AC drives take the biscuit

At the Burton Biscuits plant in Cwmbran, South Wales, drives from Control Techniques feature in two of the latest projects.

At the Burton Biscuits plant in Cwmbran, South Wales, drives from Control Techniques feature in two of the latest projects - a new wrapping machine feed conveyor and the renovation of a dough forming plant.

"We have used Control Techniques drives exclusively on this plant for many years", says Burton's Gordon Johnson.

"We have hundreds of AC drives for open and closed loop and servo applications.

So, when we order a new machine we specify Control Techniques - and when we upgrade an old machine, naturally they are the first choice".

The new machine, for the conveying and stacking of cream crackers prior to wrapping, gives variable line speed to ensure constant pressure across eight lines of biscuits.

A total of 21 Commander SE AC drives, ranging from 2.2kW for longer sections of conveyor, to 0.75 and 0.55kW receive independent analogue speed signals from the controlling PLC.

A level switch on the final section detects when the products are beginning to diverge from the vertical and sends a signal to the PLC, which speeds up the line.

A 'slug measuring device' selects a set length measurement of biscuits and brings down a slide to send the row of crackers into the wrapping machine.

"The drives came as part of the standard package from Italy", explains Johnson, but we would have insisted on Control Techniques drives if they hadn't been the OEM's choice anyway.

More recently, eddy-current drives were exchanged for Commander SE drives on a dough-forming plant.

"We have had concerns over the reliability and safety of this machine for some time", says Johnson, "and were finding it almost impossible to find spare parts.

The design of the machine wasn't ideal for a dusty environment as dust and moisture produced bridging on the eddy-current coupling, preventing slip and locking the machine onto direct motor speed.

So, once again, we chose Control Techniques drives for the task - in this case, four Unidrives - from 5 to 11kW - each with plug-in UD71 coprocessors, cascaded under digital lock via RS485 communications.

The machine utilisation has improved dramatically".

Commander SE drives, available in three-phase from 0.75 to 37kW, are a popular choice for many machine builders because of their ease of use.

As standard, the drive's first 10 parameters cover most applications, making them particularly easy to configure and, with a choice of most industry-standard networks, easy to control in automation applications.

Unidrives take functionality one stage further, with the range of AC drives spanning 0.75kW to 1MW and five operating modes including servo mode.

With plug-in modules, the drive can be tailor made to fit a vast range of different applications, with most of the industry-standard network protocols as well as Control Techniques' own high-speed network, CT-Net.

"I have used Control Techniques drives for over 20 years", adds Johnson, "and stuck with the company because of their support and training.

The drives are so easy to use these days that you hardly need training as the drives do a lot of the work for you".

The Burton Biscuits plant manufactures some 1200t per week of biscuits that include well known brands such as Jammy Dodgers, Wagon Wheels, Jaffa Cakes and Cookies as well as chocolate digestives, cream crackers and a range of snacks.

Back to top