64
Single Zone V
ertical
Air Handling Unit Installation Manual
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FINAL INSTALLATION PROCEDURES
Triple Evacuation Procedure Steps, continued.
After the vacuum pump is first operated, if hoses, manifold, and vacuum valves are leak free (and oil is not moisture laden), the gauge must read
<100 microns within one (1) minute.
Do not proceed if the gauge does not read <100 microns within one (1) minute. There is a leak in the hose,
gauge manifold, or vacuum valve, and the equipment must be replaced.
3. Operate the vacuum pump and evacuate the system to the 2,000 micron level. Isolate the pump by closing the manifold gauges and the
vacuum pump valve, and then watch the micron level. Micron level may rise a bit, but MUST eventually stop rising for fifteen (15)
minutes.
• If the micron level DOES NOT stop rising, there is a leak, and the leak test must be performed again.
• If the micron level DOES rise above 2,000 micron, re-open the manifold gauges and the vacuum pump valve and continue evacuation back
down to 2,000 micron level.
• If the micron level holds at 2,000 micron, continue to step 4.
4. Break vacuum with 50 psig nitrogen purge for an appropriate amount of time (this is to “sweep” moisture from piping).
5. Purge nitrogen from the system until the pressure drops down to 1 to 3 psig.
6. Evacuate to 1,000 micron level. Isolate the pump by closing the manifold gauges and the vacuum pump valve, and then watch the micron
level. Micron level may rise a bit, but MUST eventually stop rising for fifteen (15) minutes.
• If the micron level DOES NOT stop rising, there is a leak, and the leak test must be performed again.
• If the micron level DOES rise above 1,000 micron, re-open the manifold gauges and the vacuum pump valve, and continue evacuation back
down to 1,000 micron level.
• If the micron level holds at 1,000 microns, continue to step 7.
7. Break vacuum with 50 psig nitrogen purge for an appropriate amount of time.
8. Purge nitrogen from the system until the pressure drops down to 1 to 3 psig.
9.
Evacuate to static micron level ≤500 for at least one (1) hour.
10.
Micron level must remain ≤500 for two (2) hours. If the vacuum gauge rises and stops, the system may contain moisture, therefore, it will
be necessary to repeat the steps of vacuum break and drying.
11. After maintaining the system in vacuum for two (2) hours, check if the vacuum gauge rises or not. If it doesn’t rise, then the system is
properly evacuated.
12. Close manifold gauges.
13. Shut the valve before turning off and disconnecting the vacuum pump.
Triple Evacuation Procedure
Summary of Contents for LV181HV4
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