Trane Purge High Liquid Level

[Par_T_FouL]

Hey y'all, new here thought I'd give it a try. I have been working on a Low Pressure York chiller overhaul, R123 converted, and finally got everything up and running smoothly, except the purge. This chiller supposedly sat for 2years non-op with tube compromises so you can only imagine what the oil and refrigerant stirred up. The old purge was full of crud and scale and would alarm on high liquid level, I would think because of restrictions caused by dirty conditions. We installed a brand new purge unit, like for like, Trane MN:PRGCA011AG0A and it was running fine for a couple days. I found it today with a full evap sight glass and alarmed once on high liquid level. Little to no flow through the filter drier sight glass. We installed a clean out kit to filter the refrigerant but it will be a while until she's clean. Is it possible this new purge is restricted as well due to dirty refrigerant? Once the purge tripped and shut down, it seemed like liquid refrigerant began to flow back down into the condenser slowly, so maybe a pressure issue? This is the most work I've done on a chiller and it was a great learning experience so any advice would help. CHEERS!

[Nuclrchiller]

Change out the purge liquid return filter/drier.
Your thinking is on the right track, but it's likely the problem is "wet" refrigerant more so than dirty refrigerant. Any moisture in the chiller will end up in the purge, and that moisture (along with air) can cause corrosion in the purge tank. The filter/drier is there to catch the condensed water and any corrosion products before they return to the chiller. The pressure differential driving the liquid refrigerant back is very small and it doesn't take much of a restriction due to a dirty drier to slow it or even stop it.

[nutradesman]

Yep, what he said. Hopefully the machine was evacuated/dehydrated properly. Is the purge pumping out?

[always looking]

I have had this several times. I have had the inlet to the filter plug up with what looks like coffee crystals. It can back up all the way into the 3/8” line coming down from the purge pot. Change filter and make sure the line is clear. Make sure your return valve is open too.

[Par_T_FouL]

Yes it was evacuated well. The purge is running fine besides the liquid level. Next step will be to replace the filter drier. I appreciate all the input!!

[triggerhappy]

Yes it was evacuated well. The purge is running fine besides the liquid level. Next step will be to replace the filter drier. I appreciate all the input!!

Well most likely you are in for several filter changes.....as well as cleaning out the pumpout orfice a time or two, and possibly a gummed up level switch or two depending on how wet and dirty this machine is.

What does the moisture indicator look like downstream from the filter

Is this a Purifier or a Earthwise purge?

If Earthwise you may end up down the road replacing the carbon canister......Not sure why it would be anything other than a Purifier although. For years it was a purge 99.....don't have the new number memorized yet...lol

[Nuclrchiller]

PRGC is Purifier Purge. Not Earthwise.