Energy efficiency is a topic of growing interest across the industrial processing industry, including feed and grain. Many equipment suppliers now offer high-efficiency lines to meet the rising demand, but there are ways to decrease energy consumption without purchasing new equipment.
Retrofitting existing motor-driven machinery with NEMA Premium Efficient, or EISA-compliant, motors can decrease utility bills and greenhouse gas emissions. In some cases, simply retrofitting a smaller sized motor can be profitable. Some utility companies even offer incentives to customers who install new motors and gear drives.
But there are costs associated with motor retrofitting, and a huge return on investment isn’t always guaranteed. The application and other individual circumstances play a role in determining which motors should be retrofitted to attain maximum ROI.
Feed & Grain gathered eight critical pieces of information from motor and drive manufacturers, equipment suppliers, millwrights and engineers that will help plot a course for retrofitting motors throughout a facility.
1. Premium Efficient motors are mandated
The government has been mandating minimum efficiency levels for motors manufactured in the United States since 1997 — originally under the Energy Policy Act (EPAct), and now under the Energy Independence and Security Act (EISA). After EPAct was implemented, motor manufacturers began improving their efficiencies beyond the minimum requirements, so the National Electrical Manufacturers Association (NEMA) developed its own standard to identify motors that exceeded the mandated levels.
Recognizing the industry’s ability to meet an elevated set of standards, the EISA mandated that all motors manufactured after Dec. 19, 2010 must meet NEMA Premium Efficient™ standards.
The regulation has no impact on motors currently in use, but it means the same motor that was installed before 2010 might consume less electricity if it were purchased today. The amount varies by horsepower and other factors.
For example, the required efficiency for a 5-hp motor before EPAct went into effect was 86%, then EPAct raised it to 87.5%, and now EISA requires 90.2% efficiency. On a 100-hp motor, it raised from 93% to 93.6% to 95% efficiency.
A complete list of NEMA Premium Efficient standards is available at www.nema.org.
2. Check efficiency of current motors
When deciding whether to retrofit equipment with Premium Efficient motors, it’s essential to verify the efficiency of the current motor to accurately gauge the savings potential.
“It’s impossible to say in every instance there are huge gains to be made,” says Joe Kiolbasa, product manager for Donaldson-Torit of Minneapolis, MN. “The two main factors are the efficiency of the existing motor, and how it compares to the efficiencies on the market now.”
Jaron Vande Hoef, senior project engineer for Sioux Center, IA-based Interstates Engineering, Inc., recommends starting with the Department of Energy’s Industrial Technologies Program (ITP) for guidance. The ITP’s MotorMaster+ is an online motor selection and management tool that supports motor systems planning by identifying the most efficient action for a given repair or motor purchase decision.
“Any maintenance manager or personnel responsible for an industrial processing facility should download the ITP’s free tool MotorMaster+,” says Vande Hoef. “You simply plug in the catalog number of the motor, and it will tell you the more efficient alternative.”
The catalog includes more than 20,000 motors’ specs, and features motor inventory management tools, maintenance log tracking, efficiency analysis, savings evaluation, energy accounting and environmental reporting capabilities.
Kiolbasa mentions that most motor manufacturers’ websites also provide similar information.
“Or the operations manager at a facility can call their motor sales representative and have him work through the numbers to determine what the most efficient option is,” he adds.