Mitsubishi Electric City Multi Y Série Manuel D'installation page 19

2 Evacuation
As shown in the figure below, evacuate with the stop valve of the outdoor unit closed and evacuate both the connection piping and the indoor unit
from the service port provided on the stop valve of the outdoor unit using a vacuum pump. (Always evacuate from the service port of both the liquid
pipe and the gas pipe.) After the vacuum reaches 650 Pa, continue evacuation for at least one hour or more. Then, stop the vacuum pump and let
stand for one day and check if they vacuum does not rise. (If the vacuum rises, since water may be mixed in, pressurize up to 0.05 MPa using dry
nitrogen gas and evacuate again.)
Evacuate from the service port of the ball valve with a vacuum pump.
Finally, seal with liquid refrigerant from the liquid pipe. Moreover, during operation, adjust the refrigerant amount from the gas pipe so that the
refrigerant is always an appropriate amount.
* Never perform air purging using refrigerant.
A System analyzer
B Lo Knob
C Hi Knob
D Ball valve
E Liquid pipe
F Gas pipe
G Service port
H Three-way joint
I Valve
J Valve
K R407C cylinder
D
A
LO LO HI HI
B C
H
E
F
G
I
M
J
K
L
L Scale
Use a graviometer. (One that can measure down to 0.1 kg.)
M Vacuum pump
Use a vacuum pump with a reverse flow check valve.
(Recommended vacuum gauge: ROBINAIR 14830A Thermistor Vacuum
Gauge)
Also use a vacuum gauge that reaches 65 Pa or greater after operating for
five minutes.
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