IN-VA07-B001-00
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© Future Products Group
System Evacuation
cont.
VISAIR CABINETS
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APPENDIX A
R-290 Refrigerant
Evacuation
Procedure
1.
It is necessary to purge the system with nitrogen. This is necessary to
prevent flammable mixtures from occurring.
2.
When connecting the hoses between the system, gauge manifolds, and
vacuum pump, ensure that the connections are secure and there are no
potential ignition sources nearby.
3.
Ensure that the pump discharge is in an area free of potential ignition
sources.
4.
Ensure that a micron gauge is used since conventional manifold gauges
may not provide a proper reading.
5.
The system should be evacuated to the desired pressure (typically 250
microns or less) and then left to stand for 15 minutes to ensure that the
entire refrigerant charge has been removed from the oil and any residual
moisture has been evaporated from the system.
6.
Ensure that the vacuum pump is of good quality and of appropriate
capacity for the system, and the oil level is correct.
Charging the System
VISAIR CABINETS
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APPENDIX A
R-290 Refrigerant
WARNING
Dial-a-charge cylinders, with a sight glass, should not be used to charge
systems with flammable refrigerant.
Precautions
Although charging procedures are similar to those used with any other type of
refrigerant, the following considerations are important for R-290:
•
Prior to charging, ensure the system has been leak checked.
• Hoses or lines must be as short as possible to minimize the amount of
refrigerant contained in them.
• Evacuate the hoses and manifold prior to charging to avoid
contamination of the refrigerant.
• Upon completion of charging, a further leak check must be carried out
prior to leaving the site.
• After charging, carefully disconnect the hoses, attempting to minimize
the release of refrigerant.
• After charging, all access ports/points must be removed following the
correct procedures.
DO NOT OVERCHARGE A SYSTEM USING R-290.
Weigh in the exact charge.
