United Utilities saves £19,000 on pumping energy costs

United Utilities' Drummer's Lane water pumping station in Lancashire is reporting energy savings of more than £19,000 per year, having replaced Heenan variable-speed drives with new units from ABB.  Built in 1986, this intermediate station is used to manage the distribution of water between Prescot and Aspel reservoirs. With three pumps, it can pump a maximum of 100Ml per day in either direction. However, Tony Holden, field service engineer with United Utilities, says that the original three 400kW variable-speed drives were becoming increasingly unreliable. "The incumbent drives were aging and the components were degrading in performance," explains Holden. "They were also becoming increasingly expensive to maintain." The drives were overheating and tripping out before they could achieve full power. This caused a severe problem for the pumping station when a fire broke out in one of the drive cabinets. "This put a major strain on the station," recalls Holden. "It was particularly bad as we had peak flow at the time, because it was summer. This incident helped us decide that it was essential to replace the drives." Holden says that going for ABB drives was an obvious choice, not least because they had replaced equipment at other UU facilities. "It is a very good, reliable product, very robust with a good performance over its lifecycle. The keypad is very user friendly and the flux optimisation of the drive gives good energy savings," comments Holden. ABB Drives Alliance firm Central Group performed an energy appraisal and found that running the pumps with ABB drives could reduce load by 70A. "We installed three 400kW ABB industrial drives in the original cabinets, cleaning up the cabinet that had suffered the fire," states Central's Gary Hickey. "Because these were low harmonic drives, we could get rid of the 12-pulse transformer," he adds. Also, instead of the former seven fans, used to keep the old equipment cool, the ABB drives needed only two in the summer and none in the winter. "We are very pleased with both the drives and the standard of work that The Central Group carried out," says Holden. "The drives were installed without a hitch and we now have a very reliable process as well as gaining significant energy savings."

Author Brian Tinham