Table of Contents
Advertisement
Prohibited EEV unit orientations
PROHIBITED
B
B
A
A
5. PIPE INSTALLATION
Be more careful that foreign matter (oil, water, etc.) does not enter the piping than with
refrigerant R410A models. Also, when storing the piping, securely seal the openings
by pinching, taping, etc.
While welding the pipes, be sure to blow dry nitrogen gas through them.
5.1. Selecting the pipe material
Do not use existing pipes from another refrigeration system or refrigerant.
Use pipes that have clean external and internal sides without any contamination which
may cause trouble during use, such as sulfur, oxide, dust, cutting waste, oil, or water.
It is necessary to use seamless copper pipes.
Material : Phosphor deoxidized seamless copper pipes
It is desirable that the amount of residual oil is less than 40 mg/10 m.
Do not use copper pipes that have a collapsed, deformed, or discolored portion
(especially on the interior surface). Otherwise, the expansion valve or capillary tube
may become blocked with contaminants.
Improper pipe selection will degrade performance. As an air conditioner using R410A
incurs pressure higher than when using conventional (R22) refrigerant, it is necessary
to choose adequate materials.
• Thicknesses of copper pipes used with R410A are as shown in the table.
• Never use copper pipes thinner than those indicated in the table even if they are
available on the market.
Thicknesses of Annealed Copper Pipes (R410A)
Pipe outside diameter [mm (in.)]
Thickness [mm]
6.35 (1/4)
9.52 (3/8)
12.70 (1/2)
15.88 (5/8)
19.05 (3/4)
22.22 (7/8)
28.58 (1-1/8)
5.2. Pipe requirement
Refer to the Installation Manual of the outdoor unit for description of the length of
connecting pipe or for difference of its elevation.
• Use pipe with water-resistant heat insulation.
Install heat insulation around both the gas and liquid pipes. Failure to do so may
cause water leaks.
Use heat insulation with heat resistance above 120 °C. (Reverse cycle model only)
In addition, if the humidity level at the installation location of the refrigerant piping is
expected to exceed 70 %, install heat insulation around the refrigerant piping. If the
expected humidity level is 70 to 80 %, use heat insulation that is 15 mm or thicker and
if the expected humidity exceeds 80 %, use heat insulation that is 20 mm or thicker. If
heat insulation is used that is not as thick as specifi ed, condensation may form on the
surface of the insulation. In addition, use heat insulation with heat conductivity of
0.045 W/(m·K) or less (at 20 °C).
B
B
A
CAUTION
CAUTION
Material
0.80
0.80
COPPER
0.80
JIS H3300 C1220T-O
or equivalent
1.00
1.20
COPPER
1.00
JIS H3300 C1220T-H
1.00
or equivalent
CAUTION
CAUTION
5.3. Bending pipes
• The pipes are shaped by your hands or pipe bender. Be careful not to collapse them.
• Do not bend the pipes in an angle more than 90°.
• When pipes are repeatedly bend or stretched, the material will harden, making it diffi cult
to bend or stretch them any more. Do not bend or stretch the pipes more than 3 times.
A
To prevent breaking of the pipe, avoid sharp bends.
If the pipe is bent repeatedly at the same place, it will break.
5.4. Pipe connection
If air or another type of refrigerant enters the refrigeration cycle, the internal pressure
in the refrigeration cycle will become abnormally high and prevent the unit from
exerting its full performance.
Apply nitrogen gas while
brazing the pipes. Nitrogen
gas pressure:
0.02 MPa (= pressure felt
sufficiently on the back of
your hand)
If a pipe is brazed without applying nitrogen gas, it will create an oxidation fi lm.
This can degrade performance or damage the parts in the unit (such as the
compressor or valves).
Do not use fl ux to braze pipes. If the fl ux is the chlorine type, it will cause the pipes to
corrode. Furthermore, if the fl ux contains fl uoride, it will adversely affect the refrigerant
pipe system such as by degrading the refrigerant oil.
For brazing material, use phosphor copper that does not require fl ux.
Connection Pipe (Liquid)
Connect the EEV unit pipe to the connection pipe. Braze the connectors.
(a) Connecting 1 EEV unit
Connection pipe
(fi eld supply)
(b) Connecting 2 EEV units
If connecting 2 stacked EEV units, connect the special branch pipe (optional part).
Relay pipes: Outside dimensions Φ12.7 mm
(Field supply)
Branch pipes
(Optional parts)
CAUTION
CAUTION
Pressure regulating valve
Cap
Nitrogen gas
Brazing area
Outer diameter of pipe
12.70 mm
Connection pipe
(fi eld supply)
Branch pipes
(Optional parts)
Relay pipes: Outside dimensions Φ12.7 mm
(Field supply)
En-6
Hide quick links:
Advertisement
Table of Contents
