Retrofitting York YCAS screw chillers from R22 to R407c

It's been a while since I posted anything here.
I am about to embark on changing some R22 YCAS chillers to R407c and was wondering if anyone out there has some experience they could share with regards to what problems I can expect to come up against. The local York supplier has told me that we will lose about 5 to 6% capacity but that is not a big problem as the units are already oversized for their duty.
I would appreciate any advice regarding the above project. I have been reading some blogs where people are talking about o-rings require changing etc because they change shape with 407c?????

Hi
main thing to change R22 to 407C
is cleaning system ( very good) and putting POE type Oli in compressor .
then after running set superheat

Quote:

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Originally Posted by Miked1

It's been a while since I posted anything here.
I am about to embark on changing some R22 YCAS chillers to R407c and was wondering if anyone out there has some experience they could share with regards to what problems I can expect to come up against. The local York supplier has told me that we will lose about 5 to 6% capacity but that is not a big problem as the units are already oversized for their duty.
I would appreciate any advice regarding the above project. I have been reading some blogs where people are talking about o-rings require changing etc because they change shape with 407c?????

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“0” rings could definitely be a potential issue internal & external leakage.

Thank you gents. It seems that it shouldn't be too difficult as the systems already have POE oil in the compressors.

You can find a procedure here, I'm assuming accurate.

https://www.honeywell-refrigerants.c...07c&download=1