NO. 0466E RAS-50FH7/RAC-50YH7 SERVICE MANUAL REFER TO THE FOUNDATION MANUAL TECHNICAL INFORMATION FOR SERVICE PERSONNEL ONLY CONTENTS SPECIFICATIONS ------------------------------------------------------------------- 5 HOW TO USE ------------------------------------------------------------------------ 7 CONSTRUCTION AND DIMENSIONAL DIAGRAM --------------------- 29 MAIN PARTS COMPONENT --------------------------------------------------- 31 HITACHI WIRING DIAGRAM ---------------------------------------------------------------- 33...
Page 2
SAFETY DURING REPAIR WORK 1. In order to disassemble and repair the unit in question, be sure to disconnect the power cord plug from the power outlet before starting the work. 2. If it is necessary to replace any parts, they should be replaced with respective genuine parts for the unit, and the replacement must be effected in correct manner according to the instructions in the Service Manual of the unit.
Page 3
WORKING STANDARDS FOR PREVENTING BREAKAGE OF SEMICONDUCTORS 1. Scope The standards provide for items to be generally observed in carrying and handling semiconductors in relative manufacturers during maintenance and handling thereof. (They apply the same to handling of abnormal goods such as rejected goods being returned).
Page 4
(6) Use a three wire type soldering iron including a grounding wire. Metal plate (of aluminium, stainless steel, etc.) Working table Resistor of 1 M (1/2W) Staple Earth wire Bare copper wire (for body earth) Fig. 3. Grounding of the working table Soldering iron Grounding wire...
Page 5
CAUTION In quiet or stop operation, slight flowing noise of refrigerant in the refrigerating cycle is heard occasionally, but this noise is not abnormal for the operation. When it thunders near by, it is recommend to stop the operation and to disconnect the power cord plug from the power outlet for safety.
SPECIFICATIONS MODEL RAS-50FH7 RAC-50YH7 47 W FAN MOTOR PWM DC35V FAN MOTOR CAPACITOR FAN MOTOR PROTECTOR COMPRESSOR JU1015DA – COMPRESSOR MOTOR CAPACITOR OVERLOAD PROTECTOR YES (INTERNAL) OVERHEAT PROTECTOR FUSE (for MICROPROCESSOR) POWER RELAY POWER SWITCH TEMPORARY SWITCH TEST/SERVICE SWITCH TRANSFORMER...
Page 7
Figure showing the installation of Indoor and Outdoor unit MODEL RAS-50FH7 / RAC-50YH7 above 50mm Be sure to completely seal above 100mm any gap with putty. above 100mm 2,300mm or more Plug The indoor piping should be insulated with the enclosed insulation pipe.
1 year depending on application requirements. OUTDOOR UNIT DRAIN PIPE Condensed water drain to outside. CONNECTING CORD AIR INLET (BACK, LEFT SIDE) AIR OUTLET MODEL NAME AND DIMENSIONS MODEL WIDTH (mm) HEIGHT (mm) DEPTH (mm) RAS-50FH7 RAC-50YH7 – 7 –...
Page 9
INDOOR UNIT INDICATORS FILTER LAMP When the device is operated for a total of about 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”.
Page 10
Note Avoid to use the room air conditioner for cooling operation when the outside temperature is below –10°C (14°F). The recommended maximum and minimum operating temperatures of the hot and cold sides should be as below: Cooling Heating Minimum Maximum Minimum Maximum Dry bulb °C...
SAFETY PRECAUTION Please read the “Safety Precaution” carefully before operating the unit to ensure correct usage of the unit. Pay special attention to signs of “ Warning” and “ Caution”. The “Warning” section contains matters which, if not observed strictly, may cause death or serious injury. The “Caution” section contains matters which may result in serious consequences if not observed properly.
Page 12
PRECAUTIONS DURING OPERATION The product shall be operated under the manufacturer specification and not for any other intended use. Do not attempt to operate the unit with wet hands, this could cause fatal accident. When operating the unit with burning equipments, regularly ventilate the room to avoid oxygen insufficiency.
Page 13
NAMES AND FUNCTIONS OF REMOTE CONTROL UNIT REMOTE CONTROLLER This controls the operation of the indoor unit. The range of control is about 7 meters. If indoor lighting is controlled electronically, the range of control may be shorter. This unit can be fixed on a wall using the fixture provided. Before fixing it, make sure the indoor unit can be controlled from the remote controller.
