Six trickling filters at the Bissell Point Wastewater Treatment Plant in St. Louis, Mo., receive 110 mgd from a trickling filter pump station with two 1,650 hp centrifugal Peerless (90 mgd capacity each), and six 600 hp Peerless (40 mgd each) pumps.
The outdated analog system controlling the eddy current clutches on the large pumps caused maintenance headaches for operators: Reliability was suspect and replacement parts were hard to find.
"The many potentiometers also required frequent adjustments, usually done with a screwdriver," says Vince Stollhans, assistant manager of the Pump Station Division.
When the clutch
