8.3 BRAZING WORK
! CAUTION
• Use nitrogen gas for blowing during pipe brazing. If oxygen, acetylene
or uorocarbon gas is used, it will cause an explosion or poisonous
gas.
• A lot of oxidation lm will occur inside of tubes if no nitrogen gas
blowing is performed during brazing work. This lm will be ecked
off after operation and will circulate in the cycle, resulting in clogged
expansion valves, etc. This will cause bad inuence 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.
8.4 REFRIGERANT CHARGE
! CAUTION
• Do not charge OXYGEN, ACETYLENE, or other ammable 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 are-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 insufcient charging
could cause a compressor failure.
• Check for refrigerant leakage in detail. If a large refrigerant leakage
occurred, it would cause difculty with breathing or harmful gases
would occur if a re were being used in the room.
• If the are nut is tigthened too hard, the are nut may crack after a
long time and cause refrigerant leakage.
8.5 REFRIGERANT CHARGING QUANTITY
Outdoor unit refrigerant
charge (kg)
Chargeless length (m)
Additional refrigerant
charge (P) (g/m)
Max additional charge
(kg)
RAS-2WHVRP
RAS-2.5WHVRP
RAS-3WHVRP
1
2
! CAUTION
• When charging refrigerant accurately measure refrigerant to be charged.
• Overcharging or undercharging of refrigerant can cause compressor trouble.
• Refer to indoor unit installation manual for refrigerant charge and minimum oor requirements.
8.6 CAUTION OF THE PRESSURE BY CHECK JOINT
Cooling
operation
Heating
operation
? NOTE
Be careful that refrigerant and oil do not splash to the electrical parts at
removing the charge hoses.
PMML0509 rev.0 - 02/2019