4 of IC1 via R701 and R702 and IC1 starts to tum ON Since voltage in the direction of arrow generates at pin of Switching ...

Page 45: ...when both the indoor and outdoor units stop This reduces power loss in standby status Reference If the power circuit for P W B seems to be faulty 1 Make sure that 5V 12V 15V 17V and 5V on the control P W B power voltage are the specified values 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 ...

Page 46: ... in each operation condition is approximately as shown below when measured by tester When collector voltage of Q831 is measured Operation condition Collector voltage of Q831 Cooling Heating Dehumidifying General operation of Cooling In normal heating operation MAX rotation speed instructed by indoor microcomputer after defrost is completed Defrosting Sensor dry About 35V About 0 8V About 0 8V Abou...

Page 47: ...everse electromotive force is voltage divided by R503 R505 and R604 R011 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 R608 and inputs this to microcomputer as position detection signals for points C D and E Microcomputer switches inverter using optimum timing based on position detection s...

Page 48: ...C current flowing to power module When over current instantaneous value flows it stops upper and lower arm drive circuits and also produces lp signal to stop microcomputer This circuit detects DC current flowing to power module and produces signal to notify microcomputer of overload status This circuit voltage amplifies DC current level detected by detection resistor and sends it to microcomputer ...

Page 49: ...h as SPM As shown in diagram when current exceeding 24A flows voltage at point A detected by detection resistor is input to pin 9 of INV HIC and voltage divided by R41 and R43 is input to pin 9 of IC1 Since this voltage exceeds threshold of IC1 LO is output from pin 8 voltage at point B When LO is input to pin 9 of microcomouter microcomputer stops drive output When drive output of microcomputer s...

Page 50: ...ircuit Internal judgement DC voltage Judgement value according to the rotation speed internal judgement value OVL judgment to external set value A D converter E2PROM built in A D converter OVL judgment according to rotation speed Data selection according to rotation speed DC voltage OVL start current data Rotation speed data Motor control process AX 6M01 micro computer Detection resistor Fig 8 1 O...

Page 51: ...or is balanced by resistor R245 and C220 then input to pin 5 of IC4 IC4 composes non inverting amplifies combined with peripheral components As shown in Fig 8 5 a value varying according to rotation speed is programmed in microcomputer When DC current value exceeds this set value overload control is set Control of compressor motor is the same as that in external judgment Set value is determined by...

Page 52: ...o change in power voltage The control system deals with change in voltage as shown below 1 As shown in Fig 8 6 U and V transistors on power module are turned on to apply current to winding of motor 2 As shown in Fig 8 7 ON time of W transistor changes according to DC voltage level so that starting current is about 10A Fig 8 5 DC current 0 0 Rotation speed Amplification rate low DC voltage low DC c...

Page 53: ...er voltage of ZD201 ZD201 turns ON and Q208 and Q209 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 However Q208 is left ON since reset voltage is fed back by R294 until 12V line drops to about 7 6V This prevents chattering of reset volt...

Page 54: ... set value microcomputer enters defrost control mode During defrost operation microcomputer transfers indoor unit defrost condition command from IF transmission output at SDO pin of interface pin and X of microcomputer Outdoor temperature is always read in voltage at pin v of microcomputer by outdoor temperature thermistor and then transferred to indoor unit side According to this value compressor...

Page 55: ...e signal output from microcomputer is input to IC inverted due to active LO and 0 to 15V chopper signal is obtained This signal is then applied to transistor gate of each phase to drive Fig 11 1 Fig 11 1 shows the drive circuit The circuits for U phase V phase and W phase have the same Configuration ...

Page 56: ... 62 Fig 11 2 ...

Page 57: ...t 12V when no power is supplied When power is reset initialization is performed for 10 or 20 seconds During initialization measure all voltages at pins 4 to 1 of CN15 and CN16 using tester If there is any pin with voltage that has not changed from around 0 9V or 12V expansion valve or microcomputer is defective Fig 12 2 shows logic waveform when expansion valve is operating Table 12 1 With explosi...

Page 58: ...tate when Vsp was proceeding over than 1 7V and generate FG pulse by rotation speed FG pulse will feed back to Outdoor Microprocessor through PQ102 PQ102 is the isolator between Microprocessor circuit and DC Fan Motor circuit which has to match the Fan Motor revolution with instructed revolution Such as FG feedback Faster Instruction Slower Decrease pulse width FG feedback Slower Instruction Faste...

Page 59: ...turb the Fan rotation by inserting materials into propeller fan or ice has growing inside of outdoor unit by snowing Fan lock detecting system may be actidiated by strong wind ex 17m sec or above against the Fan rotation In this case unit will be restart again after a while Fan lock detecting system may be actidiated even though the DC Fan Motor is rotating correctly the possible cause is due to M...

