are you saying the valves are bad in one of the heads ?, is it a hot gas bypass or suction cutoff unloader ? electric or press. controlled ?
There is a computer room a/c unit with two Carlyle 06D's using R407C; Recently one lost first stage cylinders; It will run second stage when loader kicks in. I'm told that a previous tech may have errantly added R22 to this system. Would it even run with this gas mixture?
are you saying the valves are bad in one of the heads ?, is it a hot gas bypass or suction cutoff unloader ? electric or press. controlled ?
Can you give a little more info? Sounds like you have a Liebert, yes it will run but your glide would be off and depending how much was added oil return could be an issue. But I have to say I don't understand the "Recently one lost first stage cylinders; It will run second stage when loader kicks in." part. Are you saying that the first stage does not pump? again more info would be helpful, also model of what your working on.
do things right the first time is cheaper.
This is a DATA-AIRE unit with electric unloader
There is the Problem.
Yes the compressor will run but your cooling tonnage went down. How much R-22 was added? Regardless, the blend is no good now for the R407C. Time to remove and flush the system. You are going to have to drain all oil out of the compressor and flush the sump. R407C is a blended refrigerant. It has to be installed as a liquid or the blend will be off and the system won't work properly.
Unloader is located on 1 head. Sounds like compressor will run at 100% but not at any other unloaded positions? Is that correct? Does this 06D have 3 heads (6 cylinders) or 2 heads ( 4 cylinders)?
He said that another tech added R-22 to the R407C system.
Klove, Looks like I may have over looked what I wrote. My mistake....I corrected my posts.
Understandable oversight. Sometimes we all overthink things.
I went back and read that post, and the part about flushing the sump and changing oil is still there (at least on my computer). If that's correct, could you explain why all that's necessary. Why not just pull the refrigerant, evacuate, and recharge with 407C?
It is necessary due to the fact that the 22 was introduced to the system. Now the system oil has been contaminated. Check the link out for R22-R407C Coversion.
http://www.certifiedrefrigerant.com/...guidelines.pdf
4. The mineral oil must be removed from the compressortest on the lubricant removed.
crankcase. Hermetic compressors will have to be
removed from the piping and the lubricant drained out
through the suction stub. It is advisable to do an acid
Those systems that have oil separators, oil reservoirs,regulated dry nitrogen.
oil fl oats and suction line accumulators must have the
oil drained from them. If the liquid control device is going
to be replaced, it is advisable that the suction line, liquid
line, and evaporator coil be blown clean using properly
Unless the tech used a recovered jug of R-22 with a load of mineral oil in it, there is NO issue with cross contamination. I've run R-22 over POE with no problems. It doesn't hurt the oil at all.
OP,
Pull the charge, dispose of it properly. Since you've got it pulled down, do filters and driers just in case, pull a vacuum and charge with 407.
The question is How much R-22 was added. Does this unit have Air or Water Condenser? All I am saying is he needs to be on the safe side to prevent problems. Its like putting Gas in a Diesel truck. Regardless how much Gas you accidentally put in the tank, you would have to drain the whole tank on precaution to not damage the motor or would you drive it home and then drain?
For crying out loud recover the refrigerant, pull the damn oil plug and change oil in compressor why not if you want to do it then do it though you prob don't need to, replace dryers, blow the system out with nitro, pull a tripple evac, and charge the unit, if it isn't running right then you missed something like a bad valve.
“It takes courage to grow up and turn out to be who you really are.”
- E.E. Cummings
I'm sorry, but R22 will not contaminate POE oil. The refrigerant does not cause some sort of molecular level change of the oil. There are thousands of R22 systems out there that use POE. There's nothing in there that says anything at all about guidelines for service after mixing refrigerants. It does state that it's preferred to have 1% or less mineral oil left in the total oil charge. You're reading way too much into the conversion data.