Hitachi RAI-25NH4 Installation Manual Download Page 2

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. (Use
the detector provided for R410A)

FINAL ST

A

GE OF INST

ALLA

TION

Insulation And Maintenance Of Pipe Connection

1

The connected terminals should be completed 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.

If room humidity is high, cover the connecting pipe with
additional 5mm thickness insulator. This insulator shall be
purchased from field.

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 make sure, that the power voltage is 220V-230V
within the operation voltage of the unit.

Please take under consideration, that the power capacity
from your house distribution box is high enough for operating
your room air conditioner.

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

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 insert the flare nut into the pipe.

   Pipe Connection

2

INST

ALLA

TION OF REFRIGERA

TING PIPES AND AIR REMO

VA

L

CAUTION

!

Copper pipe

Trimming tool

Outer

Diameter (mm)

6.35 (1/4")

9.52 (3/8")

12.7 (1/2")

For R410A tool

0 ~ 0.5

0 ~ 0.5

0 ~ 0.5

For R22 tool

1.0

1.0

1.0

A (mm)

AIR REMO

V

A

L

THIS APPLIANCE MUST BE EARTHED.

Wiring Of The Indoor Unit

(1) Remove the cover of the electric box.
(2) Connect the connecting cords.
(3) Assemble the cover of electric box.

Procedures of Wiring

CONNECTION OF POWER CORD

A

Die

Die

Copper pipe

Wrench

Torque
wrench

Flare nut

Lo

Hi

Meter showing pressure

Manifold valve

Knob HI

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.

R410A

The body of
service valve

Cap of
valve core

Hexagonal
Wrench Key

Cap of valve head

Cap of valve head

CAUTION

!

In case of removing Flare nut of a indoor 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.

  Installation Of Optional Panel

4

Carefully read through the procedures of proper installation
before starting installation work.

<

I000: A 

>

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
gauge list below for the wiring from a switch board of fuse box to the outdoor unit in consideration of the locked rotor current.

IMPORTANT

Fuse Capacity

16A time delay fuse

IMPORTANT

Cable length

up to 

1

6m

up to 15m

up to 25m

Wire cross-section

1.5mm

2

2.5mm

2

4.0mm

2

Remote

Controller

Holder for
Remote Controller

Screw (2 pieces)

Outer

dia.of pipe

6.35 (1/4")

9.52 (3/8")

12.7 (1/2")

6.35 (1/4")

9.52 (3/8")

12.7 (1/2")

Torque N·m

(kgf  · cm)

13.7  – 18.6 (140 – 190)

34.3  – 44.1 (350 – 450)

44.1  – 53.9 (450 – 550)

19.6  – 24.5 (200 ~ 250)

19.6  – 24.5 (200 ~ 250)

29.4  – 34.3 (300 – 350)

12.3  – 15.7 (125 ~ 160)

Small dia. side

Large dia. side

Valve core cap

Small dia. side

Large dia. side

Valve

head cap

Indoor

Unit

C, D

GRN + YEL

Strip Wires

50 mm

45 mm

10mm

The naked part of the wire core should be 10 mm and fix it to the terminal tightly. 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 power cables approved from the authorities in your country. For example
in Germany: Cable type: NYM 3x1.5mm

2

.

Please refer to the installation manual for wire connection to the terminals of the units. The
cabling must meet the standards of electrical installation.

There is a AC voltage of 240V between the L and N terminals. Therefore, before servicing,
be sure to remove the plug from the AC outlet or switch off the main switch.

WARNING

!

C

BROWN : C

RED : D

Connect the earth cord

Insert and fix the 
connecting cords 
with screw

After remove the band,
put the connecting
cords and fix with screw

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