Hitachi RAM-90NP5B User manual

NO. 0586E
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
ROOM AIR CONDITIONER
OUTDOOR UNIT
FEBRUARY 2015 Refrigeration & Air-Conditioning Division
SERVICE MANUAL
PM
REFER TO THE FOUNDATION MANUAL
TECHNICAL INFORMATION
FOR SERVICE PERSONNEL ONLY
CONTENTS
SPECIFICATIONS------------------------------------------------------ 5
INSTALLATION---------------------------------------------------------16
CONSTRUCTION AND DIMENSIONAL DIAGRAM---------20
WIRING DIAGRAM ---------------------------------------------------21
MAIN PARTS COMPONENT --------------------------------------23
CIRCUIT DIAGRAM --------------------------------------------------25
BLOCK DIAGRAM ----------------------------------------------------27
PRINTED WIRING BOARD LOCATION DIAGRAM --------28
BASIC MODE ----------------------------------------------------------33
REFRIGERATING CYCLE DIAGRAM---------------------------53
DESCRIPTION OF MAIN CIRCUIT OPERATION-----------54
TROUBLE SHOOTING ----------------------------------------------65
PARTS LIST AND DIAGRAM--------------------------------------79
After installation
(W)
(A)
COOLING CAPACITY
DC INVERTER FIVE SYSTEM MULTI
TYPE
MODEL
POWER SOURCE
TOTAL INPUT
TOTAL AMPERES
SPECIFICATIONS
RAM-90NP5B
HEATING CAPACITY
DIMENSIONS (mm)
NET WEIGHT
1ø, 220 - 240V, 50/60Hz
W
H
D
(kg)
(kW)
(B.T.U.)
REFER TO THE SPECIFICATIONS PAGE
OUTDOOR UNIT
RAM-90NP5B
RAM-90NP5B
950
800
370
74
HITACHI

– 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 the 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 after reinforced or at
a new location.
10. Any inflammable object must not
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.






– 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 (I.C.)
(3) Field-effective transistor (F.E.T.)
(4) P.C. boards or the like to 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 1M 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 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 solder 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 short circuit 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 nearby, 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 air conditioner will
not start automatically. Re-press ON/OFF button after 3 minutes from when the unit off or power recovery.
4. If the room air conditioner is stopped by adjusting thermostat, or miss operation, 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 (TEST SWITCH)
TRANSFORMER
VARISTOR
NOISE SUPPRESSOR
THERMOSTAT
REMOTE CONTROL SWITCH (LIQUID CRYSTAL)
138 W
NO
NO
NO
YES
YES
20A, 5.0A
G4A
NO
NO
YES
NO
ERZVA9V431
YES
YES(IC)
NO
2700g
WITHOUT REFRIGERANT BECAUSE
COUPLING IS FLARE TYPE.
UNIT
PIPES
REFRIGERANT CHARGING
VOLUME
(Refrigerant 410A)
RAM-90NP5B
JU182XC1
MAX. 75m
In case the pipe length is more than 30m, add refrigerant R410 at 15gram per every meter exceeds.

– 6 –
SPECIFICATIONS FOR INDOOR UNITS COMBINATION
OPERATION SCOPE
TYPE DC INVERTER FIVE SYSTEM MULTI COOLING AND HEATING
MODEL OUTDOOR UNIT
PHESE/VOLTAGE/FREQUENCY
CIRCUIT AMPERES TO CONNECT (A)
COOLING
(FIVE UNITS)
CAPACITY (kW)
(B.T.U./h)
TOTAL INPUT (W)
EER (B.T.U./hW)
TOTAL AMPERES (A)
POWER FACTOR (%)
HEATING
(FIVE 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-90NP5B
1ø, 220 - 240V, 50/60Hz
25
8.5
29,020
2,230
13.01
10.20 - 9.40
99
11.00
37,540
2,460
15.26
11.3 - 10.4
99
MAX. 75m (FIVE UNIT TOTAL)
CE (EMC&LVD)
RAM-90NP5B
MODEL
W
PACKING
(mm)
H
D
cu.ft.
1,037
896
417
13.68
75
GROSS WEIGHT (kg)
6.35DX5/9.52DX3/12.70X2
FLARE NUT SIZE (SMALL/LARGE)
INDOOR SUCTION
TEMPERATURE (˚C)
COOLING OPERATION SCOPE
OUTDOOR SUCTION
TEMPERATURE (˚C)
INDOOR SUCTION
HUMIDITY (%)
HEATING OPERATION
SCOPE
16 - 32 –10 ~ 43 BELOW 80
BELOW 27 –15 ~ 21 —

– 7 –
DC INVERTER SYSTEM MULTI R.A.C. RAM-90NP5B
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.
(Reference value)
5 ROOM MULTI-SPLIT INVERTER TYPE RAC : RAM-90NP5B
POSSIBLE COMBINATION TO OPERATE (SAME TIME OPERATION)

– 8 –

– 9 –
RATING CONDITON (DRY BLUB / WET BULB)
COOLING
HEATING
INDOOR OUTDOOR
27 / 19 ˚C
20 / –˚C
35 / 24˚C
7 / 6˚C
<REMARKS>
* ONE UNIT INDICATED ARE ONLY FOR ONE UNIT OPERATION WHEN TWO OR MORE INDOOR UNITS ARE CONNECTED.
* TWO UNITS INDICATED ARE ONLY FOR TWO UNITS OPERATION WHEN TWO OR MORE INDOOR UNITS ARE CONNECTED.
* THREE UNITS INDICATED ARE ONLY FOR THREE UNITS OPERATION WHEN THREE OR MORE INDOOR UNITS ARE CONNECTED.
* FOUR UNITS INDICATED ARE ONLY FOR FOUR UNITS OPERATION WHEN FOUR OR FIVE INDOOR UNITS ARE CONNECTED.
Two indoor units should be connected at least.
Total nominal cooling capacity should not be more than 15.5kW.

