EarthLinked AVS-0030-A, Quick Start Instructions

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SD-410-QS (H) (06/15) Page 65
Triple Evacuation
Triple evacuation is implemented to evacuate a system to a deep vacuum. It is accomplished by
evacuating a system to a vacuum of 1500 microns, and then bleeding a small amount of dry nitrogen
into the system. The nitrogen is then blown out to the atmosphere. The system is then evacuated
until the vacuum is again reduced to 1500 microns. This procedure is repeated three times, with the
last vacuum level reaching a deep vacuum of 400 microns, which is held for 10 to 15 minutes. The
following is a detailed description of the triple evacuation.
1. Attach an electronic micron gage to the system. The best place is as far from the vacuum port
as possible, which would be the access port on a service valve on the EarthLinked
®
compressor unit.
2. Let the vacuum pump run until the micron gage reaches 1500 microns.
3. Allow a small amount of dry nitrogen to enter the system until the vacuum shows about 20
inches of Hg on the manifold gage. This small amount of dry nitrogen will fill the system and
mix with the other vapors.
4. Open the vacuum pump valve and start the vapor removal process from the system again.
Let the vacuum pump run until the vacuum is again reduced to 1500 microns.
Repeat Step 3.
5. After nitrogen has been added to the system a second time , open the vacuum pump valve
and again remove the vapor. Operate the vacuum pump until the vacuum on the electronic
micron gage reads
400 microns.
6. Once the micron gage reads 400 microns for 10 to 15 minutes , isolate the micron gage and
charge the system in accordance with the initial refrigerant charging procedure.