In the Reliability Forum department of Reliable Plant magazine, suppliers provide their insights to a question posed by editor Paul V. Arnold. This issue, the call went out to manufacturers of power transmission products. They were asked:
“What can a plant do to reduce its energy costs associated with electric motors?”
Baldor Electric Company
This reply came from John Malinowski, the product manager for AC and DC motors at Baldor.
“There are several things you can do to cut your energy costs.
“First, the biggest gains in efficiency come from ‘right-sizing’ the motor to the application. A recent survey on motors by the New York State Energy Research and Development Authority (NYSERDA) found that 55 percent of the motors installed in facilities were oversized. The ‘sweet spot’ for peak motor efficiency is 80 to 100 percent of full load. At less than this, efficiency falls off, as does power factor. So, right-size the motor and use one that’s rated as Premium efficient by the National Electrical Manufacturers Association (NEMA).
Baldor advises you to select the right
motor size for the application and to
seek one with a Premium rating.
“Second, use adjustable-speed drives, especially for variable torque loads such as fans and pumps. Energy savings in excess of 50 percent are possible here.
“Third, look at the machine for productivity and mechanical gains. Select the most efficient fans and pumps and use efficient gearing.
“Finally, you can reduce costs by having the right information. The Baldor Energy Savings Tool (BE$T) makes it easy for you to see what the savings are by switching to a premium-efficiency motor and/or adding an adjustable-speed drive. This software program compares the energy-saving potential between motors and drives with various energy-efficiency ratings and then selects the best choice for overall savings. BE$T also can be used in conjunction with a PDA to conduct a plant motor survey. Information is also available from the United States Department of Energy through the Energy Star program and the Industrial Technologies program. The DoE has a fantastic Internet site (www.eere.energy.gov/industry).”
For more information from Baldor, visit www.baldor.com.
This reply came from the National Electrical Manufacturers Association, a trade association representing nearly 430 companies:
“Look at the motor’s total cost.
“U.S. motor manufacturers sell products that exceed the minimum efficiency requirements set by federal legislation. These motors are slightly more costly to purchase, but yield significant additional savings over the life of the product, with a better return on investment.
“Many motor specifiers at industrial plants commonly look only at first-cost options and do not weigh the costs and benefits over time of a completely efficient system. This is a challenge that American manufacturing plants must overcome if potential efficiency gains and subsequent energy savings are to be fully realized.
NEMA says plants should examine the total
life-cycle cost of an electric motor, as
opposed to purely its product price.
“Electric motor systems currently account for 23 percent of all U.S. energy use and 70 percent of manufacturing electricity consumption, presenting one of the largest opportunities for energy conservation and efficiency.
“Manufacturing members of NEMA now offer NEMA Premium motors built to a higher efficiency standard. The NEMA Premium label helps you identify products that optimize motor system efficiency, reduce electrical power consumption and costs, and improve system reliability.”
For more information from the National Electrical Manufacturers Association, visit www.nema.org.