Hi! Michael. First of all thank a lot for providing your input.
I have attached schematics of system which I will be frequently referring in answering your queries below:
First of all, please understand normal operation first.
During normal operation, 3 out of 4 C-4202 ABCD compressors are put in operation to maintain receiver tank pressure near 7 bar. If one compressor out of these four is out of service for maintenance and we are struggling to maintain header pressure near 7 bar then C-4201 & C-4203 are put into operation.
1- Are all of the compressors set to the same discharge pressure set point? If so, do the pressure transducers or gauges all read the same?
No they are not set at same discharge pressure. There is 0.3 to 0.4 Bar variation in it.
2. Are these compressors variable speed or variable capacity?
There are variable capacity type guided by an inlet flow capacity valve and are operated on Direct On Line System.
3.If so, are they staggered to have load picked up and shed in a sequential manner as system demand changes?
Controlled through loading and unloading set points
4- Do you have a system receiver tank to help minimize load fluctuations on the system?
Yes, we have as shown in attached image.
Let me know if you require any further info.
I look forward to your response.