VARIOUS FUNCTIONS I Auto Restart Control If there is a power failure, operation will be automatically restarted when the power is resumed with previous operation mode and airflow direction. (As the operation is not stopped by remote controller.) If you intend not to continue the operation when the power is resumed, switch off the power supply. When you switch on the circuit breaker, the operation will be automatically restarted with previous operation mode and airflow direction.
HEATING OPERATION Use the device for heating when the outdoor temperature is under 21°C. When it is too warm (over 21°C), the heating function may not work in order to protect the device. In order to keep reliability of the device, please use this device above -15°C of the outdoor temperature. Press the FUNCTION selector so that the display indicates (HEAT).
DEHUMIDIFYING OPERATION Use the device for dehumidifying when the room temperature is over 16°C. When it is under 15°C, the dehumidifying function will not work. Press the FUNCTION selector so that the display indicates (DEHUMIDIFY). The FAN SPEED is set at LOW or SILENT. Set the desired room temperature with the TEMPERATURE button (the display indicates the setting).
COOLING OPERATION Use the device for cooling when the outdoor temperature is –10°C~ 43°C. If in doors humidity is very high (80%), some dew may form on the air outlet grille of the indoor unit. Press the FUNCTION selector so that the display indicates (COOL).
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 end of summer. Press the FUNCTION selector so that the display indicates (FAN). Press the (FAN SPEED) button.
Page 19
HOW TO SET THE TIMER Time Set the (TIME) button. After you change the batteries; TIME OFF TIMER ON TIMER OFF-Timer Press the (OFF-TIMER) button. The (OFF) mark blinks on the display. RESERVE Start STOP CANCEL You can set the device to turn off at the preset time.
Page 20
Set the current time with the Press the (TIME) button again. Press the TIMER control button. The time indication starts lighting (TIME) button. instead of flashing. The time indication will disappear automatically in 10 second. To check the current time setting, press the (TIME) button twice.
Page 21
HOW TO SET THE SLEEP TIMER Set the current time at first if it is not set before (see the pages for setting the current time). Press the (SLEEP) button, and the display changes as shown below. Mode Indication 1 hour 2 hours 3 hours 7 hours...
HOW TO EXCHANGE THE BATTERIES IN THE REMOTE CONTROLLER Remove the cover as shown in the figure and take out the Push and pull to the old batteries. direction of arrow Install the new batteries. The direction of the batteries should match the marks in the case.
THE IDEAL WAYS OF OPERATION Suitable Room Temperature Install curtain or blinds Warning It is possible to Freezing temperature reduce heat is bad for health and a entering the waste of electric power. room through windows. Ventilation Effective Usage Of Timer At night, please use the “OFF or ON timer Caution operation mode”, together with your wake up...
Page 24
FOR USER’S INFORMATION The Air Conditioner And The Heat Source In The Room Caution If the amount of heat in the room is above the cooling capability of the air conditioner (for example: more people entering the room, using heating equipments and etc.), the preset room temperature cannot be achieved.
Page 25
ATTACHING THE AIR CLEANSING FILTERS CAUTION Cleaning and maintenance must be carried out only by qualified service personal. Before cleaning, stop operation and switch off the power supply. Open the front panel. Pull up the front panel by holding it at both sides with both hands.
Page 26
MAINTENANCE CAUTION Cleaning and maintenance must be carried out only by qualified service personal. Before cleaning, stop operation and switch off the power supply. AIR FILTER Clean the air filter, as it removes dust inside the room. In case the air filter is full of dust, the air flow will decrease and the cooling capacity will be reduced.
Page 27
Washable Front Panel Remove the front panel and wash with clean water. Wash it with a soft sponge. After using neutral detergent, wash thoroughly with clean water. When front panel is not removed, wipe it with a soft dry cloth. Wipe the remote controller thoroughly with a soft dry cloth.
Page 28
CAUTION Cleaning and maintenance must be carried out only by qualified service personal. Before cleaning, stop operation and switch off the power supply. MAINTENANCE AT BEGINNING OF LONG OFF PERIOD Running the unit setting the operation mode to (FAN) and the fan speed to HI for about half a day on a fine day, and dry the whole of the unit.
