Codes / Standards
Motor efficiency standards to benefit from systems approach
October 3, 2016 - Members of the National Electrical Manufacturers Association (NEMA in the U.S.) Motor & Generator Section and the European Committee of Manufacturers of Electrical Machines & Power Electronics (CEMEP) say they have a “new direction for global motor efficiency standards”.
By Anthony Capkun
Once isolated system components, these standards are evolving in scope into “interconnected, multi-component systems to achieve greater energy savings than have been realized with previous motor efficiency regulation”.
“We believe the market will embrace a new systems approach to power drive standards that quantify total energy savings in place of efficiency for isolated components,” said Robert Boteler of Nidec Motor Corp. who chairs the NEMA Motor & Generator Section Energy Management Committee.
In a joint white paper (download below), NEMA and CEMEP outline an extended product approach that moves beyond single motors, inverters and controls to include electronic speed controls, power drive systems, pumps, fans, compressors and other auxiliary electronics that comprise the system.
“The motor is a critical part of any electronic system, but it only makes up a small percentage of the energy losses inherent in any electrical system,” said CEMEP president Jurgen Sander. “Incorporating power drive systems can increase energy saved by as much as six times the amount that could be saved when relying solely on the motor component.”
Motor efficiency classification in Europe started in 1998, reports NEMA; in the U.S., motor manufacturers raised efficiency levels in 2001 above the minimum requirement established by Congress in 1992. In 2010, this premium efficiency level was added to regulations, establishing it as the minimum requirement. This brought greater savings to a select category of motors known as subtype 1 and subtype 2, says NEMA, adding these market categories make up about 40% of units sold each year.
The most recent round of U.S. regulations was released in 2014; they took effect June 1, 2016, and cover all polyphase motors from 1-hp to 500-hp (0.75kW to 375kW).
Currently, the NEMA-CEMEP working group is developing a new standard that uses loss reduction versus efficiency when considering total system energy savings. The group is also establishing the losses generated at various operation points, and determining the savings in energy as a result of using a power drive system. The resulting standard will establish a series of points that can be used to evaluate and optimize energy savings.
“We believe the market will embrace a new systems approach to motor efficiency standards,” said Boteler. “This will enable us to measure and minimize power losses for all segments of the motor-driven market.”