Standards are supposed to make life easier for control panel builders, by guiding the way to which products they can safely incorporate into their designs and panels. But sometimes they can also cause confusion, such as when two standards address the same type of product.

This is certainly the case with respect to industrial motor control devices that adhere to standards from either the National Electrical Manufacturers Association (NEMA) or the International Electrotechnical Commission (IEC) in Europe. While this is certainly not a new issue - it dates back to the late 1980s - I find customers are often still confused about the differences between NEMA and IEC compatible controllers, and when to use one vs. another. In this post, I hope to clear up at least some of the confusion.

First off, NEMA is pretty much a North American standard, whereas you will find IEC devices all over Europe and elsewhere in the world. Exceptions may be areas or industries with a heavy American influence,