6.4 Installation for the first time 
Air and moisture in the refrigerant system have 
undesirable effects as below:   
●  Pressure in the system rises. 
●  Operating current rises. 
●  Cooling or heating efficiency drops. 
●  Moisture in the refrigerant circuit may 
freeze and block capillary tubing. 
●  Water may lead to corrosion of parts in the 
refrigerant system. 
Therefore, the indoor units and the pipes 
between indoor and outdoor units must be leak 
tested and evacuated to remove gas and 
moisture from the system. 
Gas leak check (Soap water method): 
Apply soap water or a liquid neutral 
detergent on the indoor unit connections or 
outdoor unit connections by a soft brush to 
check for leakage of the connecting points of 
the piping. If bubbles come out, the pipes have 
leakage. 
1. Air purging with vacuum pump 
 
1)  Completely tighten the flare nuts of the 
indoor and outdoor units, confirm that both 
the 2-way and 3-way valves are set to the 
closed position. 
2)  Connect the charge hose with the push pin 
of handle lo to the 3-way valves gas service 
port.. 
3)  Connect the charge hose of handle hi 
connection to the vacuum pump. 
4)  Fully open the handle Lo of the manifold 
valve. 
5)  Operate the vacuum pump to evacuate.   
6)  Make evacuation for 30 minutes and check 
whether the compound meter indicates 
-0.1Mpa(14.5Psi). If the meter does not 
indicate -0.1Mpa(14.5Psi) after pumping 30 
minutes, it should be pumped 20 minutes 
more. If the pressure can’t achieve 
-0.1Mpa(14.5Psi) after pumping 50 minutes, 
please check if there are some leakage 
points. Fully close the handle Lo valve of the 
manifold valve and stop the operation of the 
vacuum pump. Confirm that the gauge 
needle does not move (approximately 5 
minutes after turning off the vacuum pump). 
7)  Turn the flare nut of the 3-way valves about 
45° counterclockwise for 6 or 7seconds 
after the gas coming out, then tighten the 
flare nut again. Make sure the pressure 
display in the pressure indicator is a little 
higher than the atmosphere pressure. Then 
remove the charge hose from the 3 way 
valve. 
8)  Fully open the 2 way valve and 3 way valve   
and securely tighten the cap of the 3 way 
valve. 
 
2. Air purging by refrigerant 
 
Procedure: 
1). Confirm that both the 2-way and 3-way 
valves are set to the closed position. 
2). Connect the charge set and a charging 
cylinder to the service port of the 3-way valve.   
3). Air purging. 
Open the valves on the charging cylinder and 
the charge set. Purge the air by loosening the 
flare nut on the 2-way valve approximately 45’ 
for 3 seconds then closing it for 1 minute; repeat 
3 times.