Hitachi RAM-18QH5E User manual

RAM-18QH5E
NO. 0276E
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
ROOM AIR CONDITIONER
OUTDOOR UNIT
NOVEMBER 2005 Refrigeration & Air-Conditioning Division
SERVICE MANUAL
PM
REFER TO THE FOUNDATION MANUAL
TECHNICAL INFORMATION
FOR SERVICE PERSONNEL ONLY
CONTENTS
SPECIFICATIONS ------------------------------------------------------------------- 5
INSTALLATION ----------------------------------------------------------------------- 8
CONSTRUCTION AND DIMENSIONAL DIAGRAM --------------------- 12
MAIN PARTS COMPONENT --------------------------------------------------- 13
CAPACITY DIAGRAM ------------------------------------------------------------ 15
WIRING DIAGRAM ---------------------------------------------------------------- 20
CIRCUIT DIAGRAM --------------------------------------------------------------- 21
BLOCK DIAGRAM ----------------------------------------------------------------- 25
BASIC MODE ----------------------------------------------------------------------- 27
REFRIGERATING CYCLE DIAGRAM --------------------------------------- 40
DESCRIPTION OF MAIN CIRCUIT OPERATION ----------------------- 42
TROUBLE SHOOTING ----------------------------------------------------------- 66
PARTS LIST AND DIAGRAM -------------------------------------------------- 82
RAM-18QH5E
After installation
750
570
280
40
(W)
(A)
COOLING CAPACITY
DC INVERTER DUAL SYSTEM MULTI
TYPE
MODEL
POWER SOURCE
TOTAL INPUT
TOTAL AMPERES
SPECIFICATIONS
OUTDOOR UNIT
RAM-18QH5E
HEATING CAPACITY
DIMENSIONS (mm)
NET WEIGHT
1ø, 220 - 240V, 50Hz
W
H
D
(kg)
(kW)
(B.T.U.)
REFER TO THE SPECIFICATIONS PAGE

– 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
2
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 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.
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. The room air conditioner does not start automatically after recovery of the electric power failure for
preventing fuse blowing. Re-press START/STOP button after 3 minutes from when unit stopped.
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)
40 W
NO
NO
NO
YES
YES
5.0A
G4A
NO
NO
YES
NO
450NR
YES
YES(IC)
NO
1600g
WITHOUT REFRIGERANT BECAUSE
COUPLING IS FLARE TYPE.
UNIT
PIPES
REFRIGERANT CHARGING
VOLUME
(Refrigerant 410A)
RAM-18QH5E
JU1013D2
MAX. 35m
RAM-18QH5E
Additional charge of refrigerant is not required.

– 6 –
SPECIFICATIONS FOR INDOOR UNITS COMBINATION
OPERATION SCOPE
TYPE DC INVERTER DUAL SYSTEM MULTI COOLING AND HEATING
MODEL OUTDOOR UNIT
PHASE/VOLTAGE/FREQUENCY
CIRCUIT AMPERES TO CONNECT (A)
COOLING
(TWO UNITS)
CAPACITY (kW)
(B.T.U./h)
TOTAL INPUT (W)
EER (B.T.U./hW)
TOTAL AMPERES (A)
POWER FACTOR (%)
HEATING
(TWO UNITS)
CAPACITY (kW)
(B.T.U./h)
TOTAL INPUT (W)
EER (B.T.U./hW)
TOTAL AMPERES (A)
POWER FACTOR (%)
MAXIMUM LENGTH OF PIPING
STANDARD
RAM-18QH5E
1ø, 220 - 240V, 50Hz
16
4.0 (1.50 - 4.50)
13,660 (5,120 - 15,360)
1,245 (200 - 1,800)
10.97
5.72 - 5.24
99
5.0 (1.50 - 5.60)
17,070 (5,120 - 19,120)
1,350 (200 - 1,780)
12.64
6.20 - 5.68
99
MAX. 35m (TWO UNIT TOTAL)
CE (EMC&LVD)
RAM-18QH5E
MODEL
W
PACKING
(mm)
H
D
cu.ft.
905
633
394
8.27
43
GROSS WEIGHT (kg)
6.35D/9.52DX2
FLARE NUT SIZE (SMALL/LARGE)
INDOOR SUCTION
TEMPERATURE (˚C)
COOLING OPERATION SCOPE
OUTDOOR SUCTION
TEMPERATURE (˚C)
INDOOR SUCTION
HUMIDITY (%)
DEHUMIDIFYING
OPERATION
HEATING OPERATION
SCOPE
16 - 32 22 - 41 BELOW 80
16 - 32 22 - 42 BELOW 80
BELOW 27 –15 - 23 —

