■ Wiring sample
Indoor Unit
Use this screw when connecting
to ground the shield for the
Inter-unit
Inter-unit control wiring.
Control Wiring
Remote Control
Wiring
Power
Supply
Functional ground screw (External Electronic
Expansion Valve Kit and Schedule Timer)
Outdoor Unit
1.
Use this screw when connecting
to ground for the unit control line.
Earth
Power Supply
Unit Control Line
2.
Use this screw when connecting
to ground for the unit control line.
Earth
Power Supply
Unit Control Line
3.
Use this screw when connecting
to ground for the unit control line.
Earth
Clamper *
(Field supply)
Power Supply
Unit Control Line
* First remove the attached resin fixture. Then lead
the clamper (field supply) through the screw hole
and fix the power supply wire.
6. HOW TO INSTALL THE TIMER REMOTE
CONTROLLER (OPTIONAL PART)
N OTE
Refer to the Instruction Manual attached to the optional Timer
Remote Control Unit.
7. HOW TO PROCESS TUBING
The liquid tubing side is connected by a flare nut, and the gas
tubing side is connected by brazing.
7-1. Connecting the Refrigerant Tubing
Use of the Flaring Method
Many of conventional split system air conditioners employ the
flaring method to connect refrigerant tubes that run between
indoor and outdoor units. In this method, the copper tubes are
flared at each end and connected with flare nuts.
Flaring Procedure with a Flare Tool
(1) Cut the copper tube to the required length with a tube
cutter. It is recommended to cut approx. 30 – 50 cm longer
than the tubing length you estimate.
(2) Remove burrs at each end of the copper tubing with a
tube reamer or file. This process is important and should
be done carefully to make a good flare. Be sure to keep
any contaminants (moisture, dirt, metal filings, etc.) from
entering the tubing. (Figs. 7-1 and 7-2)
Deburring
Before
After
Copper
tubing
Reamer
Fig. 7-1
Fig. 7-2
N OTE
When reaming, hold the tube end downward and be sure that
no copper scraps fall into the tube. (Fig. 7-2)
(3) Remove the flare nut from the unit and be sure to mount it
on the copper tube.
15
(4) Make a flare at the end of the copper tube with a flare tool.
(Fig. 7-3)
Flare nut
Copper
tubing
Flare tool
Fig. 7-3
N OTE
A good flare should have the following characteristics:
● inside surface is glossy and smooth
● edge is smooth
● tapered sides are of uniform length
Flare size: A (mm)
Copper tubing
0
A
(Outer dia.)
–0.4
ø6.35
9.1
ø9.52
13.2
ø12.7
16.6
ø15.88
19.7
ø19.05
24.0
Caution Before Connecting Tubes Tightly
(1) Apply a sealing cap or water-proof tape to prevent dust or
water from entering the tubes before they are used.
(2) Be sure to apply refrigerant lubricant (ether oil) to the
inside of the flare nut before making piping connections.
This is effective for reducing gas leaks. (Fig. 7-4)
Apply refrigerant lubricant.
Fig. 7-4
(3) For proper connection, align the union tube and flare tube
straight with each other, then screw on the flare nut lightly
at first to obtain a smooth match. (Fig. 7-5)
Flare nut
Union
Fig. 7-5
● Adjust the shape of the liquid tube using a tube bender at the
installation site and connect it to the liquid tubing side valve
using a flare.
Cautions During Brazing
● Replace air inside the tube with nitrogen gas to prevent
copper oxide film from forming during the brazing
process. (Oxygen, carbon dioxide and Freon are not
acceptable.)
● Do not allow the tubing to get too hot during brazing.
The nitrogen gas inside the tubing may overheat,
causing refrigerant system valves to become damaged.
Therefore allow the tubing to cool when brazing.
● Use a reducing valve for the nitrogen cylinder.
● Do not use agents intended to prevent the formation
of oxide film. These agents adversely affect the
refrigerant and refrigerant oil, and may cause damage or
malfunctions.
7-2. Connecting Tubing Between Indoor and
Outdoor Units
(1) Preparing the Tubing.
● The tubing of the gas main has a diameter of ø25.4, but
the connection to the service valve of the outdoor unit
has a diameter of ø19.05, so a flare has to be used.
Consequently, be sure to use the enclosed joint tube and
reducing joint tube in making connections (braze).
● Align the joint tube in the direction the tubing comes out and
refer to the following references "Examples of Making Tube
Connections" 1 to 4 in cutting it to the required length and
then braze it.
● To protect the wiring and parts inside the unit, perform the
brazing outside the unit. Also, take note that each of the joint
tubes in 1 to 3 have to be installed in a specific direction, so
make sure they are as depicted in the figure when you braze
them.
Examples of Making Tube Connections
1. Out Front
Flare Process
2. Out Right
Flare Process
The connection
faces towards you
3. Out Rear
Flare Process
16