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National Electrical Manufacturers Association (NEMA) and International Electrotechnical Commission (IEC) are two organizations responsible for setting the efficiency standards for electric motors used globally. These standards play a crucial role in determining the energy efficiency of motors and the impact they have on the environment and economy. In this article, we will discuss the NEMA and IEC motor efficiency ratings, their importance, what they tell us, and the differences between the two rating systems.

NEMA vs IEC Motor Efficiency Ratings

NEMA has been setting the standards for motors used in North America since 1926 and regularly updates its publication “MG 1” which provides practical information on performance, efficiency, safety, testing, construction, and manufacturing of AC and DC motors and generators. The IEC, on the other hand, defines the standards for electric motors used globally outside of North America and publishes “Standard 60034-1” as a guide for the global market.

The NEMA philosophy prioritizes robust designs with ease of selection and breadth of application, while IEC focuses more on application and performance. The IEC efficiency standards include four IE efficiency classes for single-speed electric motors and are defined by IEC/EN 60034-30-1 published in 2014. This standard was updated in 2020 with IEC/TS 60034-30-2 for variable-speed AC motors, which covers synchronous and permanent magnet motors and creates a level playing field for established and new motor technologies.

Comparing the Two Rating Systems

NEMA has no defined standard yet for the equivalent of IE5 in the North American market, although some manufacturers market their products as “ultra-premium efficiency.” On the other hand, IEC has four defined efficiency classes for electric motors, with each class representing 10% less motor loss than the previous one:

Why are Motor Efficiency Ratings Important?

Electric motors are widely used in many industries and account for approximately 53% of global electricity consumption. Motors can stay in service for 20 years or more, so the wasted energy used by an inefficient motor accumulates over the lifetime of the product and puts unnecessary strain on power grids and the environment. By selecting an optimal motor, Original Equipment Manufacturers (OEMs) can improve overall system efficiencies, leading to reduced environmental impact, cost savings, and increased output for the end user.

The Future of Motor Efficiency Ratings

As the world becomes increasingly focused on sustainability and reducing carbon emissions, the demand for efficient motors will continue to rise. The government mandates on motors and the push for sustainability will likely lead to further updates and improvements in the NEMA and IEC efficiency standards, encouraging the use of even more efficient motors in the future.

NEMA and IEC motor efficiency ratings play a crucial role in determining the energy efficiency of electric motors and the impact they have on the environment and economy. Understanding the differences between the two rating systems and the importance of efficiency ratings can help engineers make informed decisions when selecting motors for their applications. With the push for sustainability expected to lead to further improvements in efficiency standards, the future of motor efficiency ratings looks promising.