Page 60: ...structions on How to operate the outdoor unit independently How is self diagnosis lamp LD301 lighting If fuse is blown other parts may be affected Take care Mainly varistor 2 diode stack smoothing capacitor and system power module Is the switching power circuit OK Is 3A fuse normal Refer to lighting mode of self diagnosis lamps Replace defective components Check to see whether the connected cord D...

Page 61: ...s of interface relay Is a voltage 10V or more being generated between the contact terminals of interface relay Check the interface curcuit Yes Yes No No No Yes D707 and C710 could be defective There may be defective parts between 12V output of switching power supply on control P W B and interface relay Also be care of solder touch etc Repalce the interface relay No Yes C D Indoor 1 C2 D2 Indoor 2 ...

Page 62: ... lead wire Looking at P W B diagram and circuit diagram perform continuity check of pattern and lead wire Is system power module SPM2 normal Is the drive circuit normal Is thermistor connected correctly Be careful not to forget to connect it after servicing is completed Is the continuity of thermistor normal Is the thermistor circuit normal Replace defective parts Connect the thermistor Replace th...

Page 63: ... module SPM2 normal Replace system power module SPM2 No No No Yes Yes No Yes No Yes No Yes Is the thermistor circuit normal Is the drive circuit normal Is system power module normal SPM2 Replace the main P W B Replace defective parts Replace system power module SPM2 Replace the thermistor circuit parts Looking at P W B diagram and circuit diagram perform continuity check of pattern and lead wire ...

Page 64: ...wer module normal SPM2 Yes Yes No No No Check again to see that all connectors are connected securely LD301 blinks twice Peak current cut No Is the drive circuit normal Is the reset circuit normal Perform final operation check Try operation again Is operation normal Replace defective parts Replace defective parts Replace system power module SPM2 ...

Page 65: ...s abnormal Yes Is DC voltage 330V or more present across tab of SPM2 Is OVL lamp lighting Where OVL lamp lights this indicates over load and is not abnormal Check diode stack If phenomenon persists replace system power module No Check cords connected to system power module again If any cord is disconnected connect correctly ...

Page 66: ...s completed turn the power switch OFF and then ON again HOW TO OPERATE THE OUTDOOR UNIT INDEPENDENTLY Operation method is the same as that for operation using service switch of outdoor unit described above However interface signal communication error no input at C D terminals will be displayed when operation is complete Apply vacuum and then charge refrigerant of 300g Never operate continuously fo...

Page 67: ...e power switch is turned off DANGER Across a b 0V line Across a ground Across b 0V line ground approx 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 oscilloscope DANGER Don t install the ground line Oscillosco...

Page 68: ... about 360V is charged at both ends of smoothing capacitors 400 µF X 3 High voltage DC 360V is also charged at screw and terminal sactions of system power module During continuity check for each circuit of electrical parts in outdoor unit is performed to prevent secondary trouble disconnect red gray wire connected to system power module SPM2 from diode stack Also be sure to perform discharging of ...

Page 69: ... 75 1 Outdoor unit does not operate remote control signal can be received RAM 40QH5 ...

Page 70: ...ng Capacitors C501 C502 C503 Reactor Diode stack D25 VB60 Switching Power P W B For Indoor P W B Service switch Control P W B Power P W B Terminal Board 2p Terminal Board 4p Self diagnosis lamps From left LD301 LD302 LD303 LD304 1 Location of self diagnosis lamp ...

Page 71: ... 77 Lighting mode self diagnosis lamp 2 RAM 18QH5E ...

Page 72: ... 78 TROUBLESHOOTING OF THE SYSTEM POWER MODULE ...

Page 73: ... 79 ...

Page 74: ... 80 ...

Page 75: ... 81 ELECTRIC EXPANSION VALVE PIPE THERMISTOR POSITION CHARTS MODEL RAM 18QH5E ...

Page 76: ... 82 6 22 12 36 21 3 10 10 37 35 9 8 17 24 25 39 35 32 1 20 30 31 18 15 19 38 35 5 4 23 27 26 28 33 2 34 14 13 29 11 7 16 PARTS LIST AND DIAGRAM MODEL RAM 18QH5E ...

Page 77: ...40QH5 915 1 PWB POWER 19 PMRAS 51CHA1 013 1 PWB SW POWER 20 PMRAC 18SH4 901 1 REACTOR 21 PMRAC 19SH4 904 1 REVERSING VALVE 22 PMRAM 40QH5 903 1 SIDE PLATE R 23 PMRAM 40QH5 908 1 STRAINER COND 1 24 PMRAM 40QH5 909 1 STRAINER COND 2 25 PMRAM 40QH5 904 1 STRAINER COND 26 PMRAM 40QH5 912 1 STRAINER PIPE 27 PMRAM 40QH5 913 1 STRAINER ST PIPE AS 1 28 PMRAM 40QH5 914 1 STRAINER ST PIPE AS 2 29 PMRAC 25NH...

Page 78: ...HITACHI PM NO 0276E Printed in Malaysia RAM 18QH5E ...

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