To Centrif
I have to very strongly disagree with some of your comments, and am able to back up my comments with 18 months of personal experience with 2 of these machines, with 2 more currently being installed. Our aircooled turbos were commonly operating at around 190 suction, and up to 1500 discharge (R134A),down to 550 KPA. I forced our first compressor (artificially) to begin a surge,so it just shut down, and its monitoring program told me why and when.
Their onboard conrols will rectify surge situations before they occur, anyhow. As for low load performance, our machines regularly have long overnight runs down to 12- 13 amps/ Phase, leaving compressors 1/2 their size for dead.