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Installation instruction
• Weld the pipe at the same time charge the nitrogen. Or it will cause a number
of impurity (a film of oxidation) to clog the capillary and the expansion valve,
further cause the deadly failure.
• Protect the pipe end against the water, impurity into the pipes
(welding after being flat, or being sealed with adhesive tape).
Flat
Brazing
• 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).
• 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.
(6) Leakage test
1. The outdoor unit has been executed the leakage test in the factory. After connecting the distributing pipe, execute the
leakage test from the outdoor check valve and the indoor. Besides, while testing, the valves should be close.
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 (4.0MPa), record the temp. and the pressure.
d. Leave it at 4.0MPa 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.
(7) Evacuation
Evacute at the check valve of liquid stop valve and both sides of the gas stop valve.
Operation procedure:
Adhesive tape
Nitrogen
After reaching -101KPa or
less (below -755mmHg), let
the vacuum pump running
continuously for over 1hour.
If vacuum pointer arises, it shows there is water or leakage in the
system, please check and modify it, and then evacuate again.
11
Seal the pipe end with
adhesive tape or the stopper
to increase the resistance, fill
up the pipe with nitrogen.
Taping
Only nitrogen gas
can be used
1st side
Source valve
To indoor
Gauge manifold
Lo
Hi
Lo handle
Hi handle
Leave it for over 1
hour, vacuum pointer
does not arise.
<N2>
Brazing
2nd side
0.2MPa
Hand
Check valve
Gas pipe
Gas pipe
Check hole
Outdoor
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