Installation Manual
33
Refrigerant piping installation
Leak Test and Vacuum
Lo
Nitrogen charging
cylinder
Outdoor unit
Indoor unit
Liquid side
Gas side
Check valve
3-Way
valve
(1) Leak test
Leak test should be made by pressurizing nitrogen gas to 2.94 MPa(30.0Kg/cm
2
). For the test method, refer to
the following figure. (Make a test with the service valves closed. Be also sure to pressurize Liquid pipe, Gas pipe
and High/Low Pressure Common pipe)
The test result can be judged good if the pressure has not be reduced after leaving for about one day after com-
pletion of nitrogen gas pressurization.
Note:
If the ambient temperature differs between the time when pressure is applied and when the pressure drop is
checked, apply the following correction factor
There is a pressure change of approximately 0.1 kg/cm
2
(0.01 MPa) for each 1°C of temperature difference.
Correction= (Temp. at the time of pressurization – Temp. at the time of check) X 0.1
For example: Temperature at the time of pressurization (3.8 MPa) is 27 °C
24 hour later: 3.73 MPa, 20°C
In this case the pressure drop of 0.07 is because of temperature drop
And hence there is no leakage in pipe occurred.
ENGLISH
To prevent the nitrogen from entering the refrigeration system in the liquid state, the top of the cylinder must
be at higher position than the bottom when you pressurize the system.
Usually the cylinder is used in a vertical standing position.
CAUTION
Summary of Contents for Multi V Space ARUV Series
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