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Hi, my name is Daniel from Brazil and right now Iīm having problems with R-402B. I used the R-502 and I decided to retrofit it to the Suva HP 81 (R-402B) from DuPont.
I cleaned the system and I've done everything just like I always do on these icecream machines, but on this one the semi-sintetic oil is "foaming", and sincerely I don't know what to do....
If there is someone to help me I would appreciate.
Thanx.........
I assume that you are observing this foaming through a crankcase sightglass on a semi-hermetic compressor. I have considered the "foaming" of oil in the crankcase to be symptomatic of a refrigerant flow condition.
If you changed to a different refrigerant, my first thought would be.... Is perhaps a TEV in need of adjustment, or some other refrigerant or evaporator control device, to the characteristics of the new refrigerant ?
I agree that something similar to a foam should appear in the carnkcase sightglass, but what actually happens is a foam formation all over the system, in a way that the compressor work a lot and gets very hot.
Herefishy, I donīt recognize the TEV initials,could you tell me more.
Thanks..........
....TEV = thermostatic expansion valve
dgrotti.... was the refrigerant change related to compressor failure / replacement, or what malfunction or failure necessitated the need for refrigerant ?
Your observation of compressor overheating may add a little wieght to my speculation regarding adjustment or evaluation of of the regulating device (superheat), be it an expansion valve, evaporator pressure control, or whatever.
R-402B will run higher discharge temperatures than R-502, and it will give the TEV more capacity compared to R-502. Otherwise, R-402B has P-T characteristics very similar to R-502.
R-402B has been used in ice machines, where its higher discharge temperatures can reduce harvest times.
Temperature, pressure, superheat, and subcool measurements would be in order here to further evaluate.
Hi, dgrotti:)
I have observed oil foam in liquid line sight glasses on systems with Alkabenzine oil, this is what I would class as semi sinthetic.
This symtom is usual due to liquid refrigerant washing the oil from the compressor crankcase.
Check you superheat at evaporator outlet and also you compressor discharge temps. If you have high suction superheats you compressor will overheat, if you are carrying refrigerant liquid into the compressor oil you should see a lower than normal discharge temp, requiring the expansion valve to be adjusted in or a smaller capacity valve/oriface to be fitted.
If this doesnot cure your problem, check you condensing temp and you subcooling to see if you have over-charged the system. These drop-ins require less weight of refrigerant to acomplished the same job (less dense), if you have charged the same Kg in as you took out the system is over-charged.
If all this checksout you have a mechanical problem in the compressor leading to oil carryover.
Hope this helps. Regards. Andy:)
Well everybody, I guess I have lots of things to check out in my system. I would like to thank everybody for your help and soon I will post another thread telling everybody the results I had.
Thanks again.............. D. Grotti