coppertalk

By Richard deFay, Copper Development Association Inc. Project Manager, Electrical Applications Specialist

Prior to joining CDA three years ago, Richard deFay spent five years working for Applied Proactive Technologies in the NYSERDA (New York State Energy Research and Development Authority) Premium Efficient Motor Program.

If you’re a facility manager, plant electrician or anyone who purchases motors, I encourage you to save your organization money and boost efficiency many times over by factoring in life cycle cost in addition to the initial cost of the motors you’re considering.  Since about 2000, manufacturers have been making more efficient motors which are called NEMA Premium (NEMA stands for National Electrical Manufacturers Association), and they can reduce your operating costs significantly, depending on three things:

1. How many hours you run the motor.
2. Cost of electricity.
3. Efficiency of the existing motor compared to the new one being considered.

NEMA Premium motors are almost always vastly superior when it comes to overall lifecycle cost.

A tool I use for comparing options (number 3 above) is MotorMaster+ software, developed by the U.S. Department of Energy.  It’s a database of 25,000-plus motors that enables easier industrial motor energy audits.  I have used it to assist companies and organizations, from Kodak, AMF Bowling, Roswell Cancer Center and Corning to high schools and universities in looking at their inventory of motors to determine whether it’s more beneficial to repair old ones or replace them with new, more efficient motors.  A second opportunity to replace older, running motors with newer improved efficiency motors also exists. When you run the numbers, it’s clear that NEMA Premium motors offer significant savings, sometimes tens of thousands of dollars a year.

There are less expensive motors, but less efficient motors currently available, but starting in December, NEMA Premium becomes the minimum standard efficiency for covered motors sold within the U.S. and with good reason.   Initial cost represents only 2% or so of the total cost of ownership.  Energy costs, maintenance, etc. make up the other 98% of the cost over the lifetime of the motor.  And that’s where high-efficiency NEMA Premium motors make a significant difference.

Another area where copper helps increase motor efficiency is in the rotors, which are traditionally made of aluminum.  Copper is a better conductor of electricity by 60% over aluminum, but in the past, it wasn’t possible to make copper rotors because of copper’s high melting point of 1083C compared to 660C for aluminum.  In 2001, CDA metallurgists developed the technology to enable casting of the copper rotor motor, making it possible to make them commercially viable.  Copper reduces the rotor I² R losses, improving efficiency dramatically.  CDA patented the technology and gives it away free to any motor manufacturer who wants to use it.  Siemens was an early adopter in the U.S. market, as are others across the globe, some using their own proprietary technology. As energy costs continue to rise, companies such as NYCO Minerals in upstate New York, have learned the advantages of NEMA Premium also.  I urge anyone who purchases motors commercially to consider joining them.  CDA features detailed information on its Web site about the cost savings and annual payback of different kinds of motors.  Have a look, and contact CDA so we can assist you in making the smartest, most cost-effective choices.