NO. 0509E RAS-70YH7/RAC-70YH7A SERVICE MANUAL REFER TO THE FOUNDATION MANUAL TECHNICAL INFORMATION FOR SERVICE PERSONNEL ONLY CONTENTS CAUTION ----------------------------------------------------------------- 4 SPECIFICATIONS ------------------------------------------------------ 5 INSTALLATION ---------------------------------------------------------- 6 HITACHI HOW TO USE ---------------------------------------------------------- 7 CONSTRUCTION AND DIMENSIONAL DIAGRAM ---------29 MAIN PARTS COMPONENT --------------------------------------31...
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 rela- tive 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...
CAUTION In quiet or stop operation, slight fl owing 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 RAC-70YH7A RAS-70YH7 FAN MOTOR 47 W 30 W FAN MOTOR CAPACITOR FAN MOTOR PROTECTOR – COMPRESSOR JU1015D9 COMPRESSOR MOTOR CAPACITOR OVERLOAD PROTECTOR YES (INTERNAL) OVERHEAT PROTECTOR 3.15A 3.15A FUSE (MICRO COMPUTER CIRCUIT) POWER RELAY POWER SWITCH TEMPORARY SWITCH...
Page 7
Figure showing the installation of Indoor and Outdoor unit The indoor piping should be insulated with the enclosed insulation pipe. (If the insulator is insuffi cient, please use commercial products). The difference in height ● between the indoor and outdoor unit should be kept max 20m.
Page 8
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-70YH7 1150 RAC-70YH7A – 7 –...
Page 9
INDOOR UNIT INDICATORS TIMER LAMP This lamp lights when the timer is working. OPERATION LAMP This lamp lights during operation. The OPERATION LAMP fl ashes in the following cases during heating. (1) During preheating For about 2–3 minutes after starting up. (2) During defrosting Defrosting will be performed about once an hour when frost forms on the heat exchanger of the...
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...
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.
Page 12
PRECAUTIONS DURING OPERATION The product shall be operated under the manufacturer specifi cation 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 ●...
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 fi xed on a wall using the fi xture provided. Before fi xing it, make sure the indoor unit can be ●...
Page 14
VARIOUS FUNCTIONS ■ Auto Restart Control If there is a power failure, operation will be automatically restarted when the power is resumed with previous ● operation mode and airfl ow 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.
Page 15
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. ●...
Page 16
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).
Page 17
COOLING OPERATION Use the device for cooling when the outdoor temperature is -10~ 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).
Page 18
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 OFF TIMER ON TIMER RESERVE CANCEL Press the Set the current Set the Press the (TIME) (TIME) button. time with the button again. (TIME) button. After you TIMER control button. The time indication starts change or lighting instead of fl...
Page 20
Press the Press the Set the Set the Point the signal (ON-OFF) turn-off time turn-on time window of the remote (ON- button so that with the with the controller toward the TIMER) button (OFF) TIMER control TIMER control indoor unit, and press so that the mark blinks.
Page 21
HOW TO SET THE SLEEP TIMER Set the current time at fi rst 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...
Page 22
HOW TO EXCHANGE THE BATTERIES IN THE REMOTE CONTROLLER Remove the cover as shown in the fi gure and take out the old Push and pull to the batteries. direction of arrow Install the new batteries. The direction of the batteries should match the marks in the case.
Page 23
THE IDEAL WAYS OF OPERATION Suitable Room Temperature Install curtain or blinds Warning It is possible to reduce heat Freezing temperature entering is bad for health and room through a waste of electric windows. power. Ventilation Effective Usage Of Timer At night, please use the “OFF or ON timer Caution operation mode”, together with your wake...
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 PURIFYING FILTERS CAUTION Cleaning and maintenance must be carried out only by qualifi ed service personnel. 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 ●...
Page 26
MAINTENANCE CAUTION Cleaning and maintenance must be carried out only by qualifi ed service personnel. Before cleaning, stop operation and switch off the power supply. PRE-FILTER Clean the pre-fi lter, as it removes dust inside the room. In case the pre-fi lter is full of dust, the air fl ow 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.
Page 28
CAUTION Cleaning and maintenance must be carried out only by qualifi ed service personnel. Before cleaning, stop operation and switch off the power supply. MAINTENANCE BEFORE LONG OFF PERIOD ● Run the unit by setting the operation mode to (COOL), the temperature to 32°C and the fan speed to HI for about half a day on a fi...
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 not Do the batteries need replacement? ● transmitting a signal. Is the polarity of the inserted batteries correct? ●...
CONSTRUCTION AND DIMENSIONAL DIAGRAM MODEL RAS-70YH7 About When piping is drawn horizontally, exchange Viewed from back the drain hose for the (bottom direction pipe drain cap. lead-out) Note: 1. Service space (free space needed for servicing) is 200mm on the right, 100mm on the left and 50mm on top.
MAIN PARTS COMPONENT THERMOSTAT (Room Temperature Thermistor) Thermostat Specifi cations MODEL RAS-70YH7 THERMOSTAT MODEL OPERATION MODE COOL HEAT 15.6 (60.1) 20.0 (68.0) INDICATION 15.3 (59.5) 20.7 (69.3) TEMPERATURE 23.6 (74.5) 28.0 (82.4) INDICATION °C (°F) 23.3 (73.9) 28.7 (83.7) 31.6 (88.9) 36.0 (96.8)
Page 33
COMPRESSOR MOTOR Compressor Motor Specifi cations MODEL RAC-70YH7A COMPRESSOR MODEL JU1015D9 PHASE SINGLE RATED VOLTAGE AC 220 ~ 240 V RATED FREQUENCY 50/60 Hz POLE NUMBER CONNECTION 20°C 2M = 1.2984 (68°F) RESISTANCE VALUE 75°C 2M = 1.7671 (167°F) CAUTION When the Air Conditioner has been operated for a long time with the capillary tubes clogged or crushed or with too little refrigerant, check the color of the refrigerant oil inside the compressor.
