22
Vacuum drying
f
Use a manifold gauge for R-410A to prevent the inflow of foreign substances and resist against the internal
pressure.
f
Use the vacuum pump with the check valve to prevent pump oil from flowing backward while the vacuum
pump is stopped.
f
Vacuum system to 5Torr. (666.6Pa, 0.0067 kgf/cm², 5 mmHg)
f
Close the service valve of the liquid side pipe and gas side pipe completely.
More than 5Torr
No
Connect the gauge manifold to the liquid
side pipe, gas side pipe and oil balancing
pipe(only for module).
Perform vacuum drying of the liquid
side pipe, gas side pipe and oil balancing
pipe(only for module) using the vacuum
pump.
Make sure that install check valve
to prevent pump oil from flowing
into the pipe.
While the vacuum gauge pressure is less
than 5Torr, perform the vacuum drying for
more than 1 hour and then close the valve.
Check the vacuum pressure using the vacuum gauge.
After vacuum pump stops, check whether
the pressure is maintained within 5Torr for
an hour.
Charging additional refrigerant ac-
cording to piping length
Yes
Check the gas leak again.- The pressure
rises because water is remaining in the
pipe.
Vacuum destruction
- Apply pressure with Nitrogen gas of
0.05MPa.
Perform vacuum drying again up to
666.6Pa(5mmHg) (for 2 hours or longer)
and evaluate the vacuum.
Pressure Increase
Yes
No
• If the pressure rises in an hour, either water remains inside the pipe, or there will be a leak.
CAUTION
Refrigerant piping work
Connect the gauge manifold
to the oil balancing pipe.
Vacuum
pump
