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●
For the flare nuts at tubing connections, be sure to use the
flare nuts that were supplied with the unit, or else flare nuts for
R410A, R32 (type 2). The refrigerant tubing that is used must
be of the correct wall thickness as shown in the table below.
Tube diameter Tightening torque
(approximate) Tube thickness
ø6.35 (1/4") 14 – 18 N · m
{140 – 180 kgf · cm} 0.8 mm
ø9.52 (3/8") 34 – 42 N · m
{340 – 420 kgf · cm} 0.8 mm
ø12.7 (1/2") 49 – 55 N · m
{490 – 550 kgf · cm} 0.8 mm
ø15.88 (5/8") 68 – 82 N · m
{680 – 820 kgf · cm} 1.0 mm
Because the pressure is approximately 1.6 times higher
than conventional refrigerant R22 pressure, the use of
ordinary flare nuts (type 1) or thin-walled tubes may result
in tube rupture, injury, or asphyxiation caused by refrigerant
leakage.
●In order to prevent damage to the flare caused by over-
tightening of the flare nuts, use the table above as a guide
when tightening.
●When tightening the flare nut on the liquid tube, use an
adjustable wrench with a nominal handle length of 200 mm.
Neutral cure & ammonia-free silicone sealant is only to be
applied after pressure testing and cleaning up by following
instructions of sealant, only to the outside the connection.
The aim is to prevent moisture from entering the connection
joint and possible occurrence of freezing. Curing sealant will
take some time. Make sure the sealant will not peel off when
wrapping the insulation.
Apply neutral cure & ammonia-free silicone
sealant along its circumference.
5-3. Insulating the Refrigerant Tubing
Unless the insulation is made, condensation can cause damage
to the interior of a property. Use the supplied insulation material.
Wrap the tubing so that the fold of
insulation material can be facing upward.
Refrigerant tubing
toward indoor unit
Supplied insulation material Bottom
Top
Indoor unit
Tubing Insulation
Must ensure that pipe-work shall be protected from physical
damage.
●Thermal insulation must be applied to all units tubing,
including distribution joint (field supply).
Two tubes arranged together
Liquid tubing Gas tubing
Insulation
* For gas tubing, the insulation material must be heat
resistant to 120°C or above. For other tubing, it must be
heat resistant to 80°C or above.
Insulation material thickness must be 10 mm or greater.
If the conditions inside the ceiling exceed DB 30°C and RH
70%, increase the thickness of the gas tubing insulation
material by 1 step.
CAUTION
If the exterior of the outdoor unit valves has been finished
with a square duct covering, make sure you allow sufficient
space to access the valves and to allow the panels to be
attached and removed.
N OT E
Gas Leakage Detector
Note that the gas leakage detector should be capable of
detecting the refrigerant R410A, R32.
Air Purging
Refer to “AIR PURGING” in the separate Installation
Instructions for the outdoor unit in regard to air purging with a
vacuum pump (for test run) preparation.
Taping the flare nuts
Cover up the tubing connections with the supplied flare
insulator. Then fasten the insulator at both ends with the vinyl
clamps (field supply).
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.
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