Hitachi RAS-S24H2A User manual

SM0419
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
ROOM AIR CONDITIONER
INDOOR UNIT + OUTDOOR UNIT
APRIL 2008 Refrigeration & Air-Conditioning Division
SERVICE MANUAL
REFER TO THE FOUNDATION MANUAL
TECHNICAL INFORMATION
FOR SERVICE PERSONNEL ONLY
(W)
(A)
(kW)
(B.T.U./h)
(W)
(A)
(kW)
(B.T.U./h)
W
H
D
(kg)
RAS-S24H2A RAC-S24H2
DC INVERTER (WALL TYPE)
TYPE
MODEL
POWER SOURCE
TOTAL INPUT
TOTAL AMPERES
CAPACITY
TOTAL INPUT
TOTAL AMPERES
CAPACITY
DIMENSIONS
(mm)
NET WEIGHT
SPECIFICATIONS
1,030
295
191
11
RAS-S24H2A
CONTENTS
SPECIFICATIONS ------------------------------------------------------------------- 5
HOW TO USE ------------------------------------------------------------------------ 7
CONSTRUCTION AND DIMENSIONAL DIAGRAM --------------------- 29
MAIN PARTS COMPONENT --------------------------------------------------- 31
WIRING DIAGRAM ---------------------------------------------------------------- 33
CIRCUIT DIAGRAM --------------------------------------------------------------- 34
PRINTED WIRING BOARD LOCATION DIAGRAM --------------------- 37
BLOCK DIAGRAM ----------------------------------------------------------------- 38
BASIC MODE ----------------------------------------------------------------------- 39
REFRIGERATING CYCLE DIAGRAM --------------------------------------- 46
AUTO SWING FUNCTION ------------------------------------------------------ 47
DESCRIPTION OF MAIN CIRCUIT OPERATION ----------------------- 48
SERVICE CALL Q & A ---------------------------------------------------------- 79
TROUBLE SHOOTING ----------------------------------------------------------- 82
PARTS LIST AND DIAGRAM ------------------------------------------------- 102
RAS-S24H2A/RAC-S24H2
RAC-S24H2
COOLING
HEATING
INDOOR UNIT OUTDOOR UNIT
2,300 (155 - 2500)
10.60 – 9.70
6.05 (0.90 – 6.50)
20,660
2,400 (115 - 2700)
11.0 – 10.10
7.05 (0.90 - 9.00)
24,060
After installation
1 PHASE, 50 Hz, 220 – 240V
850
650
298
45

– 1 –
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.
If the contacts of electrical parts
are defective, replace the
electrical parts without trying to
repair them.
3. After completion of repairs, the initial state
should be restored.
4. Lead wires should be connected and laid as
in the initial state.
5. Modification of the unit by user himself should
absolutely be prohibited.
6. Tools and measuring instruments for use in repairs or inspection should 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 more as measured by a 500V
DC megger.
9. The initial location of installation such as window, floor or the other should be checked for being and safe
enough to support the repaired unit again.
If it is found not so strong and safe, the unit should be installed at the initial location reinforced or at a new
location.
10. Any inflammable thing should never
be placed about the location of
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.
DANGER
First, I must disconnect
the power cord plug
from the power outlet.

– 2 –
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).
2. Object parts
(1) Micro computer
(2) Integrated circuits (IC)
(3) Field-effect transistors (FET)
(4) P.C. boards or the like on which the parts mentioned in (1) and (2) of this paragraph are equipped.
3. Items to be observed in handling
(1) Use a conductive container for carrying and storing 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 body earth is being
taken.
(4) Be sure to place a part on a metal plate with grounding.
(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.
1M
Fig. 2. Body Earth
Body earth
(Elimik conductive band)
Clip for connection with a
grounding wire
IC
A conductive polyvinyl bag IC
Conductive sponge

– 3 –
(6) Use a three wire type soldering iron including a grounding wire.
Bare copper wire (for body earth)
Working
table
Resistor of 1 M (1/2W)
Earth wire
Fig. 3. Grounding of the working table
Screw stop at 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.)
Staple

– 4 –
1. In quiet or stopping operation, slight flowing noise of refrigerant in the refrigerating cycle is heard occasionally,
but this noise is not abnormal for the operation.
2. 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.
3. In the event of power failure, the air conditioner will restart automatically in the previously selected mode
once the power is restored. In the event of power failure during TIMER operation, the timer will be reset and
the unit will begin or stop operating under a new timer setting.
4. If the room air conditioner is stopped by adjusting thermostat, or missoperation, and re-start in a moment,
there is occasion 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 (14°F).
6. This room air conditioner (the reverse cycle) should not be used when the outside temperature is below
–15°C (5°F).
If the reverse cycle is used under this condition, the outside heat exchanger is frosted and efficiency falls.
7. 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.
!
CAUTION