Page 29
AFTER SALE SERVICE AND WARRANTY WHEN ASKING FOR SERVICE, CHECK THE FOLLOWING POINTS. CONDITION CHECK THE FOLLOWING POINTS If the remote controller is Do the batteries need replacement? not transmitting a signal. Is the polarity of the inserted batteries correct? Remote controller display is dim or blank.) Is the fuse all right?
MAIN PARTS COMPONENT THERMOSTAT (Room Temperature Thermistor) Thermostat Specifications MODEL RAS-50FH7 THERMOSTAT MODEL OPERATION MODE COOL HEAT 16.7 (62.1) 20.0 (68.0) INDICATION 16.0 (60.8) 20.7 (69.3) TEMPERATURE 24.7 (76.5) 28.0 (82.4) INDICATION °C (°F) 24.0 (75.2) 28.7 83.7) 32.7 (90.9) 36.0 (96.8)
Page 33
COMPRESSOR MOTOR Compressor Motor Specifications MODEL RAC-50YH7 COMPRESSOR MODEL JU1015DA PHASE SINGLE RATED VOLTAGE AC 220 ~ 240 V RATED FREQUENCY 50/60 Hz POLE NUMBER WHITE CONNECTION YELLOW 20°C 2M = 1.579 (68°F) RESISTANCE VALUE 75°C 2M = 2.149 (167°F) W/S (RED) V/R (YELLOW) U/C (WHITE)
PRINTED WIRING BOARD LOCATION DIAGRAM RAS-50FH7 MAIN P.W.B. Marking on P.W.B. COMPONENT SIDE SOLDERING SIDE R621 RECEIVING P.W.B. TEMPORARY OPERATION Marking on P.W.B. 7 CN11 NORMAL LIGHT TEMPORARY RECEIVING UNIT SWITCH 2RZK81395A – 41 –...
Page 43
Table 1 Mode data file RAS-50FH7 LABEL NAME VALUE –1 WMAX 4400 min –1 WMAX2 4400 min –1 WSTD 4000 min –1 WBEMAX 2600 min –1 CMAX 4400 min –1 CSTD 4100 min CKYMAX 2500 min –1 –1 CJKMAX 2900 min –1...
Page 44
∆ Table 2 TCMAX Temperature Calculated difference compressor rpm 1.66 2265 min –1 2435 min –1 –1 2.33 2600 min 2.66 2765 min –1 2935 min –1 3.33 3100 min –1 –1 3.66 3265 min 3435 min –1 4.33 3600 min –1 –1 4.66...
Page 45
Cooling Sleep Operation Final set temperature (Cooling/dehumidifying set temperature (+) sleep shift) (Cooling/dehumidifying set 0.5hr 1.5hr 2.5hr 3.5hr temperature = Remote control set temperature (+) SHIFTC) Set to 7 hours Sleep key 10 mins Operation lamp Timer lamp Indoor fan See basic operation Lo (sleep) Outdoor fan...
Page 46
Delay Notes: (1) If the room temperature is (cooling preset temperature) - (1.33°C) or less after 30 seconds from starting the operation, the operation is done assuming as the preset temperature = (room temperature at the time) - (2°C). (2) The 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.
Page 47
∆ Table 3 TWMAX Basic Heating Operation Temperature Calculated difference compressor rpm 1.66 1965 min –1 –1 2135 min 2.33 2300 min –1 Heating set temperature 2.66 2465 min –1 (remote control set temperature (+)) 2635 min –1 –1 3.33 2800 min Dash period 18˚C...
Page 48
1 min WMIN Notes: The sleep operation starts when the sleep key is pressed. When the sleep key is set, the maximum compressor speed is limited to WSTD+2000/2, and the indoor fan is set to “sleep Lo”. 30 minutes after the sleep key is set, the sleep shift of set temperature starts. The maximum sleep shift of set temperature is 5°C, and the minimum is 12°C.
DESCRIPTION OF MAIN CIRCUIT OPERATION MODEL RAS-50FH7 1. Reset Circuit NORMAL : HI RESET : LO Microcomputer R522 IC521 Fig. 1-1 Voltage 5.0V Voltage supply to of IC521 Reset enter at 4.2V Reset release at 4.4V voltage 5.0V Voltage at pin of microcomputer Fig.
Page 52
2. Receiver Circuit R201 R1109 RECEIVER I/P Microcomputer Fig. 2-1 The light receiver unit receives the infrared signal from the wireless remote control. The receiver amplifies and shapes the signal and outputs it. 3. Buzzer Circuit R219 Microcomputer Buzzer output Q722 Fig.
