CD Player and Air Conditioning System-14
Pumping Out of A i r Conditioning System to the Vacuum and Addition of Refrigeration Oil
Connect the manifold pressure gauge with the pipe of air conditioner (compressor) and the multi-purpose adapter of the vacuum
pump for the purpose of pumping out of the system to the vacuum state.
Before pumping out to the vacuum, turn on the high-pressure and low-pressure valve of the
manifold pressure gauge and the end valve
(if provided) of the vacuum pump, then press the button ON to start the vacuum pump, the duration shall be more than 20 minutes
.
When the reading of manifold pressure gauge is -760mmHg or below, turn off the high-pressure and low-pressure valve (if opened)
,
and press the switch to turn off the vacuum pum
p.
1 . check the air tightness
Continue to check the pressure reading of the manifold pressure gauge after turning off the vacuum pump.
If the pressure reading remains unchanged within 20 minutes after the vacuum pump stops running, then it indicates that th
e
refrigerating system has no leakage, the operator can proceed with next work; while change of the reading indicates that the
system has the leakage. Launch the examination and pump out to the vacuum after the leakage is fixed.
2 . Injection of the refrigerant
When the air tightness of the system is verified correct, connect the refrigerant reservoir (or gas bottle) with one end of the yellow
a ir-charging hose, while other end of yellow air-charging hose is connected with the liquid injection port in the middle of the
manifold pressure gauge. Ensure that the refrigerant reservoir is connected firmly with the nut of air-charging hose, then turn on
the valve of refrigerant reservoir; at this time, the high-pressure and low-pressure is closed, use a tip screw driver or other
similar
tools and press the by-pass valve spool for 1~ 2 seconds to discharge out the air in the air-charging hose and the manifold
pressure gauge.
low p ressure
high pressure
manifold pressure gauge
quick coupler
l ow-pressure pump
high-pressure pipe
quick coupler
quick
coupler
red
blue
vacuum pum
p
manifold pressure gauge
low pressure gauge high
pressure gauge
Red
blue
yellow
yellow
4. Attention:
a. when a new compressor is used to substitute for the old one, the oil must be released to some extent that its oil volume is the
same as that of old compressor so as to avoid the influence over the refrigeration effect due to too much oil.
b. when an old or repaired compressor is employed, the volume of the refrigeration oil in the compressor must be kept the sam
e
as that of the replaced
compressor.
