ABB are preferred suppliers for Imerys

Aiming to save downtime costs of up to £10,000 an hour, Imerys Minerals have entered into an agreement with ABB to supply motors and drives all to their UK plants.

Imerys are the largest users of motors in the South West, employing more than 5,000 units and over 27MW of installed power, driving pumps and handling systems for the extraction of 2 million tonnes of china clay each year. The company make extensive use of condition monitoring and failure-mode analysis as any motor failure can lead to extended downtime.

Following exhaustive tests to satisfy themselves that their new vendor could meet their demanding requirements, Imerys selected ABB on the basis of mechanical build quality, reliability and low running costs due to high-energy efficiencies.

Dave Constance, electrical manager at Imerys, said: ‘In our experience of running motors we have never come across a motor as reliable as those from ABB. They are well designed for the harsh environment we work in, with better protection against the ingress of dust and water and improved cooling. The drives work well in the wet and harsh environment found in our quarries and are well protected against ingress of water or slurry, which could otherwise cause expensive damage and downtime.

‘We didn’t take what we were told at face value. We examined motors and drives from a number of manufacturers and conducted compatibility tests to see if they were suitable for our environment. We stripped the motors down to look at how easy they were to maintain and how this would affect the running costs. Efficiency tests were also an important part of our investigation.

‘For all criteria, ABB came out on top. We were particularly impressed with the company’s technical support.’

The five-year agreement covers the supply of ABB’s process performance motors and industrial drives. The motors, designed originally for the pulp and paper industry, have an IP56 rating, making them suitable for the constant wet and abrasive conditions of quarries. Imerys expect to spend between £200,000 and £300,000 a year on motors and £150,000 on drives.

Lifetime cost of ownership is important to Imerys and so getting maximum time between maintenance sessions was vital. The company made suggestions to improve the sealing on a motor bearing to reduce its maintenance needs and ABB altered the design of a casting to accommodate this as part of their policy of continuous improvement based on customer feedback.

ABB Ltd, 9 The Towers, Wilmslow Road, Didsbury, Manchester M20 2AB; tel: (0161) 438 3204; fax: (0161) 448 1066.