Hitachi RAI-50NH5 Service Manual
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Hitachi RAI-50NH5 Service Manual

Hitachi RAI-50NH5 Service Manual

Room air conditioner
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SERVICE MANUAL

TECHNICAL INFORMATION

FOR SERVICE PERSONNEL ONLY
SPECIFICATIONS
TYPE
MODEL
POWER SOURCE
TOTAL INPUT
TOTAL AMPERES
COOLING
CAPACITY
TOTAL INPUT
TOTAL AMPERES
HEATING
CAPACITY
DIMENSIONS
(mm)
NET WEIGHT
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
DECEMBER 2005
0274E cover(RAI-50NH5)
RAI-ECPM
RAI-50NH5
RAC-50NH5
(W)
(A)
(kW)
(B.T.U./h)
(W)
(A)
(kW)
(B.T.U./h)
W
H
D
(kg)

ROOM AIR CONDITIONER

INDOOR UNIT + OUTDOOR UNIT
Refrigeration & Air-Conditioning Division
1
PM
RAI-50NH5/RAC-50NH5
REFER TO THE FOUNDATION MANUAL
SPECIFICATIONS ------------------------------------------------------------------- 4
HOW TO USE ------------------------------------------------------------------------ 6
CONSTRUCTION AND DIMENSIONAL DIAGRAM ---------------------- 27
MAIN PARTS COMPONENT --------------------------------------------------- 29
WIRING DIAGRAM ----------------------------------------------------------------- 31
CIRCUIT DIAGRAM ---------------------------------------------------------------- 33
PRINTED WIRING BOARD LOCATION DIAGRAM ---------------------- 39
BLOCK DIAGRAM ------------------------------------------------------------------ 41
BASIC MODE ------------------------------------------------------------------------ 43
REFRIGERATING CYCLE DIAGRAM ---------------------------------------- 57
AUTO SWING FUNCTION ------------------------------------------------------- 58
DESCRIPTION OF MAIN CIRCUIT OPERATION ------------------------ 59
TROUBLE SHOOTING ------------------------------------------------------------ 93
PARTS LIST AND DIAGRAM ------------------------------------------------- 113
DC INVERTER (CEILING CASSETTE TYPE)
INDOOR UNIT
RAI-50NH5
1 PHASE, 50 Hz, 220-240V
1,990 (155~2,200)
9.10 ~ 8.37
5.00 (0.90 ~ 5.20)
17,070
2,160 (155 ~ 2,200)
9.87 ~ 9.05
6.50 (0.90 ~ 8.10)
22,190
580
285
580
20
19/10/05, 2:41 PM
NO. 0274E
CONTENTS
RAC-50NH5
850
650
298
60

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Summary of Contents for Hitachi RAI-50NH5

  • Page 1: Table Of Contents

    6.50 (0.90 ~ 8.10) CAPACITY (B.T.U./h) 22,190 DIMENSIONS (mm) NET WEIGHT (kg) SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT ROOM AIR CONDITIONER INDOOR UNIT + OUTDOOR UNIT Refrigeration & Air-Conditioning Division DECEMBER 2005 0274E cover(RAI-50NH5) 19/10/05, 2:41 PM...
  • Page 2 DANGER installation. 11. Check the grounding to see whether it is proper or not, and if it is found improper, connect the grounding terminal to the earth. – i – 0274E Pg 1-5(RAI-50NH5) 19/10/05, 2:44 PM...
  • Page 3 (5) Be careful not to fail to turn off power when you repair the printed circuit board. At the same time, try to repair the printed circuit board on a grounded metal plate. Body earth (Elimik conductive band) Clip for connection with a grounding wire Fig. 2. Body Earth – 1 – 0274E Pg 1-5(RAI-50NH5) 19/10/05, 2:44 PM...
  • Page 4 (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. – 2 – 0274E Pg 1-5(RAI-50NH5) 19/10/05, 2:44 PM...
  • Page 5 When the outside heat exchanger is frosted, the frost is melted by operating the hot gas system, it is not trouble that at this time fan stops and the vapour may rise from the outside heat exchanger. – 3 – 0274E Pg 1-5(RAI-50NH5) 19/10/05, 2:44 PM...

