ABB Cuts Maintenance Costs At Severn Trent
Severn Trent Water (STW) is achieving savings of up to GBP2,400 a week on pump maintenance after upgrading its pump control software, which was supplied by ABB . STW had installed four submersible foul pumps at its sewage treatment works in Worcester, pumping raw sewage from a new foul well. The pumps are driven by four 132kW ABB industrial drives, supplied complete with filters to reduce harmonics caused by the drives. Following commissioning of the variable speed drives (VSDs), STW experienced a number of blockages in the foul pumps, caused largely by rags sticking to the impeller. As well as downtime, clogging can lead to sewage pollution. A total system failure can lead to effluent leakage, with implications for the environment and health and safety, as well incurring clean-up costs and resulting in possible breaches of legislation. Clearing these blockages was a time-consuming process. Every time a pump became blocked, it had to be removed from the well, split open and cleaned out...