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9.2.4. Refrigerant piping
• Refrigerant is charged to the outdoor unit. For details, see
the manual for installation work of outdoor unit. (Additional
charging, etc.).
1. Brazing for piping.
a. Execute brazing before tightening the flare nut.
b. Brazing must be executed while blowing nitrogen gas.
(This prevents generation of oxidized scale in copper
pipe.)
2. When there is a lot of brazings for long piping, install a
strainer midway of the piping. (The strainer is locally
supplied.)
3. Use clean copper pipe with inner wall surface free from
mist and dust. Blow nitrogen gas or air to blow off dust in
the pipe before connection.
4. Form the piping according to its routing. Avoid bending
and bending back the same piping point more than three
times.
(This will result in hardening of the pipe).
5. After deforming the pipe, align centers of the union fitting
of the indoor unit and the piping, and tighten them firmly
with wrenches.
6. Connect pipe to the service valve or ball valve which is
located below the outdoor unit.
7. After completed the piping connection, be sure to check if
there is gas leakage in indoor and outdoor connection.
• Confirm the red mark of the union (thin side) is always at
lower direction after connecting piping.
Vacuum drying
After completing the piping connection, execute vacuum drying for the connecting piping and the indoor unit.
The vacuum drying must be carried out by using the service ports of both the liquid and gas side valves.
CAUTION Use two wrenches and tighten with regular torque.
9.2.5. Indoor unit drain piping
Flare nut fastening torque N m (kgf.cm)
ø6.355 mm 18 (180) ø12.7 mm 55 (560) ø19.05 mm 100 (1020)
ø9.52 mm 42 (430) ø15.88 mm 65 (660)
Liquid side piping Gas side piping
ø9.52 mm ø15.88 mm
• The unit has two drainage holes at both side.
The drainage hole without connection needs seal and thermal insulation with
accessories.
• Always lay the drain with downward inclination (1/50 to 1/100).
Prevent any upward flow or reverse flow in any part.
• 5mm or thicker formed thermal insulator shall always be provided for the drain
pipe.
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