  • Page 6: Specifications

    TRANSFORMER VARISTOR 450NR NOISE SUPPRESSOR THERMOSTAT YES(IC) YES(IC) REMOTE CONTROL SWITCH (LIQUID CRYSTAL) UNIT 1400g ---------- REFRIGERANT CHARGING VOLUME WITHOUT REFRIGERANT BECAUSE (Refrigerant 410A) PIPES (MAX. 20m) COUPLING IS FLARE TYPE. – 4 – 0274E Pg 1-5(RAI-50NH5) 19/10/05, 2:44 PM...
  • Page 7 Drain Pipe above 100mm ceiling of balcony Must be installed separately. give clearance as Insulate indoor part of pipe wide as possible to prevent condensation. above 100mm above 200mm above 700mm – 5 – 0274E Pg 1-5(RAI-50NH5) 19/10/05, 2:44 PM...

  • Page 8: Safety Precaution

    OFF. Do not use any conductor as fuse wire, this could cause fatal accident. During thunder storm, disconnect and turn off the circuit breaker. – 6 – 0274E Pg 6-18(RAI-50NH5) 19/10/05, 2:46 PM...
  • Page 9 This appliance 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 supervised to ensure that they do not play with the appliance. – 7 – 0274E Pg 6-18(RAI-50NH5) 19/10/05, 2:46 PM...

  • Page 10: Names And Functions Of Each Part

    This is because the indoor unit present temperature quickly. returns refrigerant to the outdoor unit to be ready for operation. – 8 – 0274E Pg 6-18(RAI-50NH5) 19/10/05, 2:46 PM...
  • Page 11 200 hours, the FILTER lamp lights to indicate that it is time to clean the filter. The lamp goes out when the “ (AUTO SWING)” button is pressed while the device is on “STANDBY MODE”. – 9 – 0274E Pg 6-18(RAI-50NH5) 19/10/05, 2:46 PM...

  • Page 12: Names And Functions Of Remote Control Unit

    This is to protect the device and does not indicate a failure. TIMER SET TIMER SELECTOR If you press the FUNCTION selector button during operation, the ON TIMER OFF TIMER device may stop for about 3 minutes for protection. AUTO SWING – 10 – 0274E Pg 6-18(RAI-50NH5) 19/10/05, 2:46 PM...

  • Page 13: Automatic Operation

    The display does not indicate the preset temperature in the AUTO mode. If you change the setting, the indoor unit will produce a beep. Press the (FAN SPEED) button, AUTO and LOW is available. – 11 – 0274E Pg 6-18(RAI-50NH5) 19/10/05, 2:46 PM...

  • Page 14: Heating Operation

    Press the button again to stop operation. STOP I As the settings are stored in memory in the remote controller, you only have to press the (START/STOP) button next time. – 12 – 0274E Pg 6-18(RAI-50NH5) 15/11/05, 9:30 AM...

  • Page 15: Dehumidifying Operation

    The function will stop (the indoor unit will stop emitting air) as soon as the room temperature becomes lower than the setting temperature. – 13 – 0274E Pg 6-18(RAI-50NH5) 19/10/05, 2:46 PM...

  • Page 16: Cooling Operation

    I As the settings are stored in memory in the remote controller, you only have to press the (START/STOP) button next time. – 14 – 0274E Pg 6-18(RAI-50NH5) 15/11/05, 9:30 AM...

  • Page 17: Fan Operation

    For the cooling operation 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. – 15 – 0274E Pg 6-18(RAI-50NH5) 19/10/05, 2:47 PM...

  • Page 18: How To Set The Timer

    (CANCEL) button. (RESERVED) sign goes out with a beep and the (TIMER) lamp turns off on the indoor unit. NOTE You can set only one of the OFF-timer, ON-timer and ON/OFF-timer. – 16 – 0274E Pg 6-18(RAI-50NH5) 19/10/05, 2:47 PM...
  • Page 19 As the time settings are stored in memory in the remote controller, you only have to press (RESERVE) button in order to use the same settings next time. – 17 – 0274E Pg 6-18(RAI-50NH5) 19/10/05, 2:47 PM...

  • Page 20: How To Set The Sleep Timer

    Point the signal window of the remote controller toward the indoor unit, and press the (CANCEL) button. (RESERVED) sign goes out with a beep and the (TIMER) lamp turns off on the indoor unit. – 18 – 0274E Pg 6-18(RAI-50NH5) 19/10/05, 2:47 PM...

