Daikin RXYQ96PYDN Service Manual page 485

Troubleshooting (OP: Unified ON/OFF Controller)
[Check 13] Vacuuming and dehydration procedure
Conduct vacuuming and dehydration in the piping system following the procedure for <Normal
vacuuming and dehydration> described below.
If moisture gets mixed in the piping system, follow the procedure for <Special vacuuming and
dehydration> described below.
<Normal vacuuming and dehydration>
N Vacuuming and dehydration
O Leaving in vacuum state
P Refrigerant charge
<Special vacuuming and dehydration> - In case moisture gets enters the piping*
N Vacuuming and dehydration
O Vacuum break
P Vacuuming and dehydration
Q Leaving in vacuum state
R Refrigerant charge
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• Use a vacuum pump that enables vacuuming up to 14.60psi (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 -100.7kPa or less.
• If the degree of vacuum does not reach -14.60psi 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 -14.60psi or less even though evacuation is conducted
for a period of three hours, conduct leak tests.
• Leave the compressor at the degree of vacuum of -14.60psi 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 there may be refrigerant leakage.
• Purge air from the manifold gauge connection hoses, and then charge the appropriate quantity
of refrigerant.
• Follow the same procedure as that for 1) Normal vacuuming and dehydration described
above.
• Pressurize with nitrogen gas up to 7.25psi.
• Conduct vacuuming and dehydration for a period of one hour or more. If the degree of vacuum
does not reach -14.60psi 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 -14.60psi 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 the appropriate quantity
of refrigerant.
∗
If extended construction takes place during a rainy season and rainwater or dew
condensation builds in the piping
SiUS34-801A_b
Troubleshooting