36
Installation and Maintenance
Service Manual
(3) Once refrigerant piping and drain piping connections are complete, fill in the gap of the through hole with putty. A gap can lead to
condensation on the refrigerant pipe, and drain pipe, and the entry of insects into the pipes.
(4) Attach the front panel and front grille in their original positions once all connections are complete.
7. Flaring the Pipe End
(1) Cut the pipe end with a pipe cutter.
(2) Remove burrs with the cut surface facing downward so that the chips do not enter the pipe.
(3) Fit the flare nut on the pipe.
(4) Flare the pipe.
(5) Check that the flaring is properly made.
(1) DO not use mineral oil on flared part.
(2) Prevent mineral oil from getting into the system as this would reduce the lifetime of the units.
(3) Never use piping which had been used for previous installations. Only use parts which are delivered with the unit.
(4) Do never install a drier to this R410A unit in order to guarantee its lifetime.
(5) The drying material may dissolve and damage the system.
(6) Incomplete flaring may cause refrigerant gas leakage.
8. Connecting the Refrigerant Pipe
(1) Use torque wrenches when tightening the flare nuts to prevent damage to the flare nuts and gas leaks.
(2) Align the centres of both flares and tighten the flares and tighten the flare nuts 3 or 4 turns by hand.
Then tighten them fully with the torque wrenches.
(3) To prevent gas leakage, apply refrigeration oil on both inner and outer surfaces in the flare. (Use refrigeration oil for R410A.)
Caution on Piping Handling
(1) Protect the open end of the pipe against dust and moisture.
(2) All pipe bends should be as gentle as possible. Use a pipe bender for bending.
(Bending radius should be 30 to 40mm or larger.)
Make sure that the
flare nut is fitted
The pipe end must
be evenly flared in
a perfect circle
Flare’s inner
surface must
be scratch-free
Cut exactly
at right
angles
Renove
burrs
Flaring
Set exactly at the position shown below
A
Die
A
0-0.5mm
1.0-1.5mm
1.5-2.0mm
Flare tool for R32
Clutch-type
Clutch-type
(Rigid-type)
Wing-nut type
(lmperial-type)
Conventional flare tool
Wrench
Indoor unit tubing
Open-end wrench (fixed)
Connection pipe
Flare nut
Coat here with refrigeration oil
Be sure to
place a cap.
If no flare cap is
available,cover
the flare mouth
with tape to keep
dirt or water out.
Flare nut tightening torque
Gas side
Liquid side
09/12K
18K
09/12K
3/8 inch
1/2 inch
1/4 inch
31-35 N.m
50-55 N.m
15-20 N.m
CAUTION
