Hitachi RAD-50DH7A User manual

NO. 0411E
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
ROOM AIR CONDITIONER
INDOOR UNIT + OUTDOOR UNIT
APRIL 2008 Refrigeration & Air-Conditioning Division
SERVICE MANUAL
PM
REFER TO THE FOUNDATION MANUAL
TECHNICAL INFORMATION
FOR SERVICE PERSONNEL ONLY
SPECIFICATIONS
RAD-50DH7A
RAD-60DH7A
RAD-70DH7A
CONTENTS
SPECIFICATIONS ----------------------------------------------------- 4
HOW TO USE ---------------------------------------------------------- 6
CONSTRUCTION AND DIMENSIONAL DIAGRAM ------- 23
MAIN PARTS COMPONENT ------------------------------------- 26
WIRING DIAGRAM -------------------------------------------------- 28
CIRCUIT DIAGRAM ------------------------------------------------- 29
BLOCK DIAGRAM --------------------------------------------------- 35
BASIC MODE --------------------------------------------------------- 39
REFRIGERATING CYCLE DIAGRAM ------------------------- 52
DESCRIPTION OF MAIN CIRCUIT OPERATION --------- 54
SERVICE CALL Q & A -------------------------------------------- 80
TROUBLE SHOOTING --------------------------------------------- 83
PARTS LIST AND DIAGRAM ----------------------------------- 103
RAD-50DH7A/RAC-50DH7
RAD-60DH7A/RAC-60DH7
RAD-70DH7A/RAC-70DH7
After installation
RAC-50DH7
RAC-60DH7
RAC-70DH7
(W)
(A)
(kW)
(B.T.U./h)
(W)
(A)
(kW)
(B.T.U./h)
W
H
D
(kg)
(DUCTING TYPE)
TYPE
MODEL
POWER SOURCE
TOTAL INPUT
TOTAL AMPERES
CAPACITY
TOTAL INPUT
TOTAL AMPERES
CAPACITY
DIMENSIONS
(mm)
NET WEIGHT
COOLING
HEATING
OUTDOOR UNIT
RAC-50DH7
INDOOR UNIT
RAD-50DH7A
900
270
720
35
1 Ø, 50 Hz, 220-240V
1,400 (200 ~ 2,100)
6.40 ~ 5.90
5.00 (0.90 ~ 6.00)
17,070 (3,073 ~ 20,490)
1,590 (200 ~ 2,200)
7.30 ~ 6.70
6.00 (0.90 ~ 7.00)
20,490 (3,073 ~ 23,901)
850
800
298
55
900
270
720
35
1 Ø, 50 Hz, 220-240V
1,870 (200 ~ 2,500)
8.55 ~ 7.90
6.00 (0.90 ~ 7.00)
20,490 (3,073 ~ 23,901)
2,130 (200 ~ 2,600)
9.75 ~ 9.00
7.30 (0.90 ~ 8.00)
24,920 (3,073 ~ 27,315)
850
800
298
55
OUTDOOR UNIT
RAC-60DH7
INDOOR UNIT
RAD-60DH7A
OUTDOOR UNIT
RAC-70DH7
INDOOR UNIT
RAD-70DH7A
900
270
720
35
1 Ø, 50 Hz, 220-240V
2,530 (200 ~ 2,920)
11.60 ~ 10.70
7.10 (0.90 ~ 8.00)
24,240 (3,073 ~ 27,310)
2,340 (200 ~ 3,100)
10.70 ~ 9.80
8.00 (0.90 ~ 9.00)
27,310 (3,073 ~ 30,730)
850
800
298
55

– 1 –
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

– 2 –
(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

– 3 –
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 recommended 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 airconditioner 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 (50°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

– 4 –
SPECIFICATIONS
MODEL
FAN MOTOR
FAN MOTOR CAPACITOR
FAN MOTOR PROTECTOR
COMPRESSOR
COMPRESSOR MOTOR CAPACITOR
OVERLOAD PROTECTOR
OVERHEAT PROTECTOR
FUSE (MICRO COMPUTER CIRCUIT)
POWER RELAY
POWER SWITCH
TEMPORARY SWITCH
SERVICE SWITCH
TRANSFORMER
VARISTOR
NOISE SUPPRESSOR
THERMOSTAT
REMOTE CONTROL SWITCH (LIQUID CRYSTAL)
RAD-50DH7A
RAD-60DH7A
RAD-70DH7A
56 W
NO
NO
–
NO
NO
NO
3.15A
G4A
NO
NO
NO
NO
416NR
NO
YES(IC)
YES
NO
NO
JU1015D4
NO
NO
YES
NO
NO
NO
NO
NO
NO
NO
NO
YES(IC)
NO
30 A TIME DELAY FUSE
---------- ❈ 1800gUNIT
REFRIGERANT CHARGING
VOLUME
(Refrigerant R410A) PIPES (MAX. 30m)
PIPES (MIN. 5m)
RAC-50DH7/RAC-60DH7/RAC-70DH7
80 W

– 5 –
Figure showing the installation of Indoor and Outdoor unit
Maximum pipe length 30m Minimum pipe length 5m
500
●Install the indoor unit with a proper clearance around it for operation and maintenance working space.
●In case that the ceiling board can not be detected for servicing, prepare a service access door below the indoor unit
for removing the indoor unit.
CAUTION
!
CAUTION
Always install the indoor unit level.
Units not installed level may leak.
!
CAUTION
●Discharge grille and suction grille
shall be cover by insulation
material to prevent water drop.
!
The indoor piping should be
insulated with the enclosed
insulation pipe. (If the insulator is
insufficient, please use
commercial products.)
Be sure to
completely seal
any gap with putty.
Drain pipe
Must be installed separately.
Insulate indoor part of pipe to
prevent condensation.
●The difference in height
between the indoor and
outdoor unit should be
kept below 20m.
●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).

