ABB drives cut costs at MINI production plant

ABB drives installed on the new MINI paintshop at BMW Group Plant Oxford are saving the company £24,000 a year in electricity costs.

Twelve ABB Comp-AC drives, ranging from 11 to 37 kW, have been installed by ABB Drives Alliance partner MKE Drive Systems to run pumps on the pre-treatment plant.

"Following an energy audit, we recommended the Comp-AC range as being the most cost-effective option for the application," says MKE drive manager Gary Palmer. "We installed the drives and also implemented a communication network that would enable BMW to control the drives from remote PLCs."

Some of the pumps on the line showed dramatic savings once they were being run by the variable speed drives. "One pump was drawing 27kW, once it was properly speed controlled by the ABB Comp-AC drive we found it needed to draw only 6 kW. We have also installed a drive on the air extraction fan on the line, reducing the demand from 75kW to only 32 kW."

Variable speed drives achieve these energy savings by driving the motor at the speed needed by the process. This contrasts with the wasteful practice of running the motor at full speed and then choking off the output, air or water in the case of fans and pumps, with some kind of mechanical device, such as a baffle or valve. 

"The main benefits we get are the flexibility to increase and decrease speed at will, compared to the previous method based on adjusting the pump valves," says Steve Edmunds, maintenance shift manager at BMW Group Plant Oxford. "We have now found the optimum speed for the pumps and are saving about 480,000 kWhrs a year on this facility."

"We have standardised on ABB motors throughout the plant, so it was natural to opt for ABB when looking for a variable speed drive for the pumps on the pre-treatment plant."

Payback time was only six months for the system. 

Variable Frequency Drive Energy Savings Calculator