14
Installation procedure
The refrigerant pipe should be clean. The nitrogen should flow under the pressure of about
0.2Mpa and when charging the nitrogen, stop up the end of the pipe by hand to enhance the
pressure in the pipe, then loose the hand (meanwhile stop up the other end).
1. The outdoor unit has been executed the leakage test in the factory. The pipe should be
executed leakage test individually and forbidden to test after connecting with stop valve.
2. Refer to the below figure to charge the nitrogen into the unit to take a test. Never use the
chlorine, oxygen, flammable gas in the leakage test. Apply pressure both on the gas pipe and
the liquid pipe.
3. Apply the pressure step by step to the target pressure.
a. Apply the pressure to 0.5MPa for more than 5 minutes, confirm if pressure goes down.
b. Apply the pressure to 1.5MPa for more than 5 minutes, confirm if pressure goes down.
c. Apply the pressure to the target pressure (4.15MPa), record the temp. and the pressure.
d. Leave it at 4.15MPa for over 1 day, if pressure does not go down, the test is passed.
Meanwhile, when the temp. changes for 1degree, pressure will change 0.01MPa as well.
Correct the pressure.
e. After confirmation of a~d, if pressure goes down, there is leakage. Check the brazing position,
flared position by laying on the soap. modify the leakage point and take another leakage test.
4. After leakage test, must execute the evacuation.
When connecting the pipes, close the valves fully.
When welding the valve and the pipes, use the wet cloth to cool down the valve and the
pipes.
B. Leakage test
