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Allen Key
23-05-2012, 11:00 AM
We have recently changed from R22 to R422D but now the compressors are running continuously any ideas on what to next

Regards

Dave

stufus
23-05-2012, 01:35 PM
Yeah give us more info :-)
plant type ,application etc.etc
Cheers
Stu

Luke.G
23-05-2012, 06:23 PM
Hope you changed every gasket/ seal on the system aswell
otherwise say goodbye to all the charge!


Luke

monkey spanners
23-05-2012, 11:23 PM
We have recently changed from R22 to R422D but now the compressors are running continuously any ideas on what to next

Regards

Dave

Put the R22 back in, you lose upto 30% capacity with R422D.

Or change the oil to poe and run it on R407F, have a word with A-Gas.

Sandro Baptista
24-05-2012, 05:16 PM
Yes, that's right. Now you have less capacity so the compressors have to work longer so the heat load energy from the refrigerated spaces can be dissipated...and probably on the summer the plant sometimes even can't reach the desired temperature.
But if the evaporator temperature is lower than the usual it may indicate that the evaporators and suction filters are dirt with oil waste.

Sandro Baptista
24-05-2012, 05:18 PM
Hope you changed every gasket/ seal on the system aswell
otherwise say goodbye to all the charge!


Luke

It is a drop in refrigerant...if you didn't changed the oil you don't need to change the elastomeric seals.

cadwaladr
25-05-2012, 12:38 AM
its the same old story like when they got rid of r12/r502 the drop ins were a nightmare condensor pipes turning blue etc!but hey we have had long enough to scrap this old plant!

Fri3Oil System
28-05-2012, 07:50 AM
It is a drop in refrigerant...if you didn't changed the oil you don't need to change the elastomeric seals.

Hi Sandro,

The "drop ins" were those which replaced R12 some years ago. Those refrigerants did not have big miscibility/sollubility problems with MO, as they were HCFC's.

The problem now, is that the new substitute gases, such as R422D are mostly HFC's blends(around 97%), so, an oil change should be recommended. Otherwise, there will be oil return problems. Sometimes these problems arise in a few minutes, some other they show up in 1 year.

Regards,

Nando.

Sandro Baptista
28-05-2012, 10:05 AM
Hi Sandro,

The "drop ins" were those which replaced R12 some years ago. Those refrigerants did not have big miscibility/sollubility problems with MO, as they were HCFC's.

The problem now, is that the new substitute gases, such as R422D are mostly HFC's blends(around 97%), so, an oil change should be recommended. Otherwise, there will be oil return problems. Sometimes these problems arise in a few minutes, some other they show up in 1 year.

Regards,

Nando.

I agree with you. An oil change should be made, specially if the plant has branches and complexity. But if it's a simple plant without that and no risers then there is no necessity of change oil, however a change is always better.

Nando, R422D is also a drop in.

Fri3Oil System
28-05-2012, 11:58 AM
I agree with you. An oil change should be made, specially if the plant has branches and complexity. But if it's a simple plant without that and no risers then there is no necessity of change oil, however a change is always better.

Nando, R422D is also a drop in.

Totally agree Sandro, the complexity and design of the plant might give problems or minimize/postpone them.

I meant that the gases that did substitute R12 were called "drop ins", because it was as as easy as changing the gas (pick up the old one, drop in the new one) and so these new ones have been so called, but now, some more operations should be done, such as the oil change, i.e. That is why I said the new blends should not be considered as drop ins, since HFC's are not miscible at all with MO.

Regards,

Nando.

Sandro Baptista
28-05-2012, 01:44 PM
ok. I agree with you.

Sinnema
25-09-2012, 02:16 PM
Hi all,

I am a new member and therefor not sure if I post this question in the right thread.

A client of us has several WCU's currently running on R22, but would like to replace this with R427a. This to comply to the phase out regulation against the lowest possible costs.
I would like to know if someone has experience with the relative new drop-in refrigerant R427a.

What is the effect on the cooling capacity, COP, the pressures, (low) part load operation, etc.? Are there better alternatives?


Best regards,

JR

Peter_1
25-09-2012, 06:22 PM
Leaking seals are not the result of the oil not changed but of the type of refrigerant used. Wether you chanegd the oil or not, the problem with the seals will stay the same and this is becauser r22 tends to expand the seals and the 'drop-ins' shrink those again.

Sandro Baptista
26-09-2012, 09:50 AM
Leaking seals are not the result of the oil not changed but of the type of refrigerant used. Wether you chanegd the oil or not, the problem with the seals will stay the same and this is becauser r22 tends to expand the seals and the 'drop-ins' shrink those again.

I would say that is the combination pair oil-refrigerant, don't you agree?