Hey everyone have a zero zone parallel refrigeration rack with 2 copeland 20t compressors. last year replaced 1 compressor toward the end of the year due windings breaking down issue but ran ok. new one came with poe oil instead of mineral oil so had to change out the oil. This year started up system and the old compressor runs good w/ 32psi oil psi new one at 42 psi. but when old compressor shuts off and new one runs solo it drops to 10 -15 psi. Also new discharge pipe gets hot where the new one is not just barely warm. Running about 190 head and 80 psi unloaded 70 loaded. superheat at header about 10 know it needs to be higher and plan to adjust txv to get closer to 20. Not sure why discharge is so much cooler on 1 and not the other. sure it causing the oil issue.