24
■
The refrigerant pipe should be clean. The nitrogen should flow under the pressure of about 0.5Mpa 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).
Source valve
Hand
1st side 2nd side
■
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.
8.6 Leakage test
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 chlorin, 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 1°C, 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.
Nitrogen
To indoor
Gauge manifold
Handle
Handle
