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High efficiency motors – the changes made simple

What the new regulations really mean;

A new harmonised European standard EN 60034-30:2009 is to replace the old voluntary Eff classes. The first phase is less than a year away so machine designers need to be conversant with the regulations now. The good news is that the changes need not cost much more, and for the end user and the environment the results are entirely positive.

The new regulations apply to 3-phase asynchronous motors in a power range 0.75 to 375kW in 2, 4 and 6 pole designs, basically the vast majority of motors and used in the construction of machinery. There are certain exceptions, for example 8 pole motors, motors that are an inseparable part of a machine and those with supply voltage over 1000V. However, the scope is predicted in Government reports to be sufficient to arrest the current increase in energy used by electric motors. This is no mean feat bearing in mind the massive number of motors in service and the fact that they consume nearly 40% of energy in industrial nations. 

Three new energy efficiency bands are defined:

  • IE1  for motors of Standard Efficiency, equivalent to Eff2
  • IE2  for motors of High Efficiency, equivalent to Eff1
  • IE3  for motors of Premium Efficiency, no previous equivalent

Looking further ahead it is anticipated that an ever higher level of efficiency IE4 will be introduced. The actual limits of the three efficiency bands vary according to motor power. As an example in round figures, the minimum efficiency for a 7.5kW motor is 85% at IE1, 88% at IE2 and 92% at IE3. 

There has been a phased introduction of the new regulations since 2011:

  • June 16th 2011 - motors must meet the IE2 efficiency level as a minimum
  • January 1st 2015 - motors from 7.5 to 375 kW must meet the higher IE3 efficiency level, or must be ‘equipped’ with an inverter variable speed drive
  • January 1st 2017 - the 2015 regulations are extended down to motors of 0.75kW

The regulations are based around the concept of motors that are “placed on the market”. This means motors delivered from motor manufacturers and their subsidiaries, including replacements for existing motors. Old stock at independent distributors or at machine manufacturers can still be sold. Repairing and rewinding old motors is permissible. Thus any new machine or old machine requiring a replacement electric motor will need to comply with the new regulations. For the end user this is almost invariably a benefit. Over the lifetime of an electric motor, energy costs amount to about 97% of the total costs of ownership. Therefore a 2-3% gain in efficiency can achieve big savings in the long term. Based on 8000 hours per year, stepping up an efficiency level can give payback times on the extra investment of about 2 years.

There are strict requirements for labelling of the motor rating plate. From June 2011 the following information must be shown on the rating plate and the motor documentation: lowest efficiency at 100%, 75% and 50% rated load, the efficiency level (IE2 or IE3) and the year of manufacture.

As stated above, from 2015 IE2 motors equipped with a frequency inverter can be used instead of IE3 premium efficiency motors. This is an attractive alternative and the IE2 + inverter combination will generally yield greater savings compared to IE3 if variable speed is required.

There is no expectation that the inverter will be integrated into the motor, although that is possible, and it is expected that many customers will purchase motors and inverters from different sources. Documentation requirements are not yet defined, but it would seem likely that a degree of self-certification will apply. 

As the efficiency levels of motors increase, so does the cost as a result of increased material and manufacturing costs. The increase in costs does depend on frame size. Changing from IE1 to IE2 currently brings in a price premium of appr.  20%. Often the motor length will increase. In a minority of cases the motor frame size may increase, e.g. from IEC90 to IEC100. In turn this may cause problems on existing machine designs with replacement motors.

Many people would say the new regulations and efficiency bands are long overdue, we are playing catch-up with countries like the USA and Australia. With the first phase less than a year away, we still have time to take the necessary steps for the changes. Increases in costs are modest compared with the lifetime costs for motors. The big winners are the end users with lower energy costs and the environment as a whole. 

Here at Scots Bearings Ltd we can offer IE3 Motors on request. We can offer short lead times and visit site to discuss the benefits of selecting an IE3 Motor.

For further information, costing’s and lead times please contact your local branch. 

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