Daikin SkyAir Super Inverter 70 D Series Service Manual page 43

Field Piping and Wiring
Tools
Several dedicated tools are required for the installation work of R-407C models. Some of conventional tools can be used except tools
actually used to the installation work for R-22 models.
Tool name
Pipe cutter
Flaring tool
Refrigeration oil
Torque wrench
Pipe expander
Pipe bender
Nitrogen
Welder
Gauge manifold
Charging hose
Vacuum pump
Charging cylinder
Weighing scale for
refrigerant charging
Gas leakage detector
Precautions for Installation Work
Joint brazing
Since stricter caution should be necessary for R-407C to
prevent intrusion of foreign matters into the refrigerant piping
line, be sure to conduct N
Flaring
Make sure to conduct chamfering (filing) at cut section, since a
large wall thickness of pipe results large burr. Be aware of no
cutting chips left inside pipe.
Refrigerant charging
Charge R-407C from service port at liquid side stop value of
outdoor unit in liquid phase. At that time, conduct vacuum
drying using vacuum pump.
34
Work process / Usage
Pipe cutting
Pipe flaring
Refrigerant Applying to flared section
piping work
Flare nut jointing
Pipe expanding in connection of pipe
Pipe bending
Oxidation proof for inside pipe
Air tight test
Pipe brazing
From air tight test
Refrigerant charging using
to refrigerant
vacuum and operation check
additional charging
Vacuum drying
Refrigerant additional charging
Gas leakage check
blowing when brazing is required.
2
Conduct installation work for R-407C model following above mentioned piping work procedure. Otherwise, unit
may have trouble. Refer to the "Work execution and control for R-407C model" for the details on handling of R-407C,
installation works and tools.
Interchangeability with conventional tool
Interchangeable and can be used.
Use dedicated ether oil, ester oil, alkyl-benzene oil or mixture of those oil.
Interchangeable and can be used.
Dedicated gauge is required due to high pressure.
For preventing refrigerant leakage and mixing of foreign matters,
dedicated charging hose is required.
Interchangeable and can be used. (Be strictly sure that oil does
not flow in reverse to the unit during pump stop.)
Not required since charging work conducted with weighing scale.
Interchangeable and can be used.
Dedicated detector is required (Detector for R134a can be used).
Other than brazing, a stricter work control including pipe
covering and drying is required to prevent pipe from intrusion of
foreign matters.
Apply appropriate amount of refrigeration oil on outer / inner
surface of flared section to prevent leakage. Make sure to
use synthetic oil (ether oil, ester oil, archi-benzene oil or
mixture of those oils) as refrigeration oil.
Air-tightness test
Make sure to conduct air-tightness test.
SiE25-110
Field Piping and Wiring