Telford based GKN AutoStructures (ASL) produces components for many vehicle manufacturers, with its Toyota line making thousands of chassis cross members a week for the Auris and Avensis vehicles. ABB proposed investigating energy usage at the plant to determine if low voltage AC drives could make a difference on any motor-driven applications.

The production line has an extraction system to remove welding fumes from the area, and this was identified as a likely candidate for the trial.

The production area for the chassis is divided into two sections, one for the Auris and one for the Avensis. Each line has an air intake and air extraction fan, driven by motors of 55kW and 30kW respectively. These were oversized for the applications and were not drawing their rated power. In a two week trial, Nigel Cook of ABB installed two temporary drives of 55kW and 30kW and turned the speed of the motors down until they were extracting a sufficient air volume to maintain the proper air quality for the workers in the production area.

The optimum speed was found to be 42.5Hz, producing an average saving on power use of 55%, with one fan motor seeing a peak saving of 64%. The drives also reduced the noise produced by the motors.

Ade Stone, energy champion for GKN?ASL, said: “Now that the full system is installed we are set to save around £20,000 on our energy costs, with a payback of between six to nine months.”