EN
21
Digital Inverter
13
FUNCTIONS TO BE IMPLEMENTED LOCALLY
Handling Existing Pipe
When using the existing pipe, carefully check for the
following:
•
Wall thickness (within the specified range)
•
Scratches and dents
•
Water, oil, dirt, or dust in the pipe
•
Flare looseness and leakage from welds
•
Deterioration of copper pipe and heat insulator
•
Before recovering the refrigerant in the existing system,
perform a cooling operation for at least 30 minutes.
Cautions for using existing pipe
•
Do not reuse a flare nut to prevent gas leaks.
Replace it with the supplied flare nut and then process it
to a flare.
•
Blow nitrogen gas or use an appropriate means to keep
the inside of the pipe clean. If discolored oil or much
residue is discharged, wash the pipe.
•
Check welds, if any, on the pipe for gas leaks.
•
There may be a problem with the pressure resistance of
the branching pipes of the existing piping. Replace them
with branch pipes (sold separately).
When the pipe corresponds to any of the following, do not
use it. Install a new pipe instead.
•
The pipe has been opened (disconnected from indoor
unit or outdoor unit) for a long period.
•
The pipe has been connected to an outdoor unit that
does not use refrigerant R22, R410A or R407C.
•
The existing pipe must have a wall thickness equal to or
larger than the following thicknesses.
•
Do not use any pipe with a wall thickness less than these
thicknesses due to insufficient pressure capacity.
•
When using a Ø19.1 mm gas pipe for the existing piping,
set bit 3 of SW802 (switch for existing pipe) on the P.C.
board of the outdoor unit to ON. In this case, the heating
performance may be reduced depending on the outside
air temperature and room temperature.
Recovering Refrigerant
Use the refrigerant recovery equipment to recover the
refrigerant.
Reference outside
diameter (mm)
Wall thickness
(mm)
Material
6.4
0.8
—
9.5
0.8
—
12.7
0.8
—
15.9
1.0
—
19.1
1.2
—
22.2
1.0
Half hard
28.6
1.0
Half hard
SW802
When shipped from factory
When using existing pipe
12
3
4
ON
12
3
4
ON