  • Page 21: Adjusting The Air Deflector

    When operating the unit in cooling operation with the air deflector facing down and moving automatically for a long period of time, water will condensed on the air deflector and drips down occasionally. This will wet your furniture. – 19 – 0274E Pg 19-26(RAI-50NH5) 19/10/05, 2:51 PM...

  • Page 22: How To Exchange The Batteries In The Remote Controller

    1. Do not use new and old batteries, or different kinds of batteries together. 2. Take out the batteries when you do not use the remote controller for 2 or 3 months. – 20 – 0274E Pg 19-26(RAI-50NH5) 19/10/05, 2:51 PM...

  • Page 23: Suitable Room Temperature

    Please pay attention to the room temperature electric energy, please clean the filter every 2 and air flow direction when operating the unit weeks. for baby, children and old folks who have difficulty in movement. – 21 – 0274E Pg 19-26(RAI-50NH5) 19/10/05, 2:51 PM...
  • Page 24 Inverter-type fluorescent To avoid noise interference, please place the indoor lamp. unit and its remote controller at least 1m away from To prevent electrical products. interference, place at least 1m away. – 22 – 0274E Pg 19-26(RAI-50NH5) 19/10/05, 2:51 PM...
  • Page 25 When washing it, shake off moisture completely and dry it in the shade; do not expose it directly to the sun. The filter may shrink. Do not operate the air conditioner with the filter removed. Dust may enter the air conditioner and cause trouble. – 23 – 0274E Pg 19-26(RAI-50NH5) 19/10/05, 2:51 PM...

  • Page 26: Cleaning Of Front Panel

    Outdoor unit may fall or drop if there is extreme rust on mounting frame or outdoor unit is unstably installed. This may cause injury. Is the plug of power line firmly plugged into the socket? (Please ensure no loose contact between them). Confirm – 24 – 0274E Pg 19-26(RAI-50NH5) 19/10/05, 2:51 PM...
  • Page 27 Inform your agent of the model of your unit, production number, date of installation. Please also inform him regarding the fault. Power supply shall be connected at the rated voltage, otherwise the unit will be broken or could not reach the specified capacity. – 25 – 0274E Pg 19-26(RAI-50NH5) 19/10/05, 2:51 PM...
  • Page 28 Dry bulb °C Outdoor Wet bulb °C MEMO ................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... – 26 – 0274E Pg 19-26(RAI-50NH5) 19/10/05, 2:51 PM...

  • Page 29: Construction And Dimensional Diagram

    Height difference of the piping between the indoor unit and the outdoor unit should be within 10m. An F-cable 1.6mm or 2.0mm dia. X 3 (control side) is used for the connection cable. – 27 – 0274E Pg 27-30(RAI-50NH5) 19/10/05, 2:57 PM...
  • Page 30 CONSTRUCTION AND DIMENSIONAL DIAGRAM FOR OUTDOOR MODEL RAC-50NH5 Handle Handle Air suction Air outlet grille Holes for anchor bolt (2-ø12) More than More than Fixing hole Service space Notch for anchor bolt (2-ø12 Notchs) – 28 – 0274E Pg 27-30(RAI-50NH5) 19/10/05, 2:57 PM...

  • Page 31: Main Parts Component

    BLU : BLUE YEL : YELLOW BRN : BROWN WHT : WHITE GRY : GRAY ORN : ORANGE GRN : GREEN RED : RED BLK : BLACK PNK : PINK VIO : VIOLET – 29 – 0274E Pg 27-30(RAI-50NH5) 19/10/05, 2:57 PM...
  • Page 32 When the refrigerating 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. – 30 – 0274E Pg 27-30(RAI-50NH5) 19/10/05, 2:57 PM...

  • Page 33: Wiring Diagram

    WIRING DIAGRAM MODEL RAI-50NH5 / RAC-50NH5 INDOOR UNIT OUTDOOR UNIT – 31 – 0274E Pg 31(RAI-50NH5) 19/10/05, 2:59 PM...

