about oil sump temperture

[wilsoncheung]

Hi,all!
I have a question to discuss with you.

Do you think scroll compressor can stand some liquid blow(Slugging)? What oil sump temperature at a certain evaporating temperature is needed to prevent the compressor from slugging?

Coperland suggests a very high oil sump temperature. It's very hard to attain that kind of temperature. You need to turn the TXV to the minimum position. In many situations, the oil sump still not qualified.

Hope you understand what I mean and tell me your experience about the oil sump temperature.

[goshen]

hi yes a scroll can indeed handel liquid slugs!! however not recomended for long !!will trash your bareings.
most scrolles have a wrap around heater ,u should not try to heat your oil on account of superheat .
a working compressor will hold the temp ok unless u got a faulty txv!!

[wilsoncheung]

hi yes a scroll can indeed handel liquid slugs!! however not recomended for long !!will trash your bareings.
most scrolles have a wrap around heater ,u should not try to heat your oil on account of superheat .
a working compressor will hold the temp ok unless u got a faulty txv!!

Faulty TXV?You mean it too large? I was told to select the TXV by 80-120% of the nominal capacity,is it right? Is 120 percent of the capacity too large?

[goshen]

Faulty TXV?You mean it too large?

no i ment if the txv is not set corectly and super heat is 2 low then liquid will reach comp and dilute oil and cause bearing failure!!!!!!!!!!!!!

[wilsoncheung]

Faulty TXV?You mean it too large?

no i ment if the txv is not set corectly and super heat is 2 low then liquid will reach comp and dilute oil and cause bearing failure!!!!!!!!!!!!!

So what kind of super heat do you think is needed to prevent slugging?

[wilsoncheung]

Sometimes super heat means nothing because the superheat is the average super heat, there might be liquid in some circuit. So you would see the super heat is qualified, still slugging exists. In this situation,what do you think is the problem? The heat transfer of the evaporator is poor? Or the distribution of the distributor is bad? I want any possibility to be discuss here.Thank you!

[Sandro Baptista]

see if the thermostatic element of the txv is making good contact with the suction pipe. Also if a large pipe you should put the thermo element on the up part of the pipe but rather at midlle more or less.

[2400martin]

if the compressro no generate enough heat - bring if in. Put your compressor on a nice silicon heater. your compressor recieves the oil from the bottom. give the compressor the oil and not a oil refrigerant mixture.