Daikin VRV II-Q RQYQ8-48PY1B Service Manual page 196

Troubleshooting by Remote Controller
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>
<Special vacuuming and dehydration> - In case moisture may get mixed in the piping*
186
Vacuuming and dehydration
• Use a vacuum pump that enables vacuuming up to 100.7kPa (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 2 or more hours to conduct evacuation to -100.7kPa or less.
• If the degree of vacuum does not reach -100.7kPa or less even though evacuation is
conducted for a period of 2 hours, moisture will have entered the system or refrigerant
leakage will have been caused. In this case, conduct evacuation for a period of another 1
hour.
• If the degree of vacuum does not reach -100.7kPa or less even though evacuation is
conducted for a period of 3 hours, conduct leak tests.
Leaving in vacuum state
• Leave the compressor at the degree of vacuum of -100.7kPa or less for a period of 1 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.)
Refrigerant charge
• Purge air from the manifold gauge connection hoses, and then charge a necessary
quantity of refrigerant.
Vacuuming and dehydration
• Follow the same procedure as that for 1) Normal vacuuming and dehydration described
above.
Vacuum break
• Pressurize with nitrogen gas up to 0.05MPa.
Vacuuming and dehydration
• Conduct vacuuming and dehydration for a period of 1 hour or more. If the degree of
vacuum does not reach -100.7kPa or less even though evacuation is conducted for a
period of two hours or more, repeat vacuum break - vacuuming and dehydration.
Leaving in vacuum state
• Leave the compressor at the degree of vacuum of -100.7kPa or less for a period of 1 hour
or more, and then check to be sure that the vacuum gauge reading does not rise.
Refrigerant charge
• Purge air from the manifold gauge connection hoses, and then charge a necessary
quantity 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:
SiBE341027
Service Diagnosis