Refrigerant Charge - Hitachi SET FREE MINI RAS-3 Manuel D'installation

11.4. PIPING AND REFRIGERANT CHARGE

11.4.1. REFRIGERANT CHARGE

Quantity of refrigerant charge in Outdoor unit
Outdoor Unit
RAS-3FSVNE
RAS-4FSVNE
RAS-5FSVNE
NOTE:
This information is necessary to define the value of
"Total Refrigerant charge of the System" See chapter
12.1 .

CAUTION:
Do not charge OXYGEN, ACETYLENE, or other
-
flammable and poisonous gases into the refrigerant
because an explosion can occur. It is recommended
that oxygen free nitrogen be charged for these types
of tests cycle when performing a leakage test or an
airtight test. These types of gases are extremely
dangerous,
Insulate the unions and flare-nuts at the piping
-
connection part completely.
Insulate the liquid piping completely to avoid a
-
decrease of performance; if not, it will cause sweating
on the surface of the pipe.
Charge refrigerant correctly. Overcharging or
-
insufficient charging could cause a compressor failure.
Check for refrigerant leakage in detail. If a large
-
refrigerant leakage occurred, it would cause difficulty
with breathing or harmful gases would occur if a fire
were being used in the room.
Refrigerant Charge
(Kg)
1.75
2.8
3.0
(Factory supplied)
REFRIGERANT PIPING & REFRIGERANT CHARGE
11.4.2. TIGHTENING FLARE NUTS
- The required tightening torque is as follows:
Pipe Size
Ø 6.35 mm
Ø 9.53 mm
Ø 12.70 mm
Ø 15.88 mm
- Tightening work on the flare nut:
11.4.3. BRAZING WORK

ATTENTION:
− Use nitrogen gas for blowing during pipe brazing. If
oxygen, acetylene or fluorocarbon gas is used, it will
cause an explosion or poisonous gas.
− A lot of oxidation film will occur inside of tubes if no
nitrogen gas blowing is performed during brazing
work. This film will be flecked off after operation and
will circulate in the cycle, resulting in clogged
expansion valves, etc. This will cause bad influence
to the compressor.
− Use a reducer valve when nitrogen gas blowing is
performed during brazing. The gas pressure should
be maintained within 0.03 to 0.05Mpa. If a
excessively high pressure is applied to a pipe, it will
cause an explosion.
Tightening Torque (Nm)
20
40
60
80
NOTE:
Use always
two spanners.
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