Mitsubishi Electric TRANE TPVFYP54AM141 Serie Manuel D'installation page 18

11. Refrigerant piping work
This piping work must be done in accordance with the installation
manuals for both outdoor unit and BC controller (R2/WR2 series).
Series R2 is designed to operate in a system that the refrigerant pipe
from an outdoor unit is received by the BC controller and branches at
the BC controller to the indoor units.
For constraints on piping length and allowable difference of
elevation, refer to the design section of the engineering manual.
The method of pipe connection on the air handler is braze
connection.
Cautions of refrigerant piping
Be sure to use non-oxidative procedures for brazing
to ensure that no foreign matter or moisture enters
the piping.
ALWAYS USE A NITROGEN PURGE IN THE PIPING DURING
BRAZING
Provide proper bracing for refrigerant piping so no load is
imparted upon the connections at the air handler.
Warning:
When installing and moving the unit, do not charge it with
refrigerant other than the refrigerant specified on the unit.
Mixing of a different refrigerant, air, etc. may cause the
refrigerant cycle to malfunction and result in severe
damage.
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Caution:
Use refrigerant piping made of C1220 (Cu-DHP)
phosphorous deoxidized copper as specified in ASTM
B280 Standard for copper and copper alloy seamless
pipes and tubes. In addition, be sure that the inner and
outer surfaces of the pipes are clean and free of hazardous
sulphur, oxides, dust/dirt, shaving particles, oils, moisture,
or any other contaminant.
Never use existing refrigerant piping.
Caution: COIL UNDER PRESSURE
Always wear safety glasses when working around
pressurized devices.
The air handlers are shipped with a nitrogen holding
charge in the coil. Carefully follow these instructions when
releasing the charge.