9
R0.4~0.8
A
45°± 2
90°± 4
Flared opening
Φ
6.35
14.2-17.2N·m
8.3-8.7mm
Φ
9.53
32.7-39.9N·m
12-12.4mm
Φ
12.7
49.5-60.3N·m
15.4-15.8mm
Φ
15.9
61.8-75.4N·m
18.6-19mm
Φ
19.1
97.2-118.6N·m
22.9-23.3mm
1 Copper piping
2
3 Nitrogen connection
4 Hand valve
5
6 Nitrogen
Unit
body
Figure 4-16
External
diameter (mm)
Tightening torque
Figure 4-18
Flared opening
diameter (A)
Caution
•
Apply
the
proper
tightening
torque
according
to
the
installation
conditions.
Excessive
torque
may
damage
the
socket
cap
and little torque will not tighten
the
cap
sufficiently,
leading to leaks.
Figure 4-17
Precautions when welding refrigerant pipes
•
Before
welding the
refrigerant
pipes, please
fill
the pipes
with
nitrogen
to exhaust
the
air
in
the
pipes.
If
no
nitrogen
is
filled
during the
welding
process,
a
large amount
of
oxide
film
will
form
inside
the
pipes,
which
may
cause
the
air conditioning system to malfunction.
•
Welding
can
be
carried
out
on
the
refrigerant
pipes
after
the
nitrogen
gas
has been replaced or refilled.
•
When
the
pipe
is
filled
with
nitrogen
during the
welding process,
the
nitrogen
must
be reduced to 0.02 MPa via the pressure release valve.
See Figure 4-18.
4.6
Refrigerant Piping Installation
4.6.1
Length
and
Height
Difference
Requirements
for
Piping
Connections to the Indoor and Outdoor Units
The
length
and
height
difference
requirements
for
the
refrigerant
piping
vary
for
different
indoor
and
outdoor
units.
Refer
to
the
installation
manual
of
the outdoor unit.
4.6.2
Piping Material and Size
1. Piping material: Copper pipes for air handling.
2. Piping
size:
Choose
and
purchase
copper
pipes
that
correspond
to
the
length
and
size
calculated
for
the
selected
model
in
the
installation
manual
of the outdoor unit and your actual project requirements.
4.6.3
Piping Layout
1. Seal
the
two
piping ends
properly
before
connecting
the
indoor
and
outdoor
piping.
Once
unsealed,
connect
the
piping
of
the
indoor
and
outdoor
units
as
quickly
as
possible
to
prevent
dust
or
other
debris
from
entering
the
piping
system
through
the
unsealed
ends,
as
this
may
cause
the
system to malfunction.
2. If
the
pipe
needs
to
go
through
walls,
drill
the
opening
in
the
wall
and
place accessories like casings and covers properly on the opening.
3. Place
the
refrigerant
connecting
piping
and
the
communication
wiring
for
the
indoor
and
outdoor
units
together,
bundle
them
tightly
to
make
sure
air
does
not
enter
and
does not produce water condensation.
4. Insert
the
bundled
piping
and
wiring
from
outside
the
room
through
the
wall
opening.
Be
careful
when
laying
out
the
piping.
Do not damage the piping.
4.6.4
Piping Installation
For the installation of the outdoor unit's
refrigerant pipe, please refer to the
installation manual provided with the outdoor unit.
All
gas
and
liquid
piping
must
be
properly
insulated;
otherwise,
this
may
cause
water
to
leak.
Use
heat
insulating
materials
that
can
withstand
high
temperatures
above
120°C
to
insulate
the
gas
pipes.
In
addition,
the
refrigerant piping insulation
should
be
reinforced
(20
mm
or
thicker)
in
situations
where
there
is
high
temperature
and/or
high
humidity
(when
sections
of
the refrigerant
piping
is
higher
than
30°C
or
when
the
humidity
exceeds
RH 80%).
Otherwise,
the
surface
of
the
heat
insulating
material
may
be
exposed.
Before
the
works
are
carried
out,
check if
the
refrigerant
is the
R410A.
If
the
wrong refrigerant is used, the unit may malfunction.
Other
than
the
specified
refrigerant,
do
not
let
air
or
other
gases
enter
the
refrigeration circuit.
If
the
refrigerant
leaks
during
installation,
make
sure
you
fully
ventilate
the
room.
Use
two
wrenches
when
installing
or
dismantling
the
piping,
a
common
wrench and a torque wrench. See Figure 4-15.
Normal wrench
Torque wrench
Pipe socket cap
Pipe fittings
Figure 4-15
Slot
the
refrigerant
piping
into
the
brass
nut
(accessory
14),
and
expand
the
pipe
socket.
Refer
to
the
following
table
for
the
pipe
socket size
and
the proper tightening torque.
Before
the
socket
cap
is
installed
on
the
pipe
socket,
apply
some
oil
oil
onto
the
socket
(both
inside
and
outside), afterwards
rotate
it
three or four
times before tightening the cap. See Figure 4-17.
Apply oil
Pressure release
valve
Section
being
welded
4.6.5
Air Tightness Test
Carry
out
the
air
tightness
test
on
the
system
according
to
the
instructions
in
the
outdoor unit installation manual.
Caution
•
The
Air
Tightness
Test
helps
ensure
that
the
air
and
liquid
shut off
valves of the outdoor unit are all closed (keep factory settings).
4.6.6
Heat
Insulation
for
Indoor Unit Gas-Liquid
Piping
Connections
Heat
insulation
is
carried
out
on
the
gas
and liquid indoor unit piping
sides, respectively.
a. The
piping
on
the
gas
side
must
use
heat
insulation
material
that
can
withstand temperatures of 120°C and more.
b. For
the
indoor unit piping
connections,
use
the copper pipes
insulation
sleeve to carry out the insulation and close all gaps.
Facing upwards
Piping side
Refrigerant pipe
insulation
Figure 4-19
4.6.7
Vacuum
Create
a
vacuum
in
the
system
according
to
the
instructions
in
the outdoor
unit
installation manual.
Caution
•
For
the
vacuum,
make
sure
that
the outdoor unit
air
and
liquid
cut-off
valves are all closed (keep factory settings).
4.6.8
Refrigerant
Charge
the
system
with
refrigerant
according
to
the
instructions
in
the
outdoor unit installation manual.
