A major metal and non-metal mining specialist based in the USA has adopted the latest Powerdrive FX variable speed drive (VSD) with dynamic braking from Leroy-Somer. The product is being used as a regenerative drive on a downhill conveyor at one of the company’s limestone mining facilities. Leroy-Somer was selected as the preferred supplier following a recommendation when the conveyor’s existing drive became obsolete.
Privately owned for three generations, Greer Industries has grown to become a diverse network of businesses managed from the company’s headquarters in Morgantown, West Virginia. Morgantown is also the location for three of the company’s four limestone mines operated by group company, Greer Limestone, a highly advanced mining operation with over 500 million tons of quality reserves.
Today, limestone production in West Virginia exceeds 10 million tons per year, with much of that supplied by Greer. Limestone is used for asphaltic concrete and concrete production, metallurgical flux, cement, agricultural lime, and construction aggregate and ballast. The best quality limestone is used as rock dust and for chemical purposes in manufacturing and water treatment.
“Conveyors are integral to our mining operations and help provide an assured supply of quality material in line with customer requirements,” explained Jim Phillips, Electrical Operations Manager at Greer. “Previously, we were using a Saftronics system that used a Fincor DC drive but it became obsolete. Without any access to service or spare parts we thought it wise to source a replacement to help avoid any potential for conveyor downtime and lost production.”
Following a recommendation from Jim Parimuha in favour of Leroy-Somer, Mr Phillips said that he chose this regenerative drive technology over other suppliers since he was aware of the company’s good reputation.
The term ‘regenerative’ describes the ability of the drive under braking conditions to convert the mechanical energy of the motor and connected load into electrical energy, which is returned (or regenerated) to the AC power source. In short, less net power usage means lower utility bills for the user.
“It proved to be a straightforward swap when it came to fitting the Powerdrive FX,” said Mr Phillips. “In fact, it provided a much cleaner connection with our PLC when it was installed in May 2016, than our previous drive. It is also much smaller.”
The Powerdrive FX VSD from Leroy-Somer offers a compact regenerative drive solution. Thanks to the latest generation control technology, it is well suited to the sensorless control of magnet motors. Furthermore, its IP54 protection rating against the ingress of airborne particles means that mining sector users such as Greer can benefit from extended operational life.
“The integrity and reliability of the Powerdrive FX is very good, while the service support provided by Leroy-Somer is second to none,” concluded Mr Phillips. “I would absolutely consider using more of the business’ products in the future.”