  • Page 34: Circuit Diagram

    D1 D2 EL-1L7 50v/1u K11K12 RB425D (1/2) 100k 100k 220k 100k R6 R9 150k 24(1/8W) 32.768 SW-187-2P 100k 220K 910kHz 2SC3443 or 2SC2982 100k 100k C2 C3 18p 22p 220k 220p 220p – 33 – 0274E Pg 33(RAI-50NH5) 19/10/05, 3:00 PM...
  • Page 35 CIRCUIT DIAGRAM MODEL RAI-50NH5 – 35 – 0274E Pg 35(RAI-50NH5) 19/10/05, 3:09 PM...
  • Page 36 CIRCUIT DIAGRAM MODEL RAC-50NH5 – 37 – 0274E Pg 37(RAI-50NH5) 19/10/05, 3:14 PM...

  • Page 37: Printed Wiring Board Location Diagram

    PRINTED WIRING BOARD LOCATION DIAGRAM MODEL RAI-50NH5 MAIN P.W.B. Marking on P.W.B. COMPONENT SIDE SOLDERING SIDE – 39 – 0274E Pg 39-40(RAI-50NH5) 19/10/05, 3:16 PM...
  • Page 38 MODEL RAC-50NH5 MAIN P.W.B. Marking on P.W.B – 40 – 0274E Pg 39-40(RAI-50NH5) 19/10/05, 3:16 PM...
  • Page 39 RAI-50NH5 / RAC-50NH5 SPM2 Outdoor unit Terminal board Trip signal synthesis circuit Wireless receive LCD wireless circuit Filter. Room temperature Operation. thermistor Timer. Drain Pump Motor Auto sweep motor for Heat exchanger Air deflector thermistor Electric Expansion valve Electric Expansion valve...
  • Page 40 – 43 – 0274E Pg 43(RAI-50NH5) 19/10/05, 3:24 PM...
  • Page 41 1800 min –1 STARTMC 60 Seconds DWNRATEW DWNRATEC SHIFTW 4.00°C SHIFTC –2.99°C CLMXTP 30.00°C YNEOF 21.00°C TEION 2.00°C TEIOF 6.00°C SFTDSW 2.66°C DFTIM1 50 Minutes DFTIM2 90 Minutes DFTIM3 60 Minutes – 45 – 0274E pg 45(RAI-50NH5) 19/10/05, 3:25 PM...
  • Page 42 (8) When fan is set to “Lo”, compressor rpm will be limited to CBEMAX. (9) During Cool Dashed, when room temperature reaches set temperature –1°C compressor rpm is actual rpm x DWNRATEC. – 47 – 0274E Pg 47(RAI-50NH5) 19/10/05, 3:29 PM...
  • Page 43 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 is cleared. – 49 – 0274E Pg 49(RAI-50NH5) 19/10/05, 3:30 PM...
  • Page 44 (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 are 3 minutes. – 51 – 0274E Pg 51(RAI-50NH5) 19/10/05, 3:31 PM...
  • Page 45 (10) During Hot Dashed or outdoor temperature is lower than –5°C, compressor rpm is WMAX2. (11) During Hot Dashed, when room temperature reaches set temperature + SFTDSW compressor rpm is actual rpm x DWNRATEW. – 53 – 0274E Pg 53(RAI-50NH5) 19/10/05, 3:32 PM...
  • Page 46 From the second time onwards, the inhibit time is set according to the time required for defrosting. Reverse cycle operation time ≥ [DEFCOL] : DFTIM1 is set. Reverse cycle operation time < [DEFCOL] : The time corresponding to outdoor tempera- ture is set. – 55 – 0274E Pg 55(RAI-50NH5) 19/10/05, 3:33 PM...

  • Page 47: Refrigerating Cycle Diagram

    SINGLE-ENDED UNION (1/4) STRAINER HEATING SERVICE VALVE OUTDOOR UNIT INDOOR UNIT (1/2) SINGLE-ENDED ADAPTOR UNION (3/8) SUCTION TANK REVERSING VALVE ELECTRIC EXPANSION VALVE SERVICE VALVE (1/4) STRAINER SINGLE-ENDED UNION (1/4) STRAINER – 57 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 48 – 58 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...

