For me a typical Kysor Warren rack has a oil separator with removable oil float, oil reservoir & AC&R oil level controls on the side of each compressor. 3 - 5 compressors piped together.
There is a common saying with some of the guys I work with when there are multiple oil failures at a time on a rack, that "one compressor failed first and robbed, or sucked the oil out of the rest of the compressors". My question: is that even possible? How could that happen? Wouldn't the oil level regulator on the side of the compressor stop any extra oil from being fed in if the float was full and closed? Most of the time what I am finding is bad valve plates that let discharge gas into the suction header and seem to "push" the oil out of the other compressors, or stuck open EPR valves or hot gas valves, or stuck closed or open bottom oil floats. Usually seems like when a rack shuts down on oil pressure it's a bigger problem, not just one compressor robbing oil from the others.
Any input would be appreciated!