NEMA vs. IEC motors – July 19, 2019

When looking at both NEMA and IEC motors there are always going to be some slight differences between the two standards, and it is important to understand them. First off, let’s establish what each of them mean. NEMA, or “National Electrical Manufacturers Association”, is the standard for electric motors in North America while IEC represents the “International Electrotechnical Commission”, which is the standard for the rest of the world. 

There is one major difference between the two standards, and it has everything to do with metrics. Sure, you could find slight miniscule differences in pricing, efficiency, or features. In many cases these differences are so small that you will find differing opinions on which is a better efficiency for your buck. The largest and most important difference is the way these things are measured. For all NEMA motors the dimensions will be measured in inches or feet and IEC motors would be measured in millimeters. The metrics are the true differentiating factor between the two standards and is the most important one to understand when making decisions regarding a motor application. When deciding between NEMA and IEC it is essential to be aware of this difference as it could lead you to getting the wrong application to fulfill your needs.