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1-7. Installing Distribution Joint Kit (for Twin &
Double-Twin) (NRF-DL16R)
●
Use a tube cutter and cut at the size position that
corresponds to the field-supply tube size selected based on
the total indoor unit capacity. (If the size is the same as the
tube end size, cutting is not necessary.)
●
If the reducer that was supplied in the package is used,
perform brazing on-site.
Note: Do not cut in such a way that applies excessive force
and causes deformation of the tube. (This will prevent
insertion of the connecting tube.)
For size selection, refer to “Information for the Person
in Charge of Installation” and other materials that were
supplied with the outdoor unit.
●
Cut at a position that is as far away as possible from the
dowel pin.
●
After cutting the tube, be sure to remove any burrs and to
finish the end surface correctly.
(If there is excessive crushing or indentation of the tube, use
a tube expander to expand it.)
●
Check that there is no dirt or other foreign substance inside
the distribution tubing.
●
Install the distribution tubing so that it is either horizontal or
vertical.
●
Use the supplied thermal insulation to insulate the
distribution tubing.
(If other insulation is used, be sure to use insulation that can
withstand temperatures of at least 120°C.)
●
For details, refer to “Information for the Person in Charge of
Installation”.
If the distribution joint will be cut before use,
cut on the line marked “cutting point” in the figure below.
Stopper (boss)
Make this as long as possible.
Insertion length of the connecting tube.
Cutting point
Horizontal Installation
Indoor unit
Side
Outdoor unit
Side
15° to 30°
upward slant
Vertical installation (directed upward or downward)
Nitrogen gas replacement required for tube brazing
If nitrogen replacement is not done when brazing is performed
on the indoor and outdoor unit refrigerant tubing, oxide scale
will occur. This scale will clog the solenoid valves, strainers, and
other parts, leading to malfunction.
Therefore be sure to replace the air in the tubing with nitrogen
when performing brazing in order to prevent problems from
oxide scale.
1-8. Installing Distribution Joint Kit (for Triple)
(NRF-DL28R)
●
Check the system combination before installing the
distribution joints.
●
Three indoor units must be installed within the same room.
●
Use the supplied tube connectors to adjust the tube sizes of
the distribution joints.
How to Install Distribution Joints
Use the supplied distribution joints to complete refrigerant
tubing work.
Install distribution joints so that the tubes are horizontal after the
branch point.
Orientation of distribution joints
Only the distribution joints are horizontal with
respect to the ground. The collective tubes are
vertical with respect to the ground.
<Gas tube side>
Collective tube
The collective tube and distribution joint
are horizontal with respect to the ground.
Distribution joint
Length requirement for strainer on main distribution tube
side
Attach a straight tube 500 mm or longer to the main tubing side
of the distribution joint (for both liquid and gas tubing).
Tubing insulation
Be sure to apply thermal insulation to both the liquid and gas
tubing.
Depending on the conditions inside the ceiling, condensation
may form on the insulation material. If high temperatures and
high humidity are expected to occur inside the ceiling, add
glass wool (16 – 20 kg/m
3
, with a thickness of 10 mm or more)
to the below insulation materials and apply sufficient thermal
insulation.
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Summary of Contents for OU-PSINV-25HR
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