Canada’s Quadra FNX Mining has commissioned Siemens to modernise the drive in a SAG mill in its Robinson open-pit copper mine in Nevada, USA. This will be the first time that an ore mill is to be equipped with a Sinamics SL150 cycloconverter, after this new drive system has already been successfully introduced in other mining and metal applications as bucket chain excavators and rolling mills. Together with a new diagnostics system, the cycloconverter will increase the operational reliability and availability of the plant while at the same time reducing maintenance costs. The modernisation concept developed by Siemens allows for most of the existing electrical equipment to be retained, which significantly reduces the conversion costs. Modernization work is scheduled to be finished in the summer of 2011.Installation of a Sinamics type SL150 cycloconverter is the center-piece of the modernisation of the ore mill in the Robinson mine. The Simine Mill GD solution concept for gearless mill drives and twin-pinion mills enables analogue or early digital control systems to be replaced without also having to replace the motor or transformers. Particularly in retrofitting projects, the control system of a cycloconverter can be replaced while retaining the power unit.The converter and associated automation equipment are pre-assembled in a container module (e-house). The scope of supply from Siemens also includes a diagnostics system, as well as operating data acquisition and remote service feature. These give the maintenance personnel a continuous, up-to-date overview of the relevant plant parameters. Unplanned shutdowns can be reduced to an absolute minimum and maintenance intervals can be adjusted to actual requirements, thus cutting maintenance costs. Siemens is responsible for hardware and software engineering, installation supervision and commissioning, and adaptation of the automation equipment. Siemens Industrial will handle a large part of the project directly in the USA.Quadra FNX Mining was created in May 2010 by the merger of Quadra and FNX Mining and is one of North America’s leading copper producers. The company runs a number of ore mines in Chile, Canada and the USA, as well as development projects in Chile and Greenland. The Robinson copper and gold mine in Nevada was bought by Quadra from BHP Billiton in 2004.