  • Page 49: Description Of Main Circuit Operation

    When power “ON” 5V voltage rises and reaches 4.4V, pin 1 of IC521 is set to “Hi”. At this time the microcomputer starts operation. When power “OFF” voltage drops and reaches 4.2V, pin 1 of IC521 is set to “Low”. This will RESET the microcomputer. – 59 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 50 12Vp-p by a transistor, it is applied to the buzzer. The piezoelectric element in Metal diaphragm Pizoelectric element the buzzer oscillates to generate the buzzer’s sound. Sound wave Fig. 3-2 Buzzer Operation – 60 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 51 Securely connect the relay connectors identified by colors when attaching the panel. Before removing the panel for servicing, be sure to disconnect the relay connector to protect the lead wires. – 61 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 52 Detection of the reversing valve non-operation or heat exchanger temperature thermistor open. The voltage at depends on the heat exchanger temperature as shown in Fig. 6-2. Heat exchanger temperature (˚C) Fig. 6-2 – 62 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 53 Data of self-diagnosis mode is stored in IC401; data will not be erased even when power is turned off. Microcomputer C401 External ROM IC401 (E PROM) Fig. 7-1 – 63 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 54 If diode stack 2 is faulty, DC voltage may not be generated and the compressor may not operate at all. Also, be aware that the 3A fuse might have blown. – 64 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 55 (6) Surge absorber, Varistor 1, 2, 3, absorbs external power surge. (7) Inrush protective resistor (R007, R008) This works to protect from overcurrent when power is turned – 65 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 56 Fig. 2-3 shows the voltages at each component when data is transferred from outdoor microcomputer to indoor microcomputer. The circuit operation of the outdoor receiving circuit is same as indoor receiving circuit. – 66 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 57 C811 C807 C802 C806 C810 NF COIL2 C812 C808 I/F 0V L802 (Communications from outdoor microcomputer to indoor microcomputer) (Communications from indoor microcomputer to outdoor microcomputer) Fig. 2-1 Indoor/outdoor interface Circuit – 67 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 58 Fig. 2-2 Voltages Waveforms of indoor / Outdoor Microcomputers (Outdoor to Indoor Communications) Outdoor HIC Indoor microcomputer DC 35V line 4.95ms. 33ms. Transmit / receive 1 frame switching time Fig. 2-3 Voltages Waveforms of indoor / Outdoor Microcomputers (Indoor to Outdoor Communications) – 68 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 59 – 69 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 60 Capacity code (1) Self-diagnosis (0 LSB) Capacity code (0 LSB) Defrost request signal Indoor in-operation bit During forced operation Operation mode (2 MSB) Operation mode (1) Multi-bit Operation mode (0 LSB) – 70 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 61 3. Power Module Circuit – 71 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:34 PM...
  • Page 62 [ Point (Fig. 3-1) (2) When U + transistor is OFF: (by inductance of motor coil) U coil [ V coil [ V – transistor [ Return diode [ Point (Fig. 3-4) – 72 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 63 (3) If normal operation continues for more than 1 minute (LD303 lights), power module is considered normal. ❈ Refer to other item (troubleshooting on page 94) for independent checking of power module. – 73 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 64 IC901 via R903 and R904 and IC901 starts to tum ON. Since voltage in the direction of arrow generates at point at the same time, current passing through R910 and D903 is positive-fed back to IC901. – 74 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 65 R904 and R903) and IC901 pin 5 (to be measured at R906 lead) may be between 11 and 16V. This is because the protection circuit of IC901 is operating.] – 75 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 66 General operation of Cooling About 35V In normal heating operation About 0.8V MAX. rotation speed instructed Heating by indoor microcomputer after About 0.8V defrost is completed Defrosting About 35V Dehumidifying Sensor dry About 35V – 76 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 67 For V phase and W phase, in the same way as above, drive signals are produced from voltages at point and point . Phases are shifted by 120° and 240°, respectively, comparing with U phase. – 77 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 68 7. Drive Circuit Fig. 7-1 shows the drive circuit. The circuits for U phase, V phase and W phase have the same Configuration. – 78 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 69 [Low speed rotation mode] Fig. 7-2 [High speed rotation mode] Fig. 7-3 – 79 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 70 Internal or external overload is judged in microcomputer. circuit Reset circuit Produces reset voltage. Trip signal Modulates chopper signal to drive signal and stops according to presence/ab- synthesis circuit sence of lp signal or reset signal. – 80 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 71 When drive output from microcomputer is stopped, all drive output goes Hi, and microcomputer is initialized to enter drive signal standby mode. 3 minutes later, microcomputer outputs drive signal again, to start operation. – 81 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 72 Fig. 8-7 shows the rotation speed control. When the voltage at pin of the microcomputer exceeds the set value, the microcomputer decreases the rotation speed of the compressor and reduces the load regardless of the rotation speed commanded by the indoor microcomputer. – 82 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 73 The set Value is determined by the amplification of the voltage amp. circuit. Amplification : high [ DC current : low Amplification : low [ DC current: high – 83 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 74 U — V — W — Detection resistor Fig. 8-9 Chopper duty: high DC voltage: low DC voltage: 280V DC voltage: high DC voltage (start current) Set value Time Start Fig. 8-10 – 84 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 75 5 V, and LD301 blinks seven times. However, an error is detected only when the OH thermistor is shorted; in such a case, the blinking mode is entered 12 minutes after the compressor starts operation. – 85 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 76 Reset voltage will be hold “Hi” until the 12V line voltage drops to 9.90V even though the power shuts down. 12V line 5V line Reset voltage Time 12V line 5V line Reset voltage Time Fig. 10-2 – 86 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 77 Fan Motor was malfunction and stop the operation. In this case, LD302 on control PWB will blink 12 times. (Fan Motor lock detected) R107 and IC4 are used for Fan Motor over current – 87 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 78 Please take care for the electrical shock by high voltage of DC Fan Motor power source which is common with compressor when you are servicing this unit. You can not confirm the coil and wiring of Motor due to the built in control circuit in Fan Motor. – 88 – 0274E Pg 57-88(RAI-50NH5) 19/10/05, 3:35 PM...
  • Page 79 (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. – 89 – 0274E Pg 89-96(RAI-50NH5) 19/10/05, 3:36 PM...

