Pulling a VAC!!!

[Costa!]

What happens when a vac is not properly pulled?
I noticed that my helper was using the 3/8 hose on the manifold and forgot to cap the other port on the vac when we got to the second job. Can I suck the Ref (410A) back into the compressor and pull a Vac or is the Ref (410A) contaminated?? The unit was running a little high but it was condensing a lot.
What should I do???

[nike123]

When you don't evacuate as it should be done, you introducing moisture from air in system and non-condensable gases.
Non-condensables take space in condenser and effectively reduces portion of condenser which reject heat. That mean you have high condensing temperatures/pressures and condenser cannot reject effectively all heat which is absorbed in refrigeration cycle.
Moisture in R410 system bonds with high hygroscopic oil and create acids which damages compressor motor insulation and metal parts. Also, unabsorbed moisture could freeze in low temperature parts of system and clog capillary or TXV.
You need to recover refrigerant, discard it, install combined filter dryer for de-humidification and de-acidification of oil and charge new fresh refrigerant after evacuation to 400-500 microns of vacuum.
If your helper used micron gauge in first time, that would not happen.

[Fri3Oil System]

There is also a way to separate non condensables from the refrigerant. You will have to discard part of the refrigerant, but not all of it. Firstly you need to recover and recycle the 410A in a cylinder. Then, there is a method to separate both. After this treatment, the refrigerant can be reused.

Anyway, as Nike123 said, the major problem remains in the circuit, as you have contaminated it with moisture, that will damage the oil, and create acid. You definitely need to clean properly the circuit. I am sorry to say that placing filter dryers does not remove the acidity.

If you want to know how to separate the air from the refrigerant, just let me know.

Regards,

Nando

[sedgy]

there are plenty of decent fridge firms in your local phone directory