Hitachi RAK-18NH6 Service Manual
  1. Manuals
  2. Brands
  3. Hitachi Manuals
  4. Air Conditioner
  5. RAK-18NH6
  6. Service manual

Hitachi RAK-18NH6 Service Manual

Indoor unit
Hide thumbs Also See for RAK-18NH6:
Table of Contents

Advertisement

Quick Links

See also: Installation Manual

SERVICE MANUAL

TECHNICAL INFORMATION

FOR SERVICE PERSONNEL ONLY
RAK-18NH6
RAK-25NH6
RAK-35NH6
RAK-50NH6
NOTE:
This manual describes only points that differ from
RAF-25, 35NH5, RAD-25, 35NH5, RAI-25, 35NH5
and RAM-55QH5 (PM No. 0312E) for items not
described in this manual.
TYPE
MODEL
POWER SOURCE
TOTAL INPUT
TOTAL AMPERES
COOLING
CAPACITY
TOTAL INPUT
TOTAL AMPERES
CAPACITY
DIMENSIONS
(mm)
NET WEIGHT
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT

ROOM AIR CONDITIONER

MARCH 2007
RAK-18NH6
(W)
(A)
(kW)
(B.T.U./h)
(W)
(A)
(kW)
(B.T.U./h)
W
H
D
(kg)
9.0
Refrigeration & Air-Conditioning Division
NO. 0355E
PM
RAK-18NH6
RAK-25NH6
RAK-35NH6
RAK-50NH6
REFER TO THE FOUNDATION MANUAL

SPECIFICATIONS ----------------------------------------------------- 5

HOW TO USE -------------------------------------------------------- 14
Main Parts Component ------------------------------------- 39
Wiring Diagram -------------------------------------------------- 40
Circuit Diagram ------------------------------------------------- 43
Block Diagram --------------------------------------------------- 47
Basic Mode --------------------------------------------------------- 49
REFRIGERATING CYCLE DIAGRAM ------------------------- 63
Auto Swing Function ---------------------------------------- 65
SERVICE CALL Q & A -------------------------------------------- 71
Parts List And Diagram ------------------------------------ 81
DC INVERTER (WALL TYPE)
INDOOR UNIT
RAK-25NH6
RAK-35NH6
1 PHASE, 50 Hz, 220-240V
REFER TO THE SPECIFICATION PAGE (6)
780
280
220
9.5
CONTENTS
RAK-50NH6
9.5
9.5

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the RAK-18NH6 and is the answer not in the manual?

Questions and answers

Related Manuals for Hitachi RAK-18NH6

Summary of Contents for Hitachi RAK-18NH6

  • Page 1: Service Manual

    NO. 0355E RAK-18NH6 RAK-25NH6 SERVICE MANUAL RAK-35NH6 TECHNICAL INFORMATION RAK-50NH6 REFER TO THE FOUNDATION MANUAL FOR SERVICE PERSONNEL ONLY CONTENTS SPECIFICATIONS ----------------------------------------------------- 5 HOW TO USE -------------------------------------------------------- 14 CONSTRUCTION AND DIMENSIONAL DIAGRAM ------- 38 MAIN PARTS COMPONENT ------------------------------------- 39 WIRING DIAGRAM -------------------------------------------------- 40...
  • 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 operation or stopping the running, 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.

  • Page 6: Specifications

    SPECIFICATIONS RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 MODEL FAN MOTOR FAN MOTOR CAPACITOR FAN MOTOR PROTECTOR COMPRESSOR – COMPRESSOR MOTOR CAPACITOR OVERLOAD PROTECTOR OVERHEAT PROTECTOR FUSE (for MICROPROCESSOR) POWER RELAY POWER SWITCH TEMPORARY SWITCH SERVICE SWITCH TRANSFORMER VARISTOR NOISE SUPPRESSOR THERMOSTAT YES(IC)
  • Page 7 SPECIFICATION OF ROOM AIR CONDITIONER RAM-55QH5 RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 TYPE COOLING/HEATING WALL TYPE RAK-25NH6 INDOOR UNIT RAK-18NH6 RAK-35NH6 RAK-50NH6 MODEL RAM-55QH5 OUTDOOR UNIT PHASE/VOLTAGE/FREQUENCY 1ø / 220V~240V / 50Hz CAPACITY (kW) 1.8 (1.00 - 2.50) 2.5 (1.00 - 3.10) 3.5 (1.00 - 4.00)
  • Page 8 DUAL SYSTEM MULTI R.A.C. RAM-55QH5 COOL / HEAT CAPACITY SPEC. FOR INDOOR UNITS COMBINATIONS TO BE ABLE TO OPERATE SIMULTANEOUSLY Whichever indoor units are installed, cooling and heating capacity depends on how many and which indoor units are operating at that time. C O O L I N G H E A T I N G POSSIBLE...
  • Page 9 DUAL SYSTEM MULTI R.A.C. RAM-55QH5 INDOOR UNITS COMBINATIONS TO BE ABLE TO INSTALL Two indoor units can be installed with one outdoor unit. And total nominal cooling capacity should not be more than 7.5kW NOMINAL CAPACITY (kW) SUITABLE ROOM SIZE (m COOLING INDOOR UNIT at one unit operation...
  • Page 10 DUAL SYSTEM MULTI R.A.C. RAM-55QH5 CONNECTING POSISION TO BE ABLE TO INSTALL CONNECTING POSITION ON OUTDOOR UNIT POSSIBLE COMBINATIONS SUITABLE ROOM SIZE (VALVE DIAMETER) TO INSTALL TO INSTALL (mm) (kW) No.1 No.2 6.35/9.52D 6.35/9.52D 1.8+1.8 (8-12) + (8-12) 1.8+2.5 (8-12) + (10-16) 1.8+3.5 (7-9) + (15-22) 1.8+5.0...
  • Page 11 – 10 –...
  • Page 12 – 11 –...
  • Page 13 – 12 –...
  • Page 14 – 13 –...

