Samsung AM FXMDCH Series Installation Manual page 25

Vacuuming a pipe and an indoor unit
X Use the tools for R410A only to prevent the inflow of foreign substances and resist X
against the internal pressure .
X Use the vacuum pump with the check valve to prevent pump oil from flowing
X
backward while the vacuum pump is stopped suddenly .
X Use the vacuum pump that can be vacuumed up to -100 . 7 kPa (gauge pressure), X
5 torr .
X Close the service valve of the liquid side pipe, gas side pipe completely when X
performing air tightening test or vacuum drying .
Connect the manifold gauge to the liquid
pipe and gas pipe .
Vacuum the liquid pipe and gas pipe
using the vacuum pump .
Vacuum those pipes for more than 2 hours
and 30 minutes .
Close the valve after checking the vacuum
gauge pressure has reached at -100 . 7 kPa
(gauge pressure), 5 torr .
Check whether the pressure is maintained
as -100 . 7 kPa (gauge pressure), 5 torr . for
an hour .
Pressure Increase
No
Charging additional refrigerant
according to piping length
No
• If the pressure rises in an hour, either water remains inside the pipe, or there will be a leak .
CAUTION
Make sure to install check valve to prevent pump oil from
flowing into the pipe .
The time of vacuum drying may differ depending on the
length of the pipe or outdoor temperature .
Perform vacuum drying for at least 2 hours and 30 minutes .
Check the vacuum pressure using the vacuum gauge .
Check the gas leak .
Yes
Vacuum destruction due to the moisture
inside the pipe
• Apply pressure with Nitrogen gas of 0 . 0 5
MPa (gauge pressure), 7 . 2 5 psig .
Perform vacuum drying again up to
(g
-100 . 7 kPa auge pressure), 5 torr
hours or longer) and evaluate the vacuum .
Pressure Increase
Vacuum
pump
(for 2
Yes
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