10
WTK-SVN001-EN
Air Evacuation
and Refrigerant Charge
Piping Per each additional
size meter of
interconnecting line
Liquid-Suction grams/meter
1/4
é
-3/8
é
23 grams/meter
1/4
é
-1/2
é
26 grams/meter
3/8
é
-5/8
é
59 grams/meter
3/8
é
-3/4
é
60 grams/meter
3/8
é
-1
1
/
8
é
68 grams/meter
1/2
é
-7/8
é
117 grams/meter
Evacuation
Air and humidity are the enemy of
the air-conditioning system because
humidity will react with R22 refrigerant
and turns into acid, which will corrode
the wire coil and reduce the
compressor oil’s efficiency. Evacuation
is a must to prevent refrigerant system
from air and humidity.
Evacuation Procedure
Connect the middle hose of service
gauge to the vacuum pump, then
connect the hose at the low side to
“service valve” of air-conditioning
at suction line. Connect the hose at
the high side to “service valve” at
liquid line (figure 13).
Fill up R22 refrigerant into the
system
To fill up R22 refrigerant is the final
step of installation. After leakage
check and power wiring, fill up R22
refrigerant to the system.
How to fill up R22 refrigerant
Normally, this needs to be done
immediately after air evacuation per
the following steps (figure 13)
•Fill up the refrigerant via valve at
liquid line until pressure of the
liquid line is around 120-150 psig
(Don’t forget to evacuate air from
liquid line before)
•Turn on evaporator and condensing
unit.
•Fill up the refrigerant into suction
line at the proper quantity while the
unit is working.
• Let machine run for at least 20
minutes. Read pressure from
pressure gauge “at both high and
low side”, and read current
from amp-meter. Usually, suction
line pressure should be around
65-70 psig , and liquid line pressure
should be around 250-275 psig.
If the pressure readings of both liquid
line and suction line are in the range
stated above and electric current
reading is at full load ampere of
condensing unit, it indicates that
refrigerant’s volume is sufficient.
• But if suction pressure is lower than
normal and electric current is far
below full load ampere, it indicates
that refrigerant is inadequate.
You need to add more refrigerant.
• If suction pressure is higher than
normal and electric current is over
the full load ampere, and you notice
some water spray holds on the
compressor, it indicates over cooling
system. You need to release some
refrigerant.
Remark: When the interconnecting
line is longer than 7.5 m, additional
charging is necessary. For the additional
amount, follow the table belows.
Liquid
pressure
Suction
pressure
Vacuum pump
R22
Service
hoses
Liquid
line
Suction
line
Electrical
connection
Figure 13
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