Johnson SUIT Serie Manual De Instrucciones página 40

Explaination:
When the horizontal
distance is over
40m, it is necessary
to add the oil return
bend in the middle.
The horizontal pipe
is divided into
each period of less than
30m. As shown in figure.
4-8 Remove foreign materials in the pipeline.
1) The refrigerant piping may be subject to foreign materials in time of installation, so it must
be cleaned with high pressure nitrogen;
2) While cleaning, never connect the indoor unit;
3) Never use refrigerant or oxygen and any other combustible toxic gas to replace nitrogen.
4-9 Gas tightness test
1) After the refrigerant piping has been installed with the indoor unit connected and before the
indoor-outdoor connecting pipe is connected to the outdoor unit valve, you must inject the nitrogen
of 40kgf / cm ² (4.0MPa) at the same time from the gas and liquid side with the pressure value
correctly identified for a 24 hours' air tightness test.
2) If the pressure is found dropping, then check the leakage of all interfaces and then keep the
pressure for 24 hours.
3) During pressure maintenance, never connect the outdoor unit.
4-10 Vacuumizing by a vacuum pump
1) The vacuum degree of the vacuum pump is -0.1MPa below and the air flow rate is 40L/min above.
2) Vacuumization for the outdoor unit is unnecessary, and it is forbidden to open the check valves at the
gas side and liquid side of the outdoor unit.
3) Make sure the vacuum pump can reach -0.1MPa below within 2 hours, and if it fails to reach -0.1MPa
below after 3 hours, it means some water or air has mixed inside, and the pump and pipeline system must be
inspected.
4) Vacuum pump must have check valve.
4.Connecting pipe installation
13
V.1