  • Page 80: Service Call Q & A

    MED after additional 30 seconds. If temperature is high in Heating operation stops the outdoor, heating while the temperature is operation may stop to preset at "30". protect internal devices. – 90 – 0274E Pg 89-96(RAI-50NH5) 19/10/05, 3:36 PM...
  • Page 81 The timer has been programmed, Is the current time past the preset time? but the preset time disappears. When the preset time reaches the current time, it disappears. – 91 – 0274E Pg 89-96(RAI-50NH5) 19/10/05, 3:36 PM...
  • Page 82 The operation lamp blinks during this time for heating. This does not indicate a fault. – 92 – 0274E Pg 89-96(RAI-50NH5) 19/10/05, 3:36 PM...

  • Page 83: Trouble Shooting

    Don’t install oscilloscope. When using an the ground oscilloscope, never line. Oscilloscope ground it. Don't forget that high voltages as noted above may apply to the oscilloscope. – 93 – 0274E Pg 89-96(RAI-50NH5) 19/10/05, 3:36 PM...
  • Page 84 By removing red/ gray lead wire from diode stack, power supply can be shut off. (corresponding to + and – System power module terminals of system power module) RAC-50NH5 SPM2 Smoothing capacitors – 94 – 0274E Pg 89-96(RAI-50NH5) 19/10/05, 3:36 PM...
  • Page 85 (After checking, be sure to press the service switch to stop the operation). See Out door unit self-diagnosis lamp lighting mode . Check the refrigerating cycle. Check the outdoor electrical parts. Check the indoor electrical parts. – 95 – 0274E Pg 89-96(RAI-50NH5) 19/10/05, 3:36 PM...
  • Page 86 (2) If the indoor unit does not operate at all, check to see if the F-cable is connected or disconnected. (3) To check operation again when the timer lamp is blinking, you can use the remote control for operation (except for mode mark – 96 – 0274E Pg 89-96(RAI-50NH5) 19/10/05, 3:36 PM...
  • Page 87 SELF-DIAGNOSIS LIGHTING MODE MODEL: RAI-50NH5 – 97 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...

