Hitachi RAC-25CNH2 Installation Manual Download Page 2

OUTDOOR UNIT

Mount the outdoor unit on stable ground to prevent vibration and
increase of noise level.

Decide the location for piping after sorting out the different types of
pipe available.

Removal Of Air From The Pipe And Gas Leakage Inspection

Gas Leakage Inspection

Please use gas leakage detector to check if leakage
occurs at the connection of Flare nut as shown on
the right.

If gas leakage occurs, further tighten the connection
to stop leakage.

FINAL ST

A

GE OF INST

ALLA

TION

Insulation And Maintenance Of Pipe Connection

1

The connected terminals should be completely sealed with
heat insulator and then tied up with rubber strap.

Please tie the pipe and power line together with vinyl tape as
shown in the figure showing the installation of indoor and
outdoor units. Then fix their position with holders.

To enchance the heat insulation and to prevent water
condensation, please cover the outdoor part of the drain hose
and pipe with insulation pipe.

Completely seal any gap with putty.

  Installation Of Remote Control

2

  Power Source And Operation Test

3

The remote controller can be placed in its holder which is
fixed on wall or beam.

To operate the remote controller at its holder, please ensure
that the unit can receive signal transmitted from the controller
at the place where the holder is to be fixed. The unit will beep
when signal is received from the remote controller. The signal
transmission is weaken by the florescent light. Therefore, during
the installation of the remote control holder, please switch on
the light, even during day time, to determine the mounting
location of the holder.

Power Source

CAUTION

!

Please use a new socket. Accident may occur due to the
use of old socket because of poor contact.

Please plug in and then remove the plug for 2 – 3 times.
This is to ensure that the plug is completely plugged into
the socket.

Keep additional length for the power cord and do not render
the plug under external force as this may cause poor
contact.

Do not fix the power cord with U-shape nail.

Operation Test

Please ensure that the air conditioner is in normal operating
condition during the operation test.

Explain to your customer the proper operation procedures
as described in the user’s manual.

Insulation material for pipe connection

Sleeve of
protection pipe

Putty

<

I141: C 

>

The controller must be hooked onto the hook at the lower
part of the holder. Push in the remote controller in the direction
as shown in figure below.

3

Procedures of using Vacuum Pump for Air Removal

As shown in figure on the right, remove
the cap of valve head and valve core
and then connect them to the vacuum
pump and manifold valve.

Fully tighten the “Hi” shuttle of the
manifold valve and completely unscrew
the  “Lo” shuttle. Run the vacuum pump
for about 10–15 minutes, then completely
tighten the “Lo” shuttle and switch off
the vacuum pump.

2

Completely unscrew the spindle of the
service valve (at 2 places) in anti-
clockwise direction to allow the flow of
coolant (using Hexagonal Wrench key).

3

Remove the Charge hose and tighten
the cap of valve head. The task is then
completed.

4

1

   Preparation of Pipe

1

Use a pipe cutter to cut the copper pipe.

Jagged edge will cause leakage.

Point the side to be trimmed downwards during trimming to prevent copper
chips from entering the pipe.

Before flaring, please put on the flare nut.

   Pipe Connection

2

INST

ALLA

TION OF REFRIGERA

TING PIPES AND AIR REMO

VA

L

CAUTION

!

Outer

diameter

of pipe

6.35 (1/4")

9.52 (3/8")

Valve head cap

Valve core cap

Torque N.m

(kgf 

 cm)

13.7  – 18.6 (140 – 190)

34.3  – 44.1 (350 – 450)

19.6  – 24.5 (200 – 250)

12.3  – 15.7 (125 – 160)

Copper pipe

Trimming tool

Outer

Diameter (ø)

6.35 (1/4")

9.52 (3/8")

Imperial flaring tool

0.8  – 1.5

1.0  – 1.8

Rigid flaring tool

0  – 0.5

0  – 0.5

A (mm)

Small diameter

side

Big diameter

side

AIR REMO

V

A

L

Procedure to remove the
cover of wiring terminals

Remove the screw (1
piece).

Hold the projected
part at the lower left
of the cover and push
the cover upwards to
remove it.

To close the cover,
insert the upper part
of the cover into the
body of outdoor unit,
then be sure that the
hook below the cover
is plugged in before
screwing.

CONDENSED WATER DISPOSAL OF OUTDOOR UNIT

There are holes on the base of outdoor unit for condensed water to
exhaust.

In order for condensed water to flow to the draining part, installed the
unit on the level ground or block so that the unit is 70mm above the
ground, same as figure shown. Join the drain pipe to one hole.

At first insert one portion of the hook to the base (Portion A), then pull
the drain pipe in the direction shown by the arrow while inserting the
hook into the base. After installation, check whether the drain pipe
cling to the base firmly.

Remote

Controller

Holder for
Remote Controller

Screw (2 pieces)

WARNING

You may not be able to close the side cover
due to the connecting cord, under such
situation, please press against the wait of
side cover to fix it.

Be sure that the hooks (2 places) are
plugged in.
Otherwise, water leakage may occur and this
causes short circuit or faults.

The naked part of the wire core should be 10 mm and the insulated part of the wire must be push into the terminal for 3 – 4 mm.
Then try to pull the individual wire to check if the contact is tight. Improper insertion may burn the terminal.

Be sure to use only wire specified for the use of air-conditioner.

