Copper Rotor Earns Prestigious Industry Award, Says CDA

December 6, 2006


Die-Casting of Copper Rotors for Siemens Line of AC Motors Captures "Technology and Innovation" Award from IndustryWeek

NEW YORK, NY— The Copper Development Association announced today that Siemens Energy & Automation in Alpharetta, Georgia, has won a prestigious industry award for a new line of AC motors featuring die-cast copper rotors. IndustryWeek magazine awarded a 2006 Technology and Innovation Award to Siemens and is featuring the new motor technology in its December 2006 issue.

Because a copper rotor has less resistance than one made with aluminum, these motors run cooler, can last longer and consume less energy than other motors. The rotor is the rotating part of the motor. Siemens claims its unique die-cast copper rotor design is one of the key elements that enable its new Ultra Efficient motors to exceed NEMA Premium® standards, an efficiency goal encouraged by the U.S. Dept. of Energy to conserve energy resources. The higher-efficiency motors take up the same space as the regular standard-efficiency product with respect to frame length and diameter.

The new copper rotor technology is the result of several years of research and development by the Copper Development Association (USA) and the International Copper Association both headquartered in New York City. Dr. John Cowie, CDA project manager of the research program, explains that the basic innovation was the technology for die casting copper rotors. "The high melting point of copper necessitated the development of special dies and processes that allow for high-volume casting of copper rotors."

Cowie notes that Siemens has been an important partner in determining the economic feasibility and profitability of commercializing the copper die-casting technology. "Siemens has raised the bar on electrical motor efficiency. We congratulate them on their achievement and look forward to more manufacturers adopting the technology."

"We are committed to bringing motor users the finest technology available to help lower operating costs through superior motor performance," said Anne Cooney, vice president of Siemens Energy & Automation's Power Conversion Division. "We have made a significant investment over the last few years in developing this product and are continuing to invest large amounts of money in the product line and manufacturing facility for the future.

"Our goal is to grow our NEMA motor business in North America to benefit our distributors, OEMs and end users with features, functionality, operating efficiency and service life second to none."

A well-designed motor with a copper rotor should boost energy efficiency, reduce size and/or weight and dramatically affect fossil fuel emissions and operating costs. "Even a one percentage point gain in efficiency results in big energy savings," says Cowie, "and less energy demand translates to reduced air pollution." These three-phase induction AC motors have many applications in industry. "When you consider that motor-driven equipment accounts for some 70 percent of our country's industrial electricity consumption, these motors are good for the environment as well as the bottom line."

For more about IndustryWeek's Technology and Innovation Awards Program, visit Additional information on the new Siemens motors can be found at CDA's copper rotor program is detailed at Also, the history of copper in electrical engineering is outlined at