– 10 –
DUAL AND TRIPLE SYSTEM MULTI R.A.C. RAM-90NP5B
INDOOR UNITS COMBINATIONS TO BE ABLE TO INSTALL
Two, three, four or five indoor units can be installed with one outdoor unit.
And total nominal cooling capacity should not be more than 15.5kW
Be sure to connect two, three or four indoor units to this outdoor unit. If not, condensed water may drop,
resulting in trouble.

– 11 –
QUADRUPLE SYSTEM MULTI R.A.C. RAM-90NP5B
INDOOR UNITS COMBINATIONS TO BE ABLE TO INSTALL

– 12 –




– 13 –
 

– 14 –

– 15 –
Fig. 6-1
Fig. 6-2
Fig. 6-3
Remove the valve cap from the service valves located at both the
large and small pipe rims
➤
Connect the charging hose A to the large service valve.
After connecting the vacuum suction pump adaptor, connect the
charging hose B to the adaptor.
During relocation or re-installed, there is a possibility of electric-
powered valve to be closed. Should the electric-powered valve be
closed, even with air purging being conducted, certain amount of air
is still trapped within that area, hence, there is a need to open up the
electric-powered valve to do an air purging. Under such circumstances,
before using the vacuum-suction pump, the main power supply (LN
terminal) should be connected to enable a complete opening up of
the valve. After connecting the power supply for approximately 90
seconds, the valve will be fully opened, after which disconnect the
power supply and start using the vacuum suction pump.
(Refer to “Power Supply Terminal Connections” in regards to the LN
terminal)
CAUTION: Ingress of air during the operating cycle may cause increase
in pressure and other breakdowns.
Switch off the outdoor unit’s power supply
Shut the manifold valve handle Hi, handle Lo need to be open and
operate the vacuum pump for approximately 60 minutes.
Upon a full shut of manifold valve handle Lo, the vacuum pump can
be stopped.
Check to ensure that there is no gas leakage.
After removing the charging hose A, rotate the service valve spindles
in an anti-clockwise direction to fully open for both valves.
Reinstall the cap nuts to their original positions and tighten them to
their specified torque.
Disconnect the charge hose from the service valve.
Tighten the valve cap of valve core.
[Torque 12.3 - 15.7 N·m (125 - 160 kgf·cm)]
Fix the valve cap to the spindles of each large and small dia. pipe
side service valves.
Tighten the valve cap of the spindle.
[Torque 19.6 - 24.5 N·m (200 - 250 kgf·cm)]
4. Air purging by using vacuum pump
➤➤➤➤➤➤➤➤➤ ➤ ➤ ➤
!
CAUTION
1. Be sure to use the vacuum pump, vacuum pump adapter and manifold gauge and refer to their instruction manuals beforehand.
2. Ascertain that the vacuum pump is filled with oil to the level designated on the oil gauge.
3. After closed the ball valve of charge hose, it should be disconnected at service port side and refrigerant cylinder side at first.
Next, after discharging the remained gas in the charge hose by opening the ball valve a little, disconnect it at manifold gauge side.
You can prevent sudden release of refrigerant by connecting the ball valve to service port. And you can work more safety.

– 16 –
INSTALLATION
PIPE LENGTH
(1) Total 75m maximum pipe length.
(2) Pipe length for one indoor unit : maximum 25m.
: minimum 3m.
HIGHT DIFFERENCE
(1) Height : maximum ± 20m
(2) Height difference between each indoor unit ≤5m.
To the outdoor unit, up to five indoor units can be connected until the total value of capacity to 15.5kW.
Make sure to connect two or more indoor units.

– 17 –
MODEL: RAM-90NP5B
Dimension of Mounting Stand
of the Outdoor unit
(unit: mm)
One unit of 1.5kW, 1.8kW, 2.5kW, 3.5kW, 5.0kW
(5.0kW unit: Optional flare adaptor for piping is necessary.)
One unit of 1.5kW, 1.8kW, 2.5kW, 3.5kW, 5.0kW
(5.0kW unit: Optional flare adaptor for piping is necessary.)
One unit of 1.5kW, 1.8kW, 2.5kW, 3.5kW, 5.0kW
(5.0kW unit: Optional flare adaptor for piping is necessary.)
One unit of 1.5kW, 1.8kW, 2.5kW, 3.5kW, 5.0kW
(1.8-3.5kW unit: Optional flare adaptor for piping is necessary.)
One unit of 1.5kW, 1.8kW, 2.5kW, 3.5kW, 5.0kW
(1.8-3.5kW unit: Optional flare adaptor for piping is necessary.)
Face this side (suction
side) of the unit to the wall.
Remove side cover when
connecting the piping and
connecting cord.
Pull downward
Flare adaptor for piping
The flare adaptor for piping is re-
quired depending on combination of
indoor units.
ø9.52 (3/8”) ➝ø 12.7 (1/2”)
Parts number TA261D-4 001
ø12.7(1/2”) ➝ø 9.52 (3/8”)
Parts number TA261D-6 002
ø12.7(1/2”) ➝ø 15.88(5/8”)
Parts number TA261D-6 003

– 18 –
BASE
DRAIN PIPE
A

– 19 –
RAM-90NP5B
Grounding rod (optional)
(Earth wire and grounding rod are not supplied. Please use optional
items below.)
Type of grounding rod
SP-EB-2
Length
900mm
Arrange power cord so they do
not touch service valve.
CAUTION
!