Optimal IP

[Superfridge]

For me, it is not clear about BPV and BPRV. At slide valve position below 75% , port will be connected to the suction and efficiency will be lost. Unless, other compressors can handle IP load, the gas at IP pressure will go to the suction(again) through BPV.
What are you going to achieve? Do you have solenoids and hand expansion valves for LP and IP receivers?

I need to re-read my post before posting
I missed the R out of the BPV. I will ammend that too.
Yes, hand expansion + soleniod valves for both receivers and you are right, at less than 75% the econ flash gas goes to suction.

Does the site manual explain function of valves , or just settings .
Sometimes someone has a bright idea in design but no one can understand it without explanation .
Where was system designed , NZ ?

The site manual states the BPRV between economiser and suction is there to provide a pressure difference at all times ie: when low load and compressor unloads and economiser to compressor BPRV is de-energised. The only settings in the manual is this 190kpa economiser pressure. I think the econ to suction BPRV was put in later as it's not on the drawings.
It's a NZ company installation but the design?