R-22 TO 407C

[HJ Controls]

I am working on a ycas0330 York screw chiller. Has any one converted over to 407c.
TXV is 22 or 407c. Anything need to done out of the ordinary. Thanks for any help

[syndicated]

I think the oil needs to be changed to POE.
And you're gonna lose capacity!

[Cmstech]

Oil change/flush is required. Use ISCEON MO99. Only need replace driers and shredder valve cores. Pressures very similar

[jpsmith1cm]

With a change like this, you'll need to change all of the o-rings in the system in addition to the oil change that is required.

R-22 causes the o-rings to swell up and the R-407c doesn't. The lack of that "swelling factor" causes the o-rings to try to revert to their original size. If they've been in for any length of time, they'll leak REAL bad.

You may want to check with the manufacturer, but this is a common component of this change-out.

[HJ Controls]

system is already poe. i knew that you would lose capacity, but manufacture said that you could freeze up the cooler barrel ? Wondering if anyone has done this to a ycas.

[klove]

I can tell you that the R22 barrels are 4 pass refrigerant and the R407C barrels are 1 pass on the YCAS's. Not positive about the reasoning for the difference. Probably has to do with oil return or refrigerant density/thermal property characteristics. I can't hardly see that you'd freeze a barrel doing this. I'd have to see some empirical data that showed why it was possible.

I know some folks have used Isceon MO99 in the DX chillers and had reasonable success with it, and it's a blend, also. If you do the job, let us know if it works. Probably open some doors for us all.

[HJ Controls]

The reason for the change was to lower the expense of r-22. MO99 is also expensive. From what I am hearing true or false ? Looks a little risky. I believe I will just keep on going with what I have.

Thanks for all the input.

[jayguy]

so you are changing it because R22 is to expensive? are you losing a lot of refrigerant? you should not be losing much. perhaps the money should be spent on figuring out why it is leaking so much and fix that part.

if you convert it, all of the old problems and any new ones will all be yours even if those old problems are not your fault.

[valdelocc]

So how it go? one of my clients wants to change an RTAA to 407c, we are in the middle of ironing the process, my plan is to leave the mineral oil in and monitor the results, the oil separator should return 98% of the oil back to the compressor, time will tell if the rest of the oil comes back or logs in the evaporator, I'm looking forward to do the job.

[traneguy123]

you are going to create more problems in my opinion. you will not be able to get 100% of the oil removed that will be required to change to poe. that along with capacity decrease and orings that will leak should make you think twice.

[EMETH]

I am unaware if the manufacturers have changed their tune, but back in the early 90's it was stated that oil logging was a potential problem in LOW TEMP applications.

I personally agree with the 407C, but strongly suggest POE oil change if possible.

[valdelocc]

I converted the RTAA to 407c without changing the oil, its been running without problems for over a month.

[sargent york]

York produced several YCAS units that was shipped with 407c. The only differences I remember seeing was they had a liquid line to suction line heat exchanger, The micro-processor has option built into it to run on either R22 or R407c with just a push of the button. If circumstances warranted it I wouldn't hesitant to convert to R407 including a couple of oil changes.