  • Page 15: Safety Precaution

    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 16 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 17: Names And Functions Of Each Part

    (Air Outlet) (Refer page 26) Remote controller Send out operation signal to the indoor unit. So as to operate the whole unit. (Refer page 16) MODEL NAME AND DIMENSIONS MODEL WIDTH (mm) HEIGHT (mm) DEPTH (mm) RAK-18NH6/RAK-25NH6/RAK-35NH6/RAK-50NH6 – 16 –...
  • Page 18 INDOOR UNIT INDICATORS FILTER LAMP When the device is operated for a total of about 100 hours, the FILTER lamp lights to indicate that it is time to clean the filter. OPERATION LAMP This lamp lights during operation. TEMPORARY The OPERATION LAMP flashes in the following cases SWITCH during heating.

  • Page 19: Names And Functions Of Remote Control Unit

    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.

  • Page 20: Automatic Operation

    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.

  • Page 21: Heating Operation

    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).

  • Page 22: Dehumidifying Operation

    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 automatically. The FAN SPEED button does not work.

  • Page 23: Cooling Operation

    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 24: Fan 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 end of summer. Press the FUNCTION selector so that the display indicates (FAN). Press the (FAN SPEED) button.

  • Page 25: How To Set The Timer

    HOW TO SET THE TIMER Time, Day, Month Set the current month and TIME, DAY, day with the TIMER control After you change the MONTH button. batteries; (current time, day, month) OFF TIMER RESET ON TIMER OFF-Timer Press the (OFF-TIMER) button.
  • Page 26 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 27: How To Set The Sleep Timer

    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...
  • Page 28 Explanation of the sleep timer The device will control the FAN SPEED and room temperature automatically so as to be quiet and good for people’s health. NOTE 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 earlier.

  • Page 29: Adjusting The Air Deflector

    ADJUSTING THE AIR DEFLECTOR Adjustment of the conditioned air in the upward and downward directions. The horizontal air deflector is automatically set to the proper angle suitable for each operation. The deflector can be swung RESET up and down continuously and also set to the desired angle using the “...

  • Page 30: How To Exchange The Batteries In The Remote Controller

    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.

  • Page 31: Suitable Room Temperature

    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 32 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 33: Attaching The Air Cleansing And Deodorizing Filters

    ATTACHING THE AIR CLEANSING AND DEODORIZING 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 34 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 35 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 36 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 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 fine day, and dry the whole of the unit.
  • Page 37 AFTER SALE SERVICE AND WARRANTY WHEN ASKING FOR SERVICE, CHECK THE FOLLOWING POINTS. CONDITION CHECK THE FOLLOWING POINTS Is the fuse all right? When it does not operate Is the voltage extremely high or low? Is the circuit breaker “ON”? Was the air filter cleaned? Does sunlight fall directly on the outdoor unit? When it does not cool well...
  • Page 38 Please note: On switching on the equipment, particularly when the room 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. Note Avoid to use the room air conditioner for cooling operation when the outside temperature is below -10°C (14°F).
  • Page 39 MODEL RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 – 38 –...

  • Page 40: Main Parts Component

    MAIN PARTS COMPONENT THERMOSTAT Thermostat Specifications MODEL RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 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 41: Wiring Diagram

    WIRING DIAGRAM MODEL RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 INDOOR UNIT – 40 –...

  • Page 42: Circuit Diagram

    CIRCUIT DIAGRAM Remote Control Key matrix table Output Input Door open Start/Stop Operation selection Fan speed selection Automatic swing Door shut Start/Stop Automatic swing – – Door open On timer Hour up Hour down • present time SEG5 SEG20 SEG0 SEG19 Door shut –...
  • Page 43 CIRCUIT DIAGRAM MODEL RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 – 43 –...

