Design motors to achieve energy efficiency requirements

Original equipment manufacturers (OEMs) and end users should build motors in compliance with current electric motor energy-efficiency requirements to provide customers with immediate energy-saving benefits as well as avoid future product redesigns.

By Brian Bannister, Lafert Electric Motors November 28, 2017

The European Commission’s statutory efficiency regulations for electric motors, which came into force in January 2017, require all ac industrial electric motors with a rated output of 0.75 to 375kW to operate within the Regulations’ specified parameters.

The most common solutions offered to achieve these efficiency levels are based on either an IE2 motor with a variable speed drive (VSD) package or a stand-alone, direct on-line IE3 motor. Compliance should be a company’s first goal; achieving it can be dictated by numerous factors. For applications where equipment is driven by motors with power ratings lower than 0.75 or above 375kW, there are no specific guidelines or requirements.

Equipment/machine manufacturers can continue to use IE1 efficiency motors in the European Union (EU) if they currently have them in stock, but they cannot continue producing these motors for customers within the EU. However, they can continue to supply IE1 motors to regions outside the EU where the same levels of efficiency are not demanded. 

IE4 and IE5 motors

High-performance permanent magnet IE4 and IE5 motors might be considered by some as ‘over the top’ solutions, but they do offer immediate and future benefits for both original equipment manufacturers (OEMs) and end users.

One immediate benefit is compliance for the foreseeable future. Design engineers can develop equipment with confidence, knowing which motors they can incorporate in their designs to achieve specific performance characteristics, while not having to change machines from a weight and size point of view. Some IE4 and IE5 motors can offer up 50% savings in weight and can offer reductions of up to two frame sizes.

When making decisions about how to meet the required efficiency standard, return on investment (ROI) should be considered. An IE3 motor carries an estimated 20% premium over an IE2 alternative, but energy savings due to the higher efficiency make it possible for users to achieve payback in less than two years.

IE4 and IE5 motors will become standard in the next few years. It is, however, worth adopting the higher efficiency motors today to start reaping the benefits of greater savings on energy now. This might be the case with VSDs because both IE4 and IE5 permanent magnet motors require them. 

Self-policing standards

While compliance is obligatory, it is down to the OEMs and end users to adhere to the standards.

According to the United Kingdom’s Department for Environment, Food and Rural Affairs’ (DEFRA’s) June 2013 environmental reporting guidelines: "The Companies Act 2006 (Strategic Report and Directors’ Reports) Regulations 2013 requires quoted companies to report on greenhouse gas (GHG) emissions for which they are responsible. Quoted companies, as defined by the Companies Act 2006, are responsible to report on environmental matters to the extent it is necessary for an understanding of the company’s business within the annual report, including where appropriate the use of key performance indicators (KPIs). If the annual report does not contain this information, then it must point out the omissions."

Some public bodies are required to, or should consider, reporting GHG emissions. To fulfill these reporting requirements, companies need to monitor and control their own emissions and the emissions of their suppliers. This will help them measure the impact of the suppliers’ operations on their own emissions so this information can be included in their calculations. Smaller companies also are being encouraged to achieve similar GHG emission reduction goals.

Purchasers of electric motors must determine whether motors supplied comply with the appropriate standards as part of the monitoring process to achieve and maintain compliance. It is still permissible to use and supply IE2 motors with power ratings above 0.75kW if they are used with a VSD, were placed on the market prior to January 2017, or comply with one of the many other rules currently in force (there are exclusions applicable to brake motors, integrated motors, and motors specified for intermittent duty).

How this reflects on the company and the product is also worth considering. It may be cost beneficial to stick with the technology, but it will impact on the end users ongoing efficiencies and GHG emissions.

It’s better for manufacturers to build in compliance with the future in mind so they can avoid product redesigns and associated price increases later on.

Brian Bannister is a motor specialist at Lafert Electric Motors. This appeared October 30 on the Control Engineering Europe website. Edited by Chris Vavra, production editor, Control Engineering, CFE Media, keywords: industrial automation, flexible automation


Key Concepts

  • European Commission statutory efficiency regulations for electric motors demand all ac industrial electric motors from 0.75 up to 375kW operate within the Regulations’ specified parameters.
  • High-performance permanent magnet IE4 and IE5 motors offer immediate and future benefits even though these capabilities aren’t required yet.
  • Manufacturers that build with future requirements can avoid product redesigns and associated price increases as standards update.

Consider this

What will future motor standards require from users and manufacturers and what will the benefits look like?

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