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07-17-2008, 06:48 AM #1
Moving box/evaps, Not condenser, Pumpdown?
We are moving the evaps and the box on a freezer- single evap remote compressor. Also cooler-two evaps on one remote compressor. Can we properly pump charges down to the compressor/condenser. We are AC guys the boss sent out to do this job.
It is a C-store that is remodeling. Thanks. Trying to keep the hackery to a minimum.......
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07-17-2008, 08:01 AM #2
It depends..........how's that for a straightforward answer?

Many times a tech is able to close the king valve on the receiver and simply pump the refrigeration lines into the receiver.
A couple things that may throw a wrench into your plans:
- If these refrigeration units are remote compressors - meaning they have a remote condenser sitting outside somewhere.......you will not be able to cut the condenser lines (should you need to) without recovering the entire system charge.
- If the receiver is too small for the line size/length of run run the risk of tripping the compressor on excessive head pressure before the liquid/suction lines pump out. You also run the risk of popping the relief on the receiver which is not a fun thing to do.
If you ARE able to do this, make sure you front seat at least the suction service valve completely....I've seen instances where the compressor valve plate is allowing high side gas to seep into the low side of the head and eventually dump the entire system charge through the suction line at the compressor.
If you have any other questions throw 'em out...........and good luck with the move
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07-17-2008, 09:24 AM #3
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Why not just recover the refrigerant, valve off the compressors and when re-installing new driers both suction and liquid.
Saves a lot of headaches. JMO.
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07-17-2008, 09:58 AM #4
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07-17-2008, 10:56 AM #5
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07-17-2008, 11:05 AM #6
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You obviously haven't had too much experience in refrigeration burnerfixer, there is no short cut about pumping down a system instead of reclaiming the refrigerant. It is a common practice used daily by any market tech or refrigeration technician. If you can pump it down and save the customer some labor and move on to the next one, thats my vote!
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07-17-2008, 11:38 AM #7
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Pump down maybe, but I have seen headaches when doing this while systems are being moved. Renovations usually lead to dirt and dust and God knows what else. Yes I've worked with my cousin doing refrigeration and though not as good as him, I would rather a job be done right the first time. JMO
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07-17-2008, 11:39 AM #8
Ben, you gotta remember that the vast majority of the guys on here deal with a package or split AC system that holds a few pounds of refrigerant.
The idea of recovering 30 lbs, 60 lbs, 100 lbs.............or 1,000 lbs of refrigerant from a unit is foreign to them - hence the "do the job right the first time" comment.
Those of us that know, know........those that don't sure make for humorous reading.
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07-17-2008, 11:44 AM #9
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Those of us that know, know........those that don't sure make for humorous reading.
[/QUOTE]
Seems to be alot more humorous reading on here lately
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07-17-2008, 11:44 AM #10
Ok - so you pinch and braze the suction and liquid line shut after pumping it down (which is a good idea anyway if the unit is going to be sitting for more than 24 hours or so).......whats the difference if the refrigerant is contained in the pressure vessel attached to the condensing unit/compressor or a recovery drum?
This has nothing whatsoever to do with changing driers and proper evacuation - anyone with 1/2 a brain already knows this is a MUST.
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07-17-2008, 11:46 AM #11
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Sorry guys don't be rough on my cousin, he only works on the small stuff.
Yes Al pump down is quite common in refrigeration, especially with large charges. Also make sure lines are capped to prevent contamination to the system.RAM Teaching Tomorrows Technicians Today.
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07-17-2008, 11:49 AM #12
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07-17-2008, 11:51 AM #13
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Hey M.T. still need us to cover for you this afternoon?


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