Howe Rapid Freeze, Service Manual

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3 Installing the Rapid Freeze Flaker
9
Follow good accepted practice and procedure to charge refrigerant into the system briefly outlined as follows.
1) Pressurize and test the system checking for leaks.
2) Use a good quality vacuum pump to evacuate the system. Make sure all shut-off valves are
OPEN
so that the entire system is evacuated. Allow vacuum pump to run for several hours.
3) Break vacuum with refrigerant and evacuate again.
4) Repeat step 3. This is called "triple evacuation". It ensures that all air and moisture has been
removed from the system. Failure to do so may result in compressor burn-out.
5) After the third evacuation, notice that the "eye" in the liquid indicator is green, (supplied by Howe
on all flakers
except bare flakers) indicating that the system is clean and dry. Then continue to
charge the system (using gas not liquid).
Above is a brief outline for charging the system. Consult the rack or condensing unit manufacturer for full
details.