Samsung AM MXVAFC Series Installation Manual page 72

Air tightness test and vacuum drying
Vacuum drying pipes and indoor units
f Use tools for R-410A to prevent the inflow of foreign substances and resist against the internal pressure . f
f Use vacuum pump that allows vacuuming under -100 . 7 kPa (5 Torr) .
f
f Use the vacuum pump with the check valve to prevent pump oil from flowing backward while the vacuum pump is
f
stopped .
f Completely close the liquid·gas side service valve of the outdoor unit . f
Connect the manifold gauge to the liquid side pipe
and gas side pipe (when installing outdoor units in
module) .
Perform vacuum drying of the liquid side pipe and
gas side pipe (when installing outdoor units in
module) using a vacuum pump .
While the vacuum gauge pressure is less than
-100 . 7 kPa (5 Torr), perform the vacuum drying for
more than 1 hour and close the valve .
After vacuum pump stops, check whether the
pressure is maintained within -100 . 7 kPa (5 Torr) for
an hour .
Over -100 . 7 kPa (5 Torr)
No
Charge additional refrigerant to the pipe
❋ ❋ If the pressure rises in an hour, either water is remaining inside the pipe or there is a leakage .
❋ ❋ When the ambient temperature of vacuuming pipe is low (less than 0°C (32°F)), moisture might remain within the pipe .
Therefore, pay special attention to the pipe sealing in the winter .
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When installing outdoor units in module, connect the manifold gauge to
liquid side pipe and the gas side pipe .
Make sure that check valve is installed to prevent pump oil from flowing
into the pipe .
Vacuum pressure must be checked with the vacuum gauge .
Check for gas leakage
Vacuum destruction
Yes
• Apply nitrogen gas to the pipe at pressure of
0 . 0 5 Mpa(7 . 2 5psi) .
Perform vacuum drying again
No
Pressure increase
Yes