Motors account for approximately 67 percent of electricity usage within industry, estimates John Malinowski, product manager for ac/dc motors at Baldor Electric Co. (www.baldor.com), Ft. Smith, Ark. So to improve return on assets (ROA), it seems obvious that using more efficient motors should be considered.
One principal way to improve productivity and reduce energy costs is through a new breed of energy efficient motors called premium motors. One type is the National Electrical Manufacturers Association (NEMA) Premium efficient motor (www.nema.org/gov/energy/efficiency/premium), says Ilene Mason, industrial program manager at the Boston-based Consortium for Energy Efficiency Inc. (CEE, www.cee1.org). A member of Motor Decisions Matter (MDM, www.motorsmatter.org), a national campaign encouraging the use of sound motor management and planning, CEE promotes the use of premium efficiency motors.
These NEMA Premium-labeled electric motors may cost 10 percent to 30 percent more than standard efficiency motors, depending upon size. But they can help purchasers optimize motor systems efficiency, reduce power consumption and costs, and improve system reliability, says NEMA. Although the amount of cost savings and the resulting return on investment depends on many variables, Malinowski says he has seen as little as six months payback, but that two years is typical. The scope of the Premium efficiency program includes NEMA Design A or B, continuous-rated, single-speed, poly-phase, squirrel-cage, induction motors up to 600 volts that are 1 to 500 horsepower and 2-, 4-, and 6-pole. They must meet or exceed nominal Premium efficiency levels contained in Tables 12-12 and 12-13 of NEMA’s Standards Publication MG 1-2003.
Smart motor-management decisions can also pay benefits in reduced maintenance costs. But while you need to work at the maintenance level in making purchase decisions, you also need to work at the purchasing and plant management levels too, says Linda Raynes, chief executive officer and president of St. Louis-based Electrical Apparatus and Service Association Inc. (www.easa.com), an MDM member and an international trade organization having more than 2,000 electromechanical sales and service firms in 50 countries.
Check your application
As a motor purchaser, you should look at your application with your motor service distributor, she says. Look at all factors, including run time. “Make the decision on how long you anticipate that motor being in service,” she advises. “Take that lifecycle cost and decide on a premium motor.” Raynes notes that there may be cases in which the difference in energy savings is negligible. But in general, she says, “We would encourage the strongest consideration of premium motors.”
Malinowksi estimates that premium efficiency motors account for approximately 20 percent of all motors being sold in the United States. “People need to look at motors from [the] lifecycle cost [perspective]. When you look at one from a lifecycle cost—say it’s got a 20-year life—the purchase price represents only about 2 percent of that total,” he says. “About 97 percent is electricity, and there’s a portion of a percent in service and maintenance.” Malinowski notes that a company should buy the most efficient motors possible, especially continuously operating motors, because the purchaser is never going to make a motor more efficient.
One tool that can help companies do just that, says CEE’s Mason, is MotorMaster+, a software tool from the Industrial Technologies Program within the Energy Efficiency and Renewable Energy program of the U.S. Department of Energy. The agency recently upgraded and published MotorMaster International (www.oit.doe.gov/bestpractices/software_tools.shtml#imssa). Among other things, it allows users to evaluate repair/replacement options on a broad range of motors, calculate efficiency benefits for utility rate schedules with demand charge and determine best available motors. “MotorMaster is a good tool,” Mason declares.
C. Kenna Amos, [email protected], is an Automation World Contributing Editor.
