Pipe Requirement; Bending Pipes; Pipe Connection; Installing Heat Insulation - Fujitsu AIRSTAGE UTP-VX30A Installation Manual

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).

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.
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)
En-5
CAUTION
CAUTION
CAUTION
CAUTION
Pressure regulating valve
Cap
Nitrogen gas
Brazing area
Outer diameter of pipe
12.70 mm
Connect the EEV unit pipe to the connection pipe. Braze the connectors.
(a) Connecting 1 EEV unit
Connection pipe
(fi eld supply)
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)
Relay pipes: Outside dimensions Φ12.7 mm
(Field supply)
Branch pipes
(Optional parts)

5.5. Installing heat insulation

After checking for gas leaks (refer to the Installation Manual of the outdoor unit),
perform this section. Failure to do so may cause water leaks.
Implement heat insulation as shown in the diagram below.
(1) Mount the rubber sheets (accessories).
(2) Mount the heat insulations (accessories). There should be no gaps between the
insulation and the product.
(3) Secure to a pipe using 2 cable ties.
(2) Heat insulations
(Accessories)
(3) Cable ties
(Large, accessories)
• Perform the work in (1), (2) and (3) for the 2 pipes.
• For the heat insulation on the separation tube (Optional parts) used to connect 2 EEV
units ,refer to the installation manual of the separation tube.
For construction other than mounting the EEV unit (e.g., mounting thermistors,
electrical wiring, and fi eld settings, etc.), see the construction manual enclosed with
the control unit.
Branch pipes
(Optional parts)
CAUTION
(1) Butyl rubber sheets
(Accessories)
No gap