Hisense DC Inverter Unitary Series Use And Installation Instructions Download

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Installation and Maintenance

8.2 Connecting Tubing between Indoor
and Outdoor Units

Be sure to apply a sealing cap or water-proof tape
to prevent dust or water from getting into the tubes
before they are used.
Be sure to apply refrigerant lubricant to the
matching surfaces of the flare and union before
connecting them together. This is effective for
reducing gas leaks.(Figure 8.4)
For proper connection, align the union tube and
flare tube straight with each other, then screw in the
flare nut lightly to obtain a smooth match. (Figure 8.5)
Tighten the setscrew with torque wrench to prevent
leak of refrigerant. Carefully test leak before running
the appliance.

Remove the burrs at the end of the copper tube
with a tube reamer or file. When reaming, hold the
tube bend downward and be sure that no copper
scraps fall into the tube. This process is important
and should be done carefully to make a good
flare.(Figure 8.1,8.2)
Remove the flare nut from the unit and be sure to
mount it on the copper tube.
Make a flare at the end of copper tube with a flare
tool.(Figure 8.3)

8.4 Taping the Tubes

Note: Do not wind the armoring tape too tightly because
this will decrease the heat insulation effect. Also be
sure the condensation drain hose splits away from
bundle and drips clear of the unit and the tubing.

The two refrigerant tubes (and electrical wire if local
codes permit)should be taped together with white
armoring tape. The drain hose may also e included
and taped together as a bundle with the tubing.
Wrap the armoring tape from the bottom of the
outdoor unit to the top of the tubing where it enters
the wall. As you wrap the tubing, overlap half of
each previous tape turn. (See Figure 8.7)
Clamp the tubing bundle to the wall, using one
clamp approx. every 120 cm.

8.5 Finishing the installation

After completion of wrapping and insulation, seal the
hole on the wall with suitable sealant against wind and rain.

To avoid loss of heat and in prevention of the
ground being wet by condensed water, all
refrigerant tubes must be insulated with suitable
insulating materials whose minimum thickness will
be 6 mm. (See Figure 8.6)

8.3 Heat Insulation of the Refrigerant Tube

9.Air purging and test run

Air and moisture remaining in the refrigerant system
have undesirable effects.
Therefore, they must be purged completely following the
steps.

9.1 Air Purging with a Vacuum Pump

(See

Figure 9.1, Figure 9.2)
(1) Check that each tube (both narrow and wide tubes
between the indoor and outdoor units) have been
properly connected and all wiring for the test run has
been completed. Note that both narrow and wide tube
valves on the outdoor unit are kept closed at this stage.
(2) Using an adjustable wrench or box wrench, remove
the bonnet from the service valve.
(3) Connect a vacuum pump and service valve together
tightly.
(4) Turn on the vacuum pump and till the pressure is

-4

lower than 15Pa(or 1.5

10 bar) for 5 minutes.

(5) With the vacuum pump still running, demount tube
of vacuum pump from the service valve. Then stop the
vacuum pump.
(6) Replace the bonnet on the service valve and fasten it
securely with an adjustable wrench or box wrench.
(7) Using an adjustable wrench or box wrench, remove
the bonnet of both narrow and wide valve.
(8) With the hex wrench, turn the wide and narrow tube
valves stem counter clockwise to fully open the valves.
(9) Replace the bonnets on the wide and narrow valves
and fasten it securely with an adjustable wrench or box
wrench.

8.1 Flaring with Tube Expander

Note: A good flare have the following characteristics:
Inside surface is glossy and smooth.
Edge is smooth.
Tapered sides are of uniform length.

8.Refrigerant Tubing