Page 53
4. Auto Sweep Motor Circuit Auto sweep motor for horizontal air defectors IC711 Rotor Microcomputer Fig.4-1 Fig. 4-1 shows the Auto sweep motor drive circuit; the signals shown in Fig.4-2 are output from pins – of microcomputer. Horizontal air Microcomputer pins Step width deflectors: 10ms.
Page 54
5. Room Temperature Thermistor Circuit Fig. 5-1 shows the room temperature The voltage at depends on the room thermistor circuit. temperature as shown in Fig. 5-2. Room Microcomputer temperature thermistor R305 Room temp. input C302 R301 Fig. 5-1 Room temperature (˚C) Fig.
Page 55
7. Initial Setting Circuit (IC401) When power is supplied, the microcomputer reads the data in IC401 or IC402 (E PROM) and sets the preheating activation value and the rating and maximum speed of the compressor, etc. to their initial values. Data of self-diagnosis mode is stored in IC401 or IC402;...
Page 56
DESCRIPTION OF MAIN CIRCUIT OPERATION MODEL RAC-50YH7 220-240 220-240 3.15A – 66 –...
Page 59
3. Reversing valve control circuit I/F 35V Reversing valve R437 D401 PQ701 Q401 R435 R436 DC voltmeter or tester I/F 0V Fig. 3 – 1 Reversing valve control circuit can switch reversing valve ON/OFF according to instruction from indoor microcomputer depending on the operation condition shows in Table 3-1. Voltage at each point in each operation condition is approximately as shown below when measured by tester.
SERVICE CALL Q & A COOLING MODE The compressor has stopped Check if indoor heat If the air conditioner operates suddenly during cooling exchanger is frosted. in cooling mode when it is cold, operation. Wait for 3-4 minutes the evaporator may get frosted. until it is defrosted.
Page 65
AUTO FRESH DEFROSTING AUTO OPERATION NICE TEMPERATURE RESERVATION – 75 –...
Page 71
CHECKING THE INDOOR TIMER LAMP IF BLINKING 1 TIME 3.15A Replace fuse or P.W.B Main. Replace P.W.Bs. circuit diagram – 81 –...
Page 72
CHECKING THE INDOOR/OUTDOOR UNIT ELECTRICAL PARTS AND REFRIGERATING CYCLE MODEL RAS-50FH7 Timer lamp See Troubleshooting when the timer lamp Does the timer lamp on the indoor unit blink? blinks . Remove the terminal cover and check the voltage between terminal (C) and terminal (D)
Page 73
TROUBLESHOOTING WHEN TIMER LAMP BLINKS. MODEL RAS-50FH7 Perform troubleshooting according to the number of times the indoor timer lamp and outdoor LD301 blink. SELF-DIAGNOSIS LIGHTING MODE Blinking of Timer lamp Reason for indication Possible cause Reversing valve defective (1) Reversing valve defective...
Page 74
CHECKING INDOOR UNIT ELECTRICAL PARTS MODEL RAC-50YH7 1. Power does not come on (no operation) Is AC 220-240V AC being generated Is DC 35V being generated between Check AC outlet and breaker, and between terminals L and N on the terminals C and D on the terminal repair any defective part.
Page 75
2. Outdoor unit does not operate (but receives remote infrared signal) – 85 –...
Page 76
3. Only indoor fan does not operate (other is normal) 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) – 86 –...
Page 77
6. Check the main P.W.B (power circuit) – 87 –...
Page 82
1. Switch OFF main power supply. 2. Short circuit between JW001 and JW002. 3. Switch ON main power supply – LD302 will blink 1 time. 4. (Within 3 minutes) Press Test/Service Switch for 1 second or more. 5. Self-diagnosis result will be shown – LD303 will ON (LIT) and LD301 will be blinking. Then refer to diagnosis table 2.
Page 87
(JUDGING BETWEEN GAS LEAKAGE AND CHECKING THE REFRIGERATING CYCLE COMPRESSOR DEFECTIVE) 1. Troubleshooting procedure (No operation, No heating, No cooling) Lighting mode Blinks Blinks Blinks Blinks Blinks Blinks Connect U,V,W phase leads to the Self- 2 times 3 times 4 times 5 times 6 times 8times...