Panasonic U-8MF1E8 Mode D'emploi page 20

Insulation material
The material used for insulation must have good insulation
characteristics, be easy to use, be age resistant, and must not
easily absorb moisture.
CAUTION
After a tube has been insulated, never try to bend it into
a narrow curve because it can cause the tube to break or
crack.
Never grasp the drain or refrigerant connecting outlets
when moving the unit.
5-4. Taping the Tubes
(1) At this time, the refrigerant tubes (and electrical wiring
if local codes permit) should be taped together with
armoring tape in 1 bundle. To prevent condensation from
overflowing the drain pan, keep the drain hose separate
from the refrigerant tubing.
(2) 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.
(3) Clamp the tubing bundle to the wall, using 1 clamp approx.
each meter. (Fig. 5-9)
Clamp
Insulated tubes Drain hose
Fig. 5-9
N OTE
Do not wind the armoring tape too tightly since this will
decrease the heat insulation effect. Also ensure that the
condensation drain hose splits away from the bundle and drips
clear of the unit and the tubing.
5-5. Finishing the Installation
After finishing insulating and taping over the tubing, use sealing
putty to seal off the hole in the wall to prevent rain and draft
from entering. (Fig. 5-10)
Apply putty here
Tubing
Fig. 5-10
SUPPLEMENT
6. AIR PURGING
Air and moisture in the refrigerant system may have undesirable
effects as indicated below.
● pressure in the system rises
● operating current rises
● cooling (or heating) efficiency drops
● moisture in the refrigerant circuit may freeze and block
capillary tubing
● water may lead to corrosion of parts in the refrigerant system
Therefore, the indoor unit and tubing between the indoor and
outdoor unit must be leak tested and evacuated to remove any
noncondensables and moisture from the system. (Figs. 6-1a
and 6-1b)
Manifold gauge Vacuum pump
Outlet
Inlet
Fig. 6-1a Fig. 6-1b
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■ Air Purging with a Vacuum Pump (for Test Run)
Preparation
Check that each tube between the indoor and outdoor units
has been properly connected and all wiring for the test run has
been completed. Remove the valve caps from all service ports
on the outdoor unit (Fig. 6-2). Note that all service valves on
the outdoor unit are kept closed at this stage (Fig. 6-3).
The balance tube leak test is not necessary if only 1 outdoor
unit is installed.
Valve cap
Flare nut
Service port cap
Fig. 6-2
Manifold valve
Pressure
gauge Lo Hi
Charge hose
Cylinder
valve
Nitrogen gas cylinder
(In vertical standing
position)
Open
Suction tube
Close
Open
Discharge tube
Close
Outdoor unit
Open
Liquid tube
Close
Open
Balance tube
Close
Fig. 6-3
Leak test
(1) Attach a manifold valve (with pressure gauges) and dry
nitrogen gas cylinder to all service ports with charge hoses.
The balance tube leak test is not necessary if only 1
outdoor unit is installed.
CAUTION
Use a manifold valve for air purging. If it is not available,
use a stop valve for this purpose. The "Hi" knob of the
manifold valve must always be kept closed.
2
(2) Pressurize the system to no more than 33 kgf/cm G with dry
nitrogen gas and close the cylinder valve when the gauge
reading reaches 33 kgf/cm 2 G. Then, test for leaks with liquid
soap.
CAUTION
To avoid nitrogen entering the refrigerant system in a
liquid state, the top of the cylinder must be higher than
the bottom when you pressurize the system. Usually, the
cylinder is used in a vertical standing position.
(3) Do a leak test of all joints of the tubing (both indoor and
outdoor) and all service valves. Bubbles indicate a leak.
Wipe off the soap with a clean cloth after the leak test.
(4) After the system is found to be free of leaks, relieve the
nitrogen pressure by loosening the charge hose connector
at the nitrogen cylinder. When the system pressure is
reduced to normal, disconnect the hose from the cylinder.
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