Refrigerant Piping Work - Mitsubishi Electric CITY MULTI PVFY-P08 NAMU-E1 Manuel D'installation

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.
Specifications are subject to change without notice.
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.
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