– 7 –
DUAL SYSTEM MULTI R.A.C. RAM-18QH5E
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.
RATING CONDITON (DRY BLUB / WET BULB)
COOLING
HEATING
INDOOR OUTDOOR
27 / 19 ˚C
20 / –˚C
35 / –˚C
7 / 6˚C
POSSIBLE
COMBINATIONS
TO OPERATE
CAPACITY RATING
(kW)
(RANGE)
POWER
CONSUMPTION
(W)
AMPERE (A)
at 230V
OUTDOOR UNIT
C O O L I N G
CAPACITY RATING
(kW)
(RANGE)
POWER
CONSUMPTION
(W)
AMPERE (A)
at 230V
OUTDOOR UNIT
H E A T I N G
ONE UNIT
TWO UNIT
1.8
2.5
3.5
1.8+1.8
1.8+2.5
2.5+2.5
1.8+3.5
2.5+3.5
1.8
(1.00-2.50)
2.5
(1.00-3.10)
3.5
(1.00-4.00)
1.8+1.8
(1.50-4.00)
1.70+2.30
(1.50-4.50)
2.00+2.00
(1.50-4.50)
1.60+2.40
(1.50-4.50)
1.80+2.20
(1.50-4.50)
560
(200-750)
750
(200-880)
1090
(200-1300)
1190
(200-1680)
1245
(200-1720)
1245
(200-1800)
1245
(200-1800)
1245
(200-1800)
2.5
3.3
4.8
5.2
5.5
5.5
5.5
5.5
2.5
(1.10-3.20)
3.4
(1.10-4.40)
4.2
(1.10-5.0)
2.25+2.25
(1.50-5.20)
2.20+2.60
(1.50-5.40)
2.50+2.50
(1.50-5.60)
1.70+3.30
(1.50-5.60)
2.00+3.00
(1.50-5.60)
690
(200-970)
870
(200-1120)
1080
(200-1300)
1100
(200-1480)
1240
(200-1750)
1350
(200-1780)
1350
(200-1780)
1350
(200-1780)
3.0
3.8
4.7
4.8
5.4
5.9
5.9
5.9
ONE UNIT : The values indicated are only for one unit operation when two indoor units are connected.
TOTAL
1.8
2.5
3.5
3.6
4
4
4
4
TOTAL
2.5
3.4
4.2
4.5
4.8
5
5
5

– 8 –

– 9 –
RAM-18QH5E
MODEL: RAM-18QH5E

–10 –

–11 –
AC 220V~240V ONLY
LN
INDOOR 1
C1 D1 C2 D2
INDOOR 2
RAM-18QH5E

–12 –
RAM-18QH5E

–13 –
MAIN PARTS COMPONENT
FAN MOTOR
Fan Motor Specifications
CONNECTION
MODEL
POWER SOURCE
OUTPUT
BLU : BLUE YEL : YELLOW BRN : BROWN WHT : WHITE
GRY : GRAY ORN : ORANGE GRN : GREEN RED : RED
BLK : BLACK PNK : PINK VIO : VIOLET
RAM-18QH5E
DC : 360V
40W
RESISTANCE VALUE
( )
20˚C
(68˚F)
75˚C
(167˚F)
—
—
M
RED
BLK
WHT
YEL
BLU
(Control circuit built in)
360V
15V
0V
0-6V
0-15V

–14 –
MODEL
COMPRESSOR MODEL
PHASE
RATED VOLTAGE
RATED FREQUENCY
POLE NUMBER
COMPRESSOR
Compressor Motor Specifications
CONNECTION
25°C
(68°F)
75°C
(167°F)
( )
RESISTANCE VALUE 2M = 1.063
2M = 1.268
RAM-18QH5E
JU1013D2
SINGLE
DC: 280-330V
50Hz
4
(U)
(V) (W)
M
M
M
WHITE
YELLOW RED
WHITE
RED
YELLOW

–15 –
CAPACITY DIAGRAM (RELATED TO THE AMBIENT TEMPERATURE)
MODEL : RAM-18QH5E
7
6
5
3.8
4.01 4.12
RATING
CAPACITY
COOLING CAPACITY (KW)
INPUT (W)
4.00
3.72
735
1050
1208 1245 1332
4
3
2
1
0
20 25 30 35 40 45
0
1000
2000
3000
COOLING CAPACITY (ROOM TEMPERATURE 27°C)
WHEN TWO INDOOR UNITS OPERATE

–16 –
CAPACITY DIAGRAM (RELATED TO THE AMBIENT TEMPERATURE)
MODEL : RAM-18QH5E
HEATING CAPACITY (ROOM TEMPERATURE 20°C)
WHEN TWO INDOOR UNITS OPERATE

–17 –
CAPACITY DIAGRAM (RELATED TO THE PIPING LENGTH)
MODEL : RAM-18QH5E
1. 0
0. 9
0. 8
0. 7
0. 6
0 5 10 20 3025 3515
PIPING LENGTH (m)
CHANGE RATIO OF
CAPACITY
HEATING
1. 0
0. 9
0. 8
0. 7
0. 6
0 5 10 20 3025 3515
PIPING LENGTH (m)
CHANGE RATIO OF
CAPACITY
COOLING

–18 –
SOUND PRESSURE LEVEL
MODEL : RAM-18QH5E (Heating)
90
NC-70
NC-60
NC-50
NC-40
NC-30
NC-20
80
70
60
50
40
Sound pressure Level [dB]
30
20
10
63
Octave band Main wavelength [Hz]
125 250 500 1000 2000 4000 8000
APPROXIMATE
THRESHOLD HEARING
FOR CONTINUROUS
NOISE

–19 –
SOUND PRESSURE LEVEL
MODEL : RAM-18QH5E (Cooling)
90
NC-70
NC-60
NC-50
NC-40
NC-30
NC-20
80
70
60
50
40
Sound pressure Level [dB]
30
20
10
63
APPROXIMATE
THRESHOLD HEARING
FOR CONTINUROUS
NOISE
Octave band Main wavelength [Hz]
125 250 500 1000 2000 4000 8000