It sounds more like predictive maintenance.Only monitoring critical pieces of equipment.At the first indicator that there is an impending problem,maintenance is scheduled.
A bad bearing will typically have a distinct metal sound like there is no lubrication .The higher the RPM,the higher the frequency. I may be able to record and convert the file to an MP3 format.What type of machine are you concerned about?
Hi KL
My first guess is suction starvation.Usually the middle pump,I am guessing you have a suction specific speed close to 3400 or so.The pumps you are describing pump such a high volume that it is a common problem if for example you shut down any one of the three then restart it.It can go...