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Step 7 Connecting the assembly pipes
to the refrigerant pipes
There are two refrigerant pipes of different diameters :
• A smaller one for the liquid refrigerant.
• A larger one for the gas refrigerant. The inside of
copper pipe must be clean and has no dust.
1 Remove the two pinch pipes and connect the field
refrigerant pipes. Tighten the flare nuts, first manually
and then with a torque wrench and a backup wrench
applying the following torque.
1
Spanner
3
Union
Outer Diameter (mm)
mm
inch
Ø6.35
1/4
Ø9.52
3/8
Ø12.70
1/2
Ø15.88
5/8
Ø19.05
3/4
2
Torque
wrench
3
Flare nut
Torque
lbf.ft
14 to 18
10.3 to 13.3
34 to 42
25.1 to 31.0
49 to 61
36.1 to 45.0
68 to 82
50.2 to 60.5
100 to 120
73.8 to 88.5
NOTE
• If the pipes must be shortened, see Step 6 Cutting
and flaring the pipes on page 12.
2 Be sure to use an insulator thick enough to cover the
refrigerant pipes to improve the efficiency of the unit
and to prevent condensate water formation on the
outside of the pipes falling onto the floor.
3 Cut off any excess foam insulation.
4 Make sure that there are no cracks or waves on the
bent area.
5 It is necessary to double the insulation thickness
(0.39inch or more) to prevent condensation on the
insulator when the installed area is warm and humid.
6 Do not use joints or extensions for the pipes
connecting the indoor and outdoor units. The only
permitted connections are those for which the units
are designed.
CAUTION
• Connect the indoor and outdoor units using pipes
with flared connections (not supplied). For the lines,
use insulated, unwelded, degreased and deoxidized
copper pipe (Cu DHP type to ISO 1337 or UNI EN
12735-1), suitable for operating pressures of at least
4.2MPa (609.2 psig) and for a burst pressure of at least
20.7MPa (3002.3 psig). Copper pipe for hydro-sanitary
applications is completely unsuitable.
• For sizing and limits (height difference, line length,
max. bends, refrigerant charge, etc.) see the outdoor
unit installation manual.
• All refrigerant connection must be accessible, in order
to permit either unit maintenance or removing it
completely.
• If the pipes require brazing, make sure that oxygen
free nitrogen (OFN) is flowing through the system.
• Nitrogen blowing pressure range is 0.02 to 0.05 MPa
(2.9 to 7.3 psig).
13
English
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