R408a

[bpdenverco]

This was my first drop in, from a R502 True 3 door reach in freezer. It has the copeland KAJ3-1100-CAV-800. the old R502 holds 21oz.
1.The original problem, was a bad fan, the customer pulled out the compressor and kinked and snapped the suction line. the unit was kept off, No burnout.
2. So I put in new line Dryer and sight glass.
3. Now the Book on R408A says to put 75% to 85% nominal of 502 requirements.
4. I have about 12 oz of 408A, I can seem to get lower than 20, I need zero, If I add more, it goes up, and if i take out less, it goes up on temp manifold's are about 25 and 210.
5. Now this is new for me, have not seen before it has a CPR/EPR valve, It a old Box..
could it be, it does not like the 408A...can it be adjusted maybe or is fixed setting.
6. Now on the sight glass..no way in hell i can fill by the glass....takes way to much to fill the sight. Thanks all

[bpdenverco]

Update, Its a sporlan ORIT Valve, looks like it for 502 and not 408A ???????

[monkey spanners]

I don't know much about ORIT valves.... Is it a txv or cap tube system?