PRINTED WIRING BOARD LOCATION DIAGRAM MODEL RAS-70YH7 MAIN P.W.B. Marking on P.W.B COMPONENT SIDE SOLDERING SIDE RECEIVING P.W.B. Marking on P.W.B – 41 –...
Page 43
Table 1 Mode data fi le RAS-70YH7 LABEL NAME VALUE WMAX 5700 min –1 WMAX2 5700 min –1 WSTD 5400 min –1 WBEMAX 4000 min –1 CMAX 5200 min –1 CSTD 4900 min –1 CKYMAX 4000 min –1 CJKMAX 4000 min –1...
Page 44
Table 2 Δ TCMAX Temperature Calculated difference compressor rpm 1.66 2265 min –1 2435 min –1 2.33 2600 min –1 2.66 2765 min –1 2935 min –1 3.33 3100 min –1 3.66 3265 min –1 3435 min –1 4.33 3600 min –1 4.66 3765 min...
Page 45
Cooling Sleep Operation Notes: The sleep operation starts when the sleep key is pressed. When the sleep key is set, the maximum compressor speed is limited, and the indoor fan is set to “sleep”. 30 minutes after the sleep key is set, the sleep shift of temperature starts, and upper shift is made at least 6 times. If 25˚C is not reached after 6 shifts, shifts repeat unit 25˚C is reached.
Page 47
Table 3 Δ TWMAX Temperature Calculated difference compressor rpm 1.66 1965 min –1 2135 min –1 2.33 2300 min –1 2.66 2465 min –1 2635 min –1 3.33 2800 min –1 3.66 2965 min –1 3135 min –1 4.33 3300 min –1 4.66 3465 min...
DESCRIPTION OF MAIN CIRCUIT OPERATION RAS-70YH7 1. Reset Circuit – 61 –...
Page 52
2. Buzzer Circuit When the buzzer is to be activated, buzzer output pin of the micro computer alternates between ON and OFF repeatedly at 4kHz and Q301 is turned ON/OFF accordingly. A 4kHz voltage/frequency is applied to the buzzer and the diaphragm of the buzzer vibrates to output 4kHz sound. 3.
Page 53
5. Auto Sweep Motor Circuit Fig. 5-1 Auto Sweep Motor Circuit (Horizontal air defl ectors only) Fig. 5-1 shows the Auto sweep motor drive circuit; the signals shown in Fig. 5-2 are output from pins ● – of the micro computer. Fig.
Page 54
6. Room Temperature Thermistor Circuit Fig. 6-1 shows the room temperature The voltage at A depends on the room ● ● thermistor circuit. temperature as shown in Fig. 6-2. 7. Heat exchanger temperature thermistor circuit The circuit detects the indoor heat ●...
Page 55
8. Temporary Switch Fig. 8-1 The temporary switch is used to operate the air conditioner temporarily when the wireless remote control ● is lost or faulty. The air conditioner operates in the previous mode at the previously set temperature. However, when the ●...
Page 73
TROUBLESHOOTING WHEN TIMER LAMP BLINKS. 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 When the indoor heat exchanger (2) Heat exchanger thermistor dis- temperature is too low in the...
Page 74
CHECKING INDOOR UNIT ELECTRICAL PARTS 1. Power does not come on (no operation) – 84 –...
Page 76
3. Only indoor fan does not operate (other is normal) 4. Air defl ector 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.
PARTS LIST AND DIAGRAM INDOOR UNIT MODEL : RAS-70YH7 – 98 –...
Page 89
MODEL RAS-70YH7 PART NO. Q’TY / UNIT PARTS NAME PMRAS-30CHP6 CABINET ASSY PMRAS-72CHA3 MOUNTING PLATE PMRAS-80YHA FAN MOTOR PMRAS-80YHA TANGENTIAL FAN PMRAS-72CHA3 P-BEARING ASSY PMRAS-72CHA3 FAN MOTOR SUPPORT PMRAS-70YH7 CYCLE ASSY PMRAS-72CHA3 BEARING COVER PMRAS-24CE9G PIPE SUPPORT (U-COVER) PMRAS-80YHA DRAIN PAN ASSY...
Page 90
PARTS LIST AND DIAGRAM OUTDOOR UNIT MODEL : RAC-70YH7A – 100 –...
Page 91
MODEL RAC-70YH7A PART N0. Q’TY / UNIT PARTS NAME PMRAC-60YH7 COMPRESSOR KPNT1 PUSH NUT RAC-2226HV COMPRESSOR RUBBER PMRAC-70YHA CONDENSER PMRAC-70YHA1 REVERSING VALVE PMRAC-25NH4 ELECTRICAL EXPANSION COIL PMRAC-80YHA VALVE (5S) PMRAC-50NH4 VALVE (2S) PMRAM-72Q8 THERMISTOR (OH) PMRAC-25NH4 OVERHEAT THERMISTOR SUPPORT PMRAC-X13CX OVERLOAD RELAY COVER PMRAC-50YHA2 THERMISTOR (DEFROST)