5.2.
LEAK TEST
Once all the refrigerant pipes have been connected, perform a test by pressurizing the
system Kith nitrogen to make sure there are no leaks.
METHOD
1. Connect the pressure gauge unit to the service valve on the outdoor unit gas pipe.
2. Kith the outdoor unit service valves closed, connect the nitrogen cylinder to the
pressure gauge unit so as to charge the pipes.
3. Charge the installation (pipes and indoor unit) Kith nitrogen at a pressure of about 40
bars.
4. Close the pressure gauge unit valves of the cylinder side. Then wait for the pressure
to stabilize.
5. Make sure that the pressure does not decrease. Once the pressure has stabilized,
the test time can be about 30 minutes.
6. After checking that the system is not leaking (using special leak detection devices),
close the valve on the pressure gauge unit to remove the nitrogen cylinder.
5.3.
CREATING THE VACUUM
After connecting the pipes and checking that there are no leaks, it is very important
to create a vacuum in the system to eliminate the moist air from inside it. Failure to
do so could cause problems to the compressor.
METHOD
1. The air conditioner gas evacuated using a vacuum pump.
Connect the pipes of indoor units and outdoor unit according to the figure below,
and tighten all the bell coupling nuts of indoor and outdoor to prevent leakage.
2. Connect the cut-off valves, charge hose, manifold valve, vacuum pump as the figure
below.
3. Please fully open the manifold valve handle Lo and H, and do the vacuum
processing, vacuum should be running more than 15 minutes, make sure the
vacuum gauge indicates the pressure has reached -0.1MPa (-76cmHg);
4. After completion of vacuum processing, use the hex wrench to open a little the liquid
valve of unit A, B and unit C, and then quickly remove the hose of gas valve
(remove the hose to prevent air from entering the system);
5. Open all the cut-off valve and check the connecting mouth of indoor and outdoor,
then cover the cut-off valves after confirm there is no leak.
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