moisture???

[edmond]

I have got seven condensors(American Standard) that I put in storage for two months while some digging was done at a school.These units are only one year old.I covered lines up on both unit and lines out of the building,but the diggers played finger punch with the tape I had on the lines out of the building.The units will not run but just a short second before cutting off by the low pressure switch.I know freon is full because of sight glass.could this be moisture in lines or dirt.THANKS

[Dad]

Finger punch is fun play for kids but no good for your lazy way of sealing the line sets. You know now you should have welded them shut. Good lesson here.

Your line sets are filled with dirt, water, and possibly urine too. What to do now?

Your line sets are now junk unless you can be 100% sure you can clean them out... good luck. You may have to install replaceable cartridge suction driers on your systems just before the compressors and replace the cartridge often until you are sure your system is clean. You will have to dump your charges because the refrigerant is now contaminated too. Ever see a construction guy relieve himself in a line set just for the fun of it? Ever see what salt can do to the inside of a refrigeration system?

Now let’s talk about your evap coil metering devices. You will now have to pull them out and clean them by hand or replace them. And if you are very lucky you will not have to pull the evap coils, you may get away with blowing them out with nitrogen.

There will be moisture in your compressor oil now since you have run the units. At the very least you should change the oil before you crank them back up. Make sure you don't have any leaks then vacuum each system down for 24 hours before charging them. New oversized liquid driers just before the metering devices are now your ticket. Keep a supply on hand and change them after an hour of operation and again in 24 hours. You will need to return and change them again in 30 days just to be sure.

I am sorry to be so bold but… a good lesson is sometimes hard to $wallow.

[d_lee1]

before you connected the unit back you should have blown through system with nitrogen.Installed suction and liquid driers.evacuated down to 500 microns. then you would have known about the moisture. I have seen sight glasses that were empty and looked like they were full.whats your suction prs and head prs? do a moisture test to see if there is moisture. look for frost on the lines at liquid drier(if there is on) and at metering device.if you have moisture and trash in the system then you have a mess like lusker explained.good luck sounds like your gonna need it.

[Freezeking2000]

I would guess you have some dirt in you txv or metering device

[beenthere]

What are the guage readings.
Like d_lee1 said, some times an empty glass will look like its full.

And now you should recover, blow out those lines, install filter driers, vac and recharge using guages and superheat, or subcool, instead of just guessing at the condition of your charge.

[R12rules]

Who cut these apart and who joined them together again?
Who did the start up? You?

What are the pressures. How many systems are we talking about here?

[R12rules]

Originally posted by lusker
Make sure you don't have any leaks then vacuum each system down for 24 hours before charging them.

Did you mean; "vacuum the system down until they reach a vacuum of 500 Microns and will hold there for at least ten minutes?"

Or did you actually intend someone to turn on a vacuum pump and let it operate and to do so based soley upon a calendar day?

Possibly I mis-understood you.