– 5 –
SPECIFICATIONS
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
REMOTE CONTROL SWITCH (LIQUID CRYSTAL)
RAS-S24H2A
PWM DC35V
NO
NO
–
NO
NO
NO
NO
NO
NO
YES
NO
NO
NO
NO
YES(IC)
YES
----------
40 W
NO
NO
NO
YES (INTERNAL)
YES
3.0A
G4A
NO
NO
YES
NO
450NR
YES
YES(IC)
NO
1420g
WITHOUT REFRIGERANT BECAUSE
COUPLING IS FLARE TYPE.
UNIT
PIPES (MAX. 30m)
REFRIGERANT CHARGING
VOLUME
(Refrigerant R410A)
RAC-S24H2
JU1013D5
Chargeless upto 20m, above 20m upto max 30m, charge refrigerant R410A 5 g/m.

– 6 –
Figure showing the installation of Indoor and Outdoor unit
above 50mm
above 100mm
above 0.45m
above 300mm
must not bend
above 100mm
2,300mm or more
Maximum pipe length 30m Minimum pipe length 5m
above 200mm
above 700mm
above 200mm
above 50mm when
installed on the
ceiling of balcony
()
above 100mm
above 100mm
give clearance as
wide as possible
Plug
●The difference in height
between the indoor and
outdoor unit should be
kept max 10m.
●The connecting pipe,
no matter big or small,
should all be insulated
with insulation pipe and
then wrapped with vinyl
tape. (The insulator will
deteriorate if it is not
wrapped with tape).
The connection of
insulated drain hose.
Please use insulated
drain hose for the indoor
piping (commercial
product).
The indoor piping should
be insulated with the
enclosed insulation pipe.
(If the insulator is
insufficient, please use
commersial products).
inner diameter ø 16mm
Be sure to
completely
seal any gap
with putty.
!
CAUTION
In case the pipe length is more than 20m, add refrigerant R410A at 5 gram per every meter exceeds.
However, pipe length shall not exceed 30m.

– 7 –
INDOOR UNIT
NAMES AND FUNCTIONS OF EACH PART
OUTDOOR UNIT
WIDTH (mm)
1030
850
MODEL
RAS-S24H2A
RAC-S24H2
HEIGHT (mm)
295
650
DEPTH (mm)
191
298
NOTE
AIR FILTER
To prevent dust from coming into the indoor unit.
(Refer Instruction manual)
FRONT PANEL (AIR INLET)
INDOOR UNIT INDICATORS
Light indicator showing the operating condition.
(Refer page 8)
HORIZONTAL DEFLECTOR ●VERTICAL
DEFLECTOR (AIR OUTLET)
REMOTE CONTROLLER
Send out operation signal to the indoor unit. So as to
operate the whole unit.
(Refer Instruction manual)
MODEL NAME AND DIMENSIONS
DRAIN PIPE
Condensed water drain to outside.
CONNECTING CORD AND INSULATION PIPE FOR
PIPING
AIR INLET (BACK AND LEFT SIDE)
AIR OUTLET
Blow out warm air.
●Air cleansing filters are washable and can be use in 1 year time. Type number for this air cleansing
filter is <SPX-CFH5>. Please use this number for ordering when you want to renew it.
●Air cleansing filter should be cleaned every month or sooner if noticeable loading occurs. When
used overtime, it may loose its deodorizing function. For maximum performance, it is recommended
to replace it every 1 year depending on application requirements.

– 8 –
INDOOR UNIT INDICATORS
OPERATION INDICATOR
TEMPORARY
SWITCH
TEMPORARY
SWITCH
●This figure shows the opening condition of
front panel. Refer to Instruction manual in
relation to how to open or close the front panel.
TEMPORARY SWITCH
Use this switch to start and stop when the remote controller does not work. [Use non-conductor stick
(example: toothpick)]
●By pressing the temporary switch, the operation is done in previously set operation mode.
●When the operation is done using the temporary switch after the power source is turned off and turn on
again, the operation is done in automatic mode.
TIMER LAMP
This lamp lights when the timer is working.
OPERATION LAMP
This lamp lights during operation.
The OPERATION LAMP flashes 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
outdoor unit, for 5–10 minutes each time.
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”.
HITACHI

– 9 –
MEMO
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Minimum Maximum Minimum Maximum
Indoor Dry bulb °C 21 32 20 27
Wet bulb °C 15 23 12 19
Outdoor Dry bulb °C 21 43 2 21
Wet bulb °C 15 26 1 15
Note
●Avoid to use the room air conditioner for cooling operation when the outside temperature is below
21°C (70°F).
The recommended maximum and minimum operating temperatures of the hot and cold sides
should be as below:
Cooling Heating