  • Page 44: Printed Wiring Board Location Diagram

    PRINTED WIRING BOARD LOCATION DIAGRAM RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 – 45 –...
  • Page 45 MODEL RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 RECEIVING P.W.B. MARKING ON P.W.B. – 46 –...
  • Page 46 RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 INDOOR UNIT 1 SPM2 Wireless receive LCD wireless circuit Filter. Outdoor Operation. unit Room temperature Timer. Terminal thermistor board Auto sweep motor for Heat exchanger Air deflector thermistor Temporary switch Trip signal synthesis circuit Initial setting circuit...
  • Page 47 Notes: Combination of operations: 1. Refer to the PWRITE-ZU data for the constants expressed by capital alphabet letters in When operation mode is selected: During automatic operation: One unit Other unit the drawing. You cannot operate the indoor units in the following combinations. When heating operation is automatically selected for the first indoor unit, the next 2.
  • Page 48 MODEL RAK-18NH6 RAK-25NH6 RAK-35NH6 RAK-50NH6 PROM REQUIRED VALUE REQUIRED VALUE REQUIRED VALUE REQUIRED VALUE LABEL NAME OF UNIT SIDE OF UNIT SIDE OF UNIT SIDE OF UNIT SIDE RTOTSA 0°C 0°C 0°C 0°C WMAX_M 5300 min-1 5300 5000 min-1 5000 min-1...
  • Page 49 – 53 –...
  • Page 50 – 55 –...
  • Page 51 Dehumidifying Dehumidifying Sleep Operation – 57 –...
  • Page 52 – 59 –...
  • Page 53 – 61 –...
  • Page 54 – 63 –...
  • Page 55 – 64 –...
  • Page 56 – 65 –...
  • Page 57 RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 – 66 –...
  • Page 58 – 67 –...
  • Page 59 – 68 –...
  • Page 60 – 69 –...
  • Page 61 – 70 –...
  • Page 62 MODEL RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 – 71 –...
  • Page 63 – 72 –...
  • Page 64 – 73 –...
  • Page 65 RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 – 74 –...
  • Page 66 – 75 –...
  • Page 67 – 76 –...
  • Page 68 – 77 –...
  • Page 69 – 78 –...
  • Page 70 RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 – 79 –...
  • Page 71 – 80 –...

  • Page 72: Parts List And Diagram

    PARTS LIST AND DIAGRAM INDOOR UNIT MODEL: RAK-18NH6, RAK-25NH6, RAK-35NH6, RAK-50NH6 – 81 –...
  • Page 73 MODEL RAK-18NH6 PART N0. Q’TY / UNIT PARTS NAME RAK-18NH6 PMRAS-25YH4 CABINET PMRAS-25YH4 FAN MOTOR PMRAS-260GA TANGENTIAL AIR FLOW FAN PMRAS-25YH4 FAN SUPPORT ASSEMBLY PMRAS-25YH4 FAN COVER PMRAS-25YH4 FAN MOTOR SUPPORT PMRAS-07GH4 CYCLE ASSY PMRAS-25YH4 UPPER COVER PMRAS-25YH4 SPRING PMRAS-25YH4...
  • Page 74 MODEL RAK-25NH6 PART N0. Q’TY / UNIT PARTS NAME RAK-25NH6 PMRAS-25YH4 CABINET PMRAS-25YH4 FAN MOTOR PMRAS-260GA TANGENTIAL AIR FLOW FAN PMRAS-25YH4 FAN SUPPORT ASSEMBLY PMRAS-25YH4 FAN COVER PMRAS-25YH4 FAN MOTOR SUPPORT PMRAK-25NH5 CYCLE ASSY PMRAS-25YH4 UPPER COVER PMRAS-25YH4 SPRING PMRAS-25YH4 TERMINAL BOARD (2P) PMRAS-260GHA THERMISTOR ASSEMBLY...
  • Page 75 MODEL RAK-35NH6 PART N0. Q’TY / UNIT PARTS NAME RAK-35NH6 PMRAS-25YH4 CABINET PMRAS-25YH4 FAN MOTOR PMRAS-260GA TANGENTIAL AIR FLOW FAN PMRAS-25YH4 FAN SUPPORT ASSEMBLY PMRAS-25YH4 FAN COVER PMRAS-25YH4 FAN MOTOR SUPPORT PMRAK-25NH5 CYCLE ASSY PMRAS-25YH4 UPPER COVER PMRAS-25YH4 SPRING PMRAS-25YH4 TERMINAL BOARD (2P) PMRAS-260GHA THERMISTOR ASSEMBLY...
  • Page 76 MODEL RAK-50NH6 PART N0. Q’TY / UNIT PARTS NAME RAK-50NH6 PMRAS-25YH4 CABINET PMRAS-25YH4 FAN MOTOR PMRAS-260GA TANGENTIAL AIR FLOW FAN PMRAS-25YH4 FAN SUPPORT ASSEMBLY PMRAS-25YH4 FAN COVER PMRAS-25YH4 FAN MOTOR SUPPORT PMRAK-25NH5 CYCLE ASSY PMRAS-25YH4 UPPER COVER PMRAS-25YH4 SPRING PMRAS-25YH4 TERMINAL BOARD (2P) PMRAS-260GHA THERMISTOR ASSEMBLY...
  • Page 77 HITACHI RAK-18NH6 RAK-25NH6 PM NO. 0355E RAK-35NH6 RAK-50NH6 Printed in Malaysia...

This manual is also suitable for:

Rak-35nh6Rak-25nh6Rak-50nh6

Table of Contents