Daikin VRV IV-S RXTQ-TAVJU Series Service Manual page 241

SiUS331604E
CHECK 8
Vacuuming and dehydration procedure
Conduct vacuuming and dehydration in the piping system following the procedure for Normal
vacuuming and dehydration described below.
Furthermore, if moisture may get mixed in the piping system, follow the procedure for Special
vacuuming and dehydration described below.
Normal vacuuming and dehydration
(1) Vacuuming and dehydration
(2) Leaving in vacuum state
(3) Additional refrigerant charge
Special vacuuming and dehydration
In case of moisture may get mixed in the piping∗
(1) Vacuuming and dehydration
(2) Vacuum break
(3) Vacuuming and dehydration
(4) Leaving in vacuum state
(5) Additional refrigerant charge
Service Diagnosis
• Use a vacuum pump that enables vacuuming up to –100.7 kPa (–14.6 psi).
• Connect manifold gauges to the service ports of liquid pipe and gas pipe and run the vacuum
pump for a period of two or more hours to conduct evacuation to –100.7 kPa (–14.6 psi) or
less.
• If the degree of vacuum does not reach –100.7 kPa (–14.6 psi) or less even though evacuation
is conducted for a period of two hours, moisture will have entered the system or refrigerant
leakage will have been caused. In this case, conduct evacuation for a period of another one
hour.
• If the degree of vacuum does not reach –100.7 kPa (–14.6 psi) or less even though evacuation
is conducted for a period of three hours, conduct the leak tests.
• Leave the compressor at the degree of vacuum of –100.7 kPa (–14.6 psi) or less for a period
of one hour or more, and then check to be sure that the vacuum gauge reading does not rise.
(If the reading rises, moisture may have remained in the system or refrigerant leakage may
have been caused.)
• Purge air from the manifold gauge connection hoses, and then charge a necessary amount of
refrigerant.
• Follow the same procedure as that for Normal vacuuming and dehydration described above.
• Pressurize with nitrogen gas up to 0.05 MPa (7.3 psi).
• Conduct vacuuming and dehydration for a period of one hour or more. If the degree of vacuum
does not reach –100.7 kPa (–14.6 psi) or less even though evacuation is conducted for a
period of two hours or more, repeat vacuum break - vacuuming and dehydration.
• Leave the compressor at the degree of vacuum of –100.7 kPa (–14.6 psi) or less for a period
of one hour or more, and then check to be sure that the vacuum gauge reading does not rise.
• Purge air from the manifold gauge connection hoses, and then charge a necessary amount of
refrigerant.
∗
In case of construction during rainy reason, if dew condensation occurs in the piping due to
extended construction period, or rainwater or else may enter the piping during construction
work:
Troubleshooting by Error Code
228