Please refer to the installation manual for wire connection and the wiring technique should meet the standards of electrical
installation.

There is a AC voltage drop between the LN terminals if the power is on. Therefore, be sure to remove the plug from its socket.

How to Remove the Front Cover

Open the cover 

1

 and remove the screw.

After open the Front Panel and remove the filter, release the axis by
pulling the center portion of front cover in the direction of arrow 

2

.

Push vertical air deflector handle to the right or left side.

After raise the front cover from bottom side as 

3

, release the front

cover by pull the right or left sides as 

4

.

How to Install the Front Cover

Insert the two hooks 

5

 at the upper side certainly.

Open Front Panel, push the center down in the direction of the arrow
to insert the axis at the center of the front cover into the hook at the
outlet frame.

Fixed the screw and cover 

1

.

Connection cord
is put under here

Side cover

Connection cord

A

B C

D

Checking for the electric source
and the voltage range

Before installation, the power source must be checked and
necessary wiring work must be completed. To make the wiring
capacity proper, use the wire gauges list below for the lead-
in from a pole transformer and for the wiring from a switch
board of fuse box to the outlet in consideration of the locked
rotor current.

Investigate the power supply capacity and other electrical
conditions at the installation location.
Depending on the model of room air conditioner to be installed,
request the customer to make arrangements for the necessary
electrical work etc.
The electrical work includes the wiring work up the outlet. In
localities where electrical conditions are poor, use of a voltage
regulation is recommended.

Install outlet for the room air conditioner within the reaching
range of the line cord.

IMPORTANT

Wire length

up to 

1

6m

up to 15m

up to 25m

Wire gauge

1.6mm

2

2.5mm

2

4.0mm

2

IMPORTANT

THIS APPLIANCE MUST BE EARTHED.

Wiring Of The Indoor Unit

For wire connection of the indoor unit, you need to remove the cover under the body
of the unit and front cover.

Method to remove the low cover

Pull the cover at 

1

 and 

2

 in

the directions as shown by
arrows to remove the cover.

1

2

When power supplied to outdoor unit

Power cannot be turned off using power
switch.
Always keep the switch “OFF” and put
the power switch fixing seal so that the
power cannot be turned off.

Power cord is not necessary, store
it in the lower-side space on the rear
side of indoor unit. When storing, wrap
the power plug with the vinyl bag for
the parts, etc. and seal with adhesive
tape to prevent dust or dirt.

Terminal A and B of indoor unit do not need to be connected.

When power supplied to outdoor unit, power is not turned off
by switching the power of indoor unit to “OFF”. In that case,
please cut the breaker.

Brown=C

Brown=D

connect the
earth cord

White=B

White=A

After remove the band, place the

connecting cords and fix with screw

cords

with screws

Procedures of Wiring

Wiring Of The Outdoor Unit

Please remove the side cover for wire connection.

!

WARNING

!

CONNECTION OF POWER CORD

Hook

Please face this side (suction side)
of the unit to the wall

Please remove
the cover for
wire connection.

BASE

DRAIN PIPE

A

A

Die

Die

Copper pipe

Wrench

Torque
wrench

Flare nut

Lo

Hi

Meter showing pressure

Manifold valve

Vacuum pump

Charge
hose

When pumping starts, slightly loosen
the flare nut to check of air sucked in.
Then tighten the flare nut.

When the meter reaches –101KPa (–76cmHg)
during pumping, fully tighten the shuttle.

The body of
service valve

Cap of
valve core

Hexagonal
Wrench Key

Cap of valve head

Cap of valve head

Adding Refrigerant

If the length of the copper pipe is over 5m, add 15g/m refrigerant.

CAUTION

!

In case of removing Flare nut of a cooling unit, first remove a nut of
small diameter side, or a seal cap of big diameter side will fly out.

Please be careful when bending the copper pipe.

Applied frozen grease to the connection points and then screw in manually. After
that, use a torque wrench to tighten the connection.

WARNING

!

Power supply shall be connected at the rated voltage, otherwise the unit will be broken or could not
reach the specified capacity.

L

N

D

C

B

A

D

C

B

A

D

C

B

A

D

C

B

A

Indoor Unit

Line Cord

AC 220-240V

Outdoor Unit

Indoor Unit

Outdoor Unit

Connecting Cord

Connecting Cord

Main
Switch

AC 220 - 240V

1.6 or

2.0

1.6 or

2.0

2.0

Strip Wires

26mm

10mm

30mm

10mm

45mm

10mm

30mm

Indoor

Unit

A, B

C, D

Outdoor

Unit

Indoor

Unit

Outdoor

Unit

10mm

10mm

GRN + YEL

GRN + YEL

GRN + YEL

GRN + YEL

GRN + YEL

70mm

Strip Wires

30mm

45mm

50mm

10mm

10mm

10mm

45mm

10mm

When power supplies to Indoor Unit

When power supplies to Outdoor Unit

A, B

C, D

A, B

C, D

C, D

Detail of cutting the
connecting cord

To remove the
connecting wires
for the indoor unit,
please remove the
low cover panel in
front of the unit.

1

2

1

3

5

5

1

1

4

Screw

Cover

Front Panel

Front Cover

2

2

Vertical Air Deflector Handle

11 Seal

9

70mm ABOVE

12

Fuse Capacity

16A time delay fuse

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