  • Page 88: Checking Indoor Unit Electrical Parts

    (pin 7 ) Hi ? any defective section. Is the microcomputer clock signal Replace the microcomputer and 10MHz at pin being 10 11 oscillator. generated normally? Replace the P.W.B Main Perform final operation check. – 98 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...
  • Page 89 2. Outdoor unit does not operate (but receives remote infrared signal) – 99 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...
  • Page 90 Replace micro computer. deflector set to auto during cooling? Is there a voltage higher than 15V Replace IC111. Replace the air deflector motor. across C114 (12 V line)? Perform final operation check. – 100 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...
  • Page 91 Check to see if the indoor fan is Can the indoor fan be lightly turned by hand? touching the chassis, etc. (Set the power switch to "off" to check.) If it does, repair. Replace the indoor fan motor. – 101 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...

  • Page 92: Checking The Remote Controller

    CHECKING THE REMOTE CONTROLLER – 102 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...
  • Page 93 CHECKING THE OUTDOOR UNIT ELECTRICAL PARTS MODEL RAI-50NH5 – 103 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...
  • Page 94 – 104 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...
  • Page 95 – 105 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...
  • Page 96 – 106 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...
  • Page 97 – 107 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...
  • Page 98 If the lamp is lit, it does not If abnormality continues, indicate fault, but the unit replace the system is overload status. power module. Overvoltage defect: system power module faulty (15-times blinking) – 108 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...

  • Page 99: Checking The Refrigerating Cycle

    Repair and seal refrigerant. 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. Perform a final check of operation. – 109 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...
  • Page 100 Furthermore, compare how indicator swings at U, V and W phases. If indicator swings the same way at each point, it is normal. – – – – – – L2 L1 – – – 110 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:37 PM...

  • Page 101: 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. – 111 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:38 PM...
  • Page 102 (excepting the reflux diode) BASE Emitter Circuit diagram of the module – Terminals symbol mark of the module See next page for measuring value using tester – L2 L1 – 112 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:38 PM...

  • Page 103: Parts List And Diagram

    PARTS LIST AND DIAGRAM MODEL RAI-ECPM RAI-50NH5 – 113 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:38 PM...
  • Page 104 MODEL RAI-ECPM/RAI-50NH5 PART N0. Q’TY / UNIT PARTS NAME RAI-ECPM/RAI-50NH5 PMRAI-ECPM HORIZONTAL AIR DEFLECTOR 1 PMRAI-ECPM HORIZONTAL AIR DEFLECTOR 2 PMRAI-ECPM STEP MOTOR PMRAI-ECPL FILTER PMRAI-ECPM SUCTION GRILL PMRAI-ECPM P.W.B. (DISPLAY) – 114 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:38 PM...
  • Page 105 PARTS LIST AND DIAGRAM INDOOR UNIT MODEL : RAI-50NH5 – 115 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:38 PM...
  • Page 106 TURBO FAN PMRAI-32CNH2 DRAIN PAN ASSEMBLY PMRAS-51CHA1 REMOTE CONTROL ASSEMBLY PMRAS-10C3M REMOTE CONTROL SUPPORT PMRAI-32CNH2 DRAIN CAP PMRAI-25NH4 DRAIN PUMP ASSEMBLY PMRAI-50NH5 CYCLE ASSEMBLY PMRAS-10C6M TERMINAL BOARD (2P) PMRAI-50NH5 P.W.B. (MAIN) – 116 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:38 PM...

  • Page 107: Outdoor Unit

    OUTDOOR UNIT MODEL : RAC-50NH5 – 117 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:38 PM...
  • Page 108 PROPELLER FAN PMRAC-40CNH2 SUPPORT (FAN MOTOR) PMRAC-40CNH2 FAN MOTOR (40W) PMRAC-50NH5 CABINET PMRAC-40CNH2 PMRAC-40CNH2 TOP COVER PMRAC-50NH4 SIDE PLATE-R PMRAC-50NH4 STRAINER PMRAC-50NH4 STRAINER PMRAC-40CNH2 SIDE PLATE-L PMRAC-40CNH2 GRILL PMRAC-25NH4 EXPANSION VALVE – 118 – 0274E Pg 97-118(RAI-50NH5) 19/10/05, 3:38 PM...
  • Page 109 HITACHI RAI-50NH5/RAC-50NH5 PM NO. 0274E Printed in Malaysia 0274E cover(RAI-50NH5) 19/10/05, 2:41 PM...

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Rac-50nh5

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