Vacuuming And Dehydration Procedure - Daikin VRV X RXQ6-48ANR Series Service Manual

Check
6.7

Vacuuming and Dehydration Procedure

CHECK 8 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
Use this procedure if moisture may get into the piping, such as construction during the rainy
season (dew condensation may occur, or rainwater may enter the piping during construction
work).
1. Vacuuming and dehydration
2. Vacuum break
3. Vacuuming and dehydration
4. Leaving in vacuum state
5. Additional refrigerant charge
268
 Use a vacuum pump that enables vacuuming up to –100.7 kPa (5 torr, –755 mmHg).
 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 or
less.
 If the degree of vacuum does not reach –100.7 kPa 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 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 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.
 Conduct vacuuming and dehydration for a period of one hour or more. If the degree of
vacuum does not reach –100.7 kPa 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 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.
SiME341909EA
Part 6 Service Diagnosis