– 6 –
INDOOR UNIT
NAMES AND FUNCTIONS OF EACH PART
WIDTH (mm)MODEL HEIGHT (mm) DEPTH (mm)
MODEL NAME AND DIMENSIONS
OUTDOOR UNIT
DRAIN PIPE
Condensed water drain to outside.
CONNECTING CORD
AIR INLET (BACK, LEFT SIDE)
AIR OUTLET
RAD-50DH7A / RAD-60DH7A / RAD-70DH7A
RAC-50DH7 / RAC-60DH7 / RAC-70DH7
900
850
270
800
720
298

– 7 –
РУССКИЙ
MEMO
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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.
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

– 8 –
!
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. Please observe all instructions strictly to ensure safety.
●
The sign indicate the following meanings.
●
Please keep this manual after reading.
WARNING
PRECAUTIONS DURING INSTALLATION
●Do not reconstruct the unit.
Water leakage, fault, short circuit or fire may occur if you reconstruct the
unit by yourself.
●Please ask your sales agent or qualified technician for the installation of
your unit. Water leakage, short circuit or fire may occur if you install the unit
by yourself.
●Please use earth line.
Do not place the earth line near water or gas pipes, lightning-conductor, or
the earth line of telephone. Improper installation of earth line may cause
electric shock.
●A circuit breaker should be installed depending on the mounting site of the
unit. Without a circuit breaker, the danger of electric shock exists.
●Do not install near location where there is flammable gas. The outdoor unit
may catch fire if flammable gas leaks around it.
●Please ensure smooth flow of water when installing the drain hose.
CAUTION
!
!
PRECAUTIONS DURING SHIFTING OR MAINTENANCE
PRECAUTIONS DURING OPERATION
●Avoid an extended period of direct air flow for your health.
W
A
R
N
I
N
G
!
●Should abnormal situation arises (like burning smell), please stop operating the unit
and turn off the circuit breaker. Contact your agent. Fault, short circuit or fire may
occur if you continue to operate the unit under abnormal situation.
●Please contact your agent for maintenance. Improper self maintenance may cause
electric shock and fire.
●Please contact your agent if you need to remove and reinstall the unit. Electric
shock or fire may occur if you remove and reinstall the unit yourself improperly.
●If the supply cord is damaged, it must be replaced by the special cord obtainable
at authorized service/parts centers.
●Do not insert a finger, a rod or other objects into the air outlet or inlet. As the
fan is rotating at a high speed, it will cause injury. Before cleaning, be sure
to stop the operation and turn the breaker OFF.
●During thunder storm, disconnect and turn off the circuit breaker.
●Do not use any conductor as fuse wire, this could cause fatal accident.
!
Make sure to connect earth line.
Indicates the instructions that must be followed.
The sign in the figure indicates prohibition.
W
A
R
N
I
N
G
!

– 9 –
PRECAUTIONS DURING OPERATION
●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.
●Do not direct the cool air coming out from the air-conditioner panel to face
household heating apparatus as this may affect the working of apparatus
such as the electric kettle, oven etc.
●Do not place plants directly under the air flow as it is bad for the plants.
●Please ensure that outdoor mounting frame is always stable, firm and
without defect. If not, the outdoor unit may collapse and cause danger.
●Do not splash or direct water to the body of the unit when cleaning it as this
may cause short circuit.
●When operating the unit with the door and windows opened, (the room humidity is always above
80%) and with the air deflector facing down or moving automatically for a long period of time,
water will condense on the air deflector and drips down occasionally. This will wet your furniture.
Therefore, do not operate under such condition for a long time.
●If the amount of heat in the room is above the cooling or heating capability of the unit (for
example: more people entering the room, using heating equipments and etc.), the preset room
temperature cannot be achieved.
●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.
●Do not climb on the outdoor unit or put objects on it.
●Please switch off the unit and turn off the circuit breaker during cleaning, the
high-speed fan inside the unit may cause danger.
●Turn off the circuit breaker if the unit is not to be operated for a long period.
C
A
U
T
I
O
N
!
●The product shall be operated under the manufacturer specification and
not for any other intended use.
●Do not put water container (like vase) on the indoor unit to avoid water
dripping into the unit. Dripping water will damage the insulator inside the unit
and causes short-circuit.
●Do not use any aerosol or hair sprays near the indoor unit. This chemical
can adhere on heat exchanger fin and blocked the evaporation water flow
to drain pan. The water will drop on tangential fan